Showing papers by "William E. Kraus published in 2018"

Moderate‐to‐Vigorous Physical Activity and All‐Cause Mortality: Do Bouts Matter?

Abstract: Background The 2008 Physical Activity Guidelines for Americans recommends that adults accumulate moderate‐to‐vigorous physical activity (MVPA) in bouts of ≥10 minutes for substantial health benefit...

Change in the Rate of Biological Aging in Response to Caloric Restriction: CALERIE Biobank Analysis.

Abstract: Biological aging measures have been proposed as proxies for extension of healthy life span in trials of geroprotective therapies that aim to slow aging. Several methods to measure biological aging show promise but it is not known if these methods are sensitive to changes caused by geroprotective therapy. We conducted analysis of two proposed methods to quantify biological aging using data from a recently concluded trial of an established geroprotector, caloric restriction. We obtained data from the National Institute on Aging CALERIE randomized trial through its public-access biobank (https://calerie.duke.edu/). The CALERIE trial randomized N = 220 nonobese adults to 25% caloric restriction (n = 145; 11.7% caloric restriction was achieved, on average) or to maintain current diet (n = 75) for 2 years. We analyzed biomarker data collected at baseline, 12-, and 24-month follow-up assessments. We applied published biomarker algorithms to these data to calculate two biological age measures, Klemera-Doubal Method Biological Age and homeostatic dysregulation. Intent-to-treat analysis using mixed-effects growth models of within-person change over time tested if caloric restriction slowed increase in measures of biological aging across follow-up. Analyses of both measures indicated caloric restriction slowed biological aging. Weight loss did not account for the observed effects. Results suggest future directions for testing of geroprotective therapies in humans.

Genetic inactivation of ANGPTL4 improves glucose homeostasis and is associated with reduced risk of diabetes

Abstract: Angiopoietin-like 4 (ANGPTL4) is an endogenous inhibitor of lipoprotein lipase that modulates lipid levels, coronary atherosclerosis risk, and nutrient partitioning. We hypothesize that loss of ANGPTL4 function might improve glucose homeostasis and decrease risk of type 2 diabetes (T2D). We investigate protein-altering variants in ANGPTL4 among 58,124 participants in the DiscovEHR human genetics study, with follow-up studies in 82,766 T2D cases and 498,761 controls. Carriers of p.E40K, a variant that abolishes ANGPTL4 ability to inhibit lipoprotein lipase, have lower odds of T2D (odds ratio 0.89, 95% confidence interval 0.85–0.92, p = 6.3 × 10−10), lower fasting glucose, and greater insulin sensitivity. Predicted loss-of-function variants are associated with lower odds of T2D among 32,015 cases and 84,006 controls (odds ratio 0.71, 95% confidence interval 0.49–0.99, p = 0.041). Functional studies in Angptl4-deficient mice confirm improved insulin sensitivity and glucose homeostasis. In conclusion, genetic inactivation of ANGPTL4 is associated with improved glucose homeostasis and reduced risk of T2D.

Ten weeks of high-intensity interval walk training is associated with reduced disease activity and improved innate immune function in older adults with rheumatoid arthritis: a pilot study

