A longitudinal analysis of salivary flow in control subjects and older adults with type 2 diabetes

Objective. Many diabetics complain of xerostomia, a condition that can affe ct oral health, nutritional status, and diet selection. This study's purpos es were (1) to investigate the effect on salivary flow of type 2 diabetes a nd change in glycemic control in a group of older adults over time and (2) to compare flow rates with subjective complaints of xerostomia. Study design. A total of 39 older adults, 24 with type 2 diabetes and 15 wh o were nondiabetic (controls), aged 54-90 years, participated in a 1-year f ollow-up study. Diabetic status was determined by means of glycosylated hem oglobin (HbA(1c)) levels and 2-hour glucose tolerance tests. Poor glycemic control was defined as HbA(1c) > 9%. Unstimulated whole, unstimulated parot id, and stimulated parotid saliva flow rates were measured for all subjects by a single examiner at baseline and 1 year later. Each subject completed a standardized xerostomia questionnaire at every visit. Results. Age, sex, and duration of diabetes did not adversely affect saliva ry flow rates. Subjects with poorly controlled diabetes had significantly l ower stimulated parotid saliva flow rates at both visits. There were no sig nificant changes in flow rates over time on the basis of diabetic status or glycemic control. Subjects with diabetes reported significantly more compl aints of thirst but not of xerostomia at 1 year. Conclusions. These results suggest that older adults with poorly controlled diabetes may have impaired salivary flow in comparison with subjects with better controlled diabetes and nondiabetic subjects, yet they may not have concomitant xerostomic complaints. There were no significant changes in sal ivary flow rates or glycemic control over the 1-year period.