Microalbuminuria is more consistent in the presence of cardiovascular risk factors

The use of microalbuminuria (MAU) to screen for cardiovascular and renal risk might be hampered by its intermittent character. This prospective observational study assessed traditional risk factors in presumed healthy workers with intermittent MAU (IMAU) compared to persistent MAU (PMAU).

A cohort of 239 Belgian workers underwent at least two consecutive occupational check-ups with a median time of 12 months. Hypertension (HT) was defined as blood pressure >/=140/90 mmHg. Impaired glucose tolerance (IGT) was defined as plasma glucose =5.6 mmol/L. MAU was defined as urinary albumin to creatinine ratio of 17-249 mg/g in men and 25-354 mg/g in women. Workers with IMAU had one positive MAU and workers with PMAU had two positive MAU during follow-up.

The mean age of this mainly male (95%) cohort was 41 ± 9 years. The prevalence of persistent risk factors (HT and/or IGT) was higher in workers with PMAU than without MAU (8/12[67%] vs. 55/210[26%], P = .005) while workers with IMAU had no increased risk (5/17[29%]). The prevalence of PMAU was higher in workers with vs. without persistent risk factors (8/68 = 12% vs. 4/171 = 2%, P = .005) while the prevalence of IMAU was the same (5/68 = 7% vs. 12/171 = 7%, P = .93). The reproducibility of initial MAU at consecutive visits was higher in workers with vs. without persistent risk factors (8/9[89%] vs. 4/11[36%] P = 0.03).

The use of MAU as a first step screening strategy in an occupational health care setting is hampered by false positives and low sensitivity to identify subjects with cardiovascular and renal risk.