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Cited by 544Gut microbiota and healthNutritional Studies and DietCardiovascular Health and Risk Factors

Gut Microbiota Metabolites and Risk of Major Adverse Cardiovascular Disease Events and Death: A Systematic Review and Meta‐Analysis of Prospective Studies

Open access
Heianza, Yoriko, Ma, Wenjie, Manson, JoAnn E., Rexrode, Kathryn M., Qi, Lu·2017·Journal of the American Heart Association
DOI 10.1161/jaha.116.004947PMC PMC5586261
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Abstract

Background: Gut microbial metabolites have been implicated as novel risk factors for cardiovascular events and premature death. The strength and consistency of associations between blood concentrations of the gut microbial metabolites, trimethylamine‐N‐oxide ( TMAO ) and its precursors, with major adverse cardiovascular events ( MACE ) or death have not been comprehensively assessed. We quantified associations of blood concentrations of TMAO and its precursors with risks of MACE and mortality. Methods and Results: PubMed and Embase databases were searched up, and a total of 19 prospective studies from 16 publications (n=19 256, including 3315 incident cases) with quantitative estimates of the associations of TMAO with the development of MACE or death were included in our main analysis. Multivariate‐adjusted relative risks ( RR s) were used when these were available. Elevated concentrations of TMAO were associated with a pooled RR of 1.62 (95% CI, 1.45, 1.80; P heterogeneity =0.2; I 2 =23.5%) for MACE compared with low TMAO levels, and 1 study of black participants influenced the heterogeneity of the association. After excluding the data of blacks, the RR s were not different according to body mass index, prevalence of diabetes mellitus, history of cardiovascular diseases, and kidney dysfunction. Furthermore, elevated TMAO concentrations were associated with a pooled RR of 1.63 (1.36, 1.95) for all‐cause mortality. Individuals with elevated concentrations of TMAO precursors ( l ‐carnitine, choline, or betaine) had an approximately 1.3 to 1.4 times higher risk for MACE compared to those with low concentrations. Conclusions: Elevated concentrations of TMAO and its precursors were associated with increased risks of MACE and all‐cause mortality independently of traditional risk factors.

AI snapshot

Written from the paper’s full text.

TL;DR

This systematic review and meta-analysis found that elevated circulating trimethylamine-N-oxide (TMAO) and its precursors were associated with higher risks of major adverse cardiovascular events (MACE) and all-cause mortality in prospective clinical cohorts. The associations were independent of traditional risk factors, but evidence was limited to higher-risk clinical populations and causality remains unestablished.

Key findings

  • In the main analysis of 19 data points from 16 publications (n=19,256; 3,315 incident cases), elevated TMAO was associated with a pooled RR of 1.62 (95% CI, 1.45–1.80; P heterogeneity=0.2; I²=23.5%) for MACE compared with low TMAO.
  • Elevated TMAO was associated with a pooled RR of 1.63 (95% CI, 1.36–1.95) for all-cause mortality; after excluding data from black participants, pooled RRs were 1.70 (95% CI, 1.52–1.91) for MACE and 1.72 (95% CI, 1.50–1.97) for all-cause mortality.
  • Elevated TMAO precursors were associated with MACE: pooled RR 1.26 (95% CI, 1.10–1.44) for L-carnitine or choline and 1.43 (95% CI, 1.19–1.73) for betaine.
  • Dose-response analyses showed adjusted pooled RRs of 1.02 (95% CI, 1.01–1.03) per 1-μmol/L increment in TMAO and 1.21 (95% CI, 1.14–1.29) per 1-SD increment in log-transformed TMAO for MACE.

Methods

  • Systematic review and meta-analysis of prospective studies identified through PubMed/MEDLINE and Embase searches up to December 6, 2016, with no language restrictions; protocol registered in PROSPERO (CRD42016052185).
  • Eligible studies reported blood TMAO concentrations and RRs with 95% CIs for MACE or death; 19 data points from 16 publications were included in the main TMAO-MACE analysis, and 15 data points from 12 articles were included for all-cause mortality.
  • Pooled RRs used fixed- or random-effects models depending on heterogeneity, with stratified/meta-regression analyses, dose-response analyses, sensitivity analyses, and Begg’s and Egger’s tests for publication bias; quality was assessed with the Newcastle–Ottawa scale.

Limitations

  • The paper states: no data were available from general populations; included studies were clinical cohorts with pre-existing cardiovascular risk; definitions of elevated TMAO differed across studies; residual confounding could not be excluded; dietary intake data were not available in all studies; participants were mostly from Europe and the United States and mainly white (approximately 65–90% of total participants in some studies); TMAO was measured at one time point; and causality cannot be inferred without clinical trials.
  • Evident from the text: all included studies were observational, MACE definitions varied across studies, and one study of black hemodialysis patients influenced heterogeneity, limiting generalizability to other race/ethnic groups and lower-risk populations.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1161/jaha.116.004947

Cites

56 of 56 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 75 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    A total of 19 prospective studies from 16 publications (n=19,256, including 3315 incident cases) with quantitative estimates of the associations of TMAO with the development of MACE or death were included in the main analysis.

