Renal dysfunction might quickly progress in patients with type 2 diabetes mellitus, when accompanied by hypertension. However, whether primary aldosteronism (PA), which autonomously over-secretes aldosterone, causes additional renal damage in patients with type 2 diabetes mellitus is unclear. We evaluated the impact of PA on renal function in patients with type 2 diabetes mellitus. A retrospective review of all patients with type 2 diabetes mellitus who visited Yokohama Rosai Hospital’s (Yokohama Japan) outpatient department between April 2017 and March 2018 was carried out. Records of patients with PA who underwent PA treatment by adrenalectomy or mineralocorticoid receptor antagonists (PA group) and those without PA (non-PA group) were extracted, and renal function was compared between the two groups. Untreated PA patients were excluded, as their renal function might be overestimated as a result of glomerular hyperfiltration. There were 83 patients in the PA group and 1,580 patients in the non-PA group. The PA group had significantly lower estimated glomerular filtration rates than the non-PA group (66.3 [52.4-78.2] vs 70.5 [56.0-85.6] mL/min/1.73 m2 , P = 0.047). Multiple regression analysis showed that PA was a factor for decreased estimated glomerular filtration rate, independent of age, sex, glycated hemoglobin, diuretic use and hypertension (P = 0.025). PA induced a 3.7-mL/min/1.73 m2 (95% confidence interval 0.47-6.9) decrease in estimated glomerular filtration rate, equivalent to that induced by 4.4 years of aging. Our results show that in patients with type 2 diabetes mellitus, PA is an independent risk factor for renal dysfunction. To prevent the progression of renal failure, PA should not be overlooked.
