Microalbuminuria and peripheral arterial disease are independent predictors of cardiovascular and all-cause mortality, especially among hypertensive subjects - Five-year follow-up of the Hoorn study

Microalbuminuria (MA) is associated with increased cardiovascular and all-c ause mortality. It has been proposed that MA reflects generalized atheroscl erosis and may thus predict mortality. To investigate this hypothesis, we s tudied the associations between, on the one hand, MA and peripheral arteria l disease (PAD), a generally accepted marker of generalized atherosclerosis , and, on the other hand, cardiovascular and all-cause mortality in an age- , sex-, and glucose tolerance-stratified sample (n = 631) of a population-b ased cohort aged 50 to 75 years followed prospectively for 5 years. At base line, the albumin-to-creatinine ratio (ACR) was measured in an overnight sp ot urine sample; MA was defined as ACR >2.0 mg/mmol. PAD was defined as an ankle-brachial pressure index below 0.90 and/or a history of a peripheral a rterial bypass or amputation. After 5 years of follow-up, 58 subjects had d ied (24 of cardiovascular causes). Both MA and PAD were associated with a 4 -fold increase in cardiovascular mortality. After adjusting for age, sex, d iabetes mellitus, hypertension, levels of total and HDL-cholesterol and tri glyceride, body mass index, smoking habits, and preexistent ischemic heart disease, the relative risks (RR) (95% confidence intervals) were 3.2 (1.3 t o 8.1) for MA and 2.4 (0.9 to 6.1) for PAD. When both MA and PAD were inclu ded in the multivariate analysis, the RRs were 2.9 (1.1 to 7.3) for MA and 2.0 (0.7 to 5.7) for PAD. MA and PAD were both associated with an about 2-f old increase in all-cause mortality. The RRs of all-cause mortality associa ted with MA and PAD were about 4 times higher among hypertensive than among normotensive subjects. We conclude that both MA and PAD are associated wit h an increased risk of cardiovascular mortality. MA and PAD are mutually in dependent risk indicators. The associations of MA and PAD with all-cause mo rtality are somewhat weaker. They are more pronounced in the presence of hy pertension than in its absence. These data suggest that MA affects mortalit y risk through a mechanism different from generalized atherosclerosis.