Total ghrelin levels during acute insulin infusion in patients with polycystic ovary syndrome
Abstract
Controversial data were reported concerning fasting ghrelin (decreased, normal or elevated) in polycystic ovary syndrome (PCOS). The aim of our study was to clarify ghrelin levels in non-obese, overweight, and obese PCOS patients; to investigate the effect of acute insulin infusion on ghrelin in PCOS as a chronic insulin-resistant state, with and without the impact of obesity, and to examine ghrelin-androgen interaction. In that order, we evaluated 1) ghrelin levels among 8 nonobese patients with PCOS [body mass index (BMI): 20.52+/-1.31 kg/m2], 8 overweight and obese patients with PCOS (BMI: 34.36+/-6.53 kg/m2) and their respective controls, 2) ghrelin suppression during euglycemic hyperinsulinemic clamp, and 3) ghrelin-androgen interrelationship. After overnight fast, 2-h euglycemic hyperinsulinemic clamp, was performed in all investigated women. Fasting ghrelin was significantly lower in non-obese PCOS than in controls (64.74+/-25.69 vs 108.36+/-52.60; p<0.05) as well as in overweight and obese PCOS in comparison with controls (38.71+/-14.18 vs 98.77+/-40.49; p<0.05). Insulin infusion significantly suppressed ghrelin in all subgroups of investigated women. Analysis of variance for repeatable measures confirmed that there was no significant difference in pattern of response between PCOS and controls. In conclusion, women with PCOS had lower fasting ghrelin and decreased insulin sensitivity independently of their BMI, compared to the controls. In addition, there were no differences between fasting ghrelin levels among non-obese, overweight, and obese women with PCOS. During euglycemic hyperinsulinemic clamp, ghrelin decreased in all studied groups to a similar extent, implying that, compared to chronic hyperinsulinemia, acute hyperinsulinemia reduces ghrelin levels independently of the degree of insulin resistance.
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Three clear outliers were identified; one was corrected and no longer an outlier, and the other two were excluded from the meta-analysis.
“This approach identified three clear outliers (Micic et al., 2007;Yang et al., 2013;Wu et al., 2014).”
From Insulin resistance in polycystic ovary syndrome: a systematic review and meta-analysis of euglycaemic–hyperinsulinaemic clamp studies (2016) · cites this paper as Micic et al., 2007
Cites
Matthews, D. R., Hosker, J. P., Rudenski, A. S., Naylor, B. A., Treacher, D. F., & Turner, R. C. (1985) · Diabetologia · doi:10.1007/bf00280883 · Cited by 31,502 · see citing works
Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus
The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus* (2002) · Diabetes Care · doi:10.2337/diacare.25.2007.s5 · Cited by 10,320 · see citing works
(2004) · Fertility and Sterility · doi:10.1016/j.fertnstert.2003.10.004 · Cited by 9,050 · see citing works
Ghrelin is a growth-hormone-releasing acylated peptide from stomach
Kojima, M., Hosoda, H., Date, Y., Nakazato, M., Matsuo, H., & Kangawa, K. (1999) · Nature · doi:10.1038/45230 · Cited by 8,479 · see citing works
Glucose clamp technique: a method for quantifying insulin secretion and resistance.
DeFronzo, R. A., Tobin, J. D., & Andres, R. (1979) · American Journal of Physiology-Endocrinology and Metabolism · doi:10.1152/ajpendo.1979.237.3.e214 · Cited by 7,425 · see citing works
Leptin and the regulation of body weight in mammals
Friedman, J. M., & Halaas, J. L. (1998) · Nature · doi:10.1038/27376 · Cited by 5,405 · see citing works
Ghrelin induces adiposity in rodents
Tschöp, M., Smiley, D. L., & Heiman, M. L. (2000) · Nature · doi:10.1038/35038090 · Cited by 3,949 · see citing works
Insulin Resistance and the Polycystic Ovary Syndrome: Mechanism and Implications for Pathogenesis
Dunaif, A. E. (1997) · Endocrine Reviews · doi:10.1210/edrv.18.6.0318 · Cited by 2,761 · see citing works
Ghrelin enhances appetite and increases food intake in humans
Wren, A. M., Seal, L. J., Cohen, M. A., Brynes, A. E., Frost, G. S., Murphy, K. G., Dhillo, W. S., Ghatei, M. A., & Bloom, S. R. (2001) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.86.12.8111 · Cited by 2,494 · see citing works
Men at risk: occupation and male infertility.
