Diabetes mellitus: an update for the general dental practitioner

Diabetes is a chronic syndrome of hyperglycemia with anomalies in carbohydrate, fat and protein metabolism due to lack of insulin production, decreased cellular sensitivity to insulin or both.^1,2,3 Most cases of diabetes fall within two main categories:

Diabetes is a major cause of multi-organ failure, heart attacks, blindness and nephropathy. It is an increasing public health concern and has been declared a pandemic.⁴ The incidence of diabetes is approximately 422 million worldwide, with 1.5 million deaths attributed to it in 2012.⁵

Twin studies have demonstrated that genetic susceptibility plays a vital role in the aetiology of Type II diabetes. An increased susceptibility can also be inherited in Type I diabetes, but to a lesser extent than in Type II.⁶ An early study found impaired glucose tolerance in 30% of subjects who were close relatives of diabetics, as opposed to 6% of subjects who had no diabetic relatives.⁷ The HLA-DR3 and DR4 serotypes increase an individual's susceptibility to diabetes 14-fold.⁸ Difference in glucose metabolism is a key factor in Type II diabetes and studies show differences amongst different races. β-cell function is thought to be inheritable.⁹ However, the precise role of genetics in diabetes remains indeterminate as environmental factors also play a modifying role.⁶