Correlation of glycyrrhetinic acid–like factors (kidney 11β-HSD2-GALFs) with urinary free cortisol and plasma renin activity in essential hypertension

Abstract

Previously we reported that urinary levels of glycyrrhetinic acid–like factors (11β-HSD2-GALFs) were increased in a subset of patients with essential hypertension when maintained on a low-Na + diet. The present studies were undertaken to correlate changes in urinary GALF levels with urinary free cortisol (UFC) and plasma renin activity (PRA). The amounts of GALFs markedly increased from 7.38 ± 0.80 to 14.58 ± 1.94 ( P < .0003) in the high/normal renin and from 5.60 ± 0.77 to 8.39 ± 1.08 ( P < .045) in the low renin patients on a low-Na + diet compared with high-Na + diet with no effect in the normotensive controls ( P < .668). The elevated GALF levels in high/normal renin hypertensives maintained on the low-Na + diet strongly correlated with the increased UFC levels and also with PRA; no such correlations were observed with either the normotensive controls or low renin hypertensives. In high/normal renin hypertensives, the elevated 11β-HSD2-GALFs may have two major functions: increased Na + retention by the kidney by allowing cortisol to access the renal mineralocorticoid receptor and increased vascular reactivity by allowing cortisol to access the vascular mineralocorticoid receptor.