Context. Obesity and insulin resistance predispose patients with the polycystic ovary syndrome (PCOS) to abnormalities in blood pressure regulation

Objective. To evaluate the impact of obesity on the blood pressure profiles of PCOS patients

Design. Case-control study

Settings. Academic hospital

Patients. Thirty-six PCOS patients and 20 healthy women.

Main Outcome Measures. Ambulatory blood pressure monitoring (ABPM) and office blood pressure determinations

Results. Hypertension (defined as increased office blood pressure confirmed by ABPM or by masked hypertension), was present in 12 PCOS patients and 8 controls (P = 0.618). No differences between patients and controls were found in office and ABPM blood pressure values and heart rate, yet the nocturnal decrease in mean blood pressure was smaller in patients (P = 0.038). Obese women (13 patients and 8 controls) had increased frequencies of office hypertension (29% compared with 3% in lean women, P = 0.005), increased diastolic (P = 0.009) and mean (P = 0.015) office blood pressure values, and increased heart rates values during the daytime (P = 0.038), nighttime (P = 0.002) and 24-hour (P= 0.009) periods, independently of having or not PCOS. The frequency of a nocturnal non-dipper pattern was 62% in obese PCOS patients, compared with 26% in lean PCOS patients (P = 0.036) and 25% in obese and lean controls.

Conclusions. Abnormalities in the regulation of blood pressure are common in young women with PCOS yet, with the exception of the non-dipper pattern, these abnormalities result from the frequent association of this syndrome with obesity.