Display options
Share it on

Clin Endocrinol (Oxf). 2021 Oct 29; doi: 10.1111/cen.14623. Epub 2021 Oct 29.

Impact of pharmacological interventions on insulin resistance in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials.

Clinical endocrinology

Mohammed A Abdalla, Najeeb Shah, Harshal Deshmukh, Amirhossein Sahebkar, Linda Östlundh, Rami H Al-Rifai, Stephen L Atkin, Thozhukat Sathyapalan

Affiliations

  1. Department of Academic Diabetes, Endocrinology and Metabolism, Hull York Medical School (HYMS), The University of Hull, Hull, UK.
  2. Biotechnology Research Centre, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
  3. Applied Biomedical Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran.
  4. College of Medicine and Health Sciences, The National Medical Library, United Arab Emirate University, Al Ain, United Arab Emirates.
  5. College of Medicine and Health Sciences, Institute of Public Health, United Arab Emirate University, Al Ain, United Arab Emirates.
  6. School of Postgraduate Studies and Research, RCSI Medical University of Bahrain, Busaiteen, Kingdom of Bahrain.

PMID: 34713480 DOI: 10.1111/cen.14623

Abstract

OBJECTIVE: Polycystic ovary syndrome (PCOS) is a complex endocrine condition affecting women of reproductive age. It is characterized by insulin resistance and is a major risk factor for type 2 diabetes mellitus (T2DM). The objective was to review the literature on the effect of different pharmacological interventions on insulin resistance in women with PCOS.

DESIGN: We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science in April 2020 and updated in March 2021. The study follows the 2020 Preferred Reporting Items for Systematic reviews and Meta-ana. Reviwers extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS: In 58 randomized controlled trials there were significant reductions in the fasting blood glucose (FBG) with metformin versus placebo (standardized mean difference [SMD]: -0.23; 95% confidence interval [CI]: -0.40, -0.06; I² = 0%, low-grade evidence), and acarbose versus metformin (mean difference [MD]: -10.50 mg/dl; 95% CI: -15.76, -5.24; I² = 0%, low-grade evidence). Significant reductions in fasting insulin (FI) with pioglitazone versus placebo (SMD: -0.55; 95% CI: -1.03, -0.07; I² = 37%; p = .02, very-low-grade evidence). A significant reduction in homoeostatic model assessment of insulin resistance (HOMA-IR) was seen with exenatide versus metformin (MD: -0.34; 95% CI: -0.65, -0.03; I² = 0%, low-grade evidence). No effect on homoeostatic model assessment of beta cells (HOMA-B) was observed.

CONCLUSIONS: Pharmacological interventions, including metformin, acarbose, pioglitazone and exenatide have significant effects on FBG, FI, HOMA-IR but not on HOMA-B.

© 2021 John Wiley & Sons Ltd.

Keywords: FBG; FI; HOMA-B; HOMA-IR; PCOS; pharmacological therapy; polycystic ovary syndrome

