Cardiovascular risk-factors predict progression of urinary albumin-excretion in a general, non-diabetic population: A gender-specific follow-up study

Increased urinary albumin-excretion (UAE) predicts cardiovascular events and clusters with the metabolic syndrome. The aim of this population-based, prospective study was to assess the relationship between baseline and longitudinal changes in cardiovascular risk-factors and 7 years’ increase in UAE. Three thousand and four hundred non-diabetic participants (1838 men, 1562 women) of the Tromsø studies in 1994/1995 and 2001/2002 were included. In each survey, first-void spot-urine-samples were collected, and albumin–creatinine ratio (ACR) was calculated. Change in ACR (ΔACR) was dichotomized into upper vs. the three lower quartiles. Median UAE in the population did not increase during follow-up. Baseline predictors for ΔACR in the upper quartile were: age (OR 1.32 per 5 years, 95% CI 1.22–1.43), HbA1c (OR 1.43 per %, 95% CI 1.08–1.91) and waist circumference (OR 1.11 per 5 cm, 95% CI 1.04–1.19) in men, and age (OR 1.14 per 5 years, 95% CI 1.04–1.25) and current smoking (OR 1.71, 95% CI 1.27–2.30) in women. Systolic blood pressure and estimated glomerular filtration rate were predictors without gender-specificity. Clustering of three or more metabolic traits did not predict ACR increase independently. Protective factors against ACR increase were initiation of antihypertensive treatment in women (OR 0.59, 95% CI 0.39–0.87) and hard physical activity in men (OR 0.70, 95% CI 0.51–0.96). In summary, cardiovascular risk-factors at baseline predicted ACR increase, but initiation of antihypertensive therapy (women) and physical activity (men) seemed to protect from ACR increase during follow-up. Endpoint-data are needed to explore the clinical significance of low-grade UAE increase.