Androgenicity in Young Women and Development of Metabolic Syndrome Before Menopause: The CARDIA and CARDIA Women's Studies.

Context: There are no reported data from prospective long-term studies on the relation of androgen levels in young women with development of metabolic syndrome (MetS) before menopause. Objective: We investigated associations of androgens and SHBG with incident MetS during 23 years of follow-up. Methods: We included 366 White and 375 Black women ages 20 to 32 years participating in the CARDIA study and CARDIA Women's study, free of MetS at baseline examination (1987-1988), and premenopausal 23 years later. Androgens and SHBG were categorized into quartiles. MetS was defined according to the American Heart Association/National Heart, Lung, and Blood Institute 2009 Joint Scientific Statement. Cox proportional hazards models were used. Results: By year 23, 30% of women developed MetS. Adjusting for baseline age, race, and education, hazard ratios (95% CI) of developing MetS were 1.46 (1.02-2.10) and 2.22 (1.53-3.21) for women in the highest vs lowest total testosterone (T) and free T quartile, respectively. The hazards of developing MetS were 47%, 59%, and 53% lower for women with SHBG in the second, third, and fourth quartiles (vs lowest quartile), respectively. Associations were attenuated for total T with further adjustments for smoking, physical activity, menstrual status, oral contraceptive/hormone (OCHM) use, insulin level, oligomenorrhea, and age at menarche, but remained statistically significant for free T and SHBG. Associations were similar for both Blacks and Whites, and OCHM nonusers, but not for OCHM users. Conclusion: High androgenicity in young premenopausal women is associated with higher risk of future MetS, suggesting that early assessment of androgens may contribute to prevention.

Advances in Adherence Reporting of Resistance Training in a Clinical Trial during Adjuvant Chemotherapy for Colon Cancer.

PURPOSE: Detailed reporting of individually tailored exercise prescriptions (ExR x ) used in clinical trials is essential to describe feasibility, tolerability, and efficacy of the intervention and to inform translation to clinical care. This article outlines the methodology used to develop a resistance training (RT) ExR x for people with colon cancer receiving chemotherapy and reports adherence to the randomized controlled trial testing the impact of RT on relative dose intensity of chemotherapy and patient-reported toxicities. METHODS: Participants randomized to the exercise arm ( n = 90) were included. To promote muscle hypertrophy, the ExR x was twice-weekly, moderate to heavy loads (65%-85% one-repetition maximum), high sets (3-5), and intermediate repetitions (6-10) of five large multijoint movements with adjustable dumbbells. Attendance (achieved frequency) and adherence (achieved volume) were calculated. Group-based trajectory modeling was used to identify clusters of individuals with similar adherence patterns and compared baseline characteristics across adherence groups. RESULTS: The median attendance was 69.1%. Adherence was 60.6% but higher for those receiving 3 versus 6 months of chemotherapy (80.4 vs 47.4%; P < 0.05 ). Participants engaged in a median of 1.4 d of RT each week, lifting 62% of the one-repetition maximum load, for 3.0 sets and 7.5 repetitions per set. Three distinct adherence groups were identified: 13% "nonstarter," 37% "tapered off," and 50% "consistent exercisers." Females were more likely to be in the nonstarter and tapered-off groups. CONCLUSIONS: This article outlines suggested methods for reporting ExR x of RT in oncology clinical trials and provides insight into the tolerance of ExR x of RT during chemotherapy treatment for colon cancer. These findings aim to foster constructive dialogue and offer a premise for designing future research to elucidate the benefits of exercise during chemotherapy.

Associations between occupational physical activity and left ventricular structure and function over 25 years in CARDIA.