References

  1. Strowitzki T. Advanced diagnosis of polycystic ovary syndrome-new prediction models with standard parameters. Fertil Steril. 2021;115(1):92-93. - PubMed
  2. Teede H, Deeks A, Moran L. Polycystic ovary syndrome: a complex condition with psychological, reproductive and metabolic manifestations that impacts on health across the lifespan. BMC Med. 2010;8:41. - PubMed
  3. Abdalla MA, Deshmukh H, Atkin S, Sathyapalan T. A review of therapeutic options for managing the metabolic aspects of polycystic ovary syndrome. Ther Adv Endocrinol Metab. 2020;11:2042018820938305. - PubMed
  4. Baptiste CG, Battista MC, Trottier A, Baillargeon JP. Insulin and hyperandrogenism in women with polycystic ovary syndrome. J Steroid Biochem Mol Biol. 2010;122(1-3):42-52. - PubMed
  5. Nestler JE. Role of hyperinsulinemia in the pathogenesis of the polycystic ovary syndrome, and its clinical implications. Semin Reprod Endocrinol. 1997;15(2):111-122. - PubMed
  6. Diamanti-Kandarakis E, Dunaif A. Insulin resistance and the polycystic ovary syndrome revisited: an update on mechanisms and implications. Endocr Rev. 2012;33(6):981-1030. - PubMed
  7. Chantrapanichkul P, Indhavivadhana S, Wongwananuruk T, Techatraisak K, Dangrat C, Sa-Nga-Areekul N. Prevalence of type 2 diabetes mellitus compared between lean and overweight/obese patients with polycystic ovarian syndrome: a 5-year follow-up study. Arch Gynecol Obstet. 2020;301(3):809-816. - PubMed
  8. Lin HV, Accili D. Hormonal regulation of hepatic glucose production in health and disease. Cell Metab. 2011;14(1):9-19. - PubMed
  9. Brown MS, Goldstein JL. Selective versus total insulin resistance: a pathogenic paradox. Cell Metab. 2008;7(2):95-96. - PubMed
  10. Santoleri D, Titchenell PM. Resolving the paradox of hepatic insulin resistance. Cell Mol Gastroenterol Hepatol. 2019;7(2):447-456. - PubMed
  11. Pirwany IR, Fleming R, Greer IA, Packard CJ, Sattar N. Lipids and lipoprotein subfractions in women with PCOS: relationship to metabolic and endocrine parameters. Clin Endocrinol. 2001;54(4):447-453. - PubMed
  12. Polak K, Czyzyk A, Simoncini T, Meczekalski B. New markers of insulin resistance in polycystic ovary syndrome. J Endocrinol Invest. 2017;40(1):1-8. - PubMed
  13. Xu Y, Wu Y, Huang Q. Comparison of the effect between pioglitazone and metformin in treating patients with PCOS: a meta-analysis. Arch Gynecol Obstet. 2017;296(4):661-677. - PubMed
  14. Rena G, Hardie DG, Pearson ER. The mechanisms of action of metformin. Diabetologia. 2017;60(9):1577-1585. - PubMed
  15. Du Q, Wang YJ, Yang S, Wu B, Han P, Zhao YY. A systematic review and meta-analysis of randomized controlled trials comparing pioglitazone versus metformin in the treatment of polycystic ovary syndrome. Curr Med Res Opin. 2012;28(5):723-730. - PubMed
  16. Hauner H. The mode of action of thiazolidinediones. Diabetes Metab Res Rev. 2002;18(suppl 2):S10-S15. - PubMed
  17. Sathyapalan T, Atkin SL. Evidence for statin therapy in polycystic ovary syndrome. Ther Adv Endocrinol Metab. 2010;1(1):15-22. - PubMed
  18. Mokhtari V, Afsharian P, Shahhoseini M, Kalantar SM, Moini A. A review on various uses of N-acetyl cysteine. Cell J. 2017;19(1):11-17. - PubMed
  19. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. - PubMed
  20. Babineau J. Product review: Covidence (systematic review software). J Can Health Libr Assoc. 2014;35(2):68-71. - PubMed
  21. Hupe M. EndNote X9. J Electron Resour Med Libr. 2019;16(3-4):117-119. - PubMed