Abstract: Rheumatoid arthritis (RA) is a chronic inflammatory disease in which adults have significant joint issues leading to poor health. Poor health is compounded by many factors, including exercise avoidance and increased risk of opportunistic infection. Exercise training can improve the health of patients with RA and potentially improve immune function; however, information on the effects of high-intensity interval training (HIIT) in RA is limited. We sought to determine whether 10 weeks of a walking-based HIIT program would be associated with health improvements as measured by disease activity and aerobic fitness. Further, we assessed whether HIIT was associated with improved immune function, specifically antimicrobial/bacterial functions of neutrophils and monocytes. Twelve physically inactive adults aged 64 ± 7 years with either seropositive or radiographically proven (bone erosions) RA completed 10 weeks of high-intensity interval walking. Training consisted of 3 × 30-minute sessions/week of ten ≥ 60-second intervals of high intensity (80–90% VO2reserve) separated by similar bouts of lower-intensity intervals (50–60% VO2reserve). Pre- and postintervention assessments included aerobic and physical function; disease activity as measured by Disease Activity score in 28 joints (DAS28), self-perceived health, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR); plasma interleukin (IL)-1β, IL-6, chemokine (C-X-C motif) ligand (CXCL)-8, IL-10, and tumor necrosis factor (TNF)-α concentrations; and neutrophil and monocyte phenotypes and functions. Despite minimal body composition change, cardiorespiratory fitness increased by 9% (change in both relative and absolute aerobic capacity; p < 0.001), and resting blood pressure and heart rate were both reduced (both p < 0.05). Postintervention disease activity was reduced by 38% (DAS28; p = 0.001) with significant reductions in ESR and swollen joints as well as improved self-perceived health. Neutrophil migration toward CXCL-8 (p = 0.003), phagocytosis of Escherichia coli (p = 0.03), and ROS production (p < 0.001) all increased following training. The frequency of cluster of differentiation 14-positive (CD14+)/CD16+ monocytes was reduced (p = 0.002), with both nonclassical (CD14dim/CD16bright) and intermediate (CD14bright/CD16positive) monocytes being reduced (both p < 0.05). Following training, the cell surface expression of intermediate monocyte Toll-like receptor 2 (TLR2), TLR4, and HLA-DR was reduced (all p < 0.05), and monocyte phagocytosis of E. coli increased (p = 0.02). No changes were observed for inflammatory markers IL-1β, IL-6, CXCL-8, IL-10, CRP, or TNF-α. We report for the first time, to our knowledge, that a high-intensity interval walking protocol in older adults with stable RA is associated with reduced disease activity, improved cardiovascular fitness, and improved innate immune functions, indicative of reduced infection risk and inflammatory potential. Importantly, the exercise program was well tolerated by these patients. ClinicalTrials.gov, NCT02528344 . Registered on 19 August 2015.

Volume of Light Versus Moderate-to-Vigorous Physical Activity: Similar Benefits for All-Cause Mortality?

Abstract: Background It is unclear whether the greater benefits of moderate‐to‐vigorous physical activity (PA) over light PA are attributed to the higher‐intensity PA or simply the greater volume of PA accumulated per unit time for moderate‐to‐vigorous PA. We examined this question using estimates of the volume of light and moderate‐to‐vigorous PA in relation to all‐cause mortality. Methods and Results We used National Health and Nutrition Examination Survey 2003–2006 accelerometer records in adults (≥40 years; n=4840) and mortality data collected through 2011 (n=700 deaths). We estimated intensity‐specific PA volume using activity counts (AC) accumulated in light (100–759 AC/min), moderate‐to‐vigorous PA (≥760 AC/min), and total PA (≥100 AC/min). We examined quartiles of each exposure using Cox proportional hazard models (hazard ratios [95% confidence interval) adjusted for demographic and behavioral risk factors, health status, and body mass index. Mortality risk was less across increasing quartiles of light PA volume (AC×1000) when compared with the least quartile (AC ≤61.8); the least risk occurred in the upper quartile of light PA, AC >98.5 (hazard ratios=0.69, 95% confidence interval: 0.47, 1.00, P trend ≤0.05). The benefits for mortality risk were greater across quartiles of moderate‐to‐vigorous PA and reached a hazard ratio of 0.28 (95% confidence interval: 0.17, 0.46, P trend ≤0.05) for AC >187.9, when compared with the referent group (AC ≤50.8). Results examining various combinations of light and moderate‐to‐vigorous intensity‐specific volumes demonstrated the strong influence of total activity on mortality risk. Conclusions In this population, increasing light PA was associated with less mortality, but at an approximately equal volume of PA, moderate‐to‐vigorous PA appeared to have greater benefits.

