Endocrine Abstracts

Introduction: There have been no studies on the prevalence of primary aldosteronism (PA) in Turkey. In this study, the prevalence of PA among the hypertensive population was investigated.

Methods/Design: The study was conducted among hypertensive patients, aged 16–88 years, who visited the out-patient clinic of Endocrinology from January 10th, 2011 to September 30th, 2011. 768 of the 774 consecutive hypertensive patients volunteered to participate. The blood pressure, height and weight were measured in all patients. The duration of the hypertensive disease, antihypertensive drug therapy, other concurrent diseases and addictions (e.g. smoking) were determined in all patients. After an 8-h fast, blood samples were collected for the determination of blood urea nitrogen, serum creatinine, sodium, potassium, plasma aldosterone concentration (PAC), and plasma–renin activity (PRA). Care was taken to ensure normal potassium serum levels in all patients before serum aldosterone/PRA ratio (ARR) test and a liberal intake of salt.

Results: ARR was found to be positive (ARR >20) in 134 of the 768 patients. Saline infusion test (SIT) was used as the confirmatory test. PAC cut-off used in SIT was 10 ng/dl in this study. The confirmatory test was applied to all 134 patients with positive ARR. The confirmatory test was found to be positive in six patients (0.8%). The prevalence was determined to be 6/768 (0.8%). The prevalence was 4.6 and 1.7% upon PAC cut-off values of 5 and 7.5 ng/dl were used respectively. The median values for potasium were found to be 4.5 (3.1–6.4) and 3.5 (2.9–4.2) in essential hypertensive and PA groups respectively (P<0.001). Three of the six patients (50%) with PA had hypopotassemia.

Conclusion: The prevalence of PA was found to be 0.8%. More epidemiological studies are needed in the different regions of the country to evaluate the prevalence of PA in Turkey.