Impact of type 2 diabetes mellitus on acute levodopa responsiveness in Parkinson's disease: A Multicenter retrospective study.

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a common comorbidity in Parkinson's disease (PD) and may influence the progression and dopaminergic function, suggesting a potential impact on levodopa responsiveness.

OBJECTIVE

To examine the impact of T2DM status on levodopa responsiveness in an acute levodopa challenge in PD.

METHODS

We retrospectively analyzed the total and subdomain motor responses in the acute levodopa challenge in 136 PD patients with normal glycemic status, prediabetes, or T2DM across three German centers.

RESULTS

Levodopa responsiveness did not differ significantly among the three glycemic groups. The only between-group difference was more severe rest tremor in T2DM patients in the OFF state, which was no longer present in the ON state due to greater levodopa-induced improvement.

CONCLUSION

An acute levodopa challenge remained similarly effective across glycemic groups in PD, suggesting that T2DM does not substantially modify acute dopaminergic treatment response. Future studies should also evaluate chronic response to levodopa across different glycemic statuses.