Is Constipation More Common in Overweight Children?

Abstract

Introduction: Obesity rates have doubled in children and quadrupled in adolescents in the past 30 years. The most important causes of obesity are sedentary life style and low fiber, high calorie diet which are also putative causes of constipation. Some studies have found a correlation between constipation and obesity while others have been inconclusive. In an effort to understand this relationship we undertook a study to assess if overweight children have a higher risk of constipation as compared to normal weight children. Methods: A retrospective review of charts of new patients seen at Pediatric GI Clinic between 1/1/11 and 12/31/12 was performed. All charts were reviewed with an emphasis on growth curves and final diagnoses. Growth status of each patient was assessed by using standard WHO charts for weight, height, and body mass index (BMI) for age and sex. Obesity was defined as a BMI above 95th percentile, overweight between 85-95th percentile, normal between 3rd-85th percentile and failure to thrive (FTT) below 3rd percentile. For statistical analysis, overweight and obese patients were combined into one single group (overweight). The final diagnosis of constipation was made by the attending Pediatric Gastroenterologist. The incidences of constipation in the overweight and FTT were compared to that in normal children using chi-squared analysis. Results: Out of 1876 (M:F, 941:935) new patients seen during study period, 295 patients were overweight (M:F 146:149, 225 obese), 211 FTT and 1370 normal weight (other GI complaints/diagnoses). Observed and expected incidence of constipation in these groups is reported in Table 1. The data was analyzed by chi-squared analysis for significance of incidence of constipation in three individual categories: obese, normal, and failure to thrive (FTT). There was a higher incidence of constipation in overweight patients than expected (a chi-square value of 25. 137 and a p-value < 0.05, CI 95%). Furthermore, the data showed that the incidence of constipation was lower than expected in FTT (a chi-square value of 15.2 and a p-value < 0.05, CI 95%).Table 1: The Observed vs Expected Total Number of Constipated and Non-Constipated PatientsConclusion: There is a higher incidence of constipation in overweight children. Children with FTT have lower incidence of constipation. An analysis of nutrition and exercise habits amongst patients with constipation, obesity, overweight, and failure to thrive could further reveal associations between constipation and BMI.