Urinary nitrite in Japanese patients with urinary tract infections

Urinary nitrite, a precursor of carcinogenic nitrosamines, and nitrate were measured in 73 Japanese patients with urinary tract infections (UTI) and in two control groups. Nitrite was detected in 12% of patients with uncomplicated UTI (226 +/- 161 mumol/l) and in 42% of those with complicated UTI (375 +/- 297 mumol/l). None of the subjects in the control groups excreted detectable amounts of nitrite. The excretion of nitrite in four out of five nitrite excretors continued for at least 14-55 days. The concentrations of urinary nitrite were significantly correlated with those of nitrate- plus nitrite-nitrogen, which reflect dietary nitrate ingestion. The results suggest the importance of close monitoring of nitrite excretor group in UTI patients, to clarify the mechanism of the association between UTI and bladder cancer.