Ten-Year Changes in Accelerometer-Based Physical Activity and Sedentary Time During Midlife: The CARDIA Study

Personality and change in physical activity across 3-10 years

OBJECTIVE

To examine the association between personality traits, defined by the Five-Factor Model, and the initiation and termination of physical activity across adulthood.

DESIGN

Longitudinal analysis of participants from nine samples (N > 28,000).

MAIN OUTCOME MEASURES

Physical activity status at follow-up.

RESULTS

A random-effect meta-analysis revealed that higher conscientiousness, extraversion, and openness were related to a higher likelihood of initiation of physical activity over time among individuals who were physically inactive at baseline and to a lower risk of termination of physical activity among those who were physically active at baseline. In contrast, higher neuroticism was associated with a lower probability of initiation of physical activity and a higher likelihood of termination over time. Although not hypothesised, agreeableness was also associated with better physical activity outcomes over time.

CONCLUSION

This study provides the largest and the longest evidence of a replicable association between personality and change in physical activity status. Personality may motivate both the initiation and termination of physical activity.

Sex-specific differences in the association between steps per day and all-cause mortality among a cohort of adult patients from the United States with congestive heart failure

BACKGROUND

There is a lack of understanding of how daily step counts differentially affect the risk of all-cause mortality in adult with congestive heart failure (CHF) by sex in the United States (US).

OBJECTIVES

To explore the relationship between daily step counts and all-cause mortality in patients with CHF by sex.

METHODS

This is a cohort analysis from the National Health and Nutrition Examination Survey from 2005 to 2006. Multiple Cox hazard regression was performed to explore the association of step counts and all-cause mortality in patients with CHF by sex.

RESULTS

In this study, 363 unweighted samples were enrolled from NHANES 2005-2006, representing about 8.4 million of the US population. Further, 46.28% were women, and the average age was 46 years. Patients with CHF in the more than 5581 steps/day group (HR, 0.31 [95% CI, 0.16-0.58]) had a significantly reduced risk of all-cause mortality compared with the patients in the less 5581 steps/day group after accounting for all covariates. In men, after accounting for all the covariates, there was a significant difference in more than 5581 steps/day group (HR, 0.33 [95% CI, 0.14-0.76]) on all-cause mortality in men with CHF compared with men in the less than 5581 steps/day group.

CONCLUSIONS

Step count is associated with all-cause mortality in patients with CHF. Taking 5581 daily steps was associated with a decreased risk of all-cause mortality in patients with CHF.

Aerobic and Muscle-Strengthening Physical Activity, Television Viewing, and Nonalcoholic Fatty Liver Disease: The CARDIA Study

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) in U.S. adults is over 30%, yet the role of lifestyle factors in the etiology of NAFLD remains understudied. We examined the associations of physical activity, by intensity and type, and television viewing with prevalent NAFLD.

METHODS

Cross-sectional analysis of a population-based sample of 2726 Black (49%) and White (51%) adults (Mean (SD) age, 50 (3.6) years; 57.3% female) from the CARDIA study. Exposures were aerobic activity by intensity (moderate, vigorous; hours/week); activity type (aerobic, muscle-strengthening; hours/week); and television viewing (hours/week), examined concurrently in all models and assessed by validated questionnaires. Our outcome was NAFLD (liver attenuation < 51 Hounsfield Units), measured by non-contrast computed tomography, after exclusions for other causes of liver fat. Covariates were sex, age, race, study center, education, diet quality, smoking status, alcohol consumption, and body mass index or waist circumference.

RESULTS

648 participants had NAFLD. In the fully adjusted modified Poisson regression model, the risk ratios per interquartile range of each exposure were moderate-intensity aerobic activity, 1.10 (95% CI, 0.97-1.26); vigorous-intensity aerobic activity, 0.72 (0.63-0.82); muscle-strengthening activity, 0.89 (0.80-1.01); and television viewing, 1.20 (1.10-1.32). Relative to less active participants with higher levels of television viewing, those who participated in ≥2 h/week of both vigorous-intensity aerobic and muscle-strengthening activity and <7 h/week of television viewing had 65% lower risk of NAFLD (risk ratio = 0.35, 95% CI = 0.23-0.51).

CONCLUSION

Adults who follow public health recommendations for vigorous-aerobic and muscle-strengthening activity, as well as minimize television viewing, are considerably less likely to have NAFLD than those who do not follow the recommendations and who have relatively high levels of television viewing.

Physical activity changes during an automated online weight loss program

Evidence-based online behavioral weight loss (BWL) treatment targets a combination of diet, physical activity, and behavioral skills training. While weight loss outcomes are well documented, little is known about changes in physical activity. This study examined changes in objectively measured physical activity across the energy expenditure spectrum during a fully automated, online BWL program. Adults with overweight or obesity (n = 63) completed a 12-week, online BWL program. Participants wore an accelerometer for 7 days and body weight was measured in-clinic at pre- and post-treatment. At post-treatment, mean daily moderate-to-vigorous physical activity increased by about 4 min (SE = 1.59, p = 0.01). There were no statistically significant changes in light physical activity or time spent sedentary (p's > 0.05). Despite only minimal changes in moderate-to-vigorous physical activity overall, larger increases correlated with greater weight loss (r = - 0.28, p = 0.02), which averaged 6.1% of baseline weight at post-treatment. Though achieving important weight loss outcomes, online programs may fail to produce clinically relevant improvements in physical activity, which can put weight loss maintenance at risk.

Is there a difference in student physical activity between a field school and a traditional classroom setting?

OBJECTIVES

We compared the physical activity of nine students participating in an anthropological field school to their activity expenditures in traditional classrooms. We predicted that the students would exhibit higher physical activity during the field school due to the substantial physical requirements associated with the program compared to traditional classroom environments which are frequently more sedentary.

METHODS

Participants (n = 9) wore wrist accelerometers for ~23 h each day for 6 days during an anthropological field school and also in a traditional classroom environment. Accelerometers were programed with participant height, weight, age, and sex. Each accelerometer recorded total energy expenditure in kilocalories (kcal), step counts, and time in four physical activity levels (vigorous, moderate, easy, and very easy) between the field school and traditional classroom settings.

RESULTS

During the field school portion of the study, participants burned more calories (p < .01), took more steps (p < .0001), and engaged in more moderate and easy exercise (p < .0001).

CONCLUSIONS

This study provides insights into the physical benefits of study abroad programs and field schools. Our multi-day accelerometer data revealed significant differences in even relatively low intensities of physical activity. This is particularly pertinent in the United States where sedentary lifestyles are increasing among college students. Taken together, the results underscore the importance of study abroad programs, field schools, and other applied learning opportunities beyond the educational, professional, and social benefits.

