Effect of Proteinuria on Mortality in NIDDM

Abstract

The effect of proteinuria (≥ ∼1 g/day) on mortality in non-insulin-dependent diabetes mellitus (NIDDM) was assessed in Pima Indians aged ≥45 yr. Among 1426 subjects, 48% with NIDDM at the beginning of followup, there were 489 deaths in 13,345 person-yr of observation. The age- and sex-adjusted mortality rate was 32.7/1000 person-yr (95% CI = 27.6, 37.8) in diabetic subjects without proteinuria, similar to the rate of 30.1/1000 person-yr (95% CI = 25.7, 34.4) in nondiabetic subjects without proteinuria. By contrast, in diabetic subjects with proteinuria the mortality rate was 121.4/1000 person-yr (95% CI = 97.5, 145.3). When controlled for age, sex, and diabetes duration, diabetic subjects with proteinuria had a death rate 3.5 times as high (95% CI = 2.8, 4.4) as those without proteinuria. Of the excess mortality associated with NIDDM in Pima Indians, 97% was found in subjects with proteinuria. The death rate in diabetic subjects without proteinuria was not appreciably greater than the rate in nondiabetic subjects. Mortality rates from uremia and cardiovascular disease were significantly higher in diabetic Pima Indians with proteinuria than in those without. These relationships are similar to observations reported in people with insulin-dependent diabetes.