Potential relationship between peripheral blood mitochondrial DNA content and insulin resistance and secretion in offspring of type 2 diabetic patients.
Both qualitative and quantitative changes in mitochondrial DNA (mtDNA) have been implicated in the pathogenesis of diabetes mellitus. In this study, we investigate whether peripheral blood mtDNA (pb-mtDNA) is decreased and if there is any relation between its content and the parameters of both insulin resistance and secretion in offspring of diabetic subjects. The pb-mtDNA content was measured by real time polymerase chain reaction with mitochondrial- specific fluorescent probe, normalized by a nuclear DNA, 28S rRNA gene, in 42 offspring of type 2 diabetic patients and 12 age-, sex- and body mass index (BMI)-matched normal subjects. The correlations between pb-mtDNA content and the parameters of insulin resistance and secretion were studied. Our results indicated that the level of pb-mtDNA was lower in offspring of diabetic subjects than in control subjects (1230 +/- 0.05 vs. 1513 +/- 0.02 in the offspring and control subjects, respectively, P < 0.05). Also, pb-mtDNA content was significantly correlated with logarithmically transformed insulin sensitivity index (r = 0.5, P < 0.05), fasting C-peptide (r = -0.8, P < 0.05), acute insulin response (r = -0.8, P < 0.05) and late insulin response (r = -0.7, P < 0.05) in offspring of diabetic subjects. In conclusion, quantitative mtDNA status might be a hereditary factor associated with type 2 diabetes and is correlated negatively with indexes of insulin resistance and insulin secretion in offspring of diabetic patients. So, pb-mtDNA content could serve as an indicator of insulin sensitivity and insulin secretion in those subjects.
el-Sharnooby
Jehan A M
JA
Department of Clinical Pathology, Tanta University, Faculty of Medicine, Tanta, Egypt.
Ahmed
Laila M Sayed
LM
D000328:Adult; D001483:Base Sequence; D016022:Case-Control Studies; D004272:DNA, Mitochondrial / Q000097:blood* / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000235:genetics*; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged
D004272:DNA, Mitochondrial; D007328:Insulin