Obesity is a common finding in PCOS and aggravates many of its reproductive and metabolic features. About 25% of asymptomatic women with regular menses have PCO morphology on ultrasound. Many of these women have elevated androgen or luteinising hormone (LH) levels, but some have normal reproductive function. Insulin resistance is a common finding in PCOS and is substantially worsened by obesity. Fasting insulin levels are increased in PCOS. Women with this condition are expected to have a high prevalence of impaired glucose tolerance
. The risk for developing glucose intolerance is increased with increasing body mass index (BMI) and obesity.
Reproductive disturbances are more common in obese women regardless of the diagnosis of PCOS. Obese women are more likely to have menstrual irregularity and anovulatory infertility than normal-weight women. Weight reduction can restore regular menstrual cycles in these women. In obesity increased androgen production has been reported especially in women with upper-body obesity. In PCOS bioavailable androgen levels are increased especially with central obesity. Androgens play an important role in determination of body composition.