Claman, P. (2004) · Fertility and Sterility · doi:10.1016/s0015-0282(03)01188-9 · Cited by 2,219 · see citing works
Circulating Ghrelin Levels Are Decreased in Human Obesity
Tschöp, M. H., Weyer, C., Tataranni, P. A., Devanarayan, V., Ravussin, É., & Heiman, M. L. (2001) · Diabetes · doi:10.2337/diabetes.50.4.707 · Cited by 1,992 · see citing works
Plasma ghrelin levels in lean and obese humans and the effect of glucose on ghrelin secretion.
Shiiya, T., Nakazato, M., Mizuta, M., Date, Y., Mondal, M. S., Tanaka, M., Nozoe, S., Hosoda, H., Kangawa, K., & Matsukura, S. (2002) · Journal of Clinical Endocrinology and Metabolism · doi:10.1210/jcem.87.1.8129 · Cited by 1,390 · see citing works
Biological, Physiological, Pathophysiological, and Pharmacological Aspects of Ghrelin
van der Lely, A. J., Tschöp, M., Heiman, M. L., & Ghigo, E. (2004) · Endocrine Reviews · doi:10.1210/er.2002-0029 · Cited by 1,187 · see citing works
The role of insulin receptor signaling in the brain
Plum, L., Schubert, M., & Brüning, J. C. (2005) · Trends in Endocrinology & Metabolism · doi:10.1016/j.tem.2005.01.008 · Cited by 604 · see citing works
Minireview: Ghrelin and the Regulation of Energy Balance--A Hypothalamic Perspective
Horváth, T. L., Diano, S., Sótonyi, P., Heiman, M. L., & Tschöp, M. H. (2001) · Endocrinology · doi:10.1210/endo.142.10.8490 · Cited by 570 · see citing works
Insulin Regulates Plasma Ghrelin Concentration
Saad, M. F., Bernaba, B., Hwu, C., Jinagouda, S. D., Fahmi, S., Kogosov, E., & Boyadjian, R. (2002) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.87.8.8879 · Cited by 512 · see citing works
The ghrelin cell: a novel developmentally regulated islet cell in the human pancreas
Wierup, N., Svensson, H., Mulder, H., & Sundler, F. (2002) · Regulatory Peptides · doi:10.1016/s0167-0115(02)00067-8 · Cited by 457 · see citing works
The influence of insulin on circulating ghrelin
Flanagan, D., Evans, M. L., Monsod, T. P., Rife, F., Heptulla, R. A., Tamborlane, W. V., & Sherwin, R. S. (2003) · American Journal of Physiology-Endocrinology and Metabolism · doi:10.1152/ajpendo.00569.2001 · Cited by 367 · see citing works
Novel Expression and Functional Role of Ghrelin in Rat Testis
Tena‐Sempere, M., Barreiro, M. L., Gonzalez, L., Gaytán, F., Zhang, F., Caminos, J. E., Pinilla, L., Casanueva, F. F., Diéguez, C., & Aguilar, E. (2002) · Endocrinology · doi:10.1210/endo.143.2.8646 · Cited by 344 · see citing works
Self-citationInsulin Signaling in the Central Nervous System
Porte, D., Baskin, D. G., & Schwartz, M. W. (2005) · Diabetes · doi:10.2337/diabetes.54.5.1264 · Cited by 336 · see citing works
le Roux, C. W., Patterson, M., Vincent, R. P., Hunt, C., Ghatei, M. A., & Bloom, S. R. (2005) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2004-1216 · Cited by 276 · see citing works
McLaughlin, T., Abbasi, F., Lamendola, C. A., Frayo, R. S., & Cummings, D. E. (2004) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2003-031572 · Cited by 274 · see citing works
Welt, C. K., Gudmundsson, J., Arason, G., Adams, J., Pálsdottir, H. S., Gudlaugsdottir, G. J., Ingadóttir, G., & Crowley, W. F. (2006) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2006-1327 · Cited by 260 · see citing works
Ikezaki, A., Hosoda, H., Ito, K., Iwama, S., Miura, N., Matsuoka, H., Kondo, C., Kojima, M., Kangawa, K., & Sugihara, S. (2002) · Diabetes · doi:10.2337/diabetes.51.12.3408 · Cited by 225 · see citing works
