Multifaceted Assessment of Nutritional Status and Gastrointestinal Health in Duchenne Muscular Dystrophy: Approaches Based on Skinfold Thickness and Mid‐Upper Arm Circumference

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disorder characterized by prominent nutritional and gastrointestinal challenges. This study aimed to evaluate the nutritional status, gastrointestinal symptoms and biochemical deficiencies in children with DMD, with a particular focus on the clinical utility of supplementary anthropometric indicators such as mid-upper arm circumference Z-score (MUAC-Z) and triceps skinfold thickness Z-score (TSF-Z). This cross-sectional study included 65 genetically confirmed DMD patients aged 5-18 years. Anthropometric data (BMI-SDS, MUAC-Z, TSF-Z), gastrointestinal complaints, serum vitamin D levels and clinical features were analysed. ROC curve analysis was conducted to determine age thresholds associated with symptom onset. The most frequently reported gastrointestinal complaints were abdominal bloating (50.8%), constipation (32.3%) and regurgitation (30.8%). Swallowing difficulties and prolonged meal times were significantly associated with older age and loss of ambulation. ROC analysis identified > 14.5 years as the age threshold for solid food dysphagia. A moderate, significant positive correlation was observed between MUAC-Z and BMI-SDS (r = 0.520; p < 0.001), whereas no significant association was found between TSF-Z and BMI-SDS. Vitamin D deficiency (< 30 ng/mL) was widespread (86.2%) and more prevalent among non-ambulatory patients (96.6% vs. 77.8%; p = 0.036). Malnutrition was more frequently observed in steroid-naïve children than in those receiving corticosteroid therapy (50% vs. 19%; p = 0.041). Nutritional deficiencies and gastrointestinal symptoms are commonly encountered in paediatric DMD and tend to increase with advancing age and functional decline. MUAC-Z and TSF-Z may offer complementary insights into muscle mass and fat distribution beyond BMI. These simple and non-invasive measurements could be useful additions to routine nutritional surveillance in DMD management.