Associations of metals and metals mixture with lipid profiles: A repeated-measures study of older adults in Beijing

Metals inevitably and easily enter into human bodies and can induce a series of pathophysiological changes, such as oxidative stress damage and lipid peroxidation, which then may further induce dyslipidemia. However, the effects of metals and metals mixture on the lipid profiles are still unclear, especially in older adults. A three-visits repeated measurement of 201 older adults in Beijing was conducted from November 2016 to January 2018. Linear Mixed Effects models and Bayesian kernel machine regression models were used to estimate associations of eight blood metals and metals mixture with lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), Castelli risk indexes I (CRI-1), Castelli risk indexes II (CRI-2), atherogenic coefficient (AC), and non-HDL cholesterol (NHC). Cesium (Cs) was positively associated with TG (beta Cs = 0.14; 95% CI: 0.02, 0.26) whereas copper (Cu) was inversely related to TG (beta Cu =-0.65; 95%CI:-1.14,-0.17) in adjusted models. Manganese (Mn) was mainly related to higher HDL-C (beta Mn = 0.14; 95% CI: 0.07, 0.21) whereas molybdenum showed opposite association. Metals mixture was marginally positive associated with HDL-C, among which Mn played a crucial role. Our findings suggest that the effects of single metal on lipid profiles may be counteracted in mixtures in the context of multiple metal exposures; however, future studies with large sample size are still needed to focus on the detrimental effects of single metals on lipid profiles as well as to identify key components.

Automated summary

Metals can enter human bodies and lead to various physiological changes, including lipid peroxidation and oxidative stress damage, which may result in dyslipidemia. The impact of metals and metal mixtures on lipid profiles, especially in older adults, is not well understood. This study conducted repeated measurements on 201 older adults in Beijing and found associations between blood metals and lipid profiles. Metals such as cesium and copper were related to triglycerides, while manganese was mainly associated with higher HDL-C. Molybdenum showed opposite effects and metal mixtures were marginally associated with HDL-C, with manganese playing a crucial role.