Insulin, Unlike Food Intake, Does Not Suppress Ghrelin in Human Subjects
Caixàs, A., Bashore, C. J., Nash, W., Pi‐Sunyer, F. X., & Laferrère, B. (2002) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.87.4.8538 · Cited by 211 · see citing works
Plasma Ghrelin Concentrations Are Not Regulated by Glucose or Insulin
Schaller, G., Schmidt, A., Pleiner, J., Woloszczuk, W., Wolzt, M., & Luger, A. (2003) · Diabetes · doi:10.2337/diabetes.52.1.16 · Cited by 205 · see citing works
Pagotto, U., Gambineri, A., Vicennati, V., Heiman, M. L., Tschöp, M. H., & Pasquali, R. (2002) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2002-020776 · Cited by 204 · see citing works
Euglycemic hyperinsulinemia, but not lipid infusion, decreases circulating ghrelin levels in humans
Möhlig, M., Spranger, J., Otto, B., Ristow, M., Tschöp, M., & Pfeiffer, A. F. H. (2002) · Journal of Endocrinological Investigation · doi:10.1007/bf03344062 · Cited by 196 · see citing works
Ghrelin and Leptin Pulse Discharge in Fed and Fasted Rats
Bagnasco, M., Kalra, P. S., & Kalra, S. P. (2002) · Endocrinology · doi:10.1210/endo.143.2.8743 · Cited by 173 · see citing works
Ravussin, É., Tschöp, M. H., Morales, S., Bouchard, C., & Heiman, M. L. (2001) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.86.9.8003 · Cited by 170 · see citing works
Moran, L., Noakes, M., Clifton, P. M., Wittert, G., Tomlinson, L., Galletly, C. A., Luscombe‐Marsh, N. D., & Norman, R. J. (2004) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2003-031583 · Cited by 170 · see citing works
Circulating Ghrelin Levels in Patients with Polycystic Ovary Syndrome
Schöfl, C., Horn, R., Schill, T., Schlösser, H. W., Müller, M. J., & Brabant, G. E. (2002) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2002-020505 · Cited by 169 · see citing works
Glintborg, D., Andersen, M., Hagen, C., Frystyk, J., Hulstrøm, V., Flyvbjerg, A., & Hermann, A. P. (2006) · European Journal of Endocrinology · doi:10.1530/eje.1.02207 · Cited by 133 · see citing works
St-Pierre, D. H., Karelis, A. D., Coderre, L., Malita, F. M., Fontaine, J., Mignault, D., Brochu, M., Bastard, J., Cianflone, K., Doucet, É., et al. (2006) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2006-1603 · Cited by 110 · see citing works
Kalra, S. P., Ueno, N., & Kalra, P. S. (2005) · Journal of Nutrition · doi:10.1093/jn/135.5.1331 · Cited by 103 · see citing works
Diagnosis of hyperandrogenism: Biochemical criteria
Stanczyk, F. Z. (2006) · Best Practice & Research Clinical Endocrinology & Metabolism · doi:10.1016/j.beem.2006.03.007 · Cited by 90 · see citing works
Gambineri, A., Pagotto, U., Tschöp, M., Vicennati, V., Manicardi, E., Carcello, A., Cacciari, M., Iasio, R. D., & Pasquali, R. (2003) · Journal of Endocrinological Investigation · doi:10.1007/bf03347020 · Cited by 86 · see citing works
Direct Peripheral Effects of Ghrelin Include Suppression of Adiponectin Expression
Ott, V., Faßhauer, M., Dalski, A., Meier, B., Perwitz, N., Klein, H. H., Tschöp, M. H., & Klein, J. C. (2002) · Hormone and Metabolic Research · doi:10.1055/s-2002-38261 · Cited by 81 · see citing works
Circulating Ghrelin Concentrations in the Polycystic Ovary Syndrome
Orio, F., Lucidi, P., Palomba, S., Tauchmanovà, L., Cascella, T., Russo, T., Zullo, F., Colao, A., Lombardi, G., & Feo, P. D. (2003) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2002-021451 · Cited by 80 · see citing works