    “a total of 19 prospective studies from 16 publications (n=19 256, including 3315 incident cases) with quantitative estimates of the associations of TMAO with the development of MACE or death were included in our main analysis.”
    Quote in the paperSubstantial claim
  • Findingown data

    After excluding the data of blacks, the RRs for TMAO and MACE were not different according to body mass index, prevalence of diabetes mellitus, history of cardiovascular diseases, and kidney dysfunction.

    “After excluding the data of blacks, the RRs were not different according to body mass index, prevalence of diabetes mellitus, history of cardiovascular diseases, and kidney dysfunction.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Individuals with elevated concentrations of TMAO precursors (l-carnitine, choline, or betaine) have approximately 1.3 to 1.4 times higher risk for MACE compared to those with low concentrations.

    “Individuals with elevated concentrations of TMAO precursors (l‐carnitine, choline, or betaine) had an approximately 1.3 to 1.4 times higher risk for MACE compared to those with low concentrations.”
    Quote in the paperSubstantial claim
  • Findingown data

    Elevated TMAO concentrations are associated with a pooled RR of 1.63 (95% CI, 1.36-1.95) for all-cause mortality.

    “Furthermore, elevated TMAO concentrations were associated with a pooled RR of 1.63 (1.36, 1.95) for all‐cause mortality.”
    Quote in the paperSubstantial claim
  • Findingown data

    Elevated concentrations of TMAO are associated with a pooled RR of 1.62 (95% CI, 1.45-1.80) for MACE compared with low TMAO levels.

    “Elevated concentrations of TMAO were associated with a pooled RR of 1.62 (95% CI, 1.45, 1.80; P heterogeneity=0.2; I2=23.5%) for MACE compared with low TMAO levels”
    Quote in the paperSubstantial claim
  • May combine two claims. 21
  • Classified as probably not a substantial claim. 28

  • May combine two claims.

    Findingown data

    Of the 22 studies, 2 only investigated combinations of TMAO and choline, betaine, or l-carnitine, so they were not included in the analysis for TMAO.

    “Of the 22 studies, 2 only investigated combinations of TMAO and choline, betaine,9 or l‐carnitine4; thus we did not include the 2 studies4, 9 in the analysis for TMAO, although these studies were eligible for the analysis of TMAO precursors and risk of MACE.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [9] Wang Z, Tang WH, Buffa JA, Fu X, Britt EB, Koeth RA, Levison BS, Fan Y, Wu Y, Hazen SL. Prognostic value of choline and betaine depends on intestinal microbiota‐generated metabolite trimethylamine‐N‐oxide. Eur Heart J. 2014; 35: 904– 910. 24497336 PMC3977137 source

      Not checked in the free run.

    • cites [4] Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Sheehy BT, Britt EB, Fu X, Wu Y, Li L, Smith JD, Didonato JA, Chen J, Li H, Wu GD, Lewis JD, Warrier M, Brown JM, Krauss RM, Tang WHW, Bushman FD, Lusis AJ, Hazen SL. Intestinal microbiota metabolism of L‐carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med. 2013; 19: 576– 585. 23563705 PMC3650111 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Of the 19 data points, the study in blacks by Shafi et al affected the heterogeneity; removal of the data in blacks resulted in a pooled RR of 1.70 (95% CI, 1.52, 1.91; P<0.001; P heterogeneity=0.9; I2=0%; fixed-effect model).

    “Of the 19 data points, the study in blacks by Shafi et al22 affected the heterogeneity; removal of the data in blacks22 resulted in a pooled RR of 1.70 (95% CI, 1.52, 1.91; P<0.001; P heterogeneity=0.9; I2=0%; fixed‐effect model; Figure S1A).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22] Shafi T, Powe NR, Meyer TW, Hwang S, Hai X, Melamed ML, Banerjee T, Coresh J, Hostetter TH. Trimethylamine N‐oxide and cardiovascular events in hemodialysis patients. J Am Soc Nephrol. 2017; 28: 321– 331. 27436853 PMC5198291 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The mean or median TMAO value ranged from 1.74 to 103.8 μmol/L across the 22 prospective studies.

    “The mean or median value of TMAO ranged from 1.74 to 103.8 μmol/L across the 22 prospective studies listed in Table 1.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Of the total 22 publications, multivariate-adjusted RRs were available for 21 (95%) publications; of the 19 data points used for the main analysis, 79% (n=15) were multivariate-adjusted data.

    “Of the total 22 publications, multivariate‐adjusted RRs were available for 21 (95%) publications; of the 19 data points used for the main analysis, 79% (n=15) were multivariate‐adjusted data.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    All included studies were clinical cohorts, including patients at higher cardiovascular risk, enriched for baseline heart disease, kidney disease, peripheral artery disease, or diabetes mellitus.

