Oligo-ovulation or anovulation and hyperandrogenemia contribute to the decreased serum adiponectin levels in normal-weight women with PCOS with obesity and insulin resistance

Abstract

To the Editor: We have read with great interest the excellent and well designed study by Aroda et al. (1Aroda V. Ciaraldi T.P. Chang S.A. Dahan M.H. Chang R.J. Henry R.R. Circulating and cellular adiponectin in polycystic ovary syndrome: relationship to glucose tolerance and insulin action.Fertil Steril. 2008; 89: 1200-1208Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar) and would like to comment on the potential relationship between serum adiponectin levels, obesity, and insulin resistance (IR) in women with polycystic ovary syndrome (PCOS). Aroda et al. (1Aroda V. Ciaraldi T.P. Chang S.A. Dahan M.H. Chang R.J. Henry R.R. Circulating and cellular adiponectin in polycystic ovary syndrome: relationship to glucose tolerance and insulin action.Fertil Steril. 2008; 89: 1200-1208Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar), in a population of 31 overweight and obese PCOS women, reported a significant correlation of serum adiponectin levels with all indices of IR. Serum adiponectin levels were significantly reduced in obese PCOS women compared with a control population matched for body mass index (BMI) (n = 6). The authors concluded that IR was the major determinant of serum adiponectin levels. In an earlier study (2Panidis D. Kourtis A. Farmakiotis D. Mouslech T. Rousso D. Koliakos G. Serum adiponectin levels in women with polycystic ovary syndrome.Hum Reprod. 2003; 18: 1790-1796Crossref PubMed Scopus (140) Google Scholar), we have noted that serum adiponectin levels in PCOS women with BMI >25 kg/m2 were significantly lower and indices of IR significantly higher (P<.001) than in PCOS control women with BMI <25 kg/m2 (P<.05). Moreover, in a subsequent study (3Panidis D. Farmakiotis D. Rousso D. Koliakos G. Kaltsas T. Krassas G. Decrease in adiponectin levels in women with polycystic ovary syndrome after an oral glucose tolerance test.Fertil Steril. 2005; 83: 232-234Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar), we have noted a significant decrease in serum adiponectin levels after an oral glucose tolerance test in both normal-weight and overweight PCOS and control women, more pronounced in obese women (P<.001). These findings are in accordance with those by Aroda et al.; therefore, we can assume that obesity and IR play a major role in determining serum adiponectin levels in PCOS women. The question that arises is whether obesity and IR are the sole determinants of serum adiponectin levels in women with PCOS, or whether chronic oligo/anovulation and hyperandrogenemia might also contribute. We have recently determined serum adiponectin levels in a cohort of 100 normal-weight PCOS women without IR who were classified according to their PCOS phenotype into four equally sized groups matched for age and BMI, and 25 control subjects matched for age and BMI (Panidis et al., unpublished observations). Adiponectin levels were significantly higher in the control group compared with groups with severe PCOS and PCOS with chronic anovulation and hyperandrogenism, but not compared with groups with ovulatory and mild PCOS (4Norman R.J. Dewailly D. Legro R.S. Hickey T.E. Polycystic ovary syndrome.Lancet. 2007; 370: 685-697Abstract Full Text Full Text PDF PubMed Scopus (1047) Google Scholar). Therefore, adiponectin levels were negatively affected by the combination of anovulation and hyperandrogenemia, but not by polycystic ovary morphology. The differences in circulating adiponectin levels between the main phenotypic groups of normal-weight PCOS women without IR seem to reflect the severity of the syndrome, independently of obesity and IR. Therefore, besides the great contribution of obesity and IR, in normal-weight PCOS women without IR an additional contribution to the decreased adiponectin serum levels should be attributed to the severity of the syndrome itself. Reply of the Authors: Oligo-ovulation or anovulation and hyperandrogenemia contribute to the decreased serum adiponectin levels in normal-weight women with PCOS with obesity and insulin resistanceFertility and SterilityVol. 91Issue 4PreviewInformation in the literature regarding the impact of polycystic ovary syndrome (PCOS) on circulating adiponectin levels is mixed. While we (1) and others (2, 3) have found adiponectin levels to be most closely associated with body mass index (BMI) and/or measures of insulin resistance, Katsikis et al. report decreased adiponectin levels in normal-weight women without insulin resistance, compared with age- and BMI-matched control women. We feel that these observations and their attendant conclusions are fully compatible. Full-Text PDF