AIMS: Leisure time physical activity (LTPA) confers cardiovascular health benefits, while occupational physical activity (OPA) may have paradoxically negative health associations. This study tested the explanatory hypothesis that unfavourable cardiac remodelling may result from chronic OPA-induced cardiovascular strain. METHODS AND RESULTS: Longitudinal associations of OPA and left ventricular (LV) structure and function were examined in 1462 participants {50.0% female, 56.4% White, aged 30.4 ± 3.4 years at baseline [Year 5 exam (1990-91)]} from the Coronary Artery Risk Development in Young Adults study. Left ventricular structure and function were measured as LV mass (LVMi), end-diastolic volume (LVEDVi), end-systolic volume (LVESVi), ejection fraction (LVEF), stroke volume (LVSVi), and e/a-wave ratio (EA ratio) via echocardiography at baseline and 25 years later. Occupational physical activity was reported at seven exams during the study period as months/year with 'vigorous job activities such as lifting, carrying, or digging' for ≥5 h/week. The 25-year OPA patterns were categorized into three trajectories: no OPA (n = 770), medium OPA (n = 410), and high OPA (n = 282). Linear regression estimated associations between OPA trajectories and echocardiogram variables at follow-up after adjusting for baseline values, individual demographic/health characteristics, and LTPA. Twenty-five-year OPA exposure was not significantly associated with LVMi, LVEDVi, LVSVi, or EA ratio (P > 0.05). However, higher LVESVi (ß = 1.84, P < 0.05) and lower LVEF (ß = -1.94, P < 0.05) were observed at follow-up among those in the high- vs. no-OPA trajectories. CONCLUSION: The paradoxically adverse association of OPA with cardiovascular health was partially supported by null or adverse associations between high OPA and echocardiogram outcomes. Confirmation is needed using more precise OPA measures.

This study tested the paradoxical notion that physical activity done for work may not have the same heart health benefits as expected for physical activity done during leisure time. Those who completed high amounts of physical activity at work had no beneficial changes and, in some cases, adverse changes to the structure and function of their hearts compared with those doing no activity at work during the same period. The adverse changes associated with physical activity at work were more apparent among men, those with greater than high school education levels, and those with low levels of physical activity outside of work.

D3-creatine dilution, computed tomography and dual-energy X-ray absorptiometry for assessing myopenia and physical function in colon cancer: A cross-sectional study.

BACKGROUND: Low skeletal muscle mass (myopenia) is common in cancer populations and is associated with functional decline and mortality, but prior oncology studies did not assess total body skeletal muscle mass. Instead, they measured surrogates such as cross-sectional area (CSA) of skeletal muscle at L3 from computed tomography (CT) or appendicular lean mass (ALM) from dual-energy X-ray absorptiometry (DXA). D3-creatine (D3Cr) dilution is a non-invasive method to assess total body skeletal muscle mass, which has been examined in a variety of populations but not in cancer. To compare the associations of D3Cr muscle mass, CT CSA, and DXA ALM with myopenia and physical function, we conducted a cross-sectional study among 119 patients with colon cancer (2018-2022). METHODS: For each technique (D3Cr, CT and DXA), myopenia was defined as the lowest sex-specific quartile of its measurement. Physical function was measured by the short physical performance battery and grip strength. We calculated Pearson correlations (r) among three techniques, computed Cohen's kappa coefficients (κ) to assess the agreement of myopenia, and estimated Pearson correlations (r) of three techniques with physical function. All analyses were sex-specific. RESULTS: Sixty-one (51.3%) participants were male, the mean (standard deviation) age was 56.6 (12.9) years, and most (68.9%) had high physical function (short physical performance battery: ≥11 points). Correlations and myopenia agreement among three techniques were greater in men than women; for example, regarding D3Cr muscle mass versus CT CSA, r was 0.73 (P < 0.001) for men versus 0.45 (P < 0.001) for women, and κ was 0.82 (95% CI: 0.65, 0.99) for men versus 0.24 (95% CI: -0.08, 0.52) for women. Among men, higher D3Cr muscle mass was significantly correlated with faster gait speed (r = 0.43, P < 0.01) and stronger grip strength (r = 0.32, P < 0.05); similar correlations were observed for CT CSA and DXA ALM. However, among women, no measure of muscle or lean mass was significantly associated with physical function. CONCLUSIONS: This is the first study using D3-creatine dilution method to assess muscle mass in a cancer population. Regardless of the techniques used for muscle or lean mass assessment, we observed stronger correlations, greater myopenia agreement, and more significant associations with physical function in men with colon cancer than women. D3Cr, CT and DXA are not interchangeable methods for assessing myopenia and physical function, especially in women with colon cancer. Future studies should consider relative advantages of these techniques and examine the D3-creatine dilution method in other cancer types.

Method for Activity Sleep Harmonization (MASH): a novel method for harmonizing data from two wearable devices to estimate 24-h sleep-wake cycles.

