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Cited by 172Bariatric Surgery and OutcomesBody Contouring and SurgeryMinimally Invasive Surgical Techniques

Cognitive Function After Bariatric Surgery: Evidence for Improvement 3 Years After Surgery

Open access
Alosco, Michael L., Galioto, Rachel, Spitznagel, Mary Beth, Strain, Gladys, Devlin, Michael, Cohen, Ronald, Crosby, Ross D., Mitchell, James E. +1 more·2014·The American Journal of Surgery
DOI 10.1016/j.amjsurg.2013.05.018PMC PMC3983172
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Abstract

Background Bariatric surgery is associated with improved cognition, and it is possible that such improvements are found at extended follow-ups. We hypothesized that cognitive improvement would be maintained 3 years after bariatric surgery.Methods Fifty bariatric patients were recruited from the Longitudinal Assessment of Bariatric Surgery parent project. Participants completed a computerized cognitive test battery to assess cognitive function at 12 weeks, 12 months, 24 months, and 36 months after surgery.Results Repeated measures revealed main effects for attention, executive function, and memory. Attention improved up to 24 months and then slightly declined although it still fell within the average range at 36 months. Improvements in executive function reached their peak at 36 months after surgery. Short-term improvements in memory were maintained at 36 months. No main effect emerged for language.Conclusions Bariatric surgery may lead to lasting improvements in cognition. Prospective studies with extended follow-ups (eg, 10 years) should examine whether bariatric surgery can attenuate cognitive decline in severely obese patients.

Integrity signals

Registry

Crossref · 10.1016/j.amjsurg.2013.05.018

Cites

35 of 35 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

0 of 19 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    No significant main effect of time was found for language over 36 months after bariatric surgery.

    “No main effect emerged for language.”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “No significant main effect emerged for language (Λ = .83, F(4, 46) = 2.32, p = .07).”
    Quote in the paperNot a substantial claim
  • Findingown data

    At baseline, the bariatric surgery sample had a mean BMI of 46.61 (SD 5.27), classified as very severely obese.

    “the current sample of bariatric surgery patients were classified as very severely obese at baseline Mean BMI = 46.61 (SD = 5.27)).”
    Quote in the paperNot a substantial claim
  • Findingown data

    Memory improved significantly from baseline to 12 weeks, 12, 24, and 36 months after bariatric surgery.

    “Follow-up analyses showed significant improvements in memory from baseline to each of the distant time points [12-weeks (Λ = .62, F(1, 49) = 30.31, p < .001), 12-months (Λ = .44, F(1, 49) = 63.40, p < .001), 24-months (Λ = .72, F(1, 49) = 19.32, p < .001), 36-months (Λ = .68, F(1, 49) = 23.56, p < .001)].”
    Quote in the paperSubstantial claim
  • Findingown data

    Executive function improved significantly from baseline to 12, 24, and 36 months after bariatric surgery.

    “executive function significantly improved from baseline to each of the distant time points [baseline to 12-months (Λ = .65, F(1, 49) = 26.76, p < .001); baseline to 24-months (Λ = .53, F(1, 49) = 44.09, p < .001); and baseline to 36-months (Λ = .45, F(1, 49) = 60.89, p < .001).”
    Quote in the paperSubstantial claim
  • Findingown data

    Attention improved significantly from baseline to 12 weeks, 12 months, and 24 months after bariatric surgery.

    “follow-up analyses showed significant improvements in attention from baseline to 12-weeks (Λ = .85, F(1, 49) = 8.47, p < .01), 12-months (Λ = .69, F(1, 49) = 22.20, p < .001) and to 24-months (Λ = .60, F(1, 49) = 33.37, p < .001).”
    Quote in the paperSubstantial claim
  • May combine two claims. 18
  • The quote only partly states this claim. 2
  • Classified as probably not a substantial claim. 4

  • May combine two claims.

    Findingown data

    Attention improved significantly over 36 months after bariatric surgery, with gains up to 24 months followed by a slight decline from 24 to 36 months, remaining in the average range at 36 months.

