CYP19 gene expression in subcutaneous adipose tissue is associated with blood pressure in women with polycystic ovary syndrome

Abstract

In polycystic ovary syndrome (PCOS), hypertension has been linked to androgen excess and insulin resistance. Aromatase, an enzyme encoded by the CYP19 gene, affects androgen metabolism and estrogen synthesis, influencing the androgen to estrogen balance. We characterized CYP19 gene expression in subcutaneous adipose tissue of women with PCOS and normal controls and evaluated the association between subcutaneous fat CYP19 mRNA, circulating hormone levels, and blood pressure. This case-control study was carried out with 31 PCOS patients and 27 BMI-matched normotensive non-hirsute women with regular cycles. Participants underwent anthropometric measurements, collection of blood samples, and adipose tissue biopsy (28 PCOS and 19 controls). Hypertension was defined as systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 85 mmHg. PCOS patients were divided into normotensive and hypertensive. Main outcome measures were serum estrogen and androgen levels, estrogen-to-androgen ratio, and CYP19 gene expression in subcutaneous fat. Subcutaneous CYP19 mRNA was higher in hypertensive PCOS than in control and normotensive PCOS women (p = 0.014). Estrogen-to-androgen ratio was lower in hypertensive PCOS than controls (p < 0.003). Estrogen-to-androgen ratio ≤ 0.06 (median for the three groups) was observed in 91% of hypertensive PCOS women, vs. 37% and 61% in the control and normotensive PCOS groups (p = 0.011). CYP19 gene expression in subcutaneous fat of PCOS patient correlated positively with systolic (p = 0.006) and diastolic blood pressure (p = 0.009). Androgen excess and hyperinsulinemia may play a role in the molecular mechanisms that activate aromatase mRNA transcription in abdominal fat tissue.