Body composition of duchenne muscular dystrophy patients supplemented with zinc: a clinical trial

Abstract

Duchenne muscular dystrophy (DMD) is a neuromuscular disease characterized by progressive muscle weakness. The increase in total fat mass and reduction in lean mass are side effects of the disease. The methods for assessing the nutritional status of boys with DMD can be imprecise, and the techniques applied to the general population are inadequate and difficult to interpret due to their altered body composition. Zinc is an essential mineral for the synthesis of lean mass. Data on zinc content in adipose tissue in obesity are still limited. Zinc supplementation affects body composition, however, this increase occurs especially in children with pre-existing stunting. To date, there are no studies that assess body composition in boys with DMD before and after zinc supplementation. Therefore, three studies were carried out. Study 1 was descriptive and cross-sectional, evaluating 49 boys through anthropometric and body composition parameters. For Study 2, an integrative review was carried out on zinc and body composition to understand what the literature had on the subject. Study 3 composed a clinical trial that evaluated dietary, biochemical, and body composition parameters before and after zinc supplementation in 21 boys with DMD. We observed an increase in fat mass and a decrease in lean mass with age/disease progression. Zinc supplementation in the population of this study was not enough to increase lean mass, but it was possible to observe the maintenance of lean and fat mass in those boys with previous serum zinc deficiency.