    “Attention improved up to 24-months and then slightly declined, though still fell within the average range at 36-months.”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “There was a significant main effect for attention across the five time points (Λ = .32, F(4, 46) = 24.15, p < .001).”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “attention generally improved up until 24-months and then declined between 24-months and 36-months post bariatric surgery (Λ = .40, F(1, 49) = 72.38, p < .001).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Memory improved significantly after bariatric surgery, with gains up to 12 months that were maintained through 36 months.

    “Short-term improvements in memory were maintained at 36-months.”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “For memory, there was a significant main effect across the five time points (Λ = .57, F(4, 46) = 15.16, p < .001).”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “memory gradually improved up until 12-months and then remained largely unchanged from 12-months to 36-months post-bariatric surgery.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Executive function improved significantly over 36 months after bariatric surgery, reaching its peak at 36 months.

    “Improvements in executive function reached its peak at 36-months post-surgery.”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “For executive function, there was also a significant main effect for time (Λ = .41, F(4, 46) = 16.75, p < .001).”
    • Also stated in: § Cognitive Function Post Bariatric Surgery · plain
      “executive function continued to improve until it reached its peak at 36-months post-operatively”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Significant weight regain occurred between 24 and 36 months after bariatric surgery, with 74.5% of participants increasing BMI, an average increase of 1.27 ± 2.30 BMI units, and 17.0% having an increase greater than 3.0 BMI units.

    “significant weight regain was observed between 24-months and 36-months post-operatively (F(1,46) = 14.42, p < .001; BMI M (SD) = 31.07 (6.67) versus 32.25 (6.66)). Specifically, 74.5% of participants exhibited an increase in BMI during this time period, with an average increase of 1.27 ± 2.30 (range from −5.16 to 8.15, 17.0% with a >3.0 BMI unit increase).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Participants who regained weight from 24 to 36 months after bariatric surgery showed significant declines in attention, with no changes in other cognitive domains.

    “Participants who exhibited weight regain from 24- to 36-months post-operatively also demonstrated significant declines in attention (F(1,34) = 67.24, p < .001). No changes were noted for any other of the cognitive domains (p > .05).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At 48 months after bariatric surgery, attention, memory, and language were in the average range, while executive function was in the high average to above average range.

    “Exploratory analyses for cognitive test performance at 48-months post bariatric surgery showed that attention, memory and language functioning fell within the average range while executive function fell within the high average to above average range.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At baseline, clinically meaningful cognitive impairment was present in 12.0% for memory, 8.0% for executive function, and 4.0% for attention and language.

    “When using a T-score cutoff of 35, 12.0% and 8.0% of patients showed impairments in memory and executive function. Impairments in attention and language were less common (4.0% of patients for both domains).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    At 36 months after bariatric surgery, cognitive performance in all domains was in the average range and impairment prevalence was lower.

    “At 36-month post-operative follow up, bariatric surgery patients cognitive test performance for all domains of cognitive function fell within the average range and prevalence of impairment was also less prevalent.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    From baseline to 48 months after bariatric surgery, executive function and memory improved significantly, while attention and language did not.

    “No such pattern emerged for attention (Λ = .99, F(1, 20) = .29, p = .60; baseline attention M(SD) = 55.02 (6.61 vs. attention at 48-months M (SD) = 54.14 (8.41) or language (Λ = .99, F(1, 49) = .14, p = .71; baseline language M (SD) = 49.44 (11.41 vs. language at 48-months M (SD) = 50.20 (10.94).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Executive function showed its largest improvement at 12 weeks after bariatric surgery, followed by a non-significant decline to 12 months, then continued improvement to a peak at 36 months.

    “The most significant improvements in executive function was found 12-weeks post bariatric surgery (Λ = .56, F(1, 49) = 38.60, p < .001), and after a slight non-significant decline from 12-weeks to 12-months (Λ = .98, F(1, 49) = .91, p = .35), executive function continued to improve until it reached its peak at 36-months post-operatively”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    There was a trend for a negative correlation between BMI increase from 24 to 36 months after surgery and 36-month attention performance, with no such pattern for other cognitive domains.

    “Bivariate correlations also revealed a trend for increase in BMI from 24- to 36-months following surgery and poorer 36-month performance in attention (r(47) = −.27, p = .069). No such pattern emerged for the other cognitive domains (p > .10).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    BMI decreased significantly from baseline to 36 months after bariatric surgery, with a mean BMI of 32.35 (SD 6.57) at 36 months.