    “All of the studies included clinical cohorts, including patients at higher cardiovascular risk, that is, enriched for baseline heart disease,3, 8, 12, 13, 14, 15, 16, 17, 21 kidney disease,10, 11, 18, 19, 20, 22, 23 peripheral artery disease,25 or diabetes mellitus.7, 26”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [3] Tang WH, Wang Z, Levison BS, Koeth RA, Britt EB, Fu X, Wu Y, Hazen SL. Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013; 368: 1575– 1584. 23614584 PMC3701945 source

      Not checked in the free run.

    • cites [8] Tang WH, Wang Z, Fan Y, Levison B, Hazen JE, Donahue LM, Wu Y, Hazen SL. Prognostic value of elevated levels of intestinal microbe‐generated metabolite trimethylamine‐N‐oxide in patients with heart failure: refining the gut hypothesis. J Am Coll Cardiol. 2014; 64: 1908– 1914. 25444145 PMC4254529 source

      Not checked in the free run.

    • cites [12] Tang WH, Wang Z, Shrestha K, Borowski AG, Wu Y, Troughton RW, Klein AL, Hazen SL. Intestinal microbiota‐dependent phosphatidylcholine metabolites, diastolic dysfunction, and adverse clinical outcomes in chronic systolic heart failure. J Card Fail. 2015; 21: 91– 96. 25459686 PMC4312712 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    In sensitivity analysis omitting 1 study at a time, pooled RRs ranged from 1.65 (95% CI, 1.47, 1.86) to 1.75 (95% CI, 1.55, 1.98), and no other study was identified as an influential outlier across the 18 studies.

    “In results of a sensitivity analysis omitting 1 study at a time and calculating the pooled RRs for the remainder of 18 studies (the data in blacks were not included), the pooled RRs ranged from 1.65 (95% CI, 1.47, 1.86) to 1.75 (95% CI, 1.55, 1.98), and no other study was identified as an influential outlier across the 18 studies (P heterogeneity ranged 0.8–0.9; I2 was consistently 0%).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The remaining 19 articles published from 2013 to 2017 assessed the RRs of TMAO and risk of MACE.

    “Subsequently, the remaining 19 articles published from 2013 to 2017 assessed the RRs of TMAO (either as a categorical or continuous variable) and risk of MACE.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    We identified 24 potentially eligible articles, including 2 cross-sectional studies and 22 prospective studies.

    “We identified 24 potentially eligible articles, including 2 cross‐sectional studies and 22 prospective studies (Figure 1).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Associations appeared stronger among studies with participants who had generally lower BMI, or lower prevalence of smoking, although such differences did not attain statistical significance.

    “Associations appeared to be stronger among studies with participants who had generally lower BMI, or lower prevalence of smoking, although such differences did not attain statistical significance.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The definition of elevated TMAO levels differed across individual studies.

    “Second, the definition of elevated TMAO levels was difference across individual studies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Positive associations between TMAO levels and the outcomes were highly consistent across studies, including studies with low (<5.0 μmol/L) baseline TMAO concentrations, particularly after excluding data among blacks.

    “We observed the highly consistent positive associations between TMAO levels and the outcomes across studies, even among studies with low (<5.0 μmol/L) concentrations of TMAO at baseline, particularly after excluding the data among blacks.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In stratified analysis using a cut-off value of 8.0 μmol/L, similarly increased risks of MACE were observed regardless of studies with <8.0 or ≥8.0 μmol/L mean/median TMAO levels, with no heterogeneity between low or high TMAO concentrations at baseline.

    “We also performed a stratified analysis using a cut‐off value of 8.0 μmol/L. We observed similarly increased risks of MACE regardless of studies with <8.0 (range, 3.0–7.9) or ≥8.0 (range, 20.41–98.4) μmol/L mean/median TMAO levels. Again, there was no heterogeneity between low or high TMAO concentrations at baseline.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    Most study participants were from Europe and the United States and included mainly approximately 65-90% whites.

    “Fifth, most of the study participants were from Europe and the United States and included mainly (approximately of 65–90% of total study participants) whites,10, 19, 20, 23 so that our results might not be applicable to other race/ethnic groups such as Asians and Africans.”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [10] Kaysen GA, Johansen KL, Chertow GM, Dalrymple LS, Kornak J, Grimes B, Dwyer T, Chassy AW, Fiehn O. Associations of trimethylamine N‐oxide with nutritional and inflammatory biomarkers and cardiovascular outcomes in patients new to dialysis. J Ren Nutr. 2015; 25: 351– 356. 25802017 PMC4469547 source

      Not checked in the free run.

    • cites [19] Stubbs JR, House JA, Ocque AJ, Zhang S, Johnson C, Kimber C, Schmidt K, Gupta A, Wetmore JB, Nolin TD, Spertus JA, Yu AS. Serum trimethylamine‐N‐oxide is elevated in CKD and correlates with coronary atherosclerosis burden. J Am Soc Nephrol. 2016; 27: 305– 313. 26229137 PMC4696571 source

      Not checked in the free run.