Background: Daily 24-h sleep-wake cycles have important implications for health, however researcher preferences in choice and location of wearable devices for behavior measurement can make 24-h cycles difficult to estimate. Further, missing data due to device malfunction, improper initialization, and/or the participant forgetting to wear one or both devices can complicate construction of daily behavioral compositions. The Method for Activity Sleep Harmonization (MASH) is a process that harmonizes data from two different devices using data from women who concurrently wore hip (waking) and wrist (sleep) devices for ≥ 4 days. Methods: MASH was developed using data from 1285 older community-dwelling women (ages: 60-72 years) who concurrently wore a hip-worn ActiGraph GT3X + accelerometer (waking activity) and a wrist-worn Actiwatch 2 device (sleep) for ≥ 4 days (N = 10,123 days) at the same time. MASH is a two-tiered process using (1) scored sleep data (from Actiwatch) or (2) one-dimensional convolutional neural networks (1D CNN) to create predicted wake intervals, reconcile sleep and activity data disagreement, and create day-level night-day-night pairings. MASH chooses between two different 1D CNN models based on data availability (ActiGraph + Actiwatch or ActiGraph-only). MASH was evaluated using Receiver Operating Characteristic (ROC) and Precision-Recall curves and sleep-wake intervals are compared before (pre-harmonization) and after MASH application. Results: MASH 1D CNNs had excellent performance (ActiGraph + Actiwatch ROC-AUC = 0.991 and ActiGraph-only ROC-AUC = 0.983). After exclusions (partial wear [n = 1285], missing sleep data proceeding activity data [n = 269], and < 60 min sleep [n = 9]), 8560 days were used to show the utility of MASH. Of the 8560 days, 46.0% had ≥ 1-min disagreement between the devices or used the 1D CNN for sleep estimates. The MASH waking intervals were corrected (median minutes [IQR]: -27.0 [-115.0, 8.0]) relative to their pre-harmonization estimates. Most correction (-18.0 [-93.0, 2.0] minutes) was due to reducing sedentary behavior. The other waking behaviors were reduced a median (IQR) of -1.0 (-4.0, 1.0) minutes. Conclusions: Implementing MASH to harmonize concurrently worn hip and wrist devices can minimizes data loss and correct for disagreement between devices, ultimately improving accuracy of 24-h compositions necessary for time-use epidemiology.

Thirteen-Year Associations of Occupational and Leisure-Time Physical Activity with Cardiorespiratory Fitness in CARDIA.

PURPOSE: Differential effects on fitness are hypothesized to contribute to the opposing health effects of leisure-time physical activity (LTPA) and occupational physical activity (OPA). As such, this study examined cross-sectional and longitudinal associations of fitness with LTPA and OPA. METHODS: This study examined fitness associations with LTPA and OPA across 13 yr in the Coronary Artery Risk Development in Young Adults study (years 7 (baseline), 10, 15, and 20 (follow-up) examinations). Fitness was measured at baseline and follow-up via symptom-limited maximal graded exercise test (GXT) duration (in seconds), whereas LTPA and OPA were self-reported during each examination. Baseline and follow-up cross-sectional associations of LTPA (low, medium, high) and OPA (0, 1-6, and ≥6 months with OPA) with fitness were examined using linear regression. Longitudinal linear regression examined associations between 13-yr LTPA (low, medium, or high) and OPA (no, decreasing, or increasing) trajectories with fitness at follow-up, adjusted for baseline values. All models adjusted for center, sex, race, age, education, smoking history, alcohol intake, resting blood pressure, diabetes status, and body mass index. Stratified analyses examined associations by sex (female/male), race (Black/White), and LTPA groups. RESULTS: Compared with low, medium, and high LTPA were positively associated with fitness in all analyses ( P < 0.001). Reporting 1-6 or ≥6 months with OPA was negatively associated with fitness in cross-sectional follow-up models ( ß = -15.6 and -15.4, respectively; P ≤ 0.01). Longitudinally, those with increasing OPA had lower follow-up fitness compared with no OPA ( ß = -16.41, P < 0.01). Negative associations of OPA with fitness were not meaningfully different across sex and race groups. Significant LTPA-OPA interactions were observed ( P < 001). CONCLUSIONS: Physical activity research and public health promotion should consider domain-specific associations on cardiovascular health.

Leisure time physical activity and bone mineral density preservation during the menopause transition and postmenopause: a longitudinal cohort analysis from the Study of Women's Health Across the Nation (SWAN).

