Randomized comparison of the influence of dietary management and/or physical exercise on ovarian function and metabolic parameters in overweight women with polycystic ovary syndrome

Objective To compare the influence of dietary management and/or physical exercise on ovarian function and metabolic variables in women with polycystic ovary syndrome (PCOS). Design Randomized 4-month trial with three interventions and a long-term follow-up. Setting Women's health clinical research unit at a university hospital. Patient(s) Fifty-seven overweight/obese women with PCOS. Intervention(s) Dietary management, physical exercise, or both, using programs individually adapted and supervised by a dietician and/or a physical therapist. Main Outcome Measure(s) Ovarian function, endocrinologic, and metabolic status and body composition. Result(s) On average, body mass index was reduced 6% by the dietary management, 3% by the exercise, and 5% by the combined interventions. Lower body fat and lean body mass were significantly decreased in the dietary groups, whereas upper body fat was lowered and lean body mass maintained by exercise alone. The menstrual pattern was significantly improved in 69% and ovulation confirmed in 34% of the patients, with no differences among the groups. The strongest predictor of resumed ovulation was a high serum level of insulin-like growth factor–binding protein 1 after the intervention. Follow-up of one-half of the patients for a median of 2.8 years revealed sustained weight reduction and improvement in menstrual pattern. Conclusion(s) Dietary management and exercise, alone or in combination, are equally effective in improving reproductive function in overweight/obese women with PCOS. The underlying mechanisms appear to involve enhanced insulin sensitivity. Supportive individualized programs for lifestyle change could exert long-term beneficial effects.