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BACKGROUND - The lifetime risk of heart failure (HF) is higher in the black population than in other racial groups in the United States.
METHODS AND RESULTS - We measured the Life's Simple 7 ideal cardiovascular health metrics in 4195 blacks in the JHS (Jackson Heart Study; 2000-2004). We evaluated the association of Simple 7 metrics with incident HF and left ventricular structure and function by cardiac magnetic resonance (n=1188). Mean age at baseline was 54.4 years (65% women). Relative to 0 to 2 Simple 7 factors, blacks with 3 factors had 47% lower incident HF risk (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.39-0.73; <0.0001); and those with ≥4 factors had 61% lower HF risk (HR, 0.39; 95% CI, 0.24-0.64; =0.0002). Higher blood pressure (HR, 2.32; 95% CI, 1.28-4.20; =0.005), physical inactivity (HR, 1.65; 95% CI, 1.07-2.55; =0.02), smoking (HR, 2.04; 95% CI, 1.43-2.91; <0.0001), and impaired glucose control (HR, 1.76; 95% CI, 1.34-2.29; <0.0001) were associated with incident HF. The age-/sex-adjusted population attributable risk for these Simple 7 metrics combined was 37.1%. Achievement of ideal blood pressure, ideal body mass index, ideal glucose control, and nonsmoking was associated with less likelihood of adverse cardiac remodeling by cardiac magnetic resonance.
CONCLUSIONS - Cardiovascular risk factors in midlife (specifically elevated blood pressure, physical inactivity, smoking, and poor glucose control) are associated with incident HF in blacks and represent targets for intensified HF prevention.
© 2017 American Heart Association, Inc.
The mesolimbic dopamine and opioid systems are postulated to influence the central control of physical activity motivation. We utilized selectively bred rats for high (HVR) or low (LVR) voluntary running behavior to examine (1) inherent differences in mu-opioid receptor (Oprm1) expression and function in the nucleus accumbens (NAc), (2) if dopamine-related mRNAs, wheel-running, and food intake are differently influenced by intraperitoneal (i.p.) naltrexone injection in HVR and LVR rats, and (3) if dopamine is required for naltrexone-induced changes in running and feeding behavior in HVR rats. Oprm1 mRNA and protein expression were greater in the NAc of HVR rats, and application of the Oprm1 agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) to dissociated NAc neurons produced greater depolarizing responses in neurons from HVR versus LVR rats. Naltrexone injection dose-dependently decreased wheel running and food intake in HVR, but not LVR, rats. Naltrexone (20mg/kg) decreased tyrosine hydroxylase mRNA in the ventral tegmental area and Fos and Drd5 mRNA in NAc shell of HVR, but not LVR, rats. Additionally, lesion of dopaminergic neurons in the NAc with 6-hydroxydopamine (6-OHDA) ablated the decrease in running, but not food intake, in HVR rats following i.p. naltrexone administration. Collectively, these data suggest the higher levels of running observed in HVR rats, compared to LVR rats, are mediated, in part, by increased mesolimbic opioidergic signaling that requires downstream dopaminergic activity to influence voluntary running, but not food intake.
Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.
Epidemiological evidence is accumulating that indicates greater time spent in sedentary behavior is associated with all-cause and cardiovascular morbidity and mortality in adults such that some countries have disseminated broad guidelines that recommend minimizing sedentary behaviors. Research examining the possible deleterious consequences of excess sedentary behavior is rapidly evolving, with the epidemiology-based literature ahead of potential biological mechanisms that might explain the observed associations. This American Heart Association science advisory reviews the current evidence on sedentary behavior in terms of assessment methods, population prevalence, determinants, associations with cardiovascular disease incidence and mortality, potential underlying mechanisms, and interventions. Recommendations for future research on this emerging cardiovascular health topic are included. Further evidence is required to better inform public health interventions and future quantitative guidelines on sedentary behavior and cardiovascular health outcomes.
© 2016 American Heart Association, Inc.
The purpose of this study was to examine post-diagnosis BMI, very low physical activity, and comorbidities, as predictors of breast cancer-specific and all-cause mortality. Data from three female US breast cancer survivor cohorts were harmonized in the After Breast Cancer Pooling Project (n = 9513). Delayed entry Cox proportional hazards models were used to examine the impact of three post-diagnosis lifestyle factors: body mass index (BMI), select comorbidities (diabetes only, hypertension only, or both), and very low physical activity (defined as physical activity <1.5 MET h/week) in individual models and together in multivariate models for breast cancer and all-cause mortality. For breast cancer mortality, the individual lifestyle models demonstrated a significant association with very low physical activity but not with the selected comorbidities or BMI. In the model that included all three lifestyle variables, very low physical activity was associated with a 22 % increased risk of breast cancer mortality (HR 1.22, 95 % CI 1.05, 1.42). For all-cause mortality, the three individual models demonstrated significant associations for all three lifestyle predictors. In the combined model, the strength and significance of the association of comorbidities (both hypertension and diabetes versus neither: HR 2.16, 95 % CI 1.79, 2.60) and very low physical activity (HR 1.35, 95 % CI 1.22, 1.51) remained unchanged, but the association with obesity was completely attenuated. These data indicate that after active treatment, very low physical activity, consistent with a sedentary lifestyle (and comorbidities for all-cause mortality), may account for the increased risk of mortality, with higher BMI, that is seen in other studies.