Background: Whether greater leisure time physical activity (LTPA) is associated with less bone mineral density (BMD) loss during the menopause transition (MT) remains an open question. We hypothesized that: 1) larger increases in LTPA from pre-/early perimenopause (period 1) to late perimenopause/postmenopause (period 2) would be associated with a slower period 2 BMD loss rate; and 2) greater entire-study LTPA levels would be associated with better final absolute BMD (g/cm2). Methods: Data were from of the Study of Women's Health Across the Nation (1996-2017). Exclusions were: bone beneficial medications, inability to identify start of the MT, and extreme BMD change rates. LTPA measures were a validated ordinal scale and number of metabolic equivalents per hour per week (MET hr wk-1) from sport/exercise. Multiply adjusted, linear regression models estimated: 1) BMD decline rate (annualized %) as a function of LTPA change; and 2) final BMD as a function of entire-study LTPA. Findings: Median [p25, p75] MET hr wk-1 were 4.2 [0.9, 10.1] and 4.9 [1.4, 11.2] in periods 1 and 2, respectively; walking was the commonest activity. In adjusted models (N = 875), greater increases in LTPA ordinal score and MET hr wk-1 were statistically significantly associated with a slower decline in femoral neck (FN) BMD. Larger entire-study averages of each LTPA measure were statistically significantly related to better final FN and lumbar spine BMD levels. Interpretation: Findings suggest that LTPA, at modest levels, mitigate MT-related BMD decline and even small increases in intensity, duration or frequency of common activities may lessen bone loss at the population level. Funding: US-NIH.

The prospective association of hyperandrogenism, oligomenorrhea and polycystic ovary syndrome with incident gestational diabetes: The coronary artery risk development in young adults women's study.

In this 28-year prospective study of 455 women (mean age: 26 years), polycystic ovary syndrome (PCOS) was associated with a 2.6-fold elevated risk of gestational diabetes (GDM). However, hyperandrogenism or oligomenorrhea in the absence of PCOS was not associated with GDM.

Analysis of Cardiorespiratory Fitness in Early Adulthood and Midlife With All-Cause Mortality and Fatal or Nonfatal Cardiovascular Disease.

Importance: Optimizing cardiovascular fitness is a prevention strategy against premature death and cardiovascular disease (CVD) events. Since this evidence has largely been established in older populations, the importance of cardiorespiratory fitness during earlier periods of adulthood remains unclear. Objective: To examine the association of early-adulthood cardiorespiratory fitness and percentage of early-adulthood cardiorespiratory fitness retained during midlife with subsequent risk of all-cause mortality and CVD-related morbidity and mortality overall as well as by sex and race. Design, Setting, and Participants: This retrospective population-based cohort study analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, an ongoing prospective cohort study conducted at field center clinics in Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. Participants in the CARDIA study were aged 18 to 30 years when they completed the baseline graded exercise test protocol in 1985 to 1986 and have since undergone follow-up examinations biannually and every 2 to 5 years. Data were collected through August 31, 2020, and were analyzed in October 2022. Exposures: Cardiorespiratory fitness was estimated from a symptom-limited, maximal graded exercise test protocol conducted at baseline and at year 7 and year 20 follow-up examinations. Main Outcomes and Measures: All-cause mortality and combined fatal and nonfatal CVD events were obtained since year 20 of follow-up examinations through August 31, 2020. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) for each primary exposure with each outcome. Results: A total of 4808 participants (mean [SD] age at baseline, 24.8 [3.7] years; 2670 females [56%]; 2438 Black individuals [51%]) were included in the sample. During 68 751 person-years of follow-up, there were 302 deaths (6.3%) and 274 CVD events (5.7%) since year 20. Every 1-minute increment in cardiorespiratory fitness at baseline was associated with a lower risk of all-cause mortality in females (HR, 0.73; 95% CI, 0.64-0.82) and males (HR, 0.87; 95% CI, 0.80-0.96). Every 5% increment in cardiorespiratory fitness retained through year 20 was associated with a lower risk of all-cause mortality (HR, 0.89; 95% CI, 0.79-0.99), but no evidence of effect modification by race or sex was found. Every 1-minute increment in cardiorespiratory fitness at baseline was associated with a lower risk of fatal or nonfatal CVD (HR, 0.89; 95% CI, 0.82-0.96), and the estimated HR per 5% increment in cardiorespiratory fitness retained throughout midlife was 0.89 (95% CI, 0.78-1.00), with no evidence for interaction by race or sex. Conclusions and Relevance: This cohort study found that higher early-adulthood cardiorespiratory fitness and greater retention of early-adulthood cardiorespiratory fitness throughout midlife were associated with a lower risk of premature death and CVD events. Additional research is needed to clarify the association of cardiorespiratory fitness timing across the life course with risk of clinical outcomes.

