Evaluation of aldosterone to direct renin ratio, low renin and related Phenotypes in Afro-Colombian patients with apparent treatment resistant hypertension

Apparent resistant hypertension (aTRH) is a significant public health issue. Once low adherence to antihypertensive treatment has been ruled out and true resistant hypertension is diagnosed, aldosterone-direct-renin-ratio (ADRR) aids in the screening of an aldosterone-producing adenoma (APA) and primary aldosteronism (PA). Once PA and other secondary causes have been ruled out, the values of aldosterone and renin allow patients to be classified into phenotypes such as low renin hypertension (LRH), Liddle's-like (LLph), and primary hyperaldosteronism (PAph). These classifications could aid in the treatment decision-making process. However, optimal cut-off points for these classifications remain uncertain. This study aims to assess the prevalence of these phenotypes and the behavior of different cut-offs of the ADRR in an Afro-Colombian population with apparent resistant hypertension, as well to describe their sodium consumption. Afro-descendant individuals 18 years of age or older, diagnosed with resistant hypertension and attending to a primary care center in Colombia were recruited as volunteers. As part of the study, their plasma renin concentration (PRC) and plasma aldosterone concentration (PAC) were measured. The phenotypes were categorized into three groups based on multiple cut-off points from different authors: low renin and low aldosterone phenotype (LLph), low renin and high aldosterone phenotype (PAph), and high renin and high aldosterone phenotype, referred to as the renal phenotype (Rph). The prevalence of ADRR values exceeding the cut-off and phenotypes were calculated. A linear regression model was derived to assess the effect of sodium consumption with PAC, PRC and ADRR. A total of 88 patients with aTRH were included. Adherence to at least 3 antihypertensive medications was 62.5%. The median age was 56 years (IQR 48-60), 44% were female, and 20% had diabetes. The study found that the prevalence of ADRR values exceeding the cut-off ranged from 4.5 to 23%, while low-renin hypertension (LRH) varied from 15 to 74%, Rph was found in approximately 30 to 34% of patients, PAph in 30 to 51%, and the LLph in 15 to 41%, respectively, depending on the specific cut-off value by different authors. Notably, sodium consumption was associated with lower aldosterone (β - 0.15, 95% CI [- 0.27, - 0.03]) and renin concentrations (β - 0.75, 95% CI [- 1.5, - 0.02]), but ADRR showed no significant association with sodium consumption. There were no significant differences in prevalences between the groups taking < 3 vs ≥ 3 antihypertensive medications. Altered aldosterone-direct-renin-ratio, low renin hypertension, Liddle's-like, and primary hyperaldosteronism are prevalent phenotypes in patients within Afro-Colombian patients with apparent treatment-Resistant hypertension.