The Effects of Insulin on the Central Nervous System - Focus on Appetite Regulation
Pliquett, R. U., Führer, D., Falk, S., Zysset, S., CRAMON, D. V., & Stümvoll, M. (2006) · Hormone and Metabolic Research · doi:10.1055/s-2006-947840 · Cited by 73 · see citing works
Elevated Ghrelin Plasma Levels in Patients with Polycystic Ovary Syndrome
Waśko, R., Komarowska, H., Warenik-Szymankiewicz, A., & Sowiński, J. (2004) · Hormone and Metabolic Research · doi:10.1055/s-2004-814341 · Cited by 56 · see citing works
Panidis, D., Farmakiotis, D., Koliakos, G., Rousso, D., Kourtis, A., Katsikis, I., Asteriadis, C., Karayannis, V., & Diamanti‐Kandarakis, E. (2005) · Human Reproduction · doi:10.1093/humrep/dei055 · Cited by 45 · see citing works
Acute insulin infusion decreases plasma ghrelin levels in uncomplicated obesity
Leonetti, F., Iacobellis, G., Ribaudo, M. C., Zappaterreno, A., Tiberti, C., Iannucci, C. V., Vecci, E., & Mario, U. D. (2004) · Regulatory Peptides · doi:10.1016/j.regpep.2004.06.014 · Cited by 38 · see citing works
Circulating ghrelin concentrations are lowered by intracerebroventricular insulin
Ueno, M., Carvalheira, J. B. C., Oliveira, R. L. G. S., Velloso, L. A., & Saad, M. J. A. (2006) · Diabetologia · doi:10.1007/s00125-006-0371-8 · Cited by 19 · see citing works
Dahan, M. H., & Goldstein, J. S. (2006) · Fertility and Sterility · doi:10.1016/j.fertnstert.2006.02.108 · Cited by 16 · see citing works
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Liu, R., Zhang, C., Shi, Y., Zhang, F., Li, L., Wang, X., Ling, Y., Fu, H., Dong, W., Shen, J., et al. (2017) · Frontiers in Microbiology · doi:10.3389/fmicb.2017.00324 · Cited by 372 · see citing works
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- Authors
- Micic, D., Sumarac-Dumanovic, M., Kendereski, A., Cvijovic, G., Zoric, S., Pejkovic, D., Micic, J., Milic, N., Dieguez, C., & Casanueva, F. F.
- Affiliations
- Univerzitetski Klinički Centar Srbije (RS)
- University of Belgrade (RS)
- Universidade de Santiago de Compostela (ES)
- Venue
- Journal of Endocrinological Investigation
- Published
- 2007-11
- Volume
- 30
- Issue
- 10
- Pages
- 820-827
- ISSN
- 0391-4097 (ISSN-L)
- 1720-8386
- OpenAlex
- W2021252611
- Cited by
- 28
- References
- 45
- Citations by year
- 2022: 3 · 2019: 4 · 2018: 1 · 2017: 4 · 2016: 2 · 2015: 1 · 2014: 2 · 2013: 1 · 2012: 3
- FWCI
- 1.11
- Type
- journal article
- Language
- en
- Open access
- closed
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Journal of Endocrinological Investigation (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Reproductive Medicine › Ovarian function and disorders
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Regulation of Appetite and Obesity
- Health Sciences › Medicine › Reproductive Medicine › Hypothalamic control of reproductive hormones
- Keywords
- ghrelin, polycystic ovary syndrome, insulin resistance, hyperinsulinemic-euglycemic clamp, obesity, body mass index, androgens, hyperinsulinemia
- MeSH terms
- Acute Disease, Adult, Fasting, Female, Humans, Hyperinsulinism, Hypoglycemic Agents, Insulin, Insulin Resistance, Obesity, Polycystic Ovary Syndrome, Sex Hormone-Binding Globulin, Testosterone, Glucose Clamp Technique, Body Mass Index, Overweight, Ghrelin
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