MICROALBUMINURIA AND CORONARY HEART-DISEASE IN NIDDM - AN INCIDENCE STUDY

In most survival studies in NIDDM, microalbuminuria (urinary albumin e xcretion rate 20-200 mu g/min) predicts early mortality; in cross-sect ional studies, it is associated with coronary heart disease (CHD) morb idity. It is unclear, however, whether microalbuminuria is a risk fact or for the development of CHD or the result of it, and little is known of the factors that predispose to the development of microalbuminuria in NIDDM. We examined these issues in a 7-year prospective study of a hospital-based cohort comprising 146 white NIDDM patients without cli nical albuminuria. Microalbuminuria was a significant risk factor for both all-cause mortality (relative risk 3.94, 95% CI 2.04-7.62) and CH D mortality (relative risk 7.40, 95% CI 2.94-18.7) when adjusted for a ge only. Its independent predictive power did not persist, however, in age-adjusted multivariable survival analysis that allowed for the oth er significant risk factors: male sex, preexisting CHD, high levels of glycated hemoglobin, and high serum cholesterol. Among men free of CH D at baseline, the independent risk factors for CHD morbidity and mort ality were microalbuminuria, current smoking, high diastolic blood pre ssure, and high serum cholesterol (all P < 0.05). For the 100 NIDDM pa tients with normoalbuminuria at baseline, the incidence of microalbumi nuria was 29% over the 7-year period. In that group, fasting plasma gl ucose, current smoking, preexisting CHD, and high initial urinary albu min excretion rate were risk factors for the development of microalbum inuria tall P < 0.05). When men and women were analyzed separately, pr eexisting CHD was a significant risk factor in men only. These results demonstrate that microalbuminuria predicts incident clinical CHD in m en with NIDDM. Preexisting CHD is also a risk factor for incident micr oalbuminuria in men, however, suggesting that microalbuminuria and CBD are not causally related but rather reflect common determinants.