Objectives: Obesity is the main risk factor for the development of obstructive sleep apnea (OSA). Hyperprolactinemia has also been related to obesity. To determine the OSA prevalence in patients with prolactinoma before and after dopamine agonist (DA) and to evaluate the correlation between the apnea-hypopnea index (AHI) and prolactin levels, body mass index (BMI), waist circumference (WC), visceral fat volume (VFV), subcutaneous fat volume, and other metabolic parameters.
Methods: Thirty-five patients with prolactinoma at baseline and twenty-one who completed the 6-month DA treatment were submitted to clinical/laboratorial evaluations, polysomnography and abdominal imaging.
Results: Before treatment, the prevalence of obesity/overweight and OSA were, respectively, 68.5 and 34.2 %. We found a positive correlation between AHI and weight (r = 0.57; p < 0.001), BMI (r = 0.56; p < 0.001), WC (r = 0.61; p < 0.001), VFV (r = 0.55; p = 0.002), insulin levels (r = 0.57; p < 0.001), and HOMA-IR index (r = 0.57; p < 0.001); and a negative correlation between AHI and HDL-cholesterol (r = -0.47; p = 0.005). After multivariate analysis, VFV and insulin levels were the most important predictors for AHI (p = 0.001 and p = 0.02, respectively). After DA, the obesity/overweight and OSA prevalence did not change.
Conclusions: The OSA prevalence in patients with prolactinoma is similar to the obese subjects and did not change after treatment. Higher BMI and visceral obesity, but not prolactin levels, seem to be the major factor involved in the occurrence of OSA in these patients.