Albuminuria within the normal range and ultrasound-assessed atherosclerosis in the AIR study: a 9-year follow-up of 58-year-old clinically healthy men.

BACKGROUND: Microalbuminuria, traditionally defined as 30-300 mg urinary albumin/24 h, predicts renal impairment and cardiovascular disease. Studies suggest that also a far lower urinary albumin excretion (UAE) can predict clinical outcome. Intima media thickness (IMT) is an established estimate of atherosclerosis. In this study, we investigated the predictive value of UAE within the normal rate (UAE-n) for the progression of IMT in the carotid and femoral arteries. METHODS: We included 325 clinically healthy men with normoalbuminuria. Anthropometrics, urine and blood samples were taken and IMT in the carotid and femoral arteries were assessed by B-mode ultrasound at baseline and after 3 and 9 years. The annual progression rate of IMT (r-IMT) was calculated. RESULTS: UAE-n correlated with carotid IMT at baseline and after 3 and 9 years, but not with r-IMT. In a regression analysis, only HDL and baseline IMT remained as statistically significant co-variates to mean IMT at 9 years. IMT in the femoral artery and r-IMT at any time-point did not correlate to baseline UAE. CONCLUSION: UAE-n was associated with carotid IMT after 3 and 9 years but not r-IMT or with femoral artery IMT. Carotid IMT after 9 years' follow-up was independently related to baseline IMT and HDL cholesterol. In this cohort of 58-year-old men, our interpretation is that UAE-n is not associated with the increase in carotid and femoral artery IMT observed after 9 years.