    • cites [20] Kim RB, Morse BL, Djurdjev O, Tang M, Muirhead N, Barrett B, Holmes DT, Madore F, Clase CM, Rigatto C, Levin A, Can PI. Advanced chronic kidney disease populations have elevated trimethylamine N‐oxide levels associated with increased cardiovascular events. Kidney Int. 2016; 89: 1144– 1152. 27083288 source

      Not checked in the free run.

    • cites [23] Robinson‐Cohen C, Newitt R, Shen DD, Rettie AE, Kestenbaum BR, Himmelfarb J, Yeung CK. Association of FMO3 variants and trimethylamine N‐oxide concentration, disease progression, and mortality in CKD patients. PLoS One. 2016; 11: e0161074. 27513517 PMC4981377 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    There were 5 studies with extremely high mean/median TMAO values (>20 μmol/L).

    “In addition, there were 5 studies with extremely high mean/median TMAO values (>20 μmol/L).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The associations of TMAO with outcomes did not significantly differ according to past histories of CVD, prevalence of diabetes mellitus, kidney dysfunction, follow-up duration, or TMAO levels at baseline.

    “The associations did not significantly differ according to the past histories of CVD, prevalence of diabetes mellitus, kidney dysfunction, follow‐up duration, or TMAO levels at baseline.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    After removal of the data in blacks, there was no heterogeneity across the studies (pooled RR, 1.72; 95% CI, 1.50, 1.97; P heterogeneity=0.7; I2=0%).

    “Again, after removal of the data in blacks, there was no heterogeneity across the studies (pooled RR, 1.72; 95% CI, 1.50, 1.97; P heterogeneity=0.7; I2=0%; Figure S1B).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The protocol of the present study was registered with the PROSPERO database (CRD42016052185).

    “The protocol of the present study was registered with the PROSPERO database: CRD42016052185.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The definition of MACE varies by study.

    “There is no standard definition for MACE, and the definition varies by study, whereas most studies include MI and death to define MACE.30”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Kip KE, Hollabaugh K, Marroquin OC, Williams DO. The problem with composite end points in cardiovascular studies: the story of major adverse cardiac events and percutaneous coronary intervention. J Am Coll Cardiol. 2008; 51: 701– 707. 18279733 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Two reviewers independently extracted data on study design and population characteristics and compared results to ensure consistency, with inconsistencies resolved by a third reviewer.

    “Two reviewers (Y.H. and W.M.) independently extracted data on study design and population characteristics and compared results to ensure consistency. Inconsistencies in data were resolved by a third reviewer (L.Q.).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Publication bias was assessed by Begg's and Egger's tests and visual inspection of the funnel plot if 10 or more studies were available.

    “We assessed publication bias by using Begg's and Egger's tests and visual inspection of the funnel plot if 10 or more studies were available.35”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [35] Sterne JA, Gavaghan D, Egger M. Publication and related bias in meta‐analysis: power of statistical tests and prevalence in the literature. J Clin Epidemiol. 2000; 53: 1119– 1129. 11106885 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    Heterogeneity was assessed by the Cochran Q test and I2 statistic, with low, moderate, and high I2 values considered to be 25%, 50%, and 75%, respectively.

    “Heterogeneity was assessed by the Cochran Q test and I2 statistic; low, moderate, and high I2 values were considered to be 25%, 50%, and 75%, respectively.32, 33”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [32] Higgins JP. Commentary: heterogeneity in meta‐analysis should be expected and appropriately quantified. Int J Epidemiol. 2008; 37: 1158– 1160. 18832388 source

      Not checked in the free run.

    • cites [33] Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta‐analyses. BMJ. 2003; 327: 557– 560. 12958120 PMC192859 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Most studies include MI and death to define MACE.

    “There is no standard definition for MACE, and the definition varies by study, whereas most studies include MI and death to define MACE.30”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Kip KE, Hollabaugh K, Marroquin OC, Williams DO. The problem with composite end points in cardiovascular studies: the story of major adverse cardiac events and percutaneous coronary intervention. J Am Coll Cardiol. 2008; 51: 701– 707. 18279733 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    A fixed-effect model using the method of Mantel and Haenszel was used when there was no significant heterogeneity, and a random effect model was used when heterogeneity was significant.

    “We used a fixed‐effect model, using the method of Mantel and Haenszel when there was no significant heterogeneity, and a random effect model when heterogeneity was significant.34”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [34] Lau J, Ioannidis JP, Schmid CH. Quantitative synthesis in systematic reviews. Ann Intern Med. 1997; 127: 820– 826. 9382404 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Quality assessment was performed using the Newcastle-Ottawa quality assessment scale.

    “Quality assessment was performed using to the Newcastle–Ottawa quality assessment scale.31”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Wells GA, Shea B, O'Connell D, Peterson J, Welch V, Losos M, Tugwell P. The Newcastle‐Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta‐analyses. 2014 Available at: http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp. Accessed May 7, 2016.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TMAO is mainly derived from choline, which is metabolized to TMA by microbiota and then to TMAO by hepatic flavin monooxygenase 3.

