Evidence of primary aldosteronism in a predominantly female cohort of normotensive individuals: a very high odds ratio for progression into arterial hypertension.

CONTEXT

Primary aldosteronism (PA) is an established cause of hypertension, whereas high-normal serum aldosterone levels have been linked to an increased risk for hypertension.

OBJECTIVE

We aimed to define the post-fludrocortisone-dexamethasone suppression test (FDST) normal cutoff values of aldosterone and the aldosterone to renin ratio and evaluate the presence of PA in normotensive individuals.

DESIGN

This study was designed as a case-control study.

SETTING

The study was performed in a tertiary general hospital.

PATIENTS

One hundred normotensive participants (80 females), mean age 53 years, were studied.

MAIN OUTCOME MEASURES

All participants underwent baseline biochemical and hormonal evaluation, FDST, and adrenal computerized tomography. Blood pressure was assessed at baseline and after 5 years.

RESULTS

Sixty-nine participants with normal adrenal computerized tomography who remained normotensive after 5 years were used as a control population to calculate the cutoff values of adequate aldosterone suppression. PA was defined as a combination of post-FDST aldosterone to renin ratio of 0.93 ng/dL · μU/mL or greater (100% sensitivity and 96% specificity) and post-FDST aldosterone of 2.96 ng/dL or greater (100% sensitivity and 61% specificity on receiver-operating characteristic analysis). Thirteen of 100 participants had PA at baseline and 11 (85%) developed hypertension, whereas only 20 of 87 without PA (23%) developed hypertension at 5 years [odds ratio (OR) 18.42, 95% confidence intervals (CI) 3.76-90.10, P < .0001]. Logistic regression analysis showed a positive relation of PA [odds ratio (OR) 16.30, confidence interval (CI) 1.78-150.30, P = .01] and a negative relation of serum potassium (OR 0.39, CI 0.19-0.79, P = .01) with the development of hypertension.

CONCLUSIONS

Normotensive PA represents a clinical entity referring to normotensive individuals with PA who are at increased risk for hypertension.