G.P.177: Constipation in Duchenne muscular dystrophy: Common, underdiagnosed and undertreated

Abstract

Duchenne muscular dystrophy (DMD) is an X-linked progressive degenerative muscle disorder. Constipation as a co-morbidity in DMD has not been subject to a systematic study. To determine the prevalence of constipation, identify its predictive factors and evaluate different screening methods in a cohort of DMD patients. Design/Methods: This was a prospective cross-sectional study that evaluated a cohort of DMD patients for constipation using the pediatric Rome-III questionnaires (QPGS-RIII) and the Bristol stool chart. Additional clinical data collected included functional assessments and medications. Fecal load was assessed on routine spine X-rays. Logistic regression with backward elimination as a variable selection procedure was used to determine possible predictors of constipation. Among 98 male DMD patients (average age 11.3±3.8years), the overall prevalence of constipation fulfilling Rome-III criteria was 44.9%, of which 45% received symptomatic treatment and 11% were asymptomatic. The age distribution of patients with constipation (<i>n</i>=44) was similar to that without (10.8±2.6 vs 11.1±3years, <i>p</i>=0.62). Prevalence of constipation did not correlate with functional status (Northstar ambulatory assessment scale, <i>p</i>=0.39), treatment with calcium supplements (<i>p</i>=0.92) or with stool load on abdominal X-ray (<i>p</i>=0.82). The regression model failed to identify any predictive variables for constipation. The Bristol stool chart, abnormal abdominal exam (fullness, distension, tenderness, palpable masses or abnormal bowel sounds) and fecal load on X-ray were inferior to the Rome-III criteria in diagnosing constipation. (1) Constipation is a common co-morbidity in DMD, irrespective of age or the stage of disease. (2) Of the tests evaluated, the Rome III criteria may be the most appropriate screening tool for constipation in DMD patients. (3) Constipation in this cohort was underdiagnosed and either not treated or treated inadequately.