Markers of Oxidative Stress in the Saliva of Type 2 Diabetic Patients

Abstract

Objective: Diabetes mellitus is associated with increased prevalence of oral diseases for which reactive oxygen species have been implicated. The saliva contains protective antioxidants which statutorily curtail these destructive oxygen molecules. A functional compromise of the antioxidants may precipitate oxidative stress leading to the increased oral disease susceptibility. However, salivary markers of oxidative stress have not been sufficiently studied in the diabetics. Methods: A total of 166 adults were recruited for this study. They comprised of 95 Type 2 diabetic patients and 71 healthy non-diabetic controls. About 3 ml of unstimulated saliva samples were collected from participants and processed, levels of salivary H2O2, NO and MDA were measured using spectrophotometry method and compared between the two groups. Data was analysed using t-test, logistic regression and receiver operating characteristics (ROC) with statistical significance set at p<0.05. Results: Salivary H2O2 (p=0.024) and NO (p=0.002) were significantly higher in the diabetic patients when compared to the healthy non-diabetic control group. Binary logistic regression showed that patients with Type 2 diabetic mellitus are more likely to have elevated salivary H2O2 (OR= 1.013; p=0.025) and NO (OR=1.016; p=0.003) levels. ROC analysis showed statistically significant performance of salivary NO levels in distinguishing between T2DM patients and healthy controls. Conclusions: Higher levels of oxidative stress markers including salivary H2O2 and NO in the diabetic groups could be a pointer to the characteristic high prevalence of oral diseases in diabetes mellitus, given that oxidative stress predisposes to disease vulnerability. This calls for increased attention to oral health in diabetes management to minimise co-morbidity.