F64 Wearable technologies for assessment of physical activity in hd: preliminary analysis of movement variability and wear time

Background Wearable technology can provide detailed information about physical activity (PA) in Huntington’s disease (HD). Most commercially available devices are however limited by the lack of disease specific validation and consideration of wear time. Aim To develop a methodology for accurate profiling of PA in HD. Methods We recruited 29 people with early stage HD (mean (SD) age 51.76 (10.27); 14 males) and 17 healthy controls (mean (SD) age 52.95 (10.76); 10 male) to a cross sectional multi-centre observational study. Participants used a wrist worn accelerometer for 7 days following the completion of a laboratory-based validation study. PA profiles (percentage time sedentary, low, moderate and high PA) were produced. Differences were assessed when accounting for wear time based on body temperature trends. Results HD mean (SD) device wear time over 7 days was 9783 mins (2192.84) (approx. 23.3 hours per day) and controls 7965 mins (1200.34) approx. 18.9 hours per day). When accounting for wear time HD participants were sedentary for 54% of the time and participated in light, moderate and vigorous PA for 27.2%, 17.4% and 0.43% of the time respectively. Control participants were sedentary for 61% of the time and participated in light, moderate and vigorous PA 26.6%, 11.2% and 1.2% of the time respectively. Conclusions Surprisingly HD participants were less sedentary than age matched controls. The impact of involuntary movements on the assessment of PA in HD needs to be explored. Critical to this is the importance of a wear time algorithm to identify true sedentary behaviour in comparison to non-wear.