Physical activity from young adulthood to middle age and premature cardiovascular disease events: a 30-year population-based cohort study

Background

Although physical activity is generally protective of cardiovascular disease (CVD), less is known about how young adult physical activity relates to premature CVD events. The objective of this study was to determine the association between level and change in physical activity from young adulthood to middle age and incidence of premature CVD events before age 60.

Methods

We analyzed data collected across four urban sites from nine visits over 30 years of follow-up (1985–2016) from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective community-based cohort study of 5115 Black and White women and men aged 18–30 years at baseline (1985–1986). Linear mixed models were used to develop individualized moderate-to-vigorous intensity self-reported physical activity trajectories per participant. Fatal and nonfatal coronary heart disease (CHD), heart failure, and stroke outcomes were analyzed separately and as a combined CVD event outcome.

Results

Overall, physical activity declined in young adults as they progressed through middle age. Lower physical activity scores (per 100 exercise units) in 18 year-olds were associated with higher odds of premature CHD (AOR 1.14, 95% CI 1.02–1.28), heart failure (AOR 1.21, 95% CI 1.05–1.38), stroke (AOR 1.20, 95% CI 1.04–1.39), and any CVD (AOR 1.15, 95% CI 1.06–1.24) events. Each additional annual 1-unit reduction in the physical activity score was associated with a higher annual odds of incident heart failure (1.07, 95% CI 1.02–1.13), stroke (1.06, 95% CI 1.00–1.13), and CVD (1.04, 95% CI 1.01–1.07) events. Meeting the minimum (AOR 0.74, 95% CI 0.0.57–0.96) and twice the minimum (AOR 0.55, 95% CI 0.34–0.91) Department of Health and Human Services physical activity guidelines through follow up was protective of premature CVD events.

Conclusions

Given recent trends in declining physical activity with age and associated premature CVD events, the transition from young adult to midlife is an important time period to promote physical activity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01357-2.

A Convergent Mixed Methods Study of Cardiovascular Disease Risk Factors among Young Black Men in the United States

Background

An understanding of the factors that influence cardiovascular (CVD) risk among young Black men is critically needed to promote cardiovascular health earlier in the life course and prevent poor outcomes later in life.

Purpose

To explore how individual (eg, depression, racial discrimination) and environmental factors (eg, neighborhood resources) are associated with CVD risk factors among young Black men.

Methods

We conducted a convergent mixed methods study (qualitative/quantitative, QUAL+quant) with Black men aged 18 to 30 years (N = 21; 3 focus groups). Participants completed a self-administered electronic survey immediately prior to the focus groups.

Results

Participants (M age = 23) reported: two or more CVD risk factors (75%; eg, high blood pressure); racial discrimination (32%); and depressive symptoms in the past 2 weeks (50%). Five themes emerged: 1) emergence and navigation of Black manhood stressors; 2) high expectations despite limited available resources; 3) heart disease socialization: explicit and vicarious experiences; 4) managing health care needs against fear, avoidance and toughing it out; and 5) camaraderie and social support can motivate or deter. The integrated qualitative and quantitative analyses highlight race, gender, and class intersectionality factors that are relevant to what it means to be young, Black, male and of lower socioeconomic status in the United States.

Conclusion

Our findings help to identify modifiable, culturally specific and contextually relevant factors that relate to CVD risk factors among young Black men. Such work is crucial to inform interventions, primary prevention efforts, policies, and social-structural changes to thwart the development of CVD and advanced disease stages.

Moderate-to-vigorous intensity physical activity from young adulthood to middle age and metabolic disease: a 30-year population-based cohort study

OBJECTIVES

To determine the association between moderate-to-vigorous intensity physical activity (MVPA) trajectories (course over age and time) through the adult life course and onset of metabolic disease (diabetes and dyslipidaemia).

METHODS

We analysed prospective community-based cohort data of 5115 participants in the Coronary Artery Risk Development in Young Adults study, who were black and white men and women aged 18-30 years at baseline (1985-1986) at four urban sites, collected through 30 years of follow-up. Individualised MVPA trajectories were developed for each participant using linear mixed models.

RESULTS

Lower estimated MVPA score at age 18 was associated with a 12% (95% CI 6% to 18%) higher odds of incident diabetes, a 4% (95% CI 1% to 7%) higher odds of incident low high-density lipoprotein (HDL) and a 6% (95% CI 2% to 11%) higher odds of incident high triglycerides. Each additional annual 1-unit reduction in the MVPA score was associated with a 6% (95% CI 4% to 9%) higher annual odds of diabetes incidence and a 4% (95% CI 2% to 6%) higher annual odds of high triglyceride incidence. Analysing various MVPA trajectory groups, participants who were in the most active group at age 18 (over 300 min/week), but with sharp declines in midlife, had higher odds of high low-density lipoprotein and low HDL incidence, compared with those in the most active group at age 18 with subsequent gains.

CONCLUSION

Given recent trends in declining MVPA across the life course and associated metabolic disease risk, young adulthood is an important time period for interventions to increase and begin the maintenance of MVPA.

T-cells in response to acute cardiorespiratory or resistance exercise in physically active or physically inactive older adults: A randomized crossover study

T-cells often undergo age-related changes, but regular exercise training may offset these age-related changes. However, the majority of literature is derived from cardiorespiratory exercise studies. The purpose of this study was to examine the effects of acute cardiorespiratory exercise and acute resistance exercise on the T-cell response among physically active older adults (PA) compared to physically inactive older adults (PI).

METHODS

Twenty-four healthy older adults (PA n=12; PI n=12; mean ± SD; age (yrs) PA 62 ± 5, PI 64 ± 5; BMI (kg/m²) PA 23.9 ± 3.0, PI 25.6 ± 3.5) completed one bout each of matched intensity cardiorespiratory exercise and resistance exercise in a randomized order. Blood samples drawn pre-exercise, post-exercise, and 1h post-exercise (recovery) were analyzed by flow cytometry for T-cells and T-cell subsets.

RESULTS

Resistance exercise mobilized more T-cell subsets in PI (10 of the measured types, including total T-cells; CD45RA+ CD62L+, CD45RA- CD62L+, CD45RA- CD62L-, and CD45RA+ CD62L- T-cells), whereas cardiorespiratory exercise mobilized more subsets in PA (CD45RA+ CD62L- and CD57+ CD45RA+ CD62L- CD4+ T-cells). Both cardiorespiratory exercise and resistance exercise elicited a significant (p<0.05) mobilization of highly-differentiated (CD45RA+ CD62L-; CD57+ CD45RA+ CD62L-) CD8+ T-cells into the circulation post-exercise in both PA and PI groups. Furthermore, cardiorespiratory exercise resulted in a decrease in the number of circulating Th17 cells post-exercise, while resistance exercise increased Th17 cell mobilization compared to the cardiorespiratory exercise response.

