Objectively Measured Physical Activity and Sedentary Time Among Adults With and Without Stroke: A National Cohort Study

We studied participants from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke), a national population-based study designed to examine racial/regional disparities in stroke.⁵ Briefly, demographic and risk factor data were collected upon enrollment (2003–2007). Thereafter, follow-up was conducted biannually by telephone to ascertain potential strokes and vital status.

Objective measures of PA were collected from 2009 to 2013. Participants who self-reported an ability to ambulate were invited to wear a hip-based Actical accelerometer during waking hours for 7 days.⁶ Present analyses included participants with compliant accelerometer wear who either had a self-reported history of stroke or an adjudicated first-time stroke that preceded accelerometer data collection.⁷ Accelerometer protocol, data processing, and stroke adjudication details are provided in the Data Supplement.

For group comparisons, participants with valid accelerometer wear and without an adjudicated/self-reported stroke were included as a control (Figure in the Data Supplement). Three age-, sex, race-, region of residence-, and body mass index-matched participants were selected for each stroke case using a propensity score model (Data Supplement). Methods were approved by Institutional Review Boards and all participants provided informed consent. STROBE reporting guidelines were followed (Data Supplement). The data that support the findings of this study are available from the corresponding author upon reasonable request.

There were 1604 participants successfully matched and included in the analysis, of which 401 had a stroke (self-report: n=281 and adjudicated: n=120) and 1203 did not (Table 1; Figure in the Data Supplement). Time (mean±SD) since the first self-reported stroke and adjudicated stroke was 14.5 (10.5) years and 2.9 (2.0) years, respectively. Compared with controls, stroke survivors had significantly greater sedentary time and accumulated a greater volume of their sedentary time in prolonged bouts of ≥30, ≥60, and ≥90 minutes (Table 2). Conversely, stroke survivors had significantly lower LIPA and MVPA compared with their nonstroke peers. With respect to activity breaks, stroke survivors accrued fewer breaks and their activity breaks were, on average, shorter in duration and at a lower intensity relative to their nonstroke peers. In sensitivity analyses, similar results were observed when defining stroke survivors by self-reported stroke and adjudicated stroke, separately (Tables I and II in the Data Supplement) and when additionally matching participants for comorbidities and marital status (Table III in the Data Supplement).

In this US national cohort study, stroke survivors accrued a higher volume of sedentary time and a lower volume of LIPA and MVPA relative to their nonstroke peers. The pattern in which PA and sedentary time was accrued also differed between participants with and without stroke. Stroke survivors accumulated fewer activity breaks, and, on average, these activity breaks were shorter in duration and lower in intensity relative to nonstroke participants. These findings emphasize LIPA and sedentary behavior (total volume and pattern), in addition to MVPA, as potential targets for behavioral interventions among stroke survivors.

English et al⁸ previously found that stroke survivors (n=40) spent significantly more time sitting (10.9±2.0 h/d versus 8.3±2.0 h/d) and less time physically active (LIPA: 3.4±1.6 versus 6.0±1.4 h/d; MVPA: 4.9±5.8 versus 38.0±31.0 min/d) compared with sex- and age-matched controls.⁸ Similarly, in a nationally representative sample (n=262), Butler and Evenson⁹ demonstrated that stroke survivors spent significantly less time in accelerometer-measured LIPA (212.0±6.0 versus 237.2±3.6 min/d) and more time in sedentary behavior (10.0±0.2 versus 9.2±0.1 h/d) compared with age-, race- and ethnicity-, and sex-matched controls.⁹ These studies provided initial evidence that stroke survivors, beyond having low MVPA, also exhibit a poorer overall PA profile relative to their peers. The present study confirms and extends upon previous work to show in a national, diverse population-based sample that stroke survivors are more sedentary and less active than their peers, even when controlling for key comorbidities. We observed differences in established determinants of PA (quality of life and depression) between participants with and without stroke, however, future research is needed to elucidate contributing factors.

Evidence indicates that the manner in which sedentary time is accumulated (eg, sitting for hours at a time) influences disease risk; suggestive that regularly breaking up sedentary time may have clinical relevance. English et al⁸ reported stroke survivors accumulated a greater percentage of their sedentary time in bouts ≥30 minutes compared with controls. Our findings confirm that stroke survivors accumulate more sedentary time not only from bouts ≥30 minutes but also from bouts ≥60 and ≥90 minutes relative to their nonstroke peers. Furthermore, our findings impart new knowledge that stroke survivors engage in fewer activity breaks than those without stroke and that these breaks, on average, are shorter in duration and intensity. Thus, future behavioral interventions may need to emphasize not only the frequency but also the quality of activity breaks.

Limitations of the present study include self-reported stroke assessment for some participants, inability of the Actical to distinguish between sitting/standing postures, lack of disability status information, use of day-level accelerometer measures (temporal patterns were not characterized), and limited generalizability to other races and ethnicities beyond Black and White participants. These limitations notwithstanding, while increasing MVPA should remain a secondary prevention target for stroke survivors, our findings highlight a potential need to promote sitting less, moving more (of any intensity), and moving frequently in this high-risk population.