    “However, the average BMI reduced to 32.35 (SD = 6.57) (i.e., moderately obese) at 36-months, which represents a significant decline (Λ = .13, F(1, 46) = 300.06, p < .001).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    At baseline, bariatric surgery patients' cognitive performance was in the low average range for memory and in the average range for other cognitive domains.

    “At baseline, when compared to normative data, cognitive test performance in the bariatric surgery patients fell within the low average range for memory and in the average range for all other cognitive domains.”
    Quote in the paperNot a substantial claim

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

    Study design and conductown data

    Participants excluded from the 48-month analyses did not differ in age or baseline diabetes or sleep apnea, but were more likely to have baseline hypertension.

    “Participants excluded as a result of incomplete data at 48-months did not differ in terms of age or baseline medical history of diabetes (χ2 (1, N = 50) = .49, p = .49) or sleep apnea (χ2 (1, N = 50) = 2.79, p = .10). However, participants excluded were more likely to have a diagnosis of hypertension at baseline (χ2 (1, N = 50) = 6.65, p = .01; 65.5% vs. 28.6%).”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Obesity is linked to neurological changes such as Alzheimer's disease, vascular dementia, and brain atrophy, and obese persons show impairments on cognitive tests of attention, executive function, and memory.

    “obesity has been linked with increased risk for neurological changes, including Alzheimer’s disease, vascular dementia, as well as brain atrophy.4,5 Indeed, obese persons also exhibit impairments on formal cognitive testing, including on tasks of attention, executive function, and memory.6,7”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [4] Fitzpatrick, 2009, Midlife and late-life obesity and the risk of dementia: cardiovascular health study, Arch Neurol source

      Not checked in the free run.

    • cites [5] Gunstad, 2008, Relationship between body mass index and brain volume in healthy adults, Int J Neurosci source

      Not checked in the free run.

    • cites [6] Cournot, 2006, Relation between body mass index and cognitive function in healthy middle-aged men and women, Neurology source

      Not checked in the free run.

    • cites [7] Gunstad, 2010, Longitudinal examination of obesity and cognitive function: results from the Baltimore Longitudinal Study of Aging, Neuroepidemiology source

      Not checked in the free run.

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

    Premisecitation

    Midlife obesity is a risk factor for Alzheimer's disease and vascular dementia.

    “extant literature that demonstrates midlife obesity as a risk factor for Alzheimer’s disease and vascular dementia.24–26”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [24] Hassing, 2009, Overweight in midlife and risk of dementia: a 40-year follow-up study, Int J Obes source

      Not checked in the free run.

    • cites [25] Whitmer, 2008, Central obesity and increased risk of dementia more than three decades later, Neurology source

      Not checked in the free run.

    • cites [26] Kivipelto, 2005, Obesity and vascular risk factors at midlife and the risk of dementia and Alzheimer disease, Arch Neurol source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The study replicates prior findings of cognitive improvement after bariatric surgery and indicates that postoperative cognitive benefits may persist up to 3 years.

    “In brief summary, this study replicates past work demonstrating improvements in cognitive function following bariatric surgery and further indicates that post-operative cognitive benefits may be maintained up to 3 years post-operatively.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisenone given

    The long-term impact of bariatric surgery on cognitive function is poorly understood.

    “Despite these findings, the long-term impact of bariatric surgery on cognitive function remains poorly understood.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductcitation

    The Integneuro cognitive test battery has excellent psychometric properties and is sensitive to the effects of obesity.

    “It has excellent psychometric properties18,19 and has been shown to be sensitive to the effects of obesity in past work.20”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [18] Paul, 2005, Preliminary validity of “integneuro” a new computerized battery of neurocognitive tests, Int J Neurosci source

      Not checked in the free run.

    • cites [19] Williams, 2005, The test-retest reliability of a standardized neurocognitive and neurophysiological test battery: “neuromarker”, Int J Neurosci source

      Not checked in the free run.

    • cites [20] Gunstad, 2007, Elevated body mass index is associated with executive dysfunction in otherwise healthy adults, Compr Psychiatry source

      Not checked in the free run.

