ALBUMIN EXCRETION RATE LEVELS IN NONDIABETIC OFFSPRING OF NIDDM PATIENTS WITH AND WITHOUT NEPHROPATHY

Familial clustering of diabetic nephropathy points to genetic suscepti bility. The observation that in non-diabetic subjects microalbuminuria occurs more frequently in the presence of a parental history of diabe tes supports this hypothesis. However, the role of inherited factors i s poorly understood in noninsulin dependent diabetes mellitus (NIDDM). This study investigated the albumin excretion rate in non-diabetic of fspring of NIDDM patients with increased albumin excretion rate (> 20 mu g/min) or normal albumin excretion rate (< 20 mu g/min). We recruit ed 20 offspring of NIDDM patients with increased albumin excretion rat e (A-off) and 20 offspring of NIDDM patients with normal albumin excre tion rate (N-off), matched for age, sex, body mass index, blood pressu re and estimated protein intake. All offspring were normotensive, had normal creatinine clearance, normal glucose tolerance and sterile urin e collection. Albumin excretion rate was measured on three sterile ove rnight urine collections and median values were used for calculations. Albumin excretion rate was significantly higher in A-off than in N-of f (7.7 +/- 1.2 vs 3.4 +/- 0.6 mu g/min p < 0.01) and significantly rel ated to parents' albumin excretion rate (p < 0.01, r = 0.53). These re sults suggest that an increased glomerular permeability is present in non-diabetic offspring of NIDDM patients with increased albumin excret ion rate.