Abdominal fat accumulation, and not insulin resistance, is associated to oligomenorrhea in non-hyperandrogenic women overweight/obese women

BACKGROUND: There is a very high prevalence of obese women in the infertile population and many studies have highlighted the link between obesity and infertility. The aim of this study was to evaluate the prevalence of oligomenorrhea in uncomplicated obesity, and to examine whether this menstrual alteration is associated with anthropometric, hormonal, and metabolic parameters. PATIENTS AND METHODS: This is a cross-sectional study of 266 overweight and obese body mass index (BMI) > or =25.0 kg x m(-2)] women, all having apparent normal fertility. Measurements included BMI, central fat accumulation (evaluated by waist circumference), blood pressure levels, and fasting insulin, glucose, and lipid (triglycerides, total and HDL-cholesterol) serum concentrations, and insulin resistance [estimated by (homeostasis model assessment) HOMAIR] during the early follicular phase (days 2-5 of the menstrual cycle). RESULTS: One hundred and seventy-one (64.3%) of 266 women had normal menstrual cycles, 57 (21.4%) had oligomenorrhea, and 38 (14.3%) had hypermenorrhea and/or polimenorrhea. Women with oligomenorrhea had higher waist circumference, BMI, HOMAIR, and insulin levels than women with normal menstrual cycles. When association among oligomenorrhea and other variables (waist circumference, BMI, insulin and HOMAIR) was evaluated by logistic regression, and odds ratio was calculated per unit of SD increase, only waist circumference maintained a significant relationship with oligomenorrhea. CONCLUSIONS: This study shows that more than 20% of women with simple obesity have oligomenorrhea, and suggests that central fat accumulation seems to have a possible direct role in this menstrual alteration, independently of hyperinsulinemia and/or insulin resistance