    “TMAO is a small organic compound, mainly derived from choline (found in foods such as red meat, fish, poultry, and eggs), which is metabolized to produce trimethylamine (TMA) by microbiota1, 4 and then to TMAO by the hepatic enzyme, flavin monooxygenase 3.1, 5”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [1] Wang Z, Klipfell E, Bennett BJ, Koeth R, Levison BS, Dugar B, Feldstein AE, Britt EB, Fu X, Chung YM, Wu Y, Schauer P, Smith JD, Allayee H, Tang WH, DiDonato JA, Lusis AJ, Hazen SL. Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease. Nature. 2011; 472: 57– 63. 21475195 PMC3086762 source

      Not checked in the free run.

    • cites [4] Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Sheehy BT, Britt EB, Fu X, Wu Y, Li L, Smith JD, Didonato JA, Chen J, Li H, Wu GD, Lewis JD, Warrier M, Brown JM, Krauss RM, Tang WHW, Bushman FD, Lusis AJ, Hazen SL. Intestinal microbiota metabolism of L‐carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med. 2013; 19: 576– 585. 23563705 PMC3650111 source

      Not checked in the free run.

    • cites [5] Bennett BJ, de Aguiar Vallim TQ, Wang Z, Shih DM, Meng Y, Gregory J, Allayee H, Lee R, Graham M, Crooke R, Edwards PA, Hazen SL, Lusis AJ. Trimethylamine‐N‐oxide, a metabolite associated with atherosclerosis, exhibits complex genetic and dietary regulation. Cell Metab. 2013; 17: 49– 60. 23312283 PMC3771112 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    There is no standard definition for MACE.

    “There is no standard definition for MACE, and the definition varies by study, whereas most studies include MI and death to define MACE.30”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Kip KE, Hollabaugh K, Marroquin OC, Williams DO. The problem with composite end points in cardiovascular studies: the story of major adverse cardiac events and percutaneous coronary intervention. J Am Coll Cardiol. 2008; 51: 701– 707. 18279733 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The reference lists of identified articles were scanned to identify other relevant studies.

    “The reference lists of identified articles were also scanned to identify any other relevant studies.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Circulating concentrations of TMAO were predictive of prevalent cardiovascular diseases and future cardiovascular events in clinical cohorts.

    “Recent studies by Wang and Tang et al reported that circulating concentrations of trimethylamine N‐oxide (TMAO), a metabolite derived from the gut microbiota, were predictive of prevalent cardiovascular diseases (CVDs)1 and future cardiovascular events3 in clinical cohorts.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [1] Wang Z, Klipfell E, Bennett BJ, Koeth R, Levison BS, Dugar B, Feldstein AE, Britt EB, Fu X, Chung YM, Wu Y, Schauer P, Smith JD, Allayee H, Tang WH, DiDonato JA, Lusis AJ, Hazen SL. Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease. Nature. 2011; 472: 57– 63. 21475195 PMC3086762 source

      Not checked in the free run.

    • cites [3] Tang WH, Wang Z, Levison BS, Koeth RA, Britt EB, Fu X, Wu Y, Hazen SL. Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013; 368: 1575– 1584. 23614584 PMC3701945 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    The study followed standard criteria for conducting meta-analyses of observational studies and reporting the results.

    “We followed the standard criteria for conducting meta‐analyses of observational studies and reporting the results.29”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [29] Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA, Thacker SB. Meta‐analysis of observational studies in epidemiology: a proposal for reporting. Meta‐analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA. 2000; 283: 2008– 2012. 10789670 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    MEDLINE (PubMed) and Embase were searched up to December 6, 2016 for eligible studies.

    “We searched MEDLINE (PubMed) and Embase up to December 6, 2016 for eligible studies with a search strategy that combined text word and Medical Subject Headings identifying reports relating blood concentrations of TMAO and the MACE.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    No language restrictions were applied in the search.

    “No language restrictions were applied.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Dose-response associations were estimated using the generalized least-squares for trend estimation method of Greenland and Longnecker.

    “We also estimated dose‐response associations based on data for categories of TMAO levels on median dose, number of cases and participants, and effect estimates with corresponding SEs using the generalized least‐squares for trend estimation method of Greenland and Longnecker.36”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [36] Greenland S, Longnecker MP. Methods for trend estimation from summarized dose‐response data, with applications to meta‐analysis. Am J Epidemiol. 1992; 135: 1301– 1309. 1626547 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Circulating TMAO is predominantly excreted by the kidneys.

    “The burden of CVD is high among patients with chronic kidney disease (CKD) or end‐stage renal disease,47 and the circulating TMAO is predominantly excreted by the kidneys.42”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [42] Tang WH, Hazen SL. The contributory role of gut microbiota in cardiovascular disease. J Clin Invest. 2014; 124: 4204– 4211. 25271725 PMC4215189 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Median TMAO concentrations in healthy individuals were reported as ranges of 3 to 6 μmol/L.