  22. Das S, Chatterjee SS. Cabell's blacklist: a new way to tackle predatory journals. Indian J Psychol Med. 2018;40(2):197-198. - PubMed
  23. Amiri M, Golsorkhtabaramiri M, Esmaeilzadeh S, et al. Effect of metformin and flutamide on anthropometric indices and laboratory tests in obese/overweight PCOS women under hypocaloric diet. J Reprod Infertil. 2014;15(4):205-213. - PubMed
  24. Aroda VR, Ciaraldi TP, Burke P, et al. Metabolic and hormonal changes induced by pioglitazone in polycystic ovary syndrome: a randomized, placebo-controlled clinical trial. J Clin Endocrinol Metab. 2009;94(2):469-476. - PubMed
  25. Brettenthaler N, De Geyter C, Huber PR, Keller U. Effect of the insulin sensitizer pioglitazone on insulin resistance, hyperandrogenism, and ovulatory dysfunction in women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2004;89(8):3835-3840. - PubMed
  26. Cetinkalp S, Karadeniz M, Erdogan M, Ozgen G, Saygl F, Ylmaz C. The effects of rosiglitazone, metformin, and estradiol-cyproterone acetate on lean patients with polycystic ovary syndrome. Endocrinologist. 2009;19(3):94-97. - PubMed
  27. Cheng F, Zhao L, Wu Y, et al. Serum vascular endothelial growth factor B is elevated in women with polycystic ovary syndrome and can be decreased with metformin treatment. Clin Endocrinol. 2016;84(3):386-393. - PubMed
  28. Cho LW, Kilpatrick ES, Keevil BG, Coady AM, Atkin SL. Effect of metformin, orlistat and pioglitazone treatment on mean insulin resistance and its biological variability in polycystic ovary syndrome. Clin Endocrinol. 2009;70(2):233-237. - PubMed
  29. Ciotta L, Calogero AE, Farina M, De Leo V, La Marca A, Cianci A. Clinical, endocrine and metabolic effects of acarbose, an alpha-glucosidase inhibitor, in PCOS patients with increased insulin response and normal glucose tolerance. Hum Reprod. 2001;16(10):2066-2072. - PubMed
  30. Devin JK, Nian H, Celedonio JE, Wright P, Brown NJ. Sitagliptin decreases visceral fat and blood glucose in women with polycystic ovarian syndrome. J Clin Endocrinol Metab. 2020;105:1. - PubMed
  31. Diamanti-Kandarakis E, Katsikis I, Piperi C, Alexandraki K, Panidis D. Effect of long-term orlistat treatment on serum levels of advanced glycation end-products in women with polycystic ovary syndrome. Clin Endocrinol. 2007;66(1):103-109. - PubMed
  32. Eisenhardt S, Schwarzmann N, Henschel V, et al. Early effects of metformin in women with polycystic ovary syndrome: a prospective randomized, double-blind, placebo-controlled trial. J Clin Endocrinol Metab. 2006;91(3):946-952. - PubMed
  33. Elkind-Hirsch KE, Paterson MS, Seidemann EL, Gutowski HC. Short-term therapy with combination dipeptidyl peptidase-4 inhibitor saxagliptin/metformin extended release (XR) is superior to saxagliptin or metformin XR monotherapy in prediabetic women with polycystic ovary syndrome: a single-blind, randomized, pilot study. Fertil Steril. 2017;107(1):253-260. - PubMed
  34. Ferjan S, Janez A, Jensterle M. DPP4 inhibitor sitagliptin as a potential treatment option in metforminintolerant obese women with polycystic ovary syndrome: a pilot randomized study. Endocr Pract. 2018;24(1):69-77. - PubMed
  35. Ferjan S, Janez A, Jensterle M. Dipeptidyl Peptidase-4 inhibitor sitagliptin prevented weight regain in obese women with polycystic ovary syndrome previously treated with liraglutide: a pilot randomized study. Metab Syndr Relat Disord. 2017;15(10):515-520. - PubMed
