A01 Dietary intakes and nutritional status in adults with Muscular Dystrophy

Abstract

Muscular dystrophy (MD) is a group of inherited conditions causing progressive muscle weakness and wasting, for which no widely implementable treatment currently exists, although resistance training (Bostock et al., 2019, Frontiers in Neurology, 10) and corticosteroid treatment (Angelini, 2007, Muscle & Nerve, 36, 424-435), have been shown to improve health-related quality of life (HQoL). Compared to physical activity, dietary manipulation may be more modifiable to improve dystrophic populations HQoL as disease outcomes often restrict physical capabilities. Data exploring the relationship between diet, disease and HQoL outcomes in adults with MD is insufficient. This study evaluated the habitual dietary intake of a sex-inclusive dystrophic population, to identify possible links between dietary intake, HQoL, and physical function. Participants included 5 women (age 65 ± 14 yrs, BMI 23.2 ± 2.7 kg/m²) and 10 men (age 55 ± 19 yrs, 31.6 ± 7.9 kg/m²) with different MDs (varied distribution and severity of muscle weakness). Participants' dietary intake data was collected using 3-day food records: analysed using Nutritics. Dominant hand maximal grip strength was measured using a hand-held dynamometer; upper extremity function and pain were assessed using the upper extremity functional index-15 and visual analogue scale, respectively. QoL was assessed through three tools: SF-36V2, Barthel Index and EQ5D, previously used in dystrophic populations. We observed that 50% of men and 20% of women did not meet the recommended daily intake (RDI) for protein (0.8 g·kg⁻¹), however women (1.13 ± 0.26 g·kg⁻¹) had increased protein intake compared to men (0.82 ± 0.27 g·kg⁻¹, p < 0.05). Of all participants 40% had a daily fat intake exceeding the RDI, with women having significantly higher relative average fat intakes (women = 1.03 ± 0.36 g·kg⁻¹, men = 0.68 ± 0.29 g·kg⁻¹, p < 0.05). RDI for calcium was met by 46% participants (1000 mg) whilst all failed to meet the vitamin D RDI (10 μg). Positive correlations between age and protein intake as a percentage of RDI (r² = 0.82), protein (r² = 0.82), carbohydrate intake (r² = 0.55) relative to body mass, vitamin D intake (r² = 0.54), and total caloric intake (r² = 0.59, all p< 0.05) were observed. No other significant associations between dietary habits, physical function or HQoL outcomes were apparent. Despite these findings being observed in a small population it is apparent that many adults with muscular dystrophy may fail to meet RDI for protein, vitamin D, and calcium. This places this population at risk for nutritional deficiencies, incurring negative impacts on the musculoskeletal system. Further study of nutritional status in a larger population sample is needed to confirm these findings.