Obesity and symptomatic cholelithiasis in childhood: Epidemiologic and case-control evidence for a strong relation

Objectives: The aims of this study were to correlate the temporal trends in obesity prevalence with hospitalization rates for symptomatic cholelithiasis and to estimate the strength of the association between obesity and symptomatic cholelithiasis in patients hospitalized at an urban childrene's hospital in New York serving a multiethnic population. METHODS: Using obesity prevalence data from the National Health and Nutrition Examination Survey and the rates of hospitalization for cholelithiasis derived from the Kids' Inpatient Database for 1997-2007, we estimated a correlation and a linear regression. We conducted a retrospective, case-control study in which each case ages 4 to 20 years with symptomatic cholelithiasis was individually matched to a control admitted with appendicitis based on age, sex, ethnicity, and race. RESULTS: The prevalence of obesity and the cholelithiasis hospitalization rate increased over time (R=0.87, P=0.0025). For every 1% increase in the obesity rate among children, the rate of hospitalization for gallstones increased by 0.65/100,000 children (R=0.75, P=0.0025, 95% confidence interval [CI] 0.32-0.99). The odds ratio for obesity in cases versus controls was 5.78 (n=518, P<0.0001, 95% CI 3.50-9.53). We found a significant dose-response effect, which showed that for every 1 z score increase in body mass index, the risk of cholelithiasis was increased by 79% (P<0.0001, 95% CI 1.5-2.13). CONCLUSIONS: The national trend in the prevalence of obesity from 1997 to 2009 was significantly correlated with increasing rates of hospitalization for pediatric cholelithiasis. Our case-control study suggests that obesity is a significant risk factor for hospital admission because of cholelithiasis.