Influence of cell distribution and diabetes status on the association between mitochondrial DNA copy number and aging phenotypes in the In CHIANTI study

• Published in: Aging cell 2018-02, Vol.17 (1)
• Main Authors: Moore, Ann Zenobia, Ding, Jun, Tuke, Marcus A., Wood, Andrew R., Bandinelli, Stefania, Frayling, Timothy M., Ferrucci, Luigi
• Format: Article
• Language: English
• ISSN: 1474-9718; 1474-9726
• DOI: 10.1111/acel.12683

Mitochondrial DNA copy number (mt DNA ‐ CN ) estimated in whole blood is a novel marker of mitochondrial mass and function that can be used in large population‐based studies. Analyses that attempt to relate mt DNA ‐ CN to specific aging phenotypes may be confounded by differences in the distribution of blood cell types across samples. Also, low or high mt DNA ‐ CN may have a different meaning given the presence of diseases associated with mitochondrial damage. We evaluated the impact of blood cell type distribution and diabetes status on the association between mt DNA ‐ CN and aging phenotypes, namely chronologic age, interleukin‐6, hemoglobin, and all‐cause mortality, among 672 participants of the In CHIANTI study. After accounting for white blood cell count, platelet count, and white blood cell proportions in multivariate models, associations of mt DNA ‐ CN with age and interleukin‐6 were no longer statistically significant. Evaluation of a statistical interaction by diabetes status suggested heterogeneity of effects in the analysis of mortality ( P