19 of 19

  • The paper relies on this without support.

    The type of bariatric surgery does not differentially affect cognitive outcomes.

    “Within the sample, just 1 bariatric surgery patient underwent gastric banding procedure and thus no comparisons for type of surgery (Roux-en-Y gastric bypass vs. gastric banding) were conducted.”

  • The paper relies on this without support.

    The differential attrition by baseline hypertension at 48 months does not bias the 48-month cognitive findings.

    “However, participants excluded were more likely to have a diagnosis of hypertension at baseline (χ2 (1, N = 50) = 6.65, p = .01; 65.5% vs. 28.6%).”
2 of 2

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?

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • Not confirmedr(47) = -0.27reported p = .069 · recomputed p = .061

    “r(47) = −.27, p = .069”

  • Consistentt(127) = 0.63reported p = .53 · recomputed p = .530

    “t(127) = .63, p = .53”

  • Consistentt(127) = 0.54reported p = .59 · recomputed p = .590

    “t(127) = .54, p = .59”

  • Consistentt(127) = 0.42reported p = .68 · recomputed p = .675

    “t(127) = .42, p = .68”

  • Consistentt(127) = 0.14reported p = .89 · recomputed p = .889

    “t(127) = .14, p = .89”

  • Consistentt(127) = 1.14reported p = .26 · recomputed p = .256

    “t(127) = 1.14, p = .26”

  • Consistentt(127) = -0.98reported p = .33 · recomputed p = .329

    “t(127) = −.98, p = .33”

  • Consistentχ²(1) = 0.49reported p = .49 · recomputed p = .484

    “χ2 (1, N = 50) = .49, p = .49”

  • Consistentχ²(1) = 2.79reported p = .1 · recomputed p = .095

    “χ2 (1, N = 50) = 2.79, p = .10”

  • Consistentχ²(1) = 6.65reported p = .01 · recomputed p = .010

    “χ2 (1, N = 50) = 6.65, p = .01”

  • ConsistentF(1, 46) = 300.06reported p < .001 · recomputed p < .001

    “F(1, 46) = 300.06, p < .001”

  • ConsistentF(4, 46) = 24.15reported p < .001 · recomputed p < .001

    “F(4, 46) = 24.15, p < .001”

  • ConsistentF(1, 49) = 72.38reported p < .001 · recomputed p < .001

    “F(1, 49) = 72.38, p < .001”

  • ConsistentF(1, 49) = 8.47reported p < .01 · recomputed p = .005

    “F(1, 49) = 8.47, p < .01”

  • ConsistentF(1, 49) = 22.2reported p < .001 · recomputed p < .001

    “F(1, 49) = 22.20, p < .001”

  • ConsistentF(1, 49) = 33.37reported p < .001 · recomputed p < .001

    “F(1, 49) = 33.37, p < .001”

  • ConsistentF(4, 46) = 16.75reported p < .001 · recomputed p < .001

    “F(4, 46) = 16.75, p < .001”

  • ConsistentF(1, 49) = 38.6reported p < .001 · recomputed p < .001

    “F(1, 49) = 38.60, p < .001”

  • ConsistentF(1, 49) = 0.91reported p = .35 · recomputed p = .345

    “F(1, 49) = .91, p = .35”

  • ConsistentF(1, 49) = 26.76reported p < .001 · recomputed p < .001

    “F(1, 49) = 26.76, p < .001”

  • ConsistentF(1, 49) = 44.09reported p < .001 · recomputed p < .001

    “F(1, 49) = 44.09, p < .001”

  • ConsistentF(1, 49) = 60.89reported p < .001 · recomputed p < .001

    “F(1, 49) = 60.89, p < .001”

  • ConsistentF(4, 46) = 15.16reported p < .001 · recomputed p < .001

    “F(4, 46) = 15.16, p < .001”

  • ConsistentF(1, 49) = 30.31reported p < .001 · recomputed p < .001

    “F(1, 49) = 30.31, p < .001”

  • ConsistentF(1, 49) = 63.4reported p < .001 · recomputed p < .001

    “F(1, 49) = 63.40, p < .001”

  • ConsistentF(1, 49) = 19.32reported p < .001 · recomputed p < .001

    “F(1, 49) = 19.32, p < .001”

