Impact of Physical Exercise on Levodopa Therapy Across Parkinson’s Disease Stages

Plain Language Summary Background Levodopa is an important treatment for Parkinson’s disease (PD). As the disease gets worse, levodopa’s effects change. A common problem is “wearing off,” where the medicine stops working sooner than expected. Some advanced PD patients say this happens faster after they exercise. Study goals The study aimed to find out if exercise changes how the body processes levodopa in patients at different stages of PD. Methods Participants: 22 PD patients (12 not yet on levodopa and 10 advanced patients- treated with levodopa with “wearing off”) and 7 healthy people. Procedure: Participants took levodopa/benserazide (200/50 mg) on two days: a rest day and an exercise day. Each day blood samples were collected at 9 set times to measure levodopa levels. PD symptoms were assessed using a scale called UPDRS III at specific times. Testing: Levodopa levels in blood were measured using a technique called liquid chromatography-tandem mass spectrometry. Results No differences: There were no differences in how the body processed levodopa among healthy people, untreated PD patients, and advanced PD patients. Exercise impact: For both healthy people and advanced PD patients, exercise did not change how the body processed levodopa. Untreated patients: In PD patients not yet on levodopa, the medicine stayed in the body longer after rest compared to after exercise. Advanced PD patients: These patients had worse PD symptoms after exercise, but this was not due to changes in how levodopa was processed. Conclusion The worsening of symptoms in advanced PD patients after exercise is not because of changes in levodopa levels. It likely involves other factors in the brain.