Quantifying physical activity across the midlife: Does consideration of perceived exertion matter?

Many questionnaires ascertain physical activity (PA) frequency, duration, and intensity to benchmark achievement of PA recommendations. However, most scoring algorithms utilize absolute intensity estimates when exertion may be influenced by age or health characteristics. This study quantified PA estimates with and without adjustments for perceived exertion and evaluated if differences were associated with individual-level characteristics. Women (n = 2,711) in the United States from the Study of Women's Health Across the Nation who completed ≥ 3 Kaiser Physical Activity Surveys (KPAS) across 8 biennial visits were included (baseline age: 46.4 ± 2.7 years). KPAS responses about activity mode and exertion were converted to metabolic equivalent of a task (METs) using the 2011 Compendium of Physical Activities to estimate absolute and perceived intensity-adjusted METs. Repeated measures (linear mixed effects) regression models were used to examine associations of sociodemographic and health-related characteristics with change in the difference between absolute MET estimates and perceived intensity-adjusted MET estimates. Older age (p < 0.001), Chinese (p < 0.001) and Japanese (p = 0.01) ethnicity, and current smoking (p = 0.001) were associated with positive differences between absolute and perceived intensity-adjusted MET estimates, which is suggestive of lower perceived-intensity physical activity. However, for most participants, absolute intensity-based estimates closely approximated perceived intensity-adjusted estimates over time. Traditional PA scoring techniques using absolute intensity estimates only may provide sufficient estimates of PA in longitudinal cohort studies of mid-life and older adult women.

Factors Associated with Age-Related Declines in Cardiorespiratory Fitness from Early Adulthood Through Midlife: CARDIA.

PURPOSE: This study aimed to describe maximal and submaximal cardiorespiratory fitness from early adulthood to midlife and examine differences in maximal fitness at age 20 yr and changes in fitness overtime by subcategories of sociodemographic, behavioral, and health-related factors. METHODS: Data include 5018 Coronary Artery Risk Development in Young Adults participants (mean (SD) age, 24.8 (3.7) yr; 53.3% female; and 51.4% Black participants) who completed at least one maximal graded exercise test at baseline and/or the year 7 and 20 exams. Maximal and submaximal fitness were estimated by exercise duration and heart rate at the end of stage 2. Multivariable adjusted linear-mixed models were used to estimate fitness trajectories using age as the mechanism for time after adjustment for covariates. Fitness trajectories from ages 20 to 50 yr in 5-yr increments were estimated overall and by subgroups determined by each factor after adjustment for duration within the less favorable category. RESULTS: Mean (95% confidence interval) maximal fitness at age 20 and 50 yr was 613 (607-616) and 357 (350-362) s; submaximal heart rate during this period also reflected age-related fitness declines (126 (125-127) and 138 (137-138) bpm). Compared with men, women had lower maximal fitness at age 20 yr (P < 0.001), which persisted over follow-up (P < 0.001); differences were also found by race within sex strata (all P < 0.001). Differences in maximal fitness at age 20 yr were noted by socioeconomic, behavioral, and health-related status in young adulthood (all P < 0.05), which persisted over follow-up (all P < 0.001) and were generally consistent in sex-stratified analyses. CONCLUSIONS: Targeting individuals experiencing accelerated fitness declines with tailored intervention strategies may provide an opportunity to preserve fitness throughout midlife to reduce lifetime cardiovascular disease risk.

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.

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.

Associations of accelerometer-determined sedentary behavior and physical activity with physical performance outcomes by race/ethnicity in older women.

