Decreased Physical Activity as an Early Digital Biomarker in Huntington's Disease: A One-Year Observational Study

Area of Science:

• Neurology
• Gerontology
• Rehabilitation Medicine

Background:

• Huntington's disease (HD) is a progressive neurodegenerative disorder impacting motor, cognitive, and psychiatric functions.
• Sarcopenia and reduced physical activity (PA) are common in HD, potentially exacerbating disease progression.

Purpose of the Study:

• To investigate the relationship between clinical characteristics, sarcopenia, and PA levels in Huntington's disease patients.
• To explore the utility of wearable technology in monitoring PA changes over time in HD.

Main Methods:

• A 1-year observational study involving symptomatic, ambulatory HD patients.
• PA was tracked using Fitbit Charge 4; sarcopenia was assessed via muscle strength, quantity, and performance.
• Participants were clustered based on age, motor (Unified HD Rating Scale), and cognitive (Mini-Mental State Examination) function.

Main Results:

• Cluster 1 (better baseline function) showed decreased PA over 1 year (p=0.035); Cluster 2 (poorer baseline function) showed a negative trend for PA decrease (p=0.006).
• Sarcopenia was more prevalent in Cluster 2 (53%) at baseline compared to Cluster 1 (13%).
• Significant differences favoring Cluster 1 were found in muscle strength, bioelectrical impedance analysis (BIA), and SPPB scores.

Conclusions:

• Reduced PA, detected by wearable sensors, may be an early indicator of functional changes in HD.
• Identifying the onset of PA reduction is crucial for timely interventions to delay HD progression.