Association of barium deficiency with Type 2 diabetes mellitus incident risk was mediated by mitochondrial DNA copy number (mtDNA-CN): A follow-up study.

Accumulating evidence indicates that plasma metals levels may associate with Type 2 diabetes mellitus (T2DM) incident risk. Mitochondrial function such as mitochondrial DNA copy number (mtDNA-CN) might be linked metal exposure and physiological metabolism. Mediation analysis was conducted to determine the mediating roles of mtDNA-CN in the associations of plasma metals with diabetes risk. In the present study, we investigated associations between plasma metals levels, mtDNA-CN and T2DM incident in elderly population with 6-year follow-up (2 times) study. Ten plasma metals (i.e. manganese (Mg), aluminium (Al), calcium (Ca), ferrum (Fe), barium (Ba), arsenic (As), copper (Cu), selenium (Se), titanium (Ti) and cesium (Sr) were measured by using inductively coupled plasma mass spectrometry (ICP-MS). Mitochondrial DNA copy number was measured by real-time PCR. Multivariable linear regression and logistic regression models were carried out to estimate the relationship between plasma metal concentrations, mtDNA-CN and T2DM incident risk in the current work. Plasma Ba deficiency and mtDNA-CN decline associated with T2DM incident risk during aging process. Meanwhile plasma Ba found to be positively associated with mtDNA-CN. Mitochondrial function mtDNA-CN demonstrated mediating effects in association between plasma Ba deficiency and T2DM incident risk, and 49.8% of the association was mediated by mtDNA-CN. These findings extend the knowledge of T2DM incident risk factors and highlight the point that mtDNA-CN may be linked metals element and T2DM incident risk.