Obesity and risk of urinary tract infection in young children presenting with fever

Obesity may increase the risk of infection, but the association between obesity and febrile urinary tract infection (fUTI) is controversial. Although the prevalence of infant and childhood obesity has been increasing worldwide, the results of previous investigations on the association with urinary tract infection (UTI) are conflicting. The purpose of this study was to evaluate the relationship between overweight and obesity and UTI in febrile children. The study reviewed medical records of a consecutive series of 472 children <2 years of age presenting with fever ≥ 38°C were retrospectively evaluated and stratified by the presence or absence of a UTI. The proportions of underweight, healthy weight, overweight, and obese children in the 2 groups were compared following calculation of individual weight-for-length percentiles. The effect of obesity on UTI risk was evaluated, and odds ratios (ORs) were calculated. A total of 212 patients with and 260 controls without UTI were included. There were more overweight and obese children with (71/212, 33.5%) than without UTIs (45/260, 17.3%; P < .001). The OR of UTI in overweight relative to healthy-weight children was 1.92 [95% confidence interval (95% CI):1.15–3.21]. The OR of UTI in obese relative to healthy weight children was 2.46 (95% CI: 1.54–3.93). Compared with previous studies that made comparison between UTI and healthy children, this is the first study to demonstrate an association of obesity and fUTI in febrile children <2 years of age. In this series of pediatric patients, obesity was strongly associated with the presence of fUTI and obese children had a higher risk of developing an UTI than nonobese children. The incidence of UTI was higher in young, overweight, and obese children presenting with fever than in normal-weight, febrile children. Control of excess body weight should be considered as early as possible. Urinalysis should be considered for obese children <2 years of age who present with fever, especially those with mild respiratory or gastrointestinal symptoms.