  • ConsistentF(1, 49) = 23.56reported p < .001 · recomputed p < .001

    “F(1, 49) = 23.56, p < .001”

  • ConsistentF(4, 46) = 2.32reported p = .07 · recomputed p = .071

    “F(4, 46) = 2.32, p = .07”

  • ConsistentF(1, 20) = 20.58reported p < .001 · recomputed p < .001

    “F(1, 20) = 20.58, p < .001”

  • ConsistentF(1, 20) = 31.6reported p < .001 · recomputed p < .001

    “F(1, 20) = 31.60, p < .001”

  • ConsistentF(1, 20) = 0.29reported p = .6 · recomputed p = .596

    “F(1, 20) = .29, p = .60”

  • ConsistentF(1, 49) = 0.14reported p = .71 · recomputed p = .710

    “F(1, 49) = .14, p = .71”

  • ConsistentF(1, 46) = 300.06reported p < .001 · recomputed p < .001

    “F(1,46) = 300.06, p < .001”

  • ConsistentF(1, 46) = 14.42reported p < .001 · recomputed p < .001

    “F(1,46) = 14.42, p < .001”

  • ConsistentF(1, 34) = 67.24reported p < .001 · recomputed p < .001

    “F(1,34) = 67.24, p < .001”

35 of 35

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Reported BMI regain does not match the stated means

    Minor

    The stated 24- and 36-month mean BMIs differ by 1.18 units, not the reported average increase of 1.27 units.

    Reported 1.27 · recomputed 1.18

  • The 48-month language analysis uses the wrong sample-size degrees of freedom

    Minor

    The paper says the 48-month analyses used 21 participants, but the language test reports F(1, 49), which corresponds to 50 participants for a two-time-point repeated-measures comparison. The other 48-month tests report F(1, 20).

  • Two different 36-month BMI averages are reported

    Minor

    The results give the 36-month mean BMI as both 32.35 and 32.25. The accompanying standard deviations also differ.

3 of 3

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Authors
Alosco, M. L., Galioto, R., Spitznagel, M. B., Strain, G., Devlin, M., Cohen, R., Crosby, R. D., Mitchell, J. E., & Gunstad, J.
Affiliations
  • Kent State University (US)
  • Summa Health System (US)
  • Weill Cornell Medicine (US)
  • Columbia University Irving Medical Center (US)
  • University of Florida (US)
  • University of North Dakota (US)
Corresponding author
Gunstad, John
ORCID
Venue
The American Journal of Surgery
Publisher
Elsevier BV
Published
2014-06
Volume
207
Issue
6
Pages
870-876
ISSN
0002-9610 (ISSN-L)
DOI
10.1016/j.amjsurg.2013.05.018
PMC
PMC3983172
OpenAlex
W2138399636
Cited by
172
References
35
Citations by year
2026: 6 · 2025: 11 · 2024: 13 · 2023: 13 · 2022: 16 · 2021: 19 · 2020: 13 · 2019: 14 · 2018: 7 · 2017: 15 · 2016: 13 · 2015: 17 · 2014: 15
FWCI
14.77
Type
journal article
Language
en
Open access
Licence
Locations
  • The American Journal of Surgery (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Institutes of Health (UL1TR000457)
  • National Institute on Aging (P30AG028740)
  • National Heart, Lung, and Blood Institute (R01HL089311, HL089311)
  • National Institute of Diabetes and Digestive and Kidney Diseases (R56DK075119, DK075119, R01DK075119, R01DK099334)
  • National Center for Advancing Translational Sciences
Topics
  • Health Sciences › Medicine › Surgery › Bariatric Surgery and Outcomes
  • Health Sciences › Medicine › Surgery › Body Contouring and Surgery
  • Health Sciences › Medicine › Surgery › Minimally Invasive Surgical Techniques
Keywords
bariatric surgery, cognitive function, obesity, attention, executive function, memory, language, cognitive decline, long-term follow-up, computerized cognitive assessment
MeSH terms
Adult, Aged, Cognition, Female, Humans, Longitudinal Studies, Male, Middle Aged, Obesity, Morbid, Prospective Studies, Psychological Tests, Treatment Outcome, Bariatric Surgery

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