CONCLUSION

There are differences between cardiorespiratory exercise and resistance exercise on the immune responses of T-cells, particularly in PI individuals.

Inactivity Causes Resistance to Improvements in Metabolism After Exercise

Prolonged sitting prevents a 1-h bout of running from improving fat oxidation and reducing plasma triglycerides. This "exercise resistance" can be prevented by taking 8500 steps·d-1 or by interrupting 8 h of sitting with hourly cycle sprints. We hypothesize that there is an interplay between background physical activity (e.g., steps·d-1) and the exercise stimuli in regulating some acute and chronic adaptations to exercise.

Five-year changes in objectively measured cardiorespiratory fitness, physical activity, and sedentary time in mid-to-late adulthood

This study examined 5-year changes in cardiorespiratory fitness, physical activity, and sedentary time in mid-to-late aged adults. Fifty-seven participants completed baseline and follow-up treadmill exercise tests and physical activity monitoring. We observed a 14% decline in fitness (p < 0.001), 12% decrease in physical activity (p = 0.010), and non-significant increase in sedentary time (p = 0.196). Age was negatively associated with 5-year change in physical activity (r = -0.31; p = 0.02) and this decline was strongest among APOE ε4 carriers (g = -0.75). Novelty: Cardiorespiratory fitness and physical activity significantly declined from mid-to-late adulthood, these findings were most pronounced among older adults and those with genetic risk for Alzheimer's disease.

Cardiovascular risk and functional burden at midlife: Prospective associations of isotemporal reallocations of accelerometer-measured physical activity and sedentary time in the CARDIA study

Cardiovascular risk and functional burden, or the accumulation of cardiovascular risk factors coupled with functional decline, may be an important risk state analogy to multimorbidity. We investigated prospective associations of sedentary time (ST), light intensity physical activity (LPA), and moderate to vigorous intensity physical activity (MVPA) with cardiovascular risk and functional burden at midlife. Participants were 1648 adults (mean ± SD age = 45 ± 4 years, 61% female, 39% Black) from Coronary Artery Risk Development in Young Adults (CARDIA) who wore accelerometers in 2005-2006 and 2015-2016. Cardiovascular risk and functional burden was defined as ≥2 cardiovascular risk factors (untreated/uncontrolled hypertension and hypercholesterolemia, type 2 diabetes, reduced kidney function) and/or functional decline conditions (reduced physical functioning and depressive symptoms). Prospective logistic regression models tested single activity, partition, and isotemporal substitution associations of accelerometer-measured ST, LPA, and MVPA with cardiovascular risk and functional burden 10 years later. In isotemporal models of baseline activity, reallocating 24 min of ST to MVPA was associated with 15% lower odds of cardiovascular risk and functional burden (OR: 0.85; CI: 0.75, 0.96). Reallocating 24 min of LPA to MVPA was associated with a 14% lower odds of cardiovascular risk and functional burden (OR: 0.86; CI: 0.75, 0.99). In longitudinal isotemporal models, similar beneficial associations were observed when 10-year increases in MVPA replaced time in ST or LPA. Findings suggest that maintaining an MVPA dose reflecting daily physical activity recommendations in early midlife is associated with lower odds of cardiovascular risk and functional burden later in midlife.

Steps per Day and All-Cause Mortality in Middle-aged Adults in the Coronary Artery Risk Development in Young Adults Study

IMPORTANCE

Steps per day is a meaningful metric for physical activity promotion in clinical and population settings. To guide promotion strategies of step goals, it is important to understand the association of steps with clinical end points, including mortality.

OBJECTIVE

To estimate the association of steps per day with premature (age 41-65 years) all-cause mortality among Black and White men and women.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was part of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants were aged 38 to 50 years and wore an accelerometer from 2005 to 2006. Participants were followed for a mean (SD) of 10.8 (0.9) years. Data were analyzed in 2020 and 2021.

EXPOSURE

Daily steps volume, classified as low (<7000 steps/d), moderate (7000-9999 steps/d), and high (≥10 000 steps/d) and stepping intensity, classified as peak 30-minute stepping rate and time spent at 100 steps/min or more.

MAIN OUTCOMES AND MEASURES

All-cause mortality.

RESULTS

A total of 2110 participants from the CARDIA study were included, with a mean (SD) age of 45.2 (3.6) years, 1205 (57.1%) women, 888 (42.1%) Black participants, and a median (interquartile range [IQR]) of 9146 (7307-11 162) steps/d. During 22 845 person years of follow-up, 72 participants (3.4%) died. Using multivariable adjusted Cox proportional hazards models, compared with participants in the low step group, there was significantly lower risk of mortality in the moderate (hazard ratio [HR], 0.28 [95% CI, 0.15-0.54]; risk difference [RD], 53 [95% CI, 27-78] events per 1000 people) and high (HR, 0.45 [95% CI, 0.25-0.81]; RD, 41 [95% CI, 15-68] events per 1000 people) step groups. Compared with the low step group, moderate/high step rate was associated with reduced risk of mortality in Black participants (HR, 0.30 [95% CI, 0.14-0.63]) and in White participants (HR, 0.37 [95% CI, 0.17-0.81]). Similarly, compared with the low step group, moderate/high step rate was associated with reduce risk of mortality in women (HR, 0.28 [95% CI, 0.12-0.63]) and men (HR, 0.42 [95% CI, 0.20-0.88]). There was no significant association between peak 30-minute intensity (lowest vs highest tertile: HR, 0.98 [95% CI, 0.54-1.77]) or time at 100 steps/min or more (lowest vs highest tertile: HR, 1.38 [95% CI, 0.73-2.61]) with risk of mortality.

CONCLUSIONS AND RELEVANCE

This cohort study found that among Black and White men and women in middle adulthood, participants who took approximately 7000 steps/d or more experienced lower mortality rates compared with participants taking fewer than 7000 steps/d. There was no association of step intensity with mortality.

Longitudinal bidirectional associations of physical activity and depressive symptoms: The CARDIA study

•

Significant inverse bidirectional associations were found between self-reported MVPA and depressive symptoms.

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No associations were observed between accelerometer MVPA estimates and depressive symptoms.

•

Both self-reported and accelerometer-estimated MVPA are valid, but may capture different aspects of the activity profile.

