Endocrine Abstracts

It has been reported that women with polycystic ovary syndrome (PCOS) show cardiovascular autonomic dysfunction, with reduced parasympathetic (vagal) and increased sympathetic activity, which are known to be independent risk factors for cardiovascular morbidity and mortality. However, it is not yet clear if PCOS per se leads to cardiovascular autonomic dysfunction independently of metabolic abnormalities. In a prospective, general population-based follow-up birth cohort (n=5889 females), postal questionnaires were sent at ages 14 (95% answered), 31 (81% answered) and 46 (72% answered). Women who reported both oligo/amenorrhea and hirsutism at age 31 and/or diagnosis of PCOS by age 46 were considered as PCOS cases (n=279) and were compared with women without PCOS symptoms or diagnosis (n=1577). Clinical examinations were performed at age 31 in 3115 women, and at age 46 in 3280 women. The cardiovascular autonomic function was evaluated at age 46 by vagal-mediated heart rate variability (rMSSD) from R-R intervals, spectral power densities (LF: low frequency and HF: high frequency) and spontaneous baroreflex sensitivity (BRS). Both rMSSD and HF describe the vagal activity. The effects of body-mass-index (BMI), hyperandrogenism and metabolic status were assessed by analysis of covariance (ANCOVA) and linear regression analysis. At baseline, vagal activity was significantly lower in women with PCOS compared with controls (rMSSD: 19.5 [12.4; 31.9] vs 24.3 [16.1; 34.8], P=0.004 and HF: 172 [75; 399] vs 261 [112; 565], P=0.002), and these differences remained significant after adjustment for BMI by ANCOVA. BRS was comparable in PCOS and control women after adjustment for BMI. In the linear regression model, PCOS and BMI both modified rMSSD (for PCOS: B=−0.108, 95%CI: −0.207 to −0.008, P=0.033 and for BMI: B=−0.026, 95%CI: −0.033 to −0.020, P<0.001), but PCOS lost its significance after adjustment for diastolic blood pressure. Then, in the linear regression model for HF, PCOS remained significant after adjustment for diastolic BP (for PCOS: B=−0.217, 95%CI: −0.415 to −0.018, P=0.033), but then lost its significance after further adjustment for HOMA-IR. Of note, testosterone or free-androgen-index did not modify rMSSD or HF in the linear regression analysis. Women with PCOS display altered cardiovascular autonomic function manifested as decreased vagal activity. However, metabolic status, but not hyperandrogenism, seems to be the strongest contributing factors. These findings indicate that metabolic abnormalities should be screened and efficiently treated in women with PCOS, already early in life, to prevent the development of cardiovascular autonomic dysfunction and cardiovascular diseases.