Aldosterone-to-Renin Ratio Is Associated with Diabetic Nephropathy in Type 2 Diabetic Patients: A Single-Center Retrospective Study

BACKGROUND: It is well established that primary aldosteronism (PA) and aldosterone-to-renin ratio (ARR) are associated with kidney disease. The aim of this study was to retrospectively investigate the relationship between ARR, urinary albumin excretion (UAE), and estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes from a single center. MATERIAL/METHODS: We included 70 patients with type 2 diabetes, UAE ≤100 mg/day, not taking renin-aldosterone system inhibitors, did not meet the diagnostic criteria for PA, and had an ARR <20. The patients were divided into 3 groups: the normal low (NL) group (33 patients) with a UAE <10 mg/day, the normal (N) group (22 patients) with a UAE of 10–29 mg/day, and the microalbuminuria (M) group (15 patients) with a UAE of 30–100 mg/day. The ARR, plasma renin activity (PRA), and plasma aldosterone (PAC) were compared among groups. RESULTS: The ARR was highest in group M (10.1±4.6), 6.5±0.3 in group NL, and 7.0±2.7 in group N. The PRA and PAC were significantly lower in group M (P<0.001). The ARR showed a significant positive correlation with log UAE (r=0.37, P<0.001) and a significant negative correlation with eGFR (r=−0.33, P<0.01). CONCLUSIONS: High levels of aldosterone relative to renin, which did not fulfill confirmatory criteria for PA, may be one of the risk factors for the development of diabetic nephropathy in patients with diabetes. The present results are supported by previous research showing that an increased ARR without PA was a risk factor for kidney disease.