Bilateral Adrenal Primary Aldosteronism Is Uniformly Present in Hypertensive Afro-Caribbean First-Generation Immigrants to Western Canada.

BACKGROUND

Uncontrolled hypertension is prevalent in sub-Saharan Africa and a major contributor to premature morbidity. The reasons may not be identical to those reported in studies of Black patients in Western countries. Recent African immigration to western Canada permits the study of hypertension mechanisms in African Black patients.

METHODS

Retrospective study of 15 years' experience (2010-2025) with hypertensive first-generation African immigrants to a resistant hypertension clinic in Alberta, Canada.

RESULTS

With uniform screening for primary aldosteronism (PA), PA was found in 93% of all African patients (n=114) versus 46.8% in non-African referred patients (n=792; P<0.0001). The majority had resistant hypertension, and hypokalemia was seen in two-thirds; 87% had aldosterone levels >277 pmol/L, so diagnosis was not due solely to low renin. Only 17% had adrenal abnormalities on imaging. In those with adrenal vein sampling, there were no cases where unilateral adrenal disease was seen both before and after cosyntropin without adrenal nodules; contralateral suppression was present in just 14%. Cortisol cosecretion was present in many of those with visible adrenal nodules and in the few with adrenalectomy, none achieved both a complete clinical and biochemical response.

CONCLUSIONS

Among first-generation African immigrants with hypertension, 93% fit a clear diagnosis of PA, a prevalence figure far in excess of any other population ever reported. Most of the PA phenotype was bilateral aldosterone excess; surgical cases and complete responders to adrenalectomy were rare. This, the largest detailed study of PA in African patients with hypertension, if confirmed, has important implications for hypertension assessment and treatment for African Black patients.