Type 2 diabetes (T2D) could have an unfavorable effect on disease progression, striatal dopamine loss, brain structural alterations, and cognitive performances in individuals with Parkinson disease (PD), according to a retrospective study published in Parkinsonism & Related Disorders.
Researchers retrospectively reviewed 671 individuals from the Yonsei Parkinson Center database and separated these individuals into 2 groups: PD group with T2D (combination group) (n=106) and PD group without T2D (n=565).
The average patient age age and age at PD symptom onset were higher in the combination group compared with the PD-alone group. The combination group also had an increased prevalence of hypertension, at 60%, compared with 38% in the PD-alone group. Additionally, the prevalence of cardiac disease was 17% in the combination group, compared with 9% in the PD-alone group, and dyslipidemia was also higher in the combination group, at 16%, compared with 11% in the PD-alone group.
Compared with the PD-alone group, the combination group had severely decreased dopamine active transporter (DAT) availability in the caudate (combination group, 1.74 vs PD-alone group, 1.94; P =.006) and ventral striatum (combination group, 1.94 vs PD-alone group, 2.13; P =.006), with comparable DAT availability in the anterior putamen (P =.536) and posterior putamen (P =.779). The combination group showed inferior cognitive performance in attention, working memory, and frontal executive function domain compared with those in the PD-alone group. The combination group also demonstrated lower performances in language and memory function (P =.069). The estimated monthly levodopa equivalent dose changes were 9.54 in the combination group and 7.09 in the PD-alone group.
The researchers concluded that “coexistent DM [T2D] had a detrimental effect on the clinical prognosis as well as the baseline striatal DAT availability, brain structural change, and level of cognitive performances in patients with PD.”
Chung SJ, Jeon S, Yoo HS, et al. Detrimental effect of type 2 diabetes mellitus in a large case series of Parkinson’s disease [published online 2018]. Parkinsonism Relat Disord. doi: 10.1016/j.parkreldis.2018.08.023