ESTIMATION OF SALIVARY PH BEFORE AND AFTER AN ACID STIMULUS IN DIABETIC PATIENTS

Background Human saliva is a viscoelastic fluid and its secretion is basically a neurally regulated mechanism. Its flow and composition depends on the functional integrity of the nerves supplying the gland. Our study aims at identifying the early autonomic neuropathic changes in diabetes by evaluating salivary gland function. Salivary testing works by placing an acid stress in the mouth to see if a person adapts a healthy response. A highly alkaline reserve to an acid stimulus is a normal response.AIMTo study the change in pH of salivary secretion in diabetic individuals following an oral acid challenge (vitamin-c) and to compare it with controls.To assess whether the duration of diabetes influences the change in pH.To correlate the diabetic neuropathy with the change in salivary pH.Materials and method 81 diabetic individuals and 54 age matched controls were tested for salivary pH before and after oral challenge of vitamin-C using a standard pH strip. Their fasting blood glucose level, the type of diabetes and the duration of diabetes along with their clinical manifestation were recorded. The data were evaluated and analyzed and their significance determined using the appropriate T test.Results The resting salivary ph of the diabetic and the control were almost same.The magnitude of change in salivary ph following an acid challenge in diabetic were significantly less (p0.001) compared to that of the controls.Longer the duration of diabetes lesser is the the magnitude of pH change to acid stress.No significant correlation between the blood glucose level and the magnitude of change in salivary pHConclusion There is a significant decrease in salivary ph change following an oral vitamin-C challenge in diabetics indicating an autonomic blunting. Sensitivity of the test is 96 and specificity of the test is 75. Thus estimation of salivary ph is a simple,effective , non-invasive method in identifying early neuronal impairment in diabetes mellitus and offers a cost-effective method for screening of large population.