Genes implicated in insulin resistance are down-regulated in primary aldosteronism patients

Primary aldosteronism (PA) patients display an increased incidence of insulin resistance. Herein we demonstrate the decreased gene expression of lipid metabolism genes PCK1, PLIN, ADIPOQ and PPARG in the visceral adipose tissue (VAT) of PA patients compared to age-, sex- and BMI-matched controls. In VAT, the expression of PCK1, PLIN, ADIPOQ and PPARG was inversely correlated with aldosterone levels; furthermore, PLIN and ADIPOQ gene expression was correlated with potassium levels. Therefore, raised aldosterone and low potassium may contribute to the reduced expression of these genes in PA patients. Finally, incubation of primary cultures of human adipocytes with aldosterone resulted in a decrease in the expression of PCK1, PLIN and ADIPOQ and this effect was blocked by eplerenone. Therefore, the characteristic aldosterone excess of PA patients may mediate the down-regulation of PCK1, PLIN and ADIPOQ in VAT that in turn may contribute to the insulin resistance observed in PA patients.