Whole-blood magnesium and blood lipids are individually and jointly associated with an elevated likelihood of youngsters being overweight or obese: A matched case-control study using the propensity score.

OBJECTIVES: Youngsters who are overweight or obese (YOO) have become an important global health concern. Some micronutrients may be modifiable influential factors. This study aimed to investigate the individual and joint association of whole-blood magnesium (WBMg) and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), or high-density lipoprotein cholesterol (HDL-C) in YOO. METHODS: This is a propensity score matching-based case-control study. YOO was defined depending on age- and sex-specific body mass index z-score, calculated with SAS macros (%group_standard and %WHO2007) from the World Health Organization website. WBMg, blood lipids, and covariates were carefully measured by trained technicians using a whole-blood, five-element, basic analyzer and atomic absorption spectrometer or automatic biochemical analyzer. Locally weighted scattered plot smoothing and multivariable conditional logistic regression models were applied to estimate the associations of WBMg and blood lipids in YOO. RESULTS: WBMg was positively associated with YOO. The adjusted likelihood of YOO significantly increased by 21% (odds ratio: 1.21; 95% confidence interval [CI], 1.10-1.33) with per-interquartile range elevation of WBMg. Compared with the 1st quartile, adjusted odds ratios among youngsters in the 2nd, 3rd, and 4th quartiles of WBMg were 1.11 (95% CI, 0.92-1.35), 1.29 (95% CI, 1.06-1.57), and 1.47 (95% CI, 1.18-1.83), respectively. Furthermore, the relationship between WBMg and YOO was moderated by lipid profiles. Compared with those having lower (< median) WBMg and TC, TG, LDL-C, or higher (≥ median) HDL-C, youngsters with both higher WBMg and TC, TG, LDL-C, or lower HDL-C had higher YOO odds, which averagely increased by 188%, 250%, 339%, and 369%, respectively. CONCLUSIONS: WBMg was an independent risk factor of YOO, and the associations were stronger among those with unhealthy blood lipids. Our findings can help to guide clinical and public health policies on the relevance of magnesium nutritional status.