Physical activity is associated with circulating 25-hydroxyvitamin D (25(OH)D). However, the influence of activity and/or sedentary behavior on the biologically active, seco-steroid hormone 1α,25-dihydroxyvitamin D (1,25(OH)2D) is unknown. We conducted a cross-sectional analysis among ursodeoxycholic acid (UDCA) randomized trial participants (n=876) to evaluate associations between physical activity, sedentary behavior, and circulating vitamin D metabolite concentrations. Continuous vitamin D metabolite measurements and clinical thresholds were evaluated using multiple linear and logistic regression models, mutually adjusted for either 1,25(OH)2D or 25(OH)D and additional confounding factors. A statistically significant linear association between 1,25(OH)2D and moderate-vigorous physical activity per week was strongest among women (β (95% CI): 3.10 (1.51-6.35)) versus men (β (95% CI): 1.35 (0.79-2.29)) in the highest tertile of activity compared to the lowest (p-interaction=0.003). Furthermore, 25(OH)D was 1.54ng/ml (95% CI 1.09-1.98) higher per hour increase in moderate-vigorous activity (p=0.001) and odds of sufficient 25(OH)D status was higher among physically active participants (p=0.001). Sedentary behavior was not significantly associated with either metabolite in linear regression models, nor was a statistically significant interaction by sex identified. The current study identified novel associations between physical activity and serum 1,25(OH)2D levels, adjusted for 25(OH)D concentrations. These results identify the biologically active form of vitamin D as a potential physiologic mechanism related to observed population-level associations between moderate-vigorous physical activity with bone health and chronic disease risk. However, future longitudinal studies are needed to further evaluate the role of physical activity and vitamin D metabolites in chronic disease prevention.
Copyright © 2015 Elsevier Inc. All rights reserved.
Regular physical activity is effective in reducing visceral white adipose tissue (AT) inflammation and oxidative stress, and these changes are commonly associated with reduced adiposity. However, the impact of multiple periods of physical activity, intercalated by periods of inactivity, i.e., intermittent physical activity, on markers of AT inflammation and oxidative stress is unknown. In the present study, 5-wk-old male C57BL/6 mice were randomized into three groups (n = 10/group): sedentary, regular physical activity, and intermittent physical activity, for 24 wk. All animals were singly housed and fed a diet containing 45% kcal from fat. Regularly active mice had access to voluntary running wheels throughout the study period, whereas intermittently active mice had access to running wheels for 3-wk intervals (i.e., 3 wk on/3 wk off) throughout the study. At death, regular and intermittent physical activity was associated with similar reductions in visceral AT mass (approximately -24%, P < 0.05) relative to sedentary. However, regularly, but not intermittently, active mice exhibited decreased expression of visceral AT genes related to inflammation (e.g., monocyte chemoattractant protein 1), immune cell infiltration (e.g., CD68, CD11c, F4/80, CD11b/CD18), oxidative stress (e.g., p47 phagocyte oxidase), and endoplasmic reticulum stress (e.g., CCAAT enhancer-binding protein homologous protein; all P < 0.05). Furthermore, regular, but not intermittent, physical activity was associated with a trend toward improvement in glucose tolerance (P = 0.059). Collectively, these findings suggest that intermittent physical activity over a prolonged period of time may lead to a reduction in adiposity but with retention of a sedentary obese white AT and metabolic phenotype.
Copyright © 2015 the American Physiological Society.
PURPOSE - The study objective was to examine the role of physical activity (PA) and sedentary time (ST) on mortality risk among a population of low-income adults with diabetes.
METHODS - Black (n = 11,137) and white (n = 4508) men and women with diabetes from the Southern Community Cohort Study self-reported total PA levels and total ST. Participants were categorized into quartiles of total PA and total ST. Hazard ratios (HRs) and 95% confidence intervals (CIs) for subsequent mortality risk were estimated from Cox proportional hazards analysis with adjustment for potential confounders.
RESULTS - During follow-up, 2370 participants died. The multivariable risk of mortality was lower among participants in the highest quartile of PA compared with those in the lowest quartile (HR, 0.64; 95% CI: 0.57-0.73). Mortality risk was significantly increased among participants in the highest compared with the lowest quartile of ST after adjusting for PA (HR, 1.21; 95% CI: 1.08-1.37). Across sex and race groups, similar trends of decreasing mortality with rising PA and increasing mortality with rising ST were observed.
CONCLUSIONS - Although causality cannot be established from these observational data, the current findings suggest that increasing PA and decreasing ST may help extend survival among individuals with diabetes irrespective of race and sex.
