Keyes triad in type 2 diabetes mellitus: A microbiological study

Background: 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. Materials and Methods: 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. Results: 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. Conclusion: 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.