Aim: The aim of this study was to investigate the clinical relevance and consequences of screening for microalbuminuria (MA) in a randomly selected, apparently healthy population sample.
Material and methods: A total of 2,113 individuals (> or = 20 years) without known diabetes and treated hypertension, all identified in the large population-based Nord-Trøndelag Health Study (HUNT) 1995-1997, (n = 65,258), delivered 3 morning urine samples for MA analysis. Those with MA, defined as at least 2 out of 3 urine samples with albumin-to-creatinine ratio (ACR) > or = 2.5 mg/mmol, were invited to a second clinical examination.
Results: In total, 54 men and 54 women had MA, and 42 men (84%) and 42 women (78%) attended the second examination. All with MA had 1 or more cardiovascular risk factors, like elevated cholesterol, c-peptides and blood pressure, and they were older than those without MA. Ten men (25%) and 19 women (46%), who were defined as MA-positive at the screening, had normal albumin excretion in the overnight collected urine sample in the second clinical examination. Five men (12%) and 2 women (5%) were still followed-up at the hospital out-patient clinic 3 years later.
Conclusions: Several individuals in the second examination had cardiovascular risk factors and other pathology, but the clinical benefit of discovering this was not obvious. Due to low positive predictive value and reduced reliability and validity, MA did not satisfy the criteria for a good screening test in this apparently healthy population.