Elevated Serum Total Renin Is Insensitive in Detecting Incipient Diabetic Nephropathy

Abstract

OBJECTIVE To assess the influence of incipient diabetic nephropathy on the levels of total renin in serum. RESEARCH DESIGN AND METHODS Fifty-five adult patients with insulin-dependent diabetes mellitus (IDDM) were examined in a cross-sectional study. The main outcome measures were serum total renin concentration and urinary albumin excretion rate. RESULTS The total renin concentrations in serum were significantly (P < 0.05) higher in 12 patients with microalbuminuria than in 43 patients without albuminuria, but this difference was significant only in men. There was a significant but weak positive correlation between urinary albumin excretion rate and serum total renin concentration in all patients (r = 0.412, P < 0.05, n = 55), but the sensitivity of high serum concentrations of total renin in detecting incipient nephropathy was low (17%). In the study group, two of the three patients suffering from proliferative retinopathy had the highest total renin concentrations in serum. CONCLUSIONS Microalbuminuric patients have higher mean serum total renin concentrations than normoalbuminuric patients, but because of low sensitivity, high total renin concentration cannot be used for screening incipient diabetic nephropathy.