Avaliação da função das células beta pancreáticas através do modelo matemático de HOMA em portadoras de síndrome dos ovários policísticos: comparação entre obesas e não-obesas

PURPOSE: to evaluate the effect of obesity on b-cell function in patients with polycystic ovary syndrome (PCOS). METHODS: this cross-section study evaluated 82 patients with PCOS selected consecutively, at the moment of the diagnosis. We compared 31 PCOS obese women (BMI >30 kg/m2) to 51 age-matched PCOS nonobese patients (BMI <30 kg/m2). Using fasting glucose and insulin levels, homeostatic model assessment values for insulin resistance (HOMA-IR and QUICKI) and percent b-cell function (HOMA-%b-cell) were calculated. As secondary variables, the age at PCOS diagnosis, age of menarche, hormonal levels (testosterone, prolactin, FSH and LH), total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol were also analyzed. RESULTS: menarche was significantly earlier in obese PCOS patients (11.7±1.8 years) than in nonobese patients (12.67±1.86 years) (p<0.05). Obese patients presented lower LH levels (7.9±5 mIU/mL) than did nonobese patients (10.6±6 mIU/mL) (p<0.05). Both groups presented mean HDL cholesterol levels below 50 mg/dL. Obese patients presented significantly higher baseline insulin levels (32.5±25.2 mIU/mL) and fasting blood glucose levels (115.9±40.7 mg/dL) than did nonobese patients (8.8±6.6 mIU/mL and 90.2±8.9 mg/dL, respectively) (p<0.01). Of the obese PCOS patients, 93% presented insulin resistance versus 25% of nonobese PCOS patients (p<0.01). Eighty-six perecent of the obese women had hyperfunction of b-cell versus 41% of nonobese with PCOS (p<0.0001). CONCLUSIONS: obese PCOS patients presented higher prevalence of insulin resistance and hyperfunction of b-cell than did nonobese PCOS patients.