  36. Gambineri A, Pelusi C, Genghini S, et al. Effect of flutamide and metformin administered alone or in combination in dieting obese women with polycystic ovary syndrome. Clin Endocrinol. 2004;60(2):241-249. - PubMed
  37. Glintborg D, Støving RK, Hagen C, et al. Pioglitazone treatment increases spontaneous growth hormone (GH) secretion and stimulated GH levels in polycystic ovary syndrome. J Clin Endocrinol Metab. 2005;90(10):5605-5612. - PubMed
  38. Glintborg D, Hermann AP, Andersen M, et al. Effect of pioglitazone on glucose metabolism and luteinizing hormone secretion in women with polycystic ovary syndrome. Fertil Steril. 2006;86(2):385-397. - PubMed
  39. Hanjalic-Beck A, Gabriel B, Schaefer W, et al. Metformin versus acarbose therapy in patients with polycystic ovary syndrome (PCOS): a prospective randomised double-blind study. Gynecol Endocrinol. 2010;26(9):690-697. - PubMed
  40. Heidari B, Lerman A, Lalia AZ, Lerman LO, Chang AY. Effect of metformin on microvascular endothelial function in polycystic ovary syndrome. Mayo Clin Proc. 2019;94(12):2455-2466. - PubMed
  41. Javanmanesh F, Kashanian M, Rahimi M, Sheikhansari N. A comparison between the effects of metformin and N-acetyl cysteine (NAC) on some metabolic and endocrine characteristics of women with polycystic ovary syndrome. Gynecol Endocrinol. 2016;32(4):285-289. - PubMed
  42. Jayagopal V, Kilpatrick ES, Holding S, Jennings PE, Atkin SL. Orlistat is as beneficial as metformin in the treatment of polycystic ovarian syndrome. J Clin Endocrinol Metab. 2005;90(2):729-733. - PubMed
  43. Jensterle M, Janez A, Mlinar B, Marc J, Prezelj J, Pfeifer M. Impact of metformin and rosiglitazone treatment on glucose transporter 4 mRNA expression in women with polycystic ovary syndrome. Eur J Endocrinol. 2008;158(6):793-801. - PubMed
  44. Jensterle M, Sebestjen M, Janez A, et al. Improvement of endothelial function with metformin and rosiglitazone treatment in women with polycystic ovary syndrome. Eur J Endocrinol. 2008;159(4):399-406. - PubMed
  45. Jensterle M, Kravos N, Janež A. Short-term effectiveness of low dose liraglutide in combination with metformin vs. high dose liraglutide alone in treatment of obesity. Diabetes. 2016;65:A70. - PubMed
  46. Jensterle M, Kravos NA, Goricar K, Janez A. Short-term effectiveness of low dose liraglutide in combination with metformin versus high dose liraglutide alone in treatment of obese PCOS: randomized trial. BMC Endocr Disord. 2017;17(1):5. - PubMed
  47. Jensterle Sever M, Kocjan T, Pfeifer M, Kravos NA, Janez A. Short-term combined treatment with liraglutide and metformin leads to significant weight loss in obese women with polycystic ovary syndrome and previous poor response to metformin. Eur J Endocrinol. 2014;170(3):451-459. - PubMed
  48. Kazerooni T, Shojaei-Baghini A, Dehbashi S, Asadi N, Ghaffarpasand F, Kazerooni Y. Effects of metformin plus simvastatin on polycystic ovary syndrome: a prospective, randomized, double-blind, placebo-controlled study. Fertil Steril. 2010;94(6):2208-2213. - PubMed
  49. Kocak M, Caliskan E, Simsir C, Haberal A. Metformin therapy improves ovulatory rates, cervical scores, and pregnancy rates in clomiphene citrate-resistant women with polycystic ovary syndrome. Fertil Steril. 2002;77(1):101-106. - PubMed
  50. Ladson G, Dodson WC, Sweet SD, et al. The effects of metformin with lifestyle therapy on polycystic ovary syndrome: a randomized double blind study. Endocr Rev. 2010;31:3. - PubMed
