SAT-076 The Effect of Body Mass Index on Diagnosis of Primary Aldosteronism

Abstract

It is well known the primary aldosteronism (PA) is most common endocrinological hypertension and accounted for 10% among all hypertension population, and it develops cardiovascular disease more frequently than blood pressure matched essential hypertension. Many literatures have been reported patients with obesity often shows hyperaldosteronism by hyperactivation of sympathetic nerves, over secretion from adipocytes themselves, or aldosterone-secreting factors from adipocytes. Thus, we investigated the impact of BMI on diagnosis of PA in this study. We investigated 328 cases of adrenal venous sampling performed patients with PA in our hospital since 2007, including 125 males and 203 females, and their mean age was 56.1 ± 11.8 years old. We evaluated the relationship of those patients’ body mass index (BMI) with gender, systolic and diastolic blood pressure (SBP and DBP, respectively), serum sodium, serum potassium, plasma renin activity (PRA), plasma aldosterone concentration (PAC), aldosterone-renin ratio (ARR), ACTH, cortisol, and the ratio of patients who showed 1 mg dexamethasone suppression test positive, and none of each showed statistical relationship with BMI. In confirmatory tests, we evaluated those values of PRA at 120 min. in upright furosemide test, either higher values of ARR at 60min. or 90 min. in captopril challenge test, and PAC at 4 hours in saline infusion test (SIT), also positive ratio of those test considered by PRA <2.0 ng/ml/hr, ARR >20, and PAC>6.0 in those tests, respectively. In adrenal venous sampling (AVS), we evaluated lateralized ratio (LR) and contralateral ratio (CR) and those positive ratios considered by LR >4 or CR<1. In our results, only positive ratio of SIT in the confirmatory tests and CR in AVS showed positive relationship with BMI. The ratio of unilateral hyperaldosteronism considered by LR>4 and CR<1 also showed no relationship. Then, we evaluated all consideration above only among 304 patients with bilateral hyperaldosteronism by AVS, suspicious of idiopathic hyperaldosteronism (IHA), because it was reported patients with obesity and hyperaldosteronism are more commonly diagnosed as IHA. Although, all evaluation showed same results. In conclusion, our result revealed the relationship of BMI with positive ratio of SIT and CR, and this means obesity, at least, could affect the diagnosis of PA. We must be very careful to make diagnosis of PA, especially in patients with obesity.