Bioelectrical impedance vector analysis for evaluating zinc supplementation in prepubertal and healthy children

Utilization of bioelectrical impedance vector analysis (BIVA) in children and adolescents without diagnosed diseases: a systematic review

Introduction. Bioelectrical impedance vector analysis (BIVA) emerges as a technique that utilizes raw parameters of bioelectrical impedance analysis and assumes the use of a reference population for information analysis.Objective. To summarize the reference values, main studies objectives, approaches, pre-test recommendations and technical characteristics of the devices employed in studies utilizing BIVA among children and adolescents without diagnosed diseases.Methods. A systematic search was conducted in nine electronic databases (CINAHL, LILACS, PubMed, SciELO, Scopus, SPORTDiscus, Science Direct, MEDLINE, and Web of Science). Studies with different designs which allowed extracting information regarding reference values of BIVA in children and adolescents without diagnosed diseases, aged 19 years or younger, were included. The systematic review followed PRISMA procedures and was registered in PROSPERO (registration: CRD42023391069).Results. After applying the eligibility criteria, 36 studies were included. Twenty studies (55.6%) analyzed body composition using BIVA, thirteen studies (36.1%) aimed to establish reference values for BIVA, and three studies (8.3%) investigated the association of physical performance with BIVA. There was heterogeneity regarding the reference populations employed by the studies. Fifteen studies used their own sample as a reference (41.6%), four studies used the adult population as a reference (11.1%), and five studies used reference values from athletes (13.9%).Conclusion. Nutricional status and body composition were the main studies objectives. References values were not always adequate or specific for the sample and population. Furthermore, there was no pattern of pre-test recommendations among the studies.

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.

Nutritional Status and Body Composition in Wilson Disease: A Cross-Sectional Study From China

Background: Abnormal nutritional status is frequently seen in patients with chronic diseases. To date, no study has investigated the detailed characteristics of abnormal nutritional status among Wilson's disease (WD) patients in the Chinese cohort. This study aimed to describe the nutritional status of WD patients, with a particular focus on the differences between patients with different phenotypes.

Methods: The study subjects comprised 119 healthy controls, 129 inpatients (hepatic subtype, n = 34; neurological subtype, n = 95) who were being treated at the affiliated hospital of the Institute of Neurology, Anhui University of Chinese Medicine. All of the subjects were assessed for body composition by using bioelectrical impedance analysis. All WD patients received anthropometry, nutritional risk screening 2002 (NRS2002), and laboratory test (hemocyte and serum biomarkers) additionally.

Results: Compared with healthy controls, the fat mass and rate of total body and trunk were significantly higher in WD patients (P < 0.001), the muscle and skeletal muscle mass of total body and trunk were significantly lower in WD patients (P < 0.001). Compared with hepatic subtype patients, the fat mass and rate of total body, trunk, and limbs were significantly lower in neurological subtype patients (P<0.01); while there were no significant differences in muscle and skeletal muscle between these two subtypes. The overall prevalence of abnormal nutritional status in WD patients was 43.41% (56/129). The prevalence of high-nutritional risk and overweight in WD patients was 17.83% (23 of 129) and 25.58% (33 of 129), respectively. Compare with patients with high nutritional risk, macro platelet ratio, alkaline phosphatase, the basal metabolic rate (p < 0.05), creatinine, trunk fat rate (p < 0.01) and appendicular skeletal muscle mass (p < 0.001) were significantly higher in patients without nutritional risk (p < 0.001). Patients with a high nutritional risk tend to have a lower cholinesterase concentration (x² = 4.227, p < 0.05).

Conclusion: Both patients with H-subtype and N-subtype are prone to have an abnormal nutritional status. Longitudinal studies are required to investigate if nutritional status and body composition could reflect prognosis in WD patients, and which of these body composition indexes contribute to malnutrition and worse prognosis.

Serum zinc reference intervals and its relationship with dietary, functional, and biochemical indicators in 6- to 9-year-old healthy children

BACKGROUND

Zinc is an important cause of morbidity, particularly among young children. The dietary, functional, and biochemical indicators should be used to assess zinc status and to indicate the need for zinc interventions.

OBJECTIVE

The purpose of this study was to determine the zinc status and reference intervals for serum zinc concentration considering dietary, functional, and biochemical indicators in apparently healthy children in the Northeast Region of Brazil.

DESIGN

The cross-sectional study included 131 healthy children: 72 girls and 59 boys, aged between 6 and 9 years. Anthropometric assessment was made by body mass index (BMI) and age; dietary assessment by prospective 3-day food register, and an evaluation of total proteins was performed. Zinc in the serum samples was analyzed in triplicate in the same assay flame, using atomic absorption spectrophotometry.

RESULTS

With respect to dietary assessment, only the intake of fiber and calcium was below the recommendations by age and gender. All subjects were eutrophic according to BMI and age classification. Zinc intake correlated with energy (p=0.0019), protein (p=0.0054), fat (p<0.0001), carbohydrate (p=0.0305), fiber (p=0.0465), calcium (p=0.0006), and iron (p=0.0003) intakes. Serum zinc correlated with protein intake (p=0.0145) and serum albumin (p=0.0141), globulin (p=0.0041), and albumin/globulin ratio (p=0.0043). Biochemical parameters were all within the normal reference range. Reference intervals for basal serum zinc concentration were 0.70-1.14 µg/mL in boys, 0.73-1.17 µg/mL in girls, and 0.72-1.15 µg/mL in the total population.

CONCLUSIONS

This study presents pediatric reference intervals for serum zinc concentration, considering dietary, functional, and biochemical indicators, which are useful to establish the zinc status in specific groups. In this regard, there are few studies in the literature conducted under these conditions, which make it an innovative methodology.