Factors associated with leukocyturia in asymptomatic pilots

We attempted to relate the prevalence of leukocyturia during annual examinations to recent activities and history data in 923 pilots. Urinary analysis was done and the results cross-tabulated with answers from a questionnaire and with a past history of leukocyturia obtained from the pilot's chart. The prevalence of 4 to 6 or more white blood cells (WBCs) in the urinary sediment was 5.3%. Leukocyturia was 35.7 times more common (odds ratio) in those with a previous history of leukocyturia and a concomitant history of urethritis (p less than 0.0001). Yet, a history of leukocyturia accounted for only 18.1% of the cases of leukocyturia. There was a trend for an association between jogging and leukocyturia. The prevalence of leukocyturia was not affected by smoking, other physical exercise, a history of nephrolithiasis, air duty in the preceding 24 h or a history of transient illness during the last 2 weeks. We conclude that there is an association between a history of both leukocyturia and urethritis and leukocyturia. In most cases, however none of the variables tested were found to be associated with leukocyturia.