Reduced peripheral blood mitochondrial DNA content is not a risk factor for Type 2 diabetes.
OBJECTIVE
Mitochondrial depletion in pancreatic beta cells is known to reduce glucose stimulated insulin secretion. We aimed to determine whether the offspring of patients with early onset Type 2 diabetes had reduced peripheral blood mitochondrial content relative to control subjects and whether this could lead to a predisposition to type 2 diabetes in later life.


METHODS
We measured the levels of mitochondria relative to a single copy genomic target by real time polymerase chain reaction in a series of peripheral blood samples taken from the offspring of Caucasian patients with Type 2 diabetes and matched controls. Measures of insulin sensitivity and beta cell function were also taken.


RESULTS
In contrast with previous studies, mitochondrial DNA content was not decreased in the offspring of patients with Type 2 diabetes relative to matched controls in our cohort. Conversely, we noted a small proliferation in mitochondrial numbers in our case subjects. In agreement with these findings, no correlations with either insulin sensitivity or beta cell function were noted.


CONCLUSIONS
Our results indicate that reduced mitochondrial DNA content in peripheral blood is not a risk factor for the development of Type 2 diabetes in the offspring of patients with early onset Type 2 diabetes.
Singh
R
R
Institute of Biomedical and Clinical Sciences, Peninsula Medical School, Exeter, UK.
Hattersley
A T
AT
Harries
L W
LW
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D004272:DNA, Mitochondrial / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012307:Risk Factors
D001786:Blood Glucose; D004272:DNA, Mitochondrial