Routine urinalysis in a male working population: effects of some personal and lifestyle factors.

The most frequently positive urinalysis findings in a population of white working men were leukocytes (78.7%), erythrocytes (37.3%) and protein (25.4%). There was a significant correlation among the variables: cells were associated with protein, protein was associated with casts, erythrocytes were associated with granular casts and oxalate crystals. Protein and granular casts were significantly associated with serum creatinine. The prevalence of blood cells varied with age, showing a bimodal distribution. Oxalate crystals were significantly more common in subjects with a history of urinary tract infection; triple phosphate crystals were associated with a history of urinary calculi. Protein and erythrocytes were significantly more frequent in smokers. Leukocytes were significantly more frequent in drinkers. We conclude that there are important factors that must be taken into account in the interpretation of urinalysis findings.