The AMPK/p27Kip1 Axis Regulates Autophagy/Apoptosis Decisions in Aged Skeletal Muscle Stem Cells

Abstract: Summary Skeletal muscle stem cell (MuSC) function declines with age and contributes to impaired muscle regeneration in older individuals. Acting through AMPK/p27Kip1, we have identified a pathway regulating the balance between autophagy, apoptosis, and senescence in aged MuSCs. While p27Kip1 is implicated in MuSC aging, its precise role and molecular mechanism have not been elucidated. Age-related MuSC dysfunction was associated with reduced autophagy, increased apoptosis, and hypophosphorylation of AMPK and its downstream target p27Kip1. AMPK activation or ectopic expression of a phosphomimetic p27Kip1 mutant was sufficient to suppress in vitro apoptosis, increase proliferation, and improve in vivo transplantation efficiency of aged MuSCs. Moreover, activation of the AMPK/p27Kip1 pathway reduced markers of cell senescence in aged cells, which was, in part, dependent on p27Kip1 phosphorylation. Thus, the AMPK/p27Kip1 pathway likely regulates the autophagy/apoptosis balance in aged MuSCs and may be a potential target for improving muscle regeneration in older individuals.

Effects of 2 years of caloric restriction on oxidative status assessed by urinary F2-isoprostanes: The CALERIE 2 randomized clinical trial.

Abstract: Summary Calorie restriction (CR) without malnutrition slows aging in animal models. Oxidative stress reduction was proposed to mediate CR effects. CR effect on urinary F2-isoprostanes, validated oxidative stress markers, was assessed in CALERIE, a two-year randomized controlled trial. Healthy volunteers (n = 218) were randomized to prescribed 25% CR (n = 143) or ad libitum control (AL, n = 75) stratifying the randomization schedule by site, sex, and BMI. F2-isoprostanes were quantified using LC-MS/MS in morning, fasted urine specimens at baseline, at 12 and 24 months. The primary measure of oxidative status was creatinine-adjusted 2,3-dinor-iPF(2α)-III concentration, additional measured included iPF(2α)-III, iPF2a-VI, and 8,12-iso-iPF2a-VI. Intention-to-treat analyses assessed change in 2,3-dinor-iPF(2α)-III using mixed models assessing treatment, time, and treatment-by-time interaction effects, adjusted for blocking variables and baseline F2-isoprostane value. Exploratory analyses examined changes in iPF(2α)-III, iPF(2α)-VI, and 8,12-iso-iPF(2α)-VI. A factor analysis used aggregate information on F2-isoprostane values. In CR group, 2,3-dinor-iPF(2α)-III concentrations were reduced from baseline by 17% and 13% at 12 and 24 months, respectively; these changes were significantly different from AL group (p < .01). CR reduced iPF(2α)-III concentrations by 20% and 27% at 12 and 24 months, respectively (p < .05). The effects were weaker on the VI-species. CR caused statistically significant reduction in isoprostane factor at both time points, and mean (se) changes were −0.36 (0.06) and −0.31 (0.06). No significant changes in isoprostane factor were at either time point in AL group (p < .01 between-group difference). We conclude that two-year CR intervention in healthy, nonobese men and women reduced whole body oxidative stress as assessed by urinary concentrations of F2-isoprostanes.

Effects of a 12-Week mHealth Program on FunctionalCapacity and Physical Activity in Patients With PeripheralArtery Disease.

Abstract: Supervised exercise is beneficial for peripheral artery disease (PAD) patients limited by intermittent claudication (IC). However, supervised exercise for PAD remains widely underutilized. Mobile health (mHealth) provides an intermediate solution between supervised and independent home-based exercise. The purpose of this study was to determine the effects on functional capacity and physical activity patterns of a 12-week mHealth program in PAD patients with IC. Twenty patients were randomized into usual care or a 12-week mHealth intervention consisting of patient education, smartphones, and physical activity trackers. Patient education was disseminated through smartphone and a daily exercise prescription was given based on steps per day. Primary outcomes were 12-week changes in peak VO2 and claudication onset time; and changes in physical activity measured by steps per/day and minutes of exercