Study of Association of Salivary Adipokines with Prediabetes and Type 2 Diabetes Mellitus

Abstract

AIM: To study the association of adipokines namely, adiponectin, apelin, visfatin and vaspin with different glycaemic states normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes (T2D) and in the presence of an inflammatory condition; periodontitis, in saliva and blood (serum) samples. METHOD: Prescreening was done to identify persons with and#8805; 3 risk factors for T2D among; age 35 -55 years, overweight/obesity, high waist circumference, family history of T2D, hypertension or sedentary habits. They were then categorised as having no diabetes (NGT + IGT, Group A) and having diabetes (T2D, Group B) based on oral glucose tolerance tests. The presence of periodontitis was assessed by an oral examination. Serum and saliva samples were collected for estimation of adiponectin, apelin, visfatin and vaspin using Enzyme-Linked ImmunoSorbent Assay (ELISA). Glycated hemoglobin A1c (HbA1c) and lipid profile were estimated. RESULTS: Among the 615 persons screened, 479 (68.9%) had less than 3 risk factors, 55 (8.9%) had T2D, and 136 (22.1%) had 3 or more risk factors. Ninety (14.6%) persons accepted to participate in the study and were categorized as NGT (n = 48), IGT (n = 17) and T2D (n = 25). Serum adiponectin was lower in T2D compared with NGT (p = 0.001) and serum visfatin was higher in T2D compared with NGT (p = 0.040) and IGT (p = 0.02). Both salivary visfatin and apelin were higher in T2D compared with NGT (p = 0.02). Serum adiponectin was inversely correlated with HbA1c, 2hr post glucose blood glucose (PBG) and salivary vaspin. Salivary adiponectin was positively correlated with serum adiponectin. Higher salivary vaspin and lower visfatin were observed in the presence of periodontitis. CONCLUSION: The utility of blood and saliva for assessing adipokines for diabetes vary considerably. In Asian Indians, lower adiponectin and higher visfatin in serum and increased salivary visfatin and apelin may be useful biomarkers of diabetes, illustrating that inflammation is involved in the pathogenes of T2D.