Depression affects many aspects of health and may be attenuated through increases in physical activity. While bidirectional associations between physical activity (PA) and depressive symptoms have been examined, few studies have examined these associations using both self-reported and accelerometer-estimated measures. Using data from Years 20 (2005–06, age 38–50) and 30 of the Coronary Artery Risk Development in Young Adults (CARDIA) study (N = 2,871), the bidirectional associations between moderate to vigorous intensity physical activity (MVPA) and depressive symptoms were examined using a cross-lagged panel model. Differences in the observed associations by physical activity assessment method were also examined. An inverse bidirectional association between self-reported MVPA and depressive symptoms was found. In subsequent analyses stratified by intensity category, higher levels of vigorous intensity physical activity at baseline, but not moderate intensity physical activity were associated with lower levels of depressive symptoms at the 10-year follow-up (ϕ = −0.04, p < 0.01; ϕ = −0.03, p = 0.15, respectively). A 10-year increase in self-reported MVPA was associated with a 10-year decrease in depressive symptoms. No associations were observed between accelerometer MVPA estimates and depressive symptoms. These findings may support the notion that each assessment method captures related, but also unique, aspects of physical activity behavior. When possible, future studies should explore measures of association by each physical activity assessment method to gain a better understanding of the complex relationship between physical activity and health.

Bidirectional associations of accelerometer-derived physical activity and stationary behavior with self-reported mental and physical health during midlife

Background

Moderate-to-vigorous intensity physical activity (MVPA) is associated with favorable self-rated mental and physical health. Conversely, poor self-rated health in these domains could precede unfavorable shifts in activity. We evaluated bidirectional associations of accelerometer-estimated time spent in stationary behavior (SB), light intensity physical activity (LPA), and MVPA with self-rated health over 10 years in in the CARDIA longitudinal cohort study.

Methods

Participants (n = 894, age: 45.1 ± 3.5; 63% female; 38% black) with valid accelerometry wear and self-rated health at baseline (2005–6) and 10-year follow-up (2015–6) were included. Accelerometry data were harmonized between exams and measured mean total activity and duration (min/day) in SB, LPA, and MVPA; duration (min/day) in long-bout and short-bout SB (≥30 min vs. < 30 min) and MVPA (≥10 min vs. < 10 min) were also quantified. The Short-Form 12 Questionnaire measured both a mental component score (MCS) and physical component score (PCS) of self-rated health (points). Multivariable linear regression associated baseline accelerometry variables with 10-year changes in MCS and PCS. Similar models associated baseline MCS and PCS with 10-year changes in accelerometry measures.

Results

Over 10-years, average (SD) MCS increased 1.05 (9.07) points, PCS decreased by 1.54 (7.30) points, and activity shifted toward greater SB and less mean total activity, LPA, and MVPA (all p < 0.001). Only baseline short-bout MVPA was associated with greater 10-year increases in MCS (+ 0.92 points, p = 0.021), while baseline mean total activity, MVPA, and long-bout MVPA were associated with greater 10-year changes in PCS (+ 0.53 to + 1.47 points, all p < 0.005). In the reverse direction, higher baseline MCS and PCS were associated with favorable 10-year changes in mean total activity (+ 9.75 cpm, p = 0.040, and + 15.66 cpm, p < 0.001, respectively) and other accelerometry measures; for example, higher baseline MCS was associated with − 13.57 min/day of long-bout SB (p < 0.001) and higher baseline PCS was associated with + 2.83 min/day of MVPA (p < 0.001) in fully adjusted models.

Conclusions

The presence of bidirectional associations between SB and activity with self-rated health suggests that individuals with low overall activity levels and poor self-rated health are at high risk for further declines and supports intervention programming that aims to dually increase activity levels and improve self-rated health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01145-4.

Physical Activity and Hypertension From Young Adulthood to Middle Age

INTRODUCTION

The optimum physical activity dose to achieve during young adulthood to prevent hypertension using the 2017 American College of Cardiology/American Heart Association guidelines remains undefined. This study aims to determine the association between level and change in physical activity through the adult life course and the onset of hypertension using these 2017 definitions.

METHODS

In 2020, prospective community-based cohort data of 5,115 Coronary Artery Risk Development in Young Adults study participants were analyzed. The cohort included Black and White men and women aged 18-30 years at baseline (1985-1986) at 4 urban sites, collected through 30 years of follow-up (2015-2016). Individualized physical activity trajectories were developed for each participant using linear mixed models.

RESULTS

Black women reported the lowest physical activity levels from young adulthood through middle age. Lower physical activity score (per 100 units) at age 18 years was associated with 4% (95% CI=1%, 7%, p=0.002) higher odds of hypertension incidence. Each additional 1-unit reduction per year in physical activity score was associated with 2% (95% CI=1%, 3%, p=0.001) higher annual odds of hypertension incidence. Meeting approximately the current minimum physical activity guideline levels at age 18 years and through follow-up was not protective of hypertension incidence; however, meeting approximately twice the current minimum physical activity guideline level at age 18 years and through follow-up was protective of hypertension incidence.

CONCLUSIONS

Moderate physical activity levels may need to exceed current minimum guidelines to prevent hypertension onset using 2017 American College of Cardiology/American Heart Association definitions.

Longitudinal Associations of Midlife Accelerometer Determined Sedentary Behavior and Physical Activity With Cognitive Function: The CARDIA Study

Background To determine if accelerometer measured sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous-intensity physical activity (MVPA) in midlife is prospectively associated with cognitive function. Methods and Results Participants were 1970 adults enrolled in the CARDIA (Coronary Artery Risk Development in Young Adults) study who wore an accelerometer in 2005 to 2006 (ages 38-50 years) and had cognitive function assessments completed 5 and/or 10 years later. SED, LPA, and MVPA were measured by an ActiGraph 7164 accelerometer. Cognitive function tests included the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop Test. Compositional isotemporal substitution analysis examined associations of SED, LPA, and MVPA with repeated measures of the cognitive function standardized scores. In men, statistical reallocation of 30 minutes of LPA with 30 minutes of MVPA resulted in an estimated difference of SD 0.07 (95% CI, 0.01-0.14), SD 0.09 (95% CI, 0.02-0.17), and SD -0.11 (95% CI, -0.19 to -0.04) in the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop scores, respectively, indicating better performance. Associations were similar when reallocating time in SED with MVPA, but results were less robust. Reallocation of time in SED with LPA resulted in an estimated difference of SD -0.05 (95% CI, -0.06 to -0.03), SD -0.03 (95% CI, -0.05 to -0.01), and SD 0.05 (95% CI, 0.03- 0.07) in the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop scores, respectively, indicating worse performance. Associations were largely nonsignificant among women. Conclusions Our findings support the idea that for men, higher-intensity activities (MVPA) may be necessary in midlife to observe beneficial associations with cognition.

