Relation of urinary albumin excretion to coronary heart disease and low renal function: Role of blood pressure

Background. Previous studies report that urinary albumin excretion is associated with coronary heart disease (CHD). The present epidemiologic study investigated if (1) blood pressure status affects the association of urinary albumin excretion with CHD; and (2) urinary albumin excretion is associated with low renal function also. Methods. The cross-sectional association was analyzed of overnight urinary albumin excretion with prevalence of CHD (myocardial infarction and/or ischemia as defined by standard electrocardiogram) and low renal function (overnight creatinine clearance <60 mL/min) in a population sample of 1632 men and women with ages 45 to 64 years. Hypertension, hypercholesterolemia, smoking habit, and diabetes mellitus were included in analyses. Results. CHD prevalence was in the whole sample 8.2% (N=134), in the hypertensive subgroup 11.9% (N=79), and in the nonhypertensive subgroup 5.7% (N=55). For the association between urinary albumin excretion (logarithm-transformed due to skewed distribution) and CHD, the multivariate logistic coefficient with 95% CI was significant in the whole sample (+0.79, 95% CI=+0.32/+1.26, P<0.001) and in the hypertensive subgroup (+0.97, 95% CI=+0.70/+1.24, P<0.001), not in the nonhypertensive subgroup (-0.06,95% CI=-0.80/+0.68, P=0.997). Prevalence of low creatinine clearance was in the whole sample 4.0% (N=66), in the hypertensive subgroup 4.8% (N=32), and in the nonhypertensive subgroup 3.5% (N=34). The logistic coefficient between urinary albumin excretion and low creatinine clearance was borderline significant in the whole sample (+0.56, 95% CI=-0.02/+1.14, P=0.090), significant in the hypertensive subgroup (+0.73, 95% CI=+0.04/+1.42, P=0.044), not significant in the nonhypertensive subgroup (-0.07,95% CI=-1.25/+1.10, P=0.913). Conclusion. Results support the use of urinary albumin excretion as marker of CHD and slightly reduced renal function in hypertensives.