Urinary albumin excretion in a population based cohort

In order to compare a 1-h daytime urine specimen collection with a timed overnight collection, as well as different ways of expressing urinary albumin excretion: (urinary albumin excretion rate (UAE), urinary albumin concentration (UAC), and urinary albumin creatinine ratio (UACR)), a population of 922 people of whom 35 had diabetes was examined. The median age was 47 (range 26-65) years. The results of the different ways of collecting urine specimens and the different expressions of urinary albumin excretion were related to known cardiovascular risk factors. The daytime collection showed higher values of urinary albumin excretion than the overnight collections. Systolic blood pressure was an important risk factor correlated to UAE and UACR in the day as well as the overnight collection, followed by HbA1C in the total group and by BMI in the non-diabetic group. UAC showed significant relation to triglycerides and HDL-cholesterol. In conclusion, urinary albumin in a 1-h daytime collection showed a similar correlation to cardiovascular risk factors as the excretion of albumin in overnight collected urine. Follow-up studies are needed to compare day collections of urine as predictors of cardiovascular disease and early death with overnight collections.