Correlates of change in accelerometer-assessed total sedentary time and prolonged sedentary bouts among older English adults: results from five-year follow-up in the EPIC-Norfolk cohort

BACKGROUND

Development of effective strategies to reduce sedentary time among older adults necessitates understanding of its determinants but longitudinal studies of this utilising objective measures are scarce.

METHODS

Among 1536 older adults (≥60 years) in the EPIC-Norfolk study, sedentary time was assessed for seven days at two time-points using accelerometers. We assessed associations of change in total and prolonged bouts of sedentary time (≥ 30 minutes) with change in demographic and behavioural factors using multi-level regression.

RESULTS

Over follow-up (5.3±1.9 years), greater increases in total sedentary time were associated with older age, being male, higher rate of increase in BMI, lower rate of increase in gardening (0.5 min/day/yr greater sedentary time per hour/week/yr less gardening, 95% CI 0.1, 1.0), a lower rate of increase in walking (0.2 min/day/yr greater sedentary time per hour/week/yr less walking, 95% CI 0.1, 0.3) and a higher rate of increase in television viewing. Correlates of change in prolonged sedentary bouts were similar.

CONCLUSION

Individuals in specific sub-groups (older, male, higher BMI) and who differentially participate in certain behaviours (less gardening, less walking and more television viewing) but not others increase their sedentary time at a higher rate than others; utilising this information could inform successful intervention content and targeting.

Percent body fat, but not lean mass, is associated with objectively measured physical function in middle-aged women

OBJECTIVES

The relationship between components of body composition and physical function is not well characterized among middle-aged women. This cross-sectional study examined the strength of the associations between lean mass and percent fat and physical function in middle-aged women.

STUDY DESIGN

Body composition, physical function and physical activity were objectively measured in 80 women (mean age 52.58 ± 6.10 years; range = 40-63 years).

MAIN OUTCOME MEASURES

Adiposity (%Fat) and lean mass were measured via dual-energy x-ray absorptiometry. Steps/day and minutes of low-, moderate- and vigorous-intensity physical activity were assessed via accelerometer. Physical function was measured via a seated transfer task, 30-second chair stand, a six-minute walk task, 8-foot timed up and go, and a lift and carry task.

RESULTS

When controlling for steps/day, measures of lean mass were related to performance on the seated transfer task (r = .25) and 30-second chair stand (-.26) (both p > 0.05), while %Fat was related to performance on the seated transfer task (r = .53), 8-foot timed up and go (r = .32), 30-second chair stand (r = -.35), and six-minute walk (r = -.48; all p ≤ 0.05). Linear regression analyses revealed: (1) age, steps/day, and %Fat were independently related to performance on the seated transfer task and 30-second chair stand (both p ≤ 0.05), (2) %Fat was associated with six-minute walk and 8-foot up-and-go performance (p ≤ 0.01); none of the variables included were associated with lift and carry.

CONCLUSIONS

Adiposity but not lean mass was associated with objectively measured physical function in middle-aged women. Interventions that focus on reducing body fat may be an effective method for improving functional performance among women in this age group.

Rationale and Design of the Women's Health And Daily Experiences Project: Protocol for an Ecological Momentary Assessment Study to Identify Real-Time Predictors of Midlife Women's Physical Activity

BACKGROUND

Midlife women are at an elevated risk for cardiovascular disease (CVD) and associated mortality. Those who have additional risk conditions such as obesity or hypertension report specific barriers to engaging in cardioprotective behaviors such as physical activity (PA). Considerable effort has been devoted to understanding PA determinants and designing interventions for midlife women, although with suboptimal success, as increasing PA could meaningfully attenuate CVD risk. An updated approach to understanding PA among midlife women could improve upon existing resources by focusing on novel psychosocial influences on PA in this population (ie, body satisfaction, social interactions, social comparisons, mood state) and within-person relations between these influences and PA in the natural environment.

OBJECTIVE

The overarching goal of Project WHADE (Women's Health And Daily Experiences) is to use an ecological momentary assessment (EMA) approach to capture ecologically valid relations between midlife women's psychosocial experiences and PA as they engage in their normal daily activities. The primary aim of the study is to identify within-person psychosocial predictors of variability in PA (ie, experiences associated with higher vs lower PA for a given individual).

METHODS

Midlife women (aged 40-60 years) with one or more additional risk markers for CVD (eg, hypertension) will be recruited from primary care clinics and the general community (target n=100). Eligible women will complete an initial survey and a face-to-face baseline session before engaging in a 10-day EMA protocol. Psychosocial experiences will be assessed using a brief self-report via a smartphone 5 times per day, and PA will be assessed throughout waking hours using a research-grade monitor. Participants will return for a brief exit interview at the end of 10 days. Multilevel models that address the nested structure of EMA data will be used to evaluate the study aims.

RESULTS

Recruitment and enrollment are ongoing, and a total of 75 women have completed the protocol to date. Data collection is expected to be completed in Fall 2020.

CONCLUSIONS

Project WHADE is designed to identify naturally occurring psychosocial experiences that predict short-term variability in midlife women's PA. As such, the results of this study should advance the current understanding of PA among midlife women by providing further insight into within-person psychosocial influences on PA in this group. In the future, this information could help inform the design of interventions for this population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/19044.

Association of Resting Heart Rate With Blood Pressure and Incident Hypertension Over 30 Years in Black and White Adults: The CARDIA Study

Few studies have assessed the association of resting heart rate (RHR) through young adulthood with incident hypertension by middle age. We investigated the association between RHR measured over 30 years with incident hypertension in a cohort of young Black and White men and women. A joint longitudinal time-to-event model consisting of a mixed random effects submodel, quadratic in follow-up time, and a survival submodel adjusted for confounders, was used to determine hazard ratios for a 10 bpm higher RHR. Race-sex specific effects were examined in a single joint model that included interactions of race-sex groups with longitudinal RHR. Out of 5115 participants enrolled in year 0 (1985-1986), after excluding prevalent cases of hypertension at baseline, 1615 men and 2273 women were included in the analytic cohort. Hypertension event rates per 1000 person-years were 42.5 and 25.7 in Black and White men, respectively, and 36.2 and 15.3 in Black and White women, respectively. The hazard ratios for a 10 bpm higher RHR were 1.47 (95% CI, 1.23-1.75), 1.51 (95% CI, 1.28-1.78), 1.48 (95% CI, 1.26-1.73), and 1.02, (95% CI, 0.89-1.17) for Black men, White men, White women, and Black women, respectively. Higher RHR during young adulthood is associated with a greater risk of incident hypertension by middle age. The association is similarly strong in Black men, White men, and White women, but absent in Black women, which may suggest racial differences in the effect of sympathetic nervous activity on hypertension among women.