  51. Li Y, Tan J, Wang Q, Duan C, Hu Y, Huang W. Comparing the individual effects of metformin and rosiglitazone and their combination in obese women with polycystic ovary syndrome: a randomized controlled trial. Fertil Steril. 2020;113(1):197-204. - PubMed
  52. Lingaiah S, Morin-Papunen L, Risteli J, Tapanainen JS. Metformin decreases bone turnover markers in polycystic ovary syndrome: a post hoc study. Fertil Steril. 2019;112(2):362-370. - PubMed
  53. Liu X, Zhang Y, Zheng SY, et al. Efficacy of exenatide on weight loss, metabolic parameters and pregnancy in overweight/obese polycystic ovary syndrome. Clin Endocrinol. 2017;87(6):767-774. - PubMed
  54. Lord J, Thomas R, Fox B, Acharya U, Wilkin T. The effect of metformin on fat distribution and the metabolic syndrome in women with polycystic ovary syndrome-a randomised, double-blind, placebo-controlled trial. BJOG. 2006;113(7):817-824. - PubMed
  55. Mehrabian F, Ghasemi-Tehrani H, Mohamadkhani M, Moeinoddini M, Karimzadeh P. Comparison of the effects of metformin, flutamide plus oral contraceptives, and simvastatin on the metabolic consequences of polycystic ovary syndrome. J Res Med Sci. 2016;21:7. - PubMed
  56. Moghetti P, Castello R, Negri C, et al. Metformin effects on clinical features, endocrine and metabolic profiles, and insulin sensitivity in polycystic ovary syndrome: a randomized, double-blind, placebo-controlled 6-month trial, followed by open, long-term clinical evaluation. J Clin Endocrinol Metab. 2000;85(1):139-146. - PubMed
  57. Mohiyiddeen L, Watson AJ, Apostolopoulos NV, Berry R, Alexandraki KI, Jude EB. Effects of low-dose metformin and rosiglitazone on biochemical, clinical, metabolic and biophysical outcomes in polycystic ovary syndrome. J Obstet Gynaecol. 2013;33(2):165-170. - PubMed
  58. Moini A, Kanani M, Kashani L, Hosseini R, Hosseini L. Effect of orlistat on weight loss, hormonal and metabolic profiles in women with polycystic ovarian syndrome: a randomized double-blind placebo-controlled trial. Endocrine. 2015;49(1):286-289. - PubMed
  59. Naka KK, Kalantaridou SN, Kravariti M, et al. Effect of the insulin sensitizers metformin and pioglitazone on endothelial function in young women with polycystic ovary syndrome: a prospective randomized study. Fertil Steril. 2011;95(1):203-209. - PubMed
  60. Navali N, Pourabolghasem S, Fouladi RF, Nikpour MA. Therapeutic effects of biguanide vs. statin in polycystic ovary syndrome: a randomized clinical trial. Pak J Biol Sci. 2011;14(11):658-663. - PubMed
  61. Nemati M, Nemati S, Taheri AM, Heidari B. Comparison of metformin and N-acetyl cysteine, as an adjuvant to clomiphene citrate, in clomiphene-resistant women with polycystic ovary syndrome. J Gynecol Obstet Hum Reprod. 2017;46(7):579-585. - PubMed
  62. Ng EH, Wat NM, Ho PC. Effects of metformin on ovulation rate, hormonal and metabolic profiles in women with clomiphene-resistant polycystic ovaries: a randomized, double-blinded placebo-controlled trial. Hum Reprod. 2001;16(8):1625-1631. - PubMed
  63. Ortega-González C, Luna S, Hernández L, et al. Responses of serum androgen and insulin resistance to metformin and pioglitazone in obese, insulin-resistant women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2005;90(3):1360-1365. - PubMed
  64. Paredes Palma JC, López Byhen E, Ibáñez L, et al. Comparative treatment between sitagliptin vs. metformin, alone or in combination, in patients with polycystic ovary syndrome. A clinical entity at high risk for developing diabetes mellitus and gestational diabetes: a pilot study. Revista Medica del Hospital General de Mexico. 2018;81(1):15-26. - PubMed
