Associations of Sleep Patterns with Physical Functioning and Physical Activity in Adults with Down Syndrome

People with Down syndrome (DS) have low sleep quality, physical functioning, and physical activity, and high levels of sedentariness and body mass index (BMI). It is not known, however, if sleep patterns are associated with physical activity, sedentariness, physical functioning, and BMI in adults with DS. PURPOSE: To examine if sleep variables are associated with physical functioning, physical activity, sedentariness, and BMI in adults with DS. METHODS: Fifteen persons with DS (8 women and 7 men; age 29 ± 14 y; BMI 32.8 ± 8.7 kg·m-2) participated in this study. Participants attended a session where time during the timed-up-and-go test and distance covered during the 6-min walk test were measured. Participants then wore for 7 days on their right wrist an accelerometer (wGT3X+, Actigraph) which provided sleep, physical activity, and sedentariness variables. We calculated descriptive statistics and we used Spearman’s rho to examine associations of sleep with physical functioning and physical activity variables, and BMI. RESULTS: Mean ± SD of sleep, physical functioning, physical activity, and sedentariness variables were: total time in bed 557 ± 61 min·day-1; total sleep time 407 ± 54 min·day-1; latency 26.8 ± 21.0 min; efficiency 73.9 ± 12.0%; wake after sleep onset 123 ± 65 min; number of awakenings 21.0 ± 6.2; average length of awakenings 6.1 ± 3.0 min; timed up-and-go 10.3 ± 3.1 s; 6-min walk distance 255.6 ± 89.6 m; moderate-to-vigorous physical activity accumulated in 10 min bouts 91.3 ± 173.0 min·week-1; total sedentary time 3165 ± 527 min·week-1; total sedentary time in 15-min bouts 731 ± 560 min·week-1. Six-minute walk distance was significantly associated with average length of awakenings (rho = -0.69; p = 0.005) and total sleep time (rho = 0.58; p = 0.024), and moderately, but non-significantly, with efficiency, latency, and number of awakenings (rho = 0.50, 0.45, and 0.40, respectively). There were no other significant correlations between sleep variables and physical activity, sedentariness, and BMI. CONCLUSIONS: Adults with DS experience difficulties in sleeping and have low physical activity and physical functioning levels, and high sedentariness levels. Indices of sleep are associated with performance during the 6-min walk test, but not with physical activity or sedentariness.