    “Nonetheless, median values of TMAO concentrations in healthy individuals were reported as ranges of 3 to 6 μmol/L,8, 17, 18, 19 and the study by Shafi et al22 consisted of hemodialysis patients with the substantially high mean vale of TMAO (101.9 μmol/L among total participants).”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [8] Tang WH, Wang Z, Fan Y, Levison B, Hazen JE, Donahue LM, Wu Y, Hazen SL. Prognostic value of elevated levels of intestinal microbe‐generated metabolite trimethylamine‐N‐oxide in patients with heart failure: refining the gut hypothesis. J Am Coll Cardiol. 2014; 64: 1908– 1914. 25444145 PMC4254529 source

      Not checked in the free run.

    • cites [17] Skagen K, Troseid M, Ueland T, Holm S, Abbas A, Gregersen I, Kummen M, Bjerkeli V, Reier‐Nilsen F, Russell D, Svardal A, Karlsen TH, Aukrust P, Berge RK, Hov JE, Halvorsen B, Skjelland M. The carnitine‐butyrobetaine‐trimethylamine‐N‐oxide pathway and its association with cardiovascular mortality in patients with carotid atherosclerosis. Atherosclerosis. 2016; 247: 64– 69. 26868510 source

      Not checked in the free run.

    • cites [18] Missailidis C, Hallqvist J, Qureshi AR, Barany P, Heimburger O, Lindholm B, Stenvinkel P, Bergman P. Serum trimethylamine‐N‐oxide is strongly related to renal function and predicts outcome in chronic kidney disease. PLoS One. 2016; 11: e0141738. 26751065 PMC4709190 source

      Not checked in the free run.

    • cites [19] Stubbs JR, House JA, Ocque AJ, Zhang S, Johnson C, Kimber C, Schmidt K, Gupta A, Wetmore JB, Nolin TD, Spertus JA, Yu AS. Serum trimethylamine‐N‐oxide is elevated in CKD and correlates with coronary atherosclerosis burden. J Am Soc Nephrol. 2016; 27: 305– 313. 26229137 PMC4696571 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Mortality risk may differ between black and white dialysis patients.

    “It has also been reported that morality risk may differ between black and white dialysis patients.46”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [46] Kucirka LM, Grams ME, Lessler J, Hall EC, James N, Massie AB, Montgomery RA, Segev DL. Association of race and age with survival among patients undergoing dialysis. JAMA. 2011; 306: 620– 626. 21828325 PMC3938098

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Gut microbiota are affected by environmental factors such as dietary intakes, which may in turn influence blood levels of TMAO and its precursors.

    “Fourth, the gut microbiota are affected by environmental factors37, 38 such as dietary intakes,39, 40, 41 which may, in turn, influence blood levels of TMAO and its precursors.4”
    Quote in the paperNot a substantial claim0 of 6 sources checked
    • cites [37] Scalbert A, Brennan L, Manach C, Andres‐Lacueva C, Dragsted LO, Draper J, Rappaport SM, van der Hooft JJ, Wishart DS. The food metabolome: a window over dietary exposure. Am J Clin Nutr. 2014; 99: 1286– 1308. 24760973 source

      Not checked in the free run.

    • cites [38] Wong JM. Gut microbiota and cardiometabolic outcomes: influence of dietary patterns and their associated components. Am J Clin Nutr. 2014; 100(suppl 1): 369S– 377S. 24898225 source

      Not checked in the free run.

    • cites [39] Claesson MJ, Jeffery IB, Conde S, Power SE, O'Connor EM, Cusack S, Harris HM, Coakley M, Lakshminarayanan B, O'Sullivan O, Fitzgerald GF, Deane J, O'Connor M, Harnedy N, O'Connor K, O'Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O'Toole PW. Gut microbiota composition correlates with diet and health in the elderly. Nature. 2012; 488: 178– 184. 22797518 source

      Not checked in the free run.

    • cites [40] Kong LC, Holmes BA, Cotillard A, Habi‐Rachedi F, Brazeilles R, Gougis S, Gausseres N, Cani PD, Fellahi S, Bastard JP, Kennedy SP, Dore J, Ehrlich SD, Zucker JD, Rizkalla SW, Clement K. Dietary patterns differently associate with inflammation and gut microbiota in overweight and obese subjects. PLoS One. 2014; 9: e109434. 25330000 PMC4203727 source

      Not checked in the free run.

    • cites [41] Cotillard A, Kennedy SP, Kong LC, Prifti E, Pons N, Le Chatelier E, Almeida M, Quinquis B, Levenez F, Galleron N, Gougis S, Rizkalla S, Batto JM, Renault P; Consortium ANRM, Dore J, Zucker JD, Clement K, Ehrlich SD. Dietary intervention impact on gut microbial gene richness. Nature. 2013; 500: 585– 588. 23985875 source

      Not checked in the free run.

    • cites [4] Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Sheehy BT, Britt EB, Fu X, Wu Y, Li L, Smith JD, Didonato JA, Chen J, Li H, Wu GD, Lewis JD, Warrier M, Brown JM, Krauss RM, Tang WHW, Bushman FD, Lusis AJ, Hazen SL. Intestinal microbiota metabolism of L‐carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med. 2013; 19: 576– 585. 23563705 PMC3650111 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    Residual confounding from unmeasured factors could not be excluded.

    “Third, similar to other observational studies, we could not exclude the possibility of residual confounding attributed to unmeasured factors.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Emerging evidence has shown associations of gut microbiota with obesity.

    “Emerging evidence has shown associations of gut microbiota with obesity.48, 49, 50, 51”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [48] Turnbaugh PJ, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, Ley RE, Sogin ML, Jones WJ, Roe BA, Affourtit JP, Egholm M, Henrissat B, Heath AC, Knight R, Gordon JI. A core gut microbiome in obese and lean twins. Nature. 2009; 457: 480– 484. 19043404 PMC2677729 source

      Not checked in the free run.

    • cites [49] Ley RE, Turnbaugh PJ, Klein S, Gordon JI. Microbial ecology: human gut microbes associated with obesity. Nature. 2006; 444: 1022– 1023. 17183309 source

      Not checked in the free run.

    • cites [50] Zhernakova A, Kurilshikov A, Bonder MJ, Tigchelaar EF, Schirmer M, Vatanen T, Mujagic Z, Vila AV, Falony G, Vieira‐Silva S, Wang J, Imhann F, Brandsma E, Jankipersadsing SA, Joossens M, Cenit MC, Deelen P, Swertz MA, Weersma RK, Feskens EJ, Netea MG, Gevers D, Jonkers D, Franke L, Aulchenko YS, Huttenhower C, Raes J, Hofker MH, Xavier RJ, Wijmenga C, Fu J. Population‐based metagenomics analysis reveals markers for gut microbiome composition and diversity. Science. 2016; 352: 565– 569. 27126040 PMC5240844 source

      Not checked in the free run.

    • cites [51] Sonnenburg JL, Backhed F. Diet‐microbiota interactions as moderators of human metabolism. Nature. 2016; 535: 56– 64. 27383980 PMC5991619 source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Detailed assessment of dietary intakes was not available in all included studies, limiting the ability to investigate potential roles of dietary factors in the associations of gut microbiota metabolites and the outcomes.

    “However, detailed assessment of dietary intakes was not available in all the included studies; this limited our abilities to investigate the potential roles of dietary factors in the associations of gut microbiota metabolites and the outcomes.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The influence of several potential confounders and traditional risk factors for cardiovascular diseases was carefully assessed.

    “We carefully assessed the influence of several potential confounders and traditional risk factors for CVDs.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In a study, plasma l-carnitine concentrations predicted major adverse cardiovascular events independent of traditional cardiovascular risk factors, but the significant association disappeared after adjustment for plasma TMAO concentration.

    “A study4 showed that plasma l‐carnitine concentrations predicted MACE independent of traditional cardiovascular risk factors, but the significant association disappeared after adjustment for plasma TMAO concentration.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Sheehy BT, Britt EB, Fu X, Wu Y, Li L, Smith JD, Didonato JA, Chen J, Li H, Wu GD, Lewis JD, Warrier M, Brown JM, Krauss RM, Tang WHW, Bushman FD, Lusis AJ, Hazen SL. Intestinal microbiota metabolism of L‐carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med. 2013; 19: 576– 585. 23563705 PMC3650111 source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    The associations of correlated gut microbiota metabolites could not be mutually adjusted, so it could not be determined whether TMAO or its precursors were independently associated with the outcomes.

    “In our analyses, the associations of these correlated gut microbiota metabolites could not be mutually adjusted; therefore, we could not determine whether the TMAO or its precursors were independently associated with the outcomes.”
    Quote in the paperSubstantial claim
42 of 42

  • The paper relies on this without support.

    No study has comprehensively analyzed the strength and consistency of associations of TMAO and its precursors with the risk of MACE.

    “No study has comprehensively analyzed the strength and consistency of associations of TMAO and its precursors with the risk of MACE.”

  • The paper relies on this without support.

    The multivariate-adjusted relative risks from the included studies adequately control for traditional cardiovascular risk factors, so the pooled associations are independent of them.

    “Multivariate‐adjusted relative risks (RRs) were used when these were available.”
    “Elevated concentrations of TMAO and its precursors were associated with increased risks of MACE and all‐cause mortality independently of traditional risk factors.”

  • The paper relies on this without support.

    The definitions of MACE across the included studies are sufficiently comparable to pool their estimates.

    “There is no standard definition for MACE, and the definition varies by study, whereas most studies include MI and death to define MACE.30”
    “In the current study, MACE was indicated by composites of MI, stroke, heart transplant, heart failure (HF), other ischemic cardiovascular events, or death (either cardiovascular or all‐cause death) as presented in Tables 1 and 2.”

