Associations of Whole Blood Minerals and Trace Elements with Body Composition in Overweight and Obese Patients: A Retrospective Cross-Sectional Study.

Abstract

Objective: To detect the levels of whole blood minerals and trace elements (calcium, iron, zinc, copper, magnesium) in overweight and obese patients, and explore their associations with body weight, body mass index (BMI) and other body composition indicators.

Methods: A retrospective cross-sectional analysis was conducted among 1220 enrolled patients. Participants were categorized into overweight and obese groups based on body mass index (BMI). We compared whole blood minerals and trace elements, body composition and weight-related indicators between the two groups, and explored correlations and independent associations of these elements with BMI, body fat percentage, visceral fat content and muscle mass. Statistical analyses included the Mann-Whitney U test, Spearman correlation analysis and multiple linear regression analysis.

Results: Concentrations of iron, zinc and magnesium were significantly elevated in the obese group (P < 0.001), while calcium concentrations were markedly lower (P < 0.001). No significant intergroup difference was observed for copper (P = 0.408). Correlation analysis revealed that iron, zinc and magnesium were positively correlated with BMI, visceral fat content and muscle mass (P < 0.001), and negatively correlated with body fat percentage (P < 0.001). Copper was positively correlated with body fat percentage (P < 0.001) and negatively correlated with muscle mass (P < 0.001). In multiple linear regression analysis adjusted for gender and age, copper (B = 0.157, P = 0.002) showed a significant independent positive association with body fat percentage. Zinc had a borderline positive association with BMI (B = 0.003, P = 0.069), indicating no statistical significance. None of the elements were significantly and independently associated with visceral fat content.

Conclusion: Iron, zinc, magnesium and copper are closely correlated with obesity-related indices. Copper shows a specific association with body fat percentage rather than visceral adipose tissue. As an observational study, we confirmed associations between these minerals and trace elements and obesity as well as body composition, yet causal relationships cannot be established.