[Microscopic hematuria in adults. Prevalence and associated factors]

The finding of microscopic haematuria in the course of systematic screening accounts for 10 percent of consultations in nephrology clinics. We carried out an investigation in a population of 8,194 workers of the metallurgical and chemical industries, 89.6 percent of whom were male and 69.8 percent were under 49 years of age; 51.2 percent were smokers or ex-smokers, 9.9 percent had arterial hypertension and 2.1 percent had diabetes mellitus. Microscopic haematuria was detected by the dipstick method in 3.53 percent of the subjects tested. Phase contrast microscopy, performed in 222 subjects, showed that the origin of the haematuria was glomerular in 90.5 percent, extraglomerular in 2.5 percent and undetermined in 0.9 percent of the cases. Urinary sediment was normal in 6.3 percent. The prevalence of microscopic haematuria was significantly higher in women, in subjects under 49 years of age, in hypertensive subjects, in smokers or ex-smokers, in subjects who has received non-steroidal anti-inflammatory drugs during the past 6 months and in chemical industry workers.