Diabetes and parkinsonian signs in older persons

We examined the relation of type 2 diabetes mellitus to parkinsonian signs in older persons. Participants were 1030 women and men (mean age 80.3 y, education 14.5 y, Mini-Mental State Examination 27.9) without dementia or Parkinson disease, enrolled in the Rush Memory and Aging Project, an epidemiologic study of aging. We used separate linear and logistic regression models, adjusted for age, sex, and education, to examine the relation of diabetes, identified by history and medication inspection, to each of the scores of global parkinsonian signs and 4 separate parkinsonian signs. Diabetes was present in 140 (14%) participants. Most participants had mild parkinsonian signs. Diabetes was associated with a more severe global parkinsonian signs score (beta=0.20, SE=0.10, P=0.05) and postural reflex impairment-gait disturbance (beta=0.40, SE=0.17, P=0.02), but not with bradykinesia, rigidity, or tremor. Associations were no longer significant after controlling for vascular risk factors or conditions, particularly body mass index and congestive heart failure. Overall, there was no evidence that vascular variables modified the relation of diabetes to parkinsonian signs. In summary, we found that diabetes was associated with parkinsonian signs, especially postural reflex impairment-gait disturbance, and that vascular factors may play a role in this association.