Association of obesity with myocardial fibrosis and adverse cardiac outcomes in duchenne muscular dystrophy: a prospective cohort study

Cardiomyopathy progression remains the predominant cause of mortality in Duchenne muscular dystrophy (DMD), with myocardial fibrosis serving as its central pathological hallmark. While obesity is highly prevalent in DMD patients and correlates with clinical outcomes, its specific role in cardiac deterioration remains undetermined.

To investigate the association between obesity and myocardial fibrosis, as well as its prognostic impact on clinical cardiac outcomes in Chinese DMD patients.

A prospective cohort study was conducted using cardiac magnetic resonance imaging (CMR) assessment. Obesity was defined by BMI z-scores ≥95th percentile for age. Myocardial fibrosis was determined through late gadolinium enhancement (LGE) on CMR. Composite cardiac endpoints included dilated cardiomyopathy, left ventricular ejection fraction (LVEF) <50%, heart failure hospitalization, recurrent angina, ventricular arrhythmias, or all-cause mortality. Multivariable linear regression and Cox proportional hazards models were employed to identify independent predictors.

A total of 198 boys with DMD (age: 8.0 years [IQR 7.0, 10.0]) were included, of whom 26.3% were classified as obese (median BMI: 21.3 [IQR 20.4-23.0]). Multivariable linear regression analysis revealed a significant association between obesity and LGE (adjusted OR: 3.57, 95% CI: 1.66, 7.71, p = 0.001). During a mean follow - up period of 38.3 ± 14.1 months, 28 boys reached cardiac endpoint. Multivariable Cox model analysis indicated that obesity (adjusted HR: 3.75, 95% CI: 1.57, 8.97, p = 0.003) and baseline LVEF (adjusted HR: 0.90, 95% CI: 0.85, 0.97, p = 0.003) were independently associated with cardiac endpoints.

Obesity independently associates with myocardial fibrosis and adverse cardiac outcomes in Chinese DMD patients. These findings underscore the imperative for early weight management strategies in multidisciplinary DMD care.

Multivariable analyses for obesity