Background: Older persons with type 2 diabetes are at higher risk for functional impairment than are their age-matched counterparts without-diabetes. We therefore sought to identify factors associated with impaired physical function in older persons with type 2 diabetes by using a cross-sectional study design.
Methods: We studied 1238 persons with type 2 diabetes who were 55 years of age or older and enrolled in the Type II Diabetes Patient Outcomes Research Team (PORT) project. Subjects were primary care patients at a large staff model health maintenance organization who had completed a mailed survey that collected information about demographics (age, race, marital status, income, education, gender, and body mass index [BMI]), health behaviors (exercise, smoking, and alcohol), care and control of diabetes (therapy, self-reported glucose control, home glucose monitoring, and disease duration), mood (Center for Epidemiologic Studies--Depression Scale [CES-D]), comorbidity, and the Short-Form-36 health survey (SF-36). We evaluated the bivariate relationships between the PFI- 10, a 10-item measure of physical function from the SF-36, and candidate independent variables from the domains described previously. Variables that were significant at an a level of .10 were entered into a multiple linear regression model.
Results: There were eight independent predictors of impaired physical function (all p < .05, R2 = .40). Factors associated with impaired function in order of their relative importance were as follows: a higher comorbidity score, older age, obesity, lack of regular exercise, CES-D score higher than 20, taking insulin, lower formal education, and abstinence from alcohol.
Conclusions: Increased comorbidity and older age are associated with poorer function, as is the severity of diabetes and less formal education. Exercise, lower BMI, and better mood are associated with better function. Therefore, promoting regular exercise and weight loss, in addition to treating depression, are likely to preserve or even improve the functional status of older persons with type 2 diabetes. Moderate alcohol use may be beneficial as well. The extent to which these relationships persist in prospective studies or clinical trials remains to be evaluated.