Association between zinc and body composition: An integrative review.

BACKGROUND: Zinc deficiency is related to lean body mass reduction, fat deposition, and obesity. Zinc acts in catalytic, structural, and regulatory functions, being an essential micronutrient to humans. It is crucial for maintaining lean body mass, synthesizing nucleic acids and proteins, and forming new tissues. Pre-existing zinc deficiency may contribute to obesity due to its relationship with fat deposition associated with short stature. This integrative review aims to analyze the association between zinc and body composition, hitherto very poorly established in previous studies. MATERIAL AND METHODS: The electronic databases utilized in this review were PubMed and Web of Science. We identified titles and abstracts from 1178 articles relating to zinc and body composition that were published in the last ten years. After duplicates were removed, the reference lists of relevant reviews were checked, and 47 articles were obtained by manual search. MAIN FINDINGS AND CONCLUSIONS: The articles were transversal or longitudinal studies, clinical trials, randomized controlled trials, reviews, systematic reviews, and meta-analysis. Although there was heterogeneity among the methodologies, the existence of an association between zinc and body composition was predominant among the studies. All articles concluded that zinc had positive effects on proteogenesis. Moreover, zinc metabolism is dysregulated in obese individuals, whose mechanisms remain controversial.

Bioelectrical impedance vector analysis and phase angle in boys with Duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a disease characterized by progressive loss of functional muscle mass followed by changes in body composition. OBJECTIVE: This study aimed to describe and evaluate bioimpedance parameters in boys with DMD. DESIGN: This cross-sectional, descriptive study investigated children and adolescents diagnosed with DMD. Age, weight, height, resistance, and reactance data were collected. Phase angle and bioelectrical impedance vector analysis were calculated based on resistance and reactance values. RESULTS: We analyzed 43 boys aged between 2.7 and 19.8 years. Low-phase angle values were observed during the investigation of bioimpedance parameters. Bioelectrical impedance vector analysis showed that approximately 87% of the subjects presented vectors outside the tolerance ellipses, and only one patient presented vectors located within the 50% tolerance ellipse, indicating normally hydrated and a good body cell mass. Compared with the reference population, boys with DMD had lower levels of body cell mass. CONCLUSION: Based on the evidence, compared with the reference population, patients with DMD had lower levels of body cell mass. This evidence points to bioimpedance parameters as useful tools for the nutritional evaluation and clinical management of patients with DMD.