Background: Obesity and polycystic ovary syndrome are commonly associated, but data regarding overweight and obesity prevalence in PCOS patients remains controversial and depends on study population (referral or unselected) and PCOS phenotype. There are few studies which present ethnic differences in prevalence of overweight and obese women with PCOS.Objective: To test the hypothesis that overweight and obesity prevalence is not similar in infertile women with PCOS and without PCOS and depends on ethnicity of patients.
Subjects and methods:A prospective study was performed in a referral (clinical) population, included 397 infertile women (134 with PCOS, aged 28.2±4.7years (Group A) and 263 without PCOS, aged 29.4±5.4years (Group B); 363 Caucasians and 34 Asians), who were referred for the evaluation of infertility at clinical research centers in Irkutsk and Ulan-Ude (Eastern Siberia) between 2007 and 2015, and agreed to participate in the prospective study. 53 fertile women aged 27.6±7.3years were recruited as controls. A complete medical history, physical examination with BMI calculation, laparoscopy, pelvic ultrasound and hormonal immunoassay analysis were performed in all patients.
Results:The mean BMI and obesity prevalence was significantly higher in both groups of infertile patients compared to controls without significant difference between women with PCOS and without PCOS. However, lower rate of subjects with normal BMI was demonstrated predominantly in the PCOS group. The increase of mean BMI vs controls was more significant in Asian infertile women with PCOS than in Caucasians.
Conclusion:Our study results suggest that the mean BMI and obesity prevalence are comparable in the referral population of infertile women with and without PCOS. Nevertheless, the lower number of patients with normal BMI, compared to fertile controls, have been found only in the group of PCOS infertile women. These findings may be explained by phenotype and ethnic heterogeneity of PCOS women. Asian infertile women with PCOS are more likely to have increased BMI than Caucasians. Due to study limitations more data is needed in referral as well as in unselected populations of PCOS women from Asian and Caucasian ethnic groups.