Copyright © 2015 Elsevier Inc. All rights reserved.
OBJECTIVE - Patients with end-stage renal disease on maintenance hemodialysis are much more sedentary than healthy individuals. The purpose of this study was to assess the feasibility and safety of a 12-week intradialysis yoga intervention versus a kidney education intervention on the promotion of physical activity.
DESIGN AND METHODS - We randomized participants by dialysis shift to either 12-week intradialysis yoga or an educational intervention. Intradialysis yoga was provided by yoga teachers to participants while receiving hemodialysis. Participants receiving the 12-week educational intervention received a modification of a previously developed comprehensive educational program for patients with kidney disease (Kidney School). The primary outcome for this study was feasibility based on recruitment and adherence to the interventions and safety of intradialysis yoga. Secondary outcomes were to determine the feasibility of administering questionnaires at baseline and 12 weeks including the Kidney Disease-Related Quality of Life-36.
RESULTS - Among 56 eligible patients who approached for the study, 31 (55%) were interested and consented to participation, with 18 assigned to intradialysis yoga and 13 to the educational program. A total of 5 participants withdrew from the pilot study, all from the intradialysis yoga group. Two of these participants reported no further interest in participation. Three withdrawn participants switched dialysis times and therefore could no longer receive intradialysis yoga. As a result, 13 of 18 (72%) and 13 of 13 (100%) participants completed 12-week intradialysis yoga and educational programs, respectively. There were no adverse events related to intradialysis yoga. Intervention participants practiced yoga for a median of 21 sessions (70% participation frequency), with 60% of participants practicing at least 2 times a week. Participants in the educational program completed a median of 30 sessions (83% participation frequency). Of participants who completed the study (n = 26), baseline and 12-week questionnaires were obtained from 85%.
CONCLUSIONS - Our pilot study of 12-week intradialysis yoga and 12-week educational intervention reached recruitment goals but with less than targeted completion and adherence to intervention rates. This study provided valuable feasibility data to increase follow-up and adherence for future clinical trials to compare efficacy.
Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
There is limited evidence demonstrating the benefits of physical activity with regard to mortality risk or the harms associated with sedentary behavior in black adults, so we examined the relationships between these health behaviors and cause-specific mortality in a prospective study that had a large proportion of black adults. Participants (40-79 years of age) enrolled in the Southern Community Cohort Study between 2002 and 2009 (n = 63,308) were prospectively followed over 6.4 years, and 3,613 and 1,394 deaths occurred in blacks and whites, respectively. Black adults who reported the highest overall physical activity level (≥32.3 metabolic equivalent-hours/day vs. <9.7 metabolic equivalent-hours/day) had lower risks of death from all causes (hazard ratio (HR) = 0.76. 95% confidence interval (CI): 0.69, 0.85), cardiovascular disease (HR = 0.81, 95% CI: 0.67, 0.98), and cancer (HR = 0.76, 95% CI: 0.62, 0.94). In whites, a higher physical activity level was associated with a lower risk of death from all causes (HR = 0.76, 95% CI: 0.64, 0.90) and cardiovascular disease (HR = 0.69, 95% CI: 0.49, 0.99) but not cancer (HR = 0.95, 95% CI: 0.67, 1.34). Spending more time being sedentary (>12 hours/day vs. <5.76 hours/day) was associated with a 20%-25% increased risk of all-cause mortality in blacks and whites. Blacks who reported the most time spent being sedentary (≥10.5 hours/day) and lowest level of physical activity (<12.6 metabolic equivalent-hours/day) had a greater risk of death (HR = 1.47, 95% CI: 1.25, 1.71). Our study provides evidence that suggests that health promotion efforts to increase physical activity level and decrease sedentary time could help reduce mortality risk in black adults.
Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.
PURPOSE - The association between physical activity and colorectal adenoma is equivocal. This study was designed to assess the relationship between physical activity and colorectal adenoma recurrence.
METHODS - Pooled analyses from two randomized, controlled trials included 1,730 participants who completed the Arizona Activity Frequency Questionnaire at baseline, had a colorectal adenoma removed within 6 months of study registration, and had a follow-up colonoscopy during the trial. Logistic regression modeling was employed to estimate the effect of sedentary behavior, light-intensity physical activity, and moderate-vigorous physical activity on colorectal adenoma recurrence.
RESULTS - No statistically significant trends were found for any activity type and odds of colorectal adenoma recurrence in the pooled population. However, males with the highest levels of sedentary time experienced 47% higher odds of adenoma recurrence. Compared to the lowest quartile of sedentary time, the ORs (95% CIs) for the second, third, and fourth quartiles among men were 1.23 (0.88, 1.74), 1.41 (0.99, 2.01), and 1.47 (1.03, 2.11), respectively (p(trend) = 0.03). No similar association was observed for women.
CONCLUSIONS - This study suggests that sedentary behavior is associated with a higher risk of colorectal adenoma recurrence among men, providing evidence of detrimental effects of a sedentary lifestyle early in the carcinogenesis pathway.