Photo Credit: Laurence Soulez

The following is a summary of “Low Cortisone as a Novel Predictor of the Low-Renin Phenotype,” published in the June 2024 issue of Endocrinology by Tapia-Castillo, et al.

A significant number of individuals diagnosed with low-renin hypertension (LRH) are found to have primary aldosteronism (PA). However, some patients with LRH exhibited low to normal levels of aldosterone. In these cases, the mechanism behind low renin was thought to involve excessive mineralocorticoids or glucocorticoids acting on mineralocorticoid receptors (MRs). For a study, researchers proposed that a state of low cortisone, commonly associated with 11βHSD2 deficiency, served as an indicator of chronic MR activation by cortisol. This chronic activation of MRs by cortisol may contribute to developing low renin, elevated blood pressure, and renal and vascular alterations. They sought to evaluate whether low cortisone levels could predict low renin activity and explore its association with kidney and vascular damage parameters.

A cross-sectional study was conducted involving 206 adult subjects. These subjects were categorized based on their plasma renin activity (<1 ng/mL × hours) and cortisone levels (<25th percentile).

The analysis revealed significant associations between plasma renin activity and both aldosterone (r = 0.36; P < .001) and cortisone (r = 0.22; P = .001). Binary logistic regression analysis demonstrated that every ug/dL increase in serum cortisone predicted the low-renin phenotype (OR 0.4, 95% CI 0.21-0.78). Receiver operating characteristic curves for cortisone showed an area under the curve of 0.6, indicating its potential to differentiate subjects with low renin activity from controls. Subjects with low cortisone levels exhibited higher levels of albuminuria and PAI-1, along with lower sodium excretion. Additionally, the association study revealed correlations between urinary cortisone and blood pressure and serum potassium levels (P < .05).

The study was the first to establish that low cortisone levels can predict a low-renin condition and are associated with vascular and renal damage markers. Given the use of the aldosterone-to-renin ratio in primary aldosteronism screening, considering low cortisone values could help prevent false positives in the calculation process.

Reference: academic.oup.com/jes/article/8/6/bvae051/7629712