The impact of a 9-month sedentary behaviour reduction intervention on frailty and brachial artery health: A feasibility study

Abstract

Many adults engage in excessive amounts of sedentary time (ST; sitting/lying while awake), which increases frailty and cardiovascular disease risk. However, there is limited evidence evaluating whether long-term sedentary behavior reduction interventions are effective at decreasing ST and improving these health outcomes. This study tested the feasibility of a 9-month intervention and hypothesized that it would reduce daily ST in adults who do not achieve national ST recommendations (i.e., >8-hours/day), as well as improve frailty index scores and brachial flow-mediated dilation (FMD) responses. Following 2 participant dropouts, 18 sedentary adults were randomly allocated to a Control (3 older females, 84±8 years; and 6 younger adults, 3♀, 23±3 years) and Intervention (5 older adults, 4♀, 75±15 years; and 4 younger adults, 3♀, 24±3 years) group. The Intervention group watched an educational video that highlighted the negative health consequences of excessive ST and received 2-4 messages/week via text or email prompting them to decrease their ST. At Baseline, 3 months, 6 months, and 9 months, a thigh-worn activPAL inclinometer recorded habitual physical and sedentary activities for 7-days and assessments of frailty and brachial FMD were conducted. No Group × Time effects were observed for ST, sedentary breaks, light-intensity physical activity, moderate-to-vigorous intensity physical activity, sleep time or standing time (all, p>0.122). There were also no interaction effects for frailty (p=0.667) or brachial FMD (p=0.502). Based on monthly follow-up phone calls with the Intervention group, there were several life factors that may have acted as barriers to changes in habitual behaviour including: mental health, work/school schedule, weather changes, and/or willingness to change. This intervention was feasible based on low drop out (10%) and high acceptability among participants. However, it was not effective at decreasing ST in adults. Future interventions may need to include more frequent prompt/phone calls and/or a better individualized approach to reducing ST in adults.