Maternal role in type 2 diabetes mellitus: indirect evidence for a mitochondrial inheritance

The role of mitochondrial inheritance in type 2 diabetes mellitus has received much attention recently. In this study, three existing datasets in Taiwan are analysed to examine this theory.

Two of the datasets were community surveys and one a hospital case series. Subjects who had information regarding their paternal or maternal diabetic status were selected for the present study. In the first dataset, 745 subjects had information about paternal diabetic status and 765 had information about maternal diabetic status. In the second dataset, 255 and 267 subjects had the paternal and maternal information, respectively. In the third, a total of 3625 subjects had information about both their paternal and maternal diabetic status. Diabetic status of the study subjects was determined by fasting plasma glucose levels and/or oral glucose tolerance test; their parental diabetic status was collected by interview.

The three datasets consistently demonstrated a significantly elevated odds ratio (OR) for reporting maternal diabetes (OR = 2.64, 95% confidence interval: 1.12-5.71) in diabetic patients as compared to non-diabetic subjects. The reporting of paternal diabetes, however, was not significantly different between diabetics and non-diabetics. In addition, the OR for reporting paternal diabetes were not significantly different between groups of different age-at-onset. With respect to maternal history, the OR increased significantly when age-at-onset was younger (test-for-trend P < 0.001).

Our findings support mitochondrial inheritance of type 2 diabetes mellitus in the human population. The age-modifying effect was also in accordance with the mitochondrial oxidative phosphorylation paradigm for degenerative diseases.