EFFECTS OF FEMALE SEX HORMONES AND CONTRACEPTIVE PILL ON THE DIAGNOSTIC WORK-UP FOR PRIMARY ALDOSTERONISM: PP.18.181

Abstract

Objectives: Due to the widespread use of the aldosterone to renin ratio (ARR), primary aldosteronism (PA) is currently recognized as a frequent cause of secondary hypertension. After a positive screening, PA diagnosis needs confirmation by an inhibitory test such as intravenous saline load (ivSLT). Aim of the present study was to investigate the role of female hormones in PA diagnosis, by evaluating possible differences by gender on ARR screening, on the rate of ivSLT response and analysing the influence of free and oral contraceptive (OC)-induced menstrual cycle on ARR. Methods: We examined ARR in 103 healthy normotensive volunteers, 81 hypertensive patients who underwent ivSLT, 33 healthy women during free menstrual cycle and after OC therapy. Results: A significant higher proportion of normotensive women than males had an elevated ARR (13.6% versus 2.3 %, P < 0.05). In 44 out of 81 hypertensive patients diagnosis of PA was confirmed by ivSLT. Patients with positive and negative ivSLT differed only for gender distribution: 85.2 % of males had the PA diagnosis confirmed, compared with 38.9 % of females. In healthy women renin and aldosterone concentrations increased from follicular to luteal phase of menstrual period, with unchanged ARR. By contrast, renin nearly halved, aldosterone slightly decreased and ARR doubled after OC therapy. Conclusions: ARR screening fails to predict positive ivSLT in most (60.2%) hypertensive women as compared with14.8% of hypertensive men. ARR is more often increased in normotensive women than men. Oral contraceptive may affect ARR contributing to the diagnostic inaccuracy in females.