Peripheral blood mitochondrial DNA content correlates with lipid oxidationrate during euglycemic clamps in healthy young men

Both qualitative and quantitative changes in mitochondrial DNA (mtDNA) have been implicated in the pathogenesis of diabetes mellitus. It was previousl y found that decreased mtDNA content preceded the development of diabetes a nd mtDNA content correlated with the clinical parameters of insulin resista nce syndrome, including diastolic blood pressure and waist-hip ratio. These results prompted one to look whether there are correlations between mtDNA content and the biochemical parameters of insulin resistance in non-diabeti c subjects. MtDNA content of peripheral blood leukocytes was measured in Ko rean healthy young men, and this was correlated with various parameters of fuel metabolism at baseline and during euglycemic hyperinsulinemic clamps w ith indirect calorimetry, MtDNA content in peripheral blood leukocytes did not correlate with insulin sensitivity index or other metabolic variables s uch as body mass index (BMI), waist-to-hip ratio (WHR) and blood pressure. However, mtDNA content showed a positive significant correlation with fat o xidation rate during euglycemic clamps (r = 0.61, P < 0.05). Changes in fat oxidation rate and carbohydrate oxidation rate during the clamps were sign ificantly correlated with mtDNA content (r = 0.65, P < 0.05, r = - 0.65, P < 0.05, respectively). These results suggest that mtDNA content in peripher al blood may not correlate with insulin resistance per se but with some asp ect of insulin resistance in healthy young men. (C) 1999 Elsevier Science I reland Ltd. All rights reserved.