Associations of accelerometer-measured physical activity and sedentary time with chronic kidney disease: The Framingham Heart Study

BACKGROUND

Few studies examined the individual and conjoint associations of accelerometer-measured physical activity (PA) and sedentary times with the prevalence of chronic kidney disease (CKD) among older adults.

METHODS

We evaluated 1,268 Framingham Offspring Study participants (mean age 69.2 years, 53.8% women) between 2011 and 2014. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.732 and/or urine albumin-to-creatinine ratio (UACR) ≥25/35 μg/mg (men/women). We used multivariable logistic regression models to relate time spent being sedentary and active with the odds of CKD. We then performed compositional data analysis to estimate the change in the eGFR and UACR when a fixed proportion of time in one activity behavior (among the following: moderate to vigorous physical activity [MVPA], light intensity physical activity [LIPA], and sedentary) is reallocated to another activity behavior.

RESULTS

Overall, 258 participants had prevalent CKD (20.4%; 120 women). Higher total PA ([MVPA+LIPA], adjusted-odds ratio [OR] per 30 minutes/day increase, 0.86; 95% CI, 0.78-0.96) and higher LIPA (OR per 30 minutes/day increase, 0.87; 95% CI, 0.76-0.99) were associated with lower odds of CKD. Additionally, higher sedentary time (OR per 30 minutes/day increase, 1.16; 95% CI, 1.04-1.29) was associated with higher odds of CKD. Reallocating 5% of the time from LIPA to sedentary was associated with the largest predicted difference in eGFR (-1.06 ml/min/1.73m2). Reallocating 1% of time spent in MVPA to sedentary status predicted the largest difference in UACR (14.37 μg/mg).

CONCLUSION

The findings suggest that increasing LIPA and maintaining MVPA at the expense of sedentary time may be associated with a lower risk of CKD in community-based older adults.

Effects of six month personalized endurance training on work ability in middle-aged sedentary women: a secondary analysis of a randomized controlled trial

Background

To test the effects of guided endurance training on work ability in middle-aged female hospital workers of various occupations.

Methods

We randomized 265 healthy, sedentary, middle-aged women (45–65 years) to an endurance training group (EG 210 min/week) or a wait-list control group (CG). At baseline and at 6-month follow-up, we assessed work ability (Work Ability Index [WAI]), physical activity (Freiburger activity questionnaire) and peak oxygen uptake (VO_2peak) by cardiopulmonary exercise testing. To examine the influence of baseline work ability, participants were divided into poor-moderate (WAI 1, 7–36 points, n = 83), good (WAI 2, 37–43 points, n = 136) and excellent (WAI 3, 44–49 points, n = 46) WAI subgroups.

Results

Cardiorespiratory fitness improved significantly after 6 months in the EG but not in the CG. The WAI total score increased significantly in the EG (38.3 ± 5.0 to 39.8 ± 4.9 points) but not in the CG (39.4 ± 4.7 to 39.3 ± 4.9 points), with a significant difference between groups (p < 0.01). In the EG, only the poor-moderate subgroup (WAI 1, 33.0 ± 2.9 to 36.6 ± 4.8 points, p < 0.05) increased the WAI total score, with this increase being significantly higher compared to the good (WAI 2, 40.2 ± 2.1 to, 40.4 ± 3.7 points) and excellent (WAI 3, 45.6 ± 1.5 to 45.7 ± 1.8 points) subgroup.

Conclusions

A 6-month guided exercise training intervention significantly increases cardiorespiratory fitness with concomitant improvements in work ability in middle-aged previously sedentary hospital employees. Women with low baseline work ability seem to particularly benefit from the intervention, which implies that similar interventions may be particularly beneficial for this group of individuals.

Trial registration

German Clinical Trails Register Identifier: DRKS00005159. Registered 25 September 2013.

Differences between accelerometer cut point methods among midlife women with cardiovascular risk markers

OBJECTIVE

Midlife women experience elevated risk for cardiovascular disease and often receive advice to increase physical activity to mitigate this risk. Use of accelerometers to measure ambulatory physical activity requires selection of appropriate thresholds for estimating moderate-to-vigorous physical activity (MVPA), and choice of cut points may lead to meaningfully different conclusions about midlife women's physical activity (PA) engagement. This is particularly important given the recent elimination of 10-minute bout requirements for MVPA. This two-phase study examined differences between four cut point methods among midlife women with cardiovascular disease (CVD) risk. We used findings from Study 1 (exploratory) to generate hypotheses for Study 2 (confirmatory).

METHODS

Across studies, participants (N = 65) were midlife women with an additional CVD risk factor (eg, hypertension). Participants wore waistband accelerometers for seven days. Daily totals were calculated for minutes in light and MVPA using four common quantification methods (Freedson, Matthews, Swartz, and Troiano).

RESULTS

Multilevel models showed meaningful differences between methods (P < 0.0001). For total (non-bouted) minutes of MVPA, Freedson and Troiano methods showed that participants barely met MVPA recommendations (30 min per day), whereas Matthews and Swartz methods showed that participants greatly exceeded this goal. As differences between methods were smaller using MVPA bouts of 10 minutes or more (though remained significant), the observed variation was due in part to small bursts of MVPA dispersed throughout the day.

CONCLUSIONS

Findings demonstrate the need for careful consideration of PA quantification among midlife women with CVD risk, and for further investigation to determine the most appropriate quantification method. : Video Summary:http://links.lww.com/MENO/A545.