  65. Penna IA, Canella PR, Reis RM, Silva de Sá MF, Ferriani RA. Acarbose in obese patients with polycystic ovarian syndrome: a double-blind, randomized, placebo-controlled study. Hum Reprod. 2005;20(9):2396-2401. - PubMed
  66. Puurunen J, Piltonen T, Puukka K, et al. Statin therapy worsens insulin sensitivity in women with polycystic ovary syndrome (PCOS): a prospective, randomized, double-blind, placebo-controlled study. J Clin Endocrinol Metab. 2013;98(12):4798-4807. - PubMed
  67. Rezai M, Jamshidi M, Mohammadbeigi R, Seyedoshohadaei F, Mohammadipour S, Moradi G. Comparing the effect of metformin and acarbose accompanying clomiphene on the successful ovulation induction in infertile women with polycystic ovary syndrome. Glob J Health Sci. 2016;8(9):54516. - PubMed
  68. Sathyapalan T, Kilpatrick ES, Coady AM, Atkin SL. The effect of atorvastatin in patients with polycystic ovary syndrome: a randomized double-blind placebo-controlled study. J Clin Endocrinol Metab. 2009;94(1):103-108. - PubMed
  69. Shahebrahimi K, Jalilian N, Bazgir N, Rezaei M. Comparison clinical and metabolic effects of metformin and pioglitazone in polycystic ovary syndrome. Indian J Endocrinol Metab. 2016;20(6):805-809. - PubMed
  70. Sohrevardi SM, Nosouhi F, Hossein Khalilzade S, et al. Evaluating the effect of insulin sensitizers metformin and pioglitazone alone and in combination on women with polycystic ovary syndrome: an RCT. Int J Reprod Biomed. 2016;14(12):743-754. - PubMed
  71. Sönmez AS, Yasar L, Savan K, et al. Comparison of the effects of acarbose and metformin use on ovulation rates in clomiphene citrate-resistant polycystic ovary syndrome. Hum Reprod. 2005;20(1):175-179. - PubMed
  72. Sova H, Puistola U, Morin-Papunen L, Karihtala P. Metformin decreases serum 8-hydroxy-2'-deoxyguanosine levels in polycystic ovary syndrome. Fertil Steril. 2013;99(2):593-598. - PubMed
  73. Steiner CA, Janez A, Jensterle M, Reisinger K, Forst T, Pfützner A. Impact of treatment with rosiglitazone or metformin on biomarkers for insulin resistance and metabolic syndrome in patients with polycystic ovary syndrome. J Diabetes Sci Technol. 2007;1(2):211-217. - PubMed
  74. Tao T, Wu P, Wang Y, Liu W. Comparison of glycemic control and β-cell function in new onset T2DM patients with PCOS of metformin and saxagliptin monotherapy or combination treatment. BMC Endocr Disord. 2018;18(1):14. - PubMed
  75. Trolle B, Lauszus FF, Frystyk J, Flyvbjerg A. Adiponectin levels in women with polycystic ovary syndrome: impact of metformin treatment in a randomized controlled study. Fertil Steril. 2010;94(6):2234-2238. - PubMed
  76. Underdal MO, Stridsklev S, Oppen IH, Høgetveit K, Andersen MS, Vanky E. Does metformin treatment during pregnancy modify the future metabolic profile in women with PCOS? J Clin Endocrinol Metab. 2018;103(6):2408-2413. - PubMed
  77. Vandermolen DT, Ratts VS, Evans WS, Stovall DW, Kauma SW, Nestler JE. Metformin increases the ovulatory rate and pregnancy rate from clomiphene citrate in patients with polycystic ovary syndrome who are resistant to clomiphene citrate alone. Fertil Steril. 2001;75(2):310-315. - PubMed
  78. Yarali H, Yildiz BO, Demirol A, et al. Co-administration of metformin during rFSH treatment in patients with clomiphene citrate-resistant polycystic ovarian syndrome: a prospective randomized trial. Hum Reprod. 2002;17(2):289-294. - PubMed