To determine the cross-sectional associations of accelerometer-measured time spent in physical activity intensity categories (sedentary, low and high light intensity, or moderate to vigorous intensity physical activity (MVPA) with physical performance outcomes [stair climb ascent, 40 foot walk test, and short physical performance battery (SPPB)] in older women and examine differences by race/ethnicity. Data were from 1,256 Study of Women's Health Across the Nation (SWAN) participants [aged 64.9 (2.7) years at Visit 15 (2015-16); 54.1% non-White]. Three sets of adjusted multivariable linear or logistic regression models were built to test the study objectives using the backward elimination approach to identify relevant covariates. In the full analytic sample, a 10 min increment in MVPA was related to faster performance on the stair climb [ß = -0.023 (95% CI: -0.04, -0.005) seconds] and 40 foot walk test [ß = -0.066 (95% CI: -0.133, -0.038) seconds], and a 9% lower odds [OR: 0.91; 95% CI: 0.87, 0.96; p = 0.004] of limitations based on the SPPB. Statistically significant differences by race/ethnicity were found for the stair climb ascent time as MVPA was associated with better performance for White, Chinese, and Japanese participants while high light intensity physical activity, but not MVPA, was deemed beneficial in Black women. Findings from the isotemporal substitution models were consistent. Findings further support the importance of MVPA on physical performance outcomes in older women. Further research is needed to examine the complex associations between physical (in)activity and physical performance outcomes by race/ethnicity to provide more targeted recommendations.

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.

Bidirectional associations of accelerometer measured sedentary behavior and physical activity with knee pain, stiffness, and physical function: The CARDIA study.

The objective was to examine bidirectional associations of accelerometer estimated sedentary time and physical activity with reported knee symptoms. Participants were 2,034 adults (mean age 45.3 ± 3.6 years, 58.7% female) from CARDIA. Generalized estimating equations for logistic regression and linear mixed regression models examined associations of accelerometer estimated sedentary time, light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA) at baseline (2005-06) with knee discomfort, pain, stiffness, and physical function (yes/no and continuous scores from short-form WOMAC function scale) at the 5- and 10-year follow-up exams. Linear regression models examined associations between knee symptoms at the 5-year follow-up with accelerometer estimates at the 10-year follow-up. Models were adjusted for confounders; individuals with comorbidities were excluded in sensitivity analyses. A 30 min/day increment in sedentary time at baseline was associated with lower odds of knee symptoms at the 5- and 10-year follow-up (OR: 0.95, 95% CI range: 0.92-0.98), while LPA and MVPA were associated with greater odds of knee symptoms (LPA OR range: 1.04-1.05, 95% CI range: 1.01-1.09; MVPA OR range: 1.17-1.19, 95% CI range: 1.06-1.32). Report of knee symptoms at the 5-year follow-up was associated with 13.52-17.51 (95% CI range: -29.90, -0.56) fewer minutes/day of sedentary time and 14.58-17.51 (95% CI range: 2.48, 29.38) more minutes/day of LPA at the 10-year follow-up, compared to those reporting no symptoms. Many associations were no longer statistically significant when excluding individuals with comorbidities. Findings support a bidirectional association of accelerometer estimated sedentary time and physical activity with knee symptoms across midlife.

Associations between longitudinal trajectories of insomnia symptoms and sleep duration with objective physical function in postmenopausal women: the Study of Women's Health Across the Nation.

STUDY OBJECTIVES: Examine the association between trajectories of self-reported insomnia symptoms and sleep duration over 13 years with objective physical function. METHODS: We utilized data from 1,627 Study of Women's Health Across the Nation participants, aged 61.9 ± 2.7 years at the end of the 13-year follow-up. Latent class growth models identified trajectories of insomnia symptoms (trouble falling asleep, frequent night-time awakenings, and/or early morning awakening) and sleep duration over 13 years. Physical function tests were performed at the end of the 13-year period: 40-ft walk, 4-m walk, repeated chair stand, grip strength, and balance. Multivariable regression analyses examined each physical function measure according to the insomnia symptom or sleep duration trajectory group. RESULTS: Five insomnia symptom trajectories and two sleep duration trajectories were identified. Women with a consistently high likelihood of insomnia symptoms and women with a decreased likelihood of insomnia symptoms (i.e. improving) had slower gait speed (3.5% slower 40-ft walk [consistently high], 3.7% slower 4-m walk [improving]; each p ≤ .05) than those with a consistently low likelihood of insomnia symptoms. In contrast, women with a steep increase in the likelihood of insomnia symptoms over time and women with persistent insufficient sleep duration had lower odds of having a balance problem (odds ratio [OR] = 0.36 and OR = 0.61, respectively; each p < .02) compared to those with a consistently low likelihood of insomnia symptoms and those with persistent sufficient sleep duration, respectively. CONCLUSION: These results suggest that women's sleep during midlife has important implications for maintaining physical function during the transition into older adulthood.