Persistent reflux, younger age predict significant weight gain in children at risk of UTI
Patients at risk of urinary tract infections (UTIs) are also highly likely to experience excessive weight gain, with risk factors including persistent reflux, younger age and Hispanic/Latino ethnicity, according to a secondary analysis of two prospective studies.
On the other hand, prophylactic antibiotics, which have been a long-standing management strategy for patients with vesicoureteral reflux (VUR) and a history of febrile UTIs, are not associated with the risk of becoming overweight, the investigators said.
The analysis included 446 children who participated in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) and Careful Urinary Tract Infection Evaluation (CUTIE) trials. Half (51 percent) were aged <1 year at study entry (median age 12 months), and the majority (89 percent) were girls. The median body mass index (BMI) was 54 kg/m2.
Over the 2-year study period, 84 children (17 percent) became clinically overweight (>85th BMI percentile for sex and age). On multivariable logistic regression, such an outcome was more likely to occur in Hispanic/Latino children vs whites (adjusted odds ratio [aOR], 3.3; 95 percent CI, 1.7–6.4), those who were infant vs noninfant at study enrolment (aOR, 2.1; 1.2–3.8) and those with persistent reflux (aOR, 2.1; 1.0–4.3). [J Pediatr Urol 2018;doi:10.1016/j.jpurol.2018.09.002]
Neither patients assigned to prophylactic antibiotics (aOR, 1.1; 0.6–1.8) nor those presenting with bladder and bowel dysfunction (aOR, 1.2; 0.6–2.3) were more likely to gain significant BMI percentiles.
The investigators explained that while prophylactic antibiotics had no association with significant weight gain, an initial treatment course of antibiotics for UTI might have a greater impact on the developing infant gut microbiota when compared to the more mature and established microbiota in noninfants. This is one possible reason for the finding that infants are at greater risk of becoming overweight.
With respect to the association between persistent reflux and significant BMI percentile gain, the underlying mechanism is unknown, although it may be mediated via an inflammatory response, the investigators continued.“Another explanation is reverse causation, as patients who gained more weight may be less likely to resolve their reflux. Recurrent UTIs may also mediate this relationship.”
Meanwhile, the increased risk of becoming overweight in Hispanic/Latino children observed in the present analysis likely represents the well documented high prevalence of childhood obesity in this population. [JAMA 2012;307:4883-4901; Obesity 2008;16:2566-2577]
“Reasons for this differential effect by race/ethnicity have been proposed, including higher rates of maternal depression and introduction of solid foods before 4 months of age… Whether these results are specific to Hispanic/Latino children at risk for UTIs is unclear, [and] more data are needed in this important ethnic subgroup,” the investigators noted.Despite the presence of several limitations, the present analysis highlights the importance of considering the risk of significant weight gain among infants with UTIs, as well as exploring areas for prevention, they added.