  79. Yilmaz M, Karakoç A, Törüner FB, et al. The effects of rosiglitazone and metformin on menstrual cyclicity and hirsutism in polycystic ovary syndrome. Gynecol Endocrinol. 2005;21(3):154-160. - PubMed
  80. Qian SQ, He SR, Li BB, Qian J, Zheng XD. Short term monotherapy with exenatide is superior to metformin in weight loss, improving insulin resistance and inflammation in Chinese overweight/obese PCOS women. Obes Med. 2017;477:15-20. - PubMed
  81. Ziaee A, Oveisi S, Abedini A, Hashemipour S, Karimzadeh T, Ghorbani A. Effect of metformin and pioglitazone treatment on cardiovascular risk profile in polycystic ovary syndrome. Acta Med Indones. 2012;44(1):16-22. - PubMed
  82. Higgins JP, Altman DG, Gøtzsche PC, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. BMJ. 2011;343:d5928. - PubMed
  83. Higgins JP, Thomas J, Chandler J, et al. Cochrane Handbook for Systematic Reviews of Interventions. John Wiley & Sons; 2019. - PubMed
  84. Guyatt GH, Oxman AD, Vist GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336(7650):924-926. - PubMed
  85. Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome. Fertil Steril. 2004;81(1):19-25. - PubMed
  86. Anaforoglu I, Algun E, Incecayir O, Ersoy K. Higher metabolic risk with National Institutes of Health versus Rotterdam diagnostic criteria for polycystic ovarian syndrome in Turkish women. Metab Syndr Relat Disord. 2011;9(5):375-380. - PubMed
  87. Chou KH, von Eye Corleta H, Capp E, Spritzer PM. Clinical, metabolic and endocrine parameters in response to metformin in obese women with polycystic ovary syndrome: a randomized, double-blind and placebo-controlled trial. Horm Metab Res. 2003;35(2):86-91. - PubMed
  88. Kilicdag EB, Bagis T, Zeyneloglu HB, et al. Homocysteine levels in women with polycystic ovary syndrome treated with metformin versus rosiglitazone: a ragndomized study. Hum Reprod. 2005;20(4):894-899. - PubMed
  89. Elkind-Hirsch K, Marrioneaux O, Bhushan M, Vernor D, Bhushan R. Comparison of single and combined treatment with exenatide and metformin on menstrual cyclicity in overweight women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2008;93(7):2670-2678. - PubMed
  90. Pernicova I, Korbonits M. Metformin-mode of action and clinical implications for diabetes and cancer. Nat Rev Endocrinol. 2014;10(3):143-156. - PubMed
  91. Morgante G, Massaro MG, Scolaro V, et al. Metformin doses and body mass index: clinical outcomes in insulin resistant polycystic ovary syndrome women. Eur Rev Med Pharmacol Sci. 2020;24(15):8136-8142. - PubMed
  92. Patel R, Shah G. Effect of metformin on clinical, metabolic and endocrine outcomes in women with polycystic ovary syndrome: a meta-analysis of randomized controlled trials. Curr Med Res Opin. 2017;33(9):1545-1557. - PubMed
  93. Guan Y, Wang D, Bu H, Zhao T, Wang H. The effect of metformin on polycystic ovary syndrome in overweight women: a systematic review and meta-analysis of randomized controlled trials. Int J Endocrinol. 2020;2020:5150684. - PubMed
  94. Li XJ, Yu YX, Liu CQ, et al. Metformin vs thiazolidinediones for treatment of clinical, hormonal and metabolic characteristics of polycystic ovary syndrome: a meta-analysis. Clin Endocrinol. 2011;74(3):332-339. - PubMed
  95. Song Y, Wang H, Huang H, Zhu Z. Comparison of the efficacy between NAC and metformin in treating PCOS patients: a meta-analysis. Gynecol Endocrinol. 2020;36(3):204-210. - PubMed

Publication Types