Keyes triad in type 2 diabetes mellitus: A microbiological study

With the increasing prevalence of type 2 diabetes mellitus (DM), there is a need to assess if the elevated salivary glucose levels provide an environment conducive to the growth of cariogenic microorganisms specifically Streptocooccus mutans and Lactobacillus acidophilus.

Forty‑five patients were divided into three groups consisting of patients with type 2 DM with caries, patients with type 2 DM without caries and age‑matched healthy nondiabetic individuals (control). Saliva samples were subjected to semiautomatic salivary glucose estimation by the glucose oxidase‑peroxidase method, using the Tulip glucose estimation kit. Swabs were immediately inoculated onto Mitis Salivarius Bacitracin agar and Man Rogosa Sharpe agar.

In Group A, statistically significant positive correlation was found between S. mutans and salivary glucose (r = 0.858) as well as L. acidophilus and salivary glucose ( r = 0.853). In Group B, a statistically significant positive correlation was found only between S. mutans and salivary glucose (r = 0.705) and not between L. acidophilus and salivary glucose (r = 0.387). The control group did not show a statistically significant correlation.

It is established that salivary glucose levels reflect the diabetic state of an individual. The salivary glucose level predicted a 1.7 times higher caries susceptibility in a diabetic, as shown by results in this study. Salivary glucose causes an increase in the cariogenic load in diabetic patients, thus warranting a modification of the Keyes triad.