Sundquist K, Sundquist J, Palmer K, et al. - Findings demonstrate that lower mitochondrial DNA copy number (mtDNA-CN) not only can independently predict future cardiovascular disease (CVD) but also has a mediating impact between the link of CVD and type 2 diabetes (T2D).

• A population-based follow-up study of middle aged (52–65 years) women (n = 3062) was conducted with median follow-up period of 17 years.

• By employing droplet digital PCR method, absolute mtDNA-CN was quantified.

• Low baseline levels of mtDNA-CN (<111 copies/μL) were identified to be linked with an elevated risk of CVD (HR = 1.32) as well as with specific CVDs: coronary heart disease (HR = 1.28), stroke (HR = 1.26) and abdominal aortic aneurysm (HR = 2.61).

• The links reduced but persisted even post-adjustment for potential confounders.

• Reduction in the total impact of T2D on future risk of CVD was noted after controlling for mtDNA-CN and the proportion mediated by mtDNA-CN was 4.9%.