Salivary Biomarkers and Periodontal Status in Diabetes Mellitus and Obesity

Objectives: In this pilot study, we aim to introduce a non-invasive approach using salivary insulin(sINS) and adiponectin(sADP) and comparing their levels among obese(BMI: >27.5kg/m^2,), non-obese and non-insulin dependent type-2 diabetes mellitus(T2DM) and healthy control subjects. We would also like to study the association of these salivary biomarkers with periodontal status in each of these conditions. This ultimately provide an insight of the use of salivary-biomarkers in predicting metabolic-syndrome and periodontal condition in high-risk population.
Methods: 77 random saliva samples were obtained from obese(n=26), non-obese and non-insulin dependent T2DM(HbA1c: 6-9%, n=25) and healthy control subjects(n=26). 20 diabetic subjects had HbA1c level above the recommended level of excellent glycemic control(6.5%). The samples were analyzed for sINS and sADP using ELISA. Periodontal status was assessed using Basic Periodontal Examination(BPE). Data was analysed using SPSS. The statistical significance level was set at p<0.05.
Results: A trend was observed, where the average levels of sINS were highest in diabetic subjects, followed by obese subjects and then healthy subjects. The opposite held true regarding sADP levels, where diabetic subjects recorded the lowest levels, followed by obese subjects and then healthy subjects. BPE scores were significantly correlated with sADP(r=0.408,p=0.043) and sINS(r=-0.417,p=0.038) only in diabetic subjects. The concentration of sADP were negatively correlated to sINS(r=-0.328; p=0.004).
Conclusions: Findings from this study indicates that the changes in the expression of sINS and sADP begin with increase in adiposity and continue further in impaired insulin sensitivity, with or without the former. The inflammatory changes such as the deterioration of periodontal status that accompany poor glycemic control are associated with elevated sADP. Lower levels of sINS seen with poorer BPE scores and high levels of SADP may indicate beta-cell failure in producing insulin. This study suggests that sINS and sADP are potential biomarkers to study metabolic derangement and prognosticating periodontal condition in obesity and T2DM.