  • The paper relies on this without support.

    The highest versus lowest TMAO categories across the included studies represent comparable contrasts of high versus low TMAO exposure.

    “The original articles used tertiles, quartiles, or quintiles as categories for TMAO levels.”
    “The high TMAO group was indicated by the highest tertile,13, 16, 19, 23, 26 the top 2 tertiles18 (because a RR of the top 2 tertiles vs the lowest tertile was presented in the original study), the highest quartile,1 or the highest quintile.7, 22”

  • The paper relies on this without support.

    The included prospective studies are sufficiently similar in design and population to be combined in a single pooled estimate.

    “We performed a main analysis to estimate a pooled RR of MACE associated with high concentrations of TMAO in comparison with low concentrations.”
    “Results stratified by disease status at baseline or ethnicity were treated as 2 separate data points.7, 11, 22”

  • The paper relies on this without support.

    Blood TMAO concentrations measured by different assays across studies are comparable.

    “One study14 introduced a newly developed method for the measurement of TMAO showing the lowest value of TMAO.”
    “One study14 introduced a newly developed method for the measurement of TMAO, and their IQRs of TMAO were lower than other studies, so that we calculated a RR without data from the study.”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Elevated circulating TMAO levels are associated with both CVD and mortality risks across multiple cohorts and continents, supporting clinical prognostic value.

    “Notably, a clinical prognostic value of TMAO has been supported by multiple meta-analyses reaffirming that elevated circulating TMAO levels are associated with both CVD and mortality risks across multiple cohorts and continents.[10][11][12]”

    From Impact of chronic dietary red meat, white meat, or non-meat protein on trimethylamine N-oxide metabolism and renal excretion in healthy men and women (2019) · cites this paper as [12]

  • Meta-analyses confirm a strong clinical association between increased TMAO levels and incident adverse cardiovascular events and mortality risks in multiple populations.

    “several recent meta-analyses confirm a strong clinical association between increased levels of TMAO and incident adverse cardiovascular event and mortality risks in multiple populations25–27.”

    From Development of a gut microbe–targeted nonlethal therapeutic to inhibit thrombosis potential (2018) · cites this paper as [25]

  • Meta-analyses have concluded that a strong relationship exists between elevated circulating trimethylamine N-oxide levels and both cardiovascular disease risk and mortality in multiple cohorts on different continents.

    “While not all studies have observed the relationship between heightened TMAO levels and incident CVD risks, examination of extant clinical studies with TMAO in multiple meta-analyses have concluded that a strong relationship indeed exists between elevated circulating TMAO levels and both CVD risk and mortality in multiple cohorts on different continents105–107.”

    From Gut microbiota and cardiovascular disease. (2020) · cites this paper as [107]

  • These observations have been replicated in multiple independent observational cohorts across a spectrum of CKD patients.

    “These observations have since been replicated in multiple independent observational cohorts across a spectrum of CKD patients199–203.”

    From Dietary metabolism, the gut microbiome, and heart failure (2019) · cites this paper as [201]

  • Black CKD populations tended to have better survival than white CKD counterparts within the same quintile of TMAO levels.

    “Shafi et al. reported that black CKD populations tended to have better survival than their white CKD counterparts within the same quintile of TMAO levels201.”

    From Dietary metabolism, the gut microbiome, and heart failure (2019) · cites this paper as [201]

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Authors
Heianza, Y., Ma, W., Manson, J. E., Rexrode, K. M., & Qi, L.
Affiliations
  • Tulane University (US)
  • Harvard University (US)
  • Brigham and Women's Hospital (US)
Corresponding author
Qi, Lu
ORCID
Venue
Journal of the American Heart Association
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
2017-07
Volume
6
Issue
7
ISSN
2047-9980 (ISSN-L)
DOI
10.1161/jaha.116.004947
PMC
PMC5586261
OpenAlex
W2729775538
Semantic Scholar
060117517ad12c4072a097f695692a8320ea7b5b
Cited by
544
References
56
Citations by year
2026: 39 · 2025: 59 · 2024: 49 · 2023: 58 · 2022: 65 · 2021: 77 · 2020: 92 · 2019: 48 · 2018: 50 · 2017: 4
FWCI
4.96
Type
journal article
Language
en
Open access
Licence
cc-by-nc
Locations
  • Journal of the American Heart Association (publishedVersion, cc-by-nc)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Digital Access to Scholarship at Harvard (DASH) (Harvard University) (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
National Heart, Lung, and Blood Institute (R01HL034594, R01HL088521)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiovascular Health and Risk Factors
Keywords
gut microbiota metabolites, trimethylamine N-oxide, major adverse cardiovascular events, all-cause mortality, cardiovascular risk factors, L-carnitine, choline, betaine, gut microbiota, Black participants
MeSH terms
Gastrointestinal Microbiome, Aged, Cardiovascular Diseases, Cause of Death, Humans, Methylamines, Middle Aged, Prospective Studies, Risk Factors, Biomarkers

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-07.

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