Primary aldosteronism was confirmed in 14% of patients.
Some studies have suggested that primary aldosteronism is a more common secondary cause of hypertension than clinicians generally believe. In this study from Emory University, researchers identified 100 consecutive diabetic patients (mean age, 59) with resistant hypertension — defined as blood pressure >140/90 mm Hg while taking at least three antihypertensive drugs — and screened them for primary aldosteronism. Mean duration of hypertension was 16 years, and 93% of patients were black.
Thirty-four patients had an elevated aldosterone-to-renin ratio (defined here as >30) and then underwent confirmatory testing (salt loading followed by aldosterone measurements), resulting in a final diagnosis of primary aldosteronism in 14 patients. Information on results of adrenal imaging and response to treatment were not provided in the report.
Comment: The 14% prevalence of primary aldosteronism in these diabetic patients referred with resistant hypertension is quite high, but consistent with other studies of patients referred with resistant hypertension (for example, Journal Watch General Medicine May 1 2001). A large study of the prevalence of primary aldosteronism in primary care settings — and the optimal cutoff for the aldosterone-to-renin ratio — would be helpful. In the meantime, clinicians should have a low threshold for considering this diagnosis in patients whose hypertension is resistant to multidrug therapy.
Published in Journal Watch General Medicine July 26, 2007
Umpierrez GE et al. Primary aldosteronism in diabetic subjects with resistant hypertension. Diabetes Care 2007 Jul; 30:1699-703.