Prevalence of Primary Aldosteronism Among Patients With Hypertension

Despite being a leading cause of secondary hypertension and association with a higher incidence of cardiovascular morbidity and mortality the prevalence of primary aldosteronism (PA) is poorly studied.

We assessed the prevalence of PA in participants being treated as essential hypertension (EHTN).

In this prospective, cross-sectional study, 492 participants with diagnosis of EHTN were evaluated. The screening for PA was conducted by measuring plasma aldosterone concentration (PAC) and direct renin concentration (DRC), from which the aldosterone-to-renin ratio (ARR) was calculated. Based on Endocrine Society guidelines, screening test was followed by a confirmatory recumbent saline infusion test (SIT). Participants who showed a post-SIT PAC greater than 5 ng/dL were diagnosed with PA.

Of 492 EHTN participants, 91 (18.49%) had positive screening test. Out of 91 participants, 59 agreed for SIT and PA was confirmed in 37 participants (8.04%) (Excluding 32 screened positive participants who were non-compliant to SIT). The mean age was 49.98 ± 7.76 years, and median duration of hypertension was 5 (0-24) years. The prevalence of PA increased with grade of hypertension (5.97% in grade 1%-12.03% in grade 3), hypertension daily dose (HDD) (3.57% in those with HDD < 1% to 27.27% in those with HDD ≥ 4). No significant difference in hypokalaemia in PA and EHTN (2.70% and 3.54% respectively, p: 0.7815).

Our study shows a high prevalence of PA in subjects treated as a case of EHTN.