Associations of physical activity and sleep with cardiometabolic risk in older women

In this study, we investigate the associations of objectively measured waking (sedentary, light physical activity [LPA] and moderate-to-vigorous physical activity [MVPA]) and sleep duration and quality characteristics with cardiometabolic risk among older women. Participants from the Healthy Women Study 2010–11 follow-up visit (n = 136, age = 73 ± 2 years, white = 91.9%) concurrently wore an ActiGraph GT1M accelerometer and Actiwatch-2 for seven days. A composite cardiometabolic risk score was calculated by transforming metabolic syndrome (MetS) components and summing z-scores. Multivariable regression models were fitted to relate waking and sleep estimates with the MetS z-score after adjustment for covariates. Compositional data analysis was used to predict the MetS z-score when fixed durations of time were reallocated from one characteristic to another. MVPA (per 10 min/day increase; β = −7.80, P < 0.01), LPA (per 30 min/day increase; β = −0.29, P = 0.04), and sleep efficiency (β = −0.10, P = 0.04) were inversely associated with MetS z-score, while sedentary time (per 30 min/day increase; β = 0.34, P = 0.01) was positively associated with MetS z-score. Reallocation of 5 min from MVPA to sleep, sedentary, or LPA resulted in the greatest predicted change in MetS z-score. On average, the reallocation of 5 min from MVPA to other characteristics predicted an 11% increase in triglycerides, 6% decrease in HDL-C, and 5% increase in waist circumference. Lastly, reallocating 30 min of sedentary time to LPA was associated with a modestly lower predicted MetS z-score. This study suggests that MVPA is the most important contributor of MetS and that maintaining MVPA and increasing LPA may be beneficial for reducing cardiometabolic risk among older women.

The impact of breast cancer on physical activity from midlife to early older adulthood and predictors of change post-diagnosis

PURPOSE

To examine physical activity (PA) patterns from pre- to post-diagnosis, and compare these changes to women without breast cancer. To determine pre-diagnosis predictors of PA change, post-diagnosis, in breast cancer survivors (BCS).

METHODS

Data were from 2314 Study of Women's Health Across the Nation (SWAN) participants, average age of 46.4 ± 2.7 years at baseline (1996-1997). In Pink SWAN, 151 women who reported an incident breast cancer diagnosis over 20 years were classified as BCS; the remaining 2163 women were controls. LOESS plots and linear mixed models were used to illustrate and compare PA changes (sports/exercise [primary measure] and total PA) from pre- to post-diagnosis (or corresponding period) in BCS versus controls. Adjusted linear regression models were used to determine pre-diagnosis predictors of at-risk post-diagnosis PA change patterns (consistently low and decreased PA).

RESULTS

No differences in pre- to post-diagnosis PA (or corresponding period) were observed in BCS versus controls. Among BCS, the odds of at-risk post-diagnosis PA change patterns was 2.50 (95% CI 0.96-6.48) times higher for those who reported sleep problems at ≥ 50% (compared to 0%) of pre-diagnosis visits and 3.49 (95% CI 1.26-9.65) times higher for those who were overweight or obese at all (compared to no) pre-diagnosis visits. No other statistically significant predictors were noted.

CONCLUSIONS

Age-related declines in PA were not amplified by a breast cancer diagnosis. Given the beneficial role of PA across the cancer control continuum, efforts to increase or maintain adequate PA, post-diagnosis, should be continued.

IMPLICATIONS FOR CANCER SURVIVORS

While age-related physical activity declines were not amplified breast cancer diagnosis, efforts to identify breast cancer survivors at increased risk for post-diagnosis physical activity declines (or maintenance of low activity) may be a high-yield strategy to improve prognosis and quality of life.

Bidirectional 10-year associations of accelerometer-measured sedentary behavior and activity categories with weight among middle-aged adults

BACKGROUND

Although higher sedentary behavior (SB) with low light intensity (LPA) and moderate-to-vigorous intensity physical activity (MVPA) are thought to increase risk for obesity, other data suggest excess weight may precede these behaviors in the causal pathway. We aimed to investigate 10-year bidirectional associations between SB and activity with weight.

METHODS

Analysis included 886 CARDIA participants (aged 38-50 years, 62% female, 38% black) with weight and accelerometry ( ≥ 4 days with ≥ 10 h/day) collected in 2005-6 (ActiGraph 7164) and 2015-6 (ActiGraph wGT3X-BT). Accelerometer data were calibrated, harmonized, and expressed as counts per minute (cpm) and time-dependent intensity categories (min/day of SB, LPA, and MVPA; SB and MVPA were also separated into long-bout and short-bout categories). Linear regression models were constructed to estimate adjusted associations of baseline activity with 10-year change in weight and vice versa. When activity categories were the independent variables, standardized regression coefficients (βstd.) estimated associations of replacing SB with a one SD increase in other categories, adjusted for accelerometer wear time.

RESULTS

Over 10-years, weight increased by a mean 2.55 ± 8.05 kg and mean total activity decreased by 50 ± 153 cpm. In adjusted models, one SD higher baseline mean total activity (βstd. = -1.4 kg, p < 0.001), LPA (βstd. = -0.80 kg, p = 0.013), total MVPA (βstd. = -1.07 kg, p = 0.001), and long-bout MVPA (βstd. = -1.20 kg, p < 0.001) were associated with attenuated 10-year weight gain. Conversely, a one SD higher baseline weight was associated with unfavorable 10-year changes in daily activity profile including increases in SB (βstd. = 12.0 min, p < 0.001) and decreases in mean total activity (βstd. = 14.9 cpm, p = 0.004), LPA (βstd. = 8.9, p = 0.002), and MVPA (βstd. = 3.5 min, p = 0.001). Associations varied by race and gender.

CONCLUSIONS

Higher SB with lower activity and body weight were bidirectionally related. Interventions that work simultaneously to replace SB with LPA and long-bout MVPA while also using other methods to address excess weight may be optimal.

Increasing Energy Flux to Maintain Diet-Induced Weight Loss

Long-term maintenance of weight loss requires sustained energy balance at the reduced body weight. This could be attained by coupling low total daily energy intake (TDEI) with low total daily energy expenditure (TDEE; low energy flux), or by pairing high TDEI with high TDEE (high energy flux). Within an environment characterized by high energy dense food and a lack of need for movement, it may be particularly difficult for weight-reduced individuals to maintain energy balance in a low flux state. Most of these individuals will increase body mass due to an inability to sustain the necessary level of food restriction. This increase in TDEI may lead to the re-establishment of high energy flux at or near the original body weight. We propose that following weight loss, increasing physical activity can effectively re-establish a state of high energy flux without significant weight regain. Although the effect of extremely high levels of physical activity on TDEE may be constrained by compensatory reductions in non-activity energy expenditure, moderate increases following weight loss may elevate energy flux and encourage physiological adaptations favorable to weight loss maintenance, including better appetite regulation. It may be time to recognize that few individuals are able to re-establish energy balance at a lower body weight without permanent increases in physical activity. Accordingly, there is an urgent need for more research to better understand the role of energy flux in long-term weight maintenance.

Daily Step Counts for Measuring Physical Activity Exposure and Its Relation to Health

PURPOSE

A systematic primary literature review was conducted to evaluate the relationship of physical activity-as measured by daily step counts-with all-cause mortality, cardiovascular disease mortality, incident cardiovascular disease, and type 2 diabetes mellitus; to evaluate the shape of dose-response relationships; and to interpret findings in the context of development of the Physical Activity Guidelines for Americans, Second Edition.

