Impact of a Simulated Workday of Sit-stand Desk Use on Sleep Among Adults Screened as High Risk for Sleep Apnea

Exercise improves sleep and reduces apnea severity in adults with obstructive sleep apnea (OSA). However, whether reducing sedentary behavior impacts sleep and apnea severity is unknown. PURPOSE: To examine whether reducing prolonged sitting during a simulated workday by use of a sit-stand desk leads to changes in sleep compared to a sedentary workday in a sample of adults at high risk for OSA. METHODS: Eight inactive adults (5 males, 53.8±8.5 yr, body mass index: 29.8±5.5 kg/m2) who were classified as 'high risk' for OSA based upon the STOP-BANG screening algorithm participated in a randomized crossover trial consisting of two simulated 8-h workdays: (1) continuous sitting (SIT); and (2) alternating periods of sitting and standing every 30 min (SIT-STAND). Sleep and apnea were assessed on the night following each simulated workday by wrist-worn actigraphy and a portable OSA testing device, respectively. Actigraphic measures of total sleep time (TST) and wake after sleep onset (WASO) served as the primary sleep variables, while the apnea-hypopnea index (AHI) assessed OSA severity from the OSA testing device by a blinded assessor. Natural logarithm transformation of AHI was performed due to non-normality. Effect sizes (Hedges' g) and Pearson correlations evaluated differences in sleep following each condition and associations between changes in sleep measures, respectively. RESULTS: In the full sample, trivial improvements in WASO (g=0.16) and TST (g=0.03) were observed following SIT-STAND compared to SIT. In contrast, a small increase in AHI (i.e., worsening of OSA) was observed following SIT-STAND compared to SIT (g=0.31). The change in AHI was associated with the change in actigraphic WASO (r=.63, P=.09). Four of the 8 adults had clinically significant OSA (i.e., mean AHI≥10 across conditions). Among those with clinically significant OSA, large increases in WASO and AHI were seen following SIT-STAND relative to SIT (g=1.16 and 0.89, respectively). In those without significant OSA, small- to moderate-sized reductions in WASO and AHI were observed following SIT-STAND compared to SIT (g=0.68 and 0.30, respectively). CONCLUSION: Following sedentary behavior reduction during a simulated workday, changes in sleep and apnea seemed to differ based upon the presence of clinically significant OSA.