METHODS

A primary literature search encompassing 2011 to March 2018 for existing literature reporting on these relationships was conducted.

RESULTS

Eleven pertinent articles were identified. Seven longitudinal studies examined the relationship between daily step counts and mortality, disease incidence, or risk. Two studies examined objectively measured steps per day and all-cause mortality; one was restricted to a relatively small elderly population. One study examined cardiovascular events, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. The other four longitudinal studies addressed incident type 2 diabetes. All longitudinal studies reported an inverse relationship between steps per day and outcome risk. In one study, 531 cardiovascular events occurred during more than 45,000 person-years of follow-up. Before intervention, each increment of 2000 steps per day up to 10,000 steps was associated with a 10% lower cardiovascular event rate. Also, for every increase of 2000 steps per day over baseline, there was an 8% yearly reduction in cardiovascular event rate in individuals with impaired glucose tolerance.

CONCLUSIONS

Daily step count is a readily accessible means by which to monitor and set physical activity goals. Recent evidence supports previously limited evidence of an inverse dose-response relationship of daily steps with important health outcomes, including all-cause mortality, cardiovascular events, and type 2 diabetes. However, more independent studies will be required before these observations can be translated into public health guidelines.

Association of commuting mode with dyslipidemia and its components after accounting for air pollution in the working population of Beijing, China

Background

Evidence of the association between dyslipidemia and its components with commuting mode after adjusting for air pollution is limited. This study aimed to explore the association of dyslipidemia and its components with the modes used to commute to and from work after accounting for air pollution and other potential confounding factors.

Methods

This cross–sectional study was based on data collected from a working population of 69 functional communities in Beijing in 2016. A final sample of 8090 adults aged 18–65 years (mean age: 38.36 ± 9.75 years) was enrolled in the study. Risk estimates and their corresponding 95% confidence intervals (CIs) for the associations of dyslipidemia and its components with commuting mode were determined using multivariate logistic regression models.

Results

Of the 8090 subjects, 2419 (29.90%) met the criteria for dyslipidemia. Compared with car or taxi commuters, walking (OR 0.79, 95% CI 0.64 to 0.97), cycling (OR 0.71, 95% CI 0.58 to 0.86) and bus-riding commuters (OR 0.78, 95% CI 0.66 to 0.91) had a lower risk for dyslipidemia. Compared with car or taxi commuting, walking, cycling and bus-riding commuting were also associated with a lower risk for some components of dyslipidemia. Among the walking, cycling and bus-riding commuters, a dose-response trend of the association between dyslipidemia, some of its components and commuting mode by commuting time was also observed.

Conclusions

Walking, cycling and bus-riding commuting can reduce the risk for dyslipidemia and some of its components. Education on the prevention of dyslipidemia should be emphasized among higher-risk people who usually commute by car or taxi. Population-wide health may be improved by policies that encourage active commuting, particularly cycling and walking.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6887-x) contains supplementary material, which is available to authorized users.

Rationale and design of Smart Walk: A randomized controlled pilot trial of a smartphone-delivered physical activity and cardiometabolic risk reduction intervention for African American women

BACKGROUND

African American (AA) women perform low levels of physical activity (PA) and are disproportionally burdened by cardiometabolic disease conditions when compared to White women and the U.S. population as a whole. These disparities emphasize the need for innovative and effective interventions to increase PA and reduce cardiometabolic disease risk among AA women. Recent evidence suggests that mobile health (mHealth) interventions have the potential to increase PA and reduce cardiometabolic disease risk factors. Few studies have examined the efficacy of mHealth PA interventions among racial/ethnic minorities, including AA women. This represents a missed opportunity given the reported success of technology-delivered PA interventions in predominately White populations and the high use of technology among AA women.

OBJECTIVE

To describe the design, theoretical rationale, and cultural relevance of Smart Walk, a culturally sensitive smartphone-delivered PA intervention for AA women.

DESIGN AND METHODS

Smart Walk is an 8-month, randomized controlled pilot trial designed to increase PA and reduce cardiometabolic disease risk among AA women. Sixty physically inactive AA women with obesity will be assigned to receive either a culturally relevant intervention designed to increase PA (by targeting leisure-time, household chore/task-related, and occupational PA) or a culturally relevant wellness attention-matched control condition. Outcomes will be assessed at baseline, 4 months, and 8 months, and include feasibility and acceptability of the PA intervention and evaluation of effects on PA and cardiometabolic risk factors.

SUMMARY

Smart Walk represents a culturally relevant, theory-based approach to promote PA and reduce cardiometabolic disease risk in AA women.

Descriptive epidemiology of changes in objectively measured sedentary behaviour and physical activity: six-year follow-up of the EPIC-Norfolk cohort

BACKGROUND

Sedentary time increases and total physical activity decreases with age. The magnitude and correlates of changes in sedentary time, light-intensity physical activity (LPA), moderate-to-vigorous intensity physical activity (MVPA), and overall physical activity remain unclear. We quantified these changes and identified their individual and sociodemographic correlates.

METHODS

We used data from 1259 adults (67.8 ± 6.9 years; 41.9% women) who participated in the EPIC-Norfolk Study. Activity was assessed at baseline (2004-2011) and follow-up (2012-2016) for 7 days using accelerometers. Potential correlates of change were specified a priori. We used unadjusted and adjusted sex-stratified linear regressions to identify correlates of change.

RESULTS

Only 3.7% of adults met the current MVPA recommendations. Sedentary time increased by 3.0 min/day/year (SD = 12.3). LPA, MVPA, and overall PA decreased by 1.7 min/day/year (SD = 5.4), 3.0 min/day/year (SD = 6.0), and 8.8 cpm/year (SD = 18.8), respectively. Correlates of greater rates of increase in sedentary time included older age and higher BMI in men, and older age, higher BMI, smoking, and urban dwelling in women. Correlates of greater rates of decrease in physical activity included older age, higher BMI, living alone, depression, car use, and/or fair/poor self-rated health in men, and older age, higher BMI, depression, smoking, and/or urban dwelling in women (e.g. depressed women had a 1.0 min/day/year greater rate of decline in MVPA than non-depressed women, 95% CI -1.8, - 0.2).

CONCLUSIONS

Most (> 95%) adults are insufficiently active. Sedentary time increases and LPA, MVPA and overall physical activity decreases over time, with more pronounced rates of change observed in specific sub-groups (e.g. among older and depressed adults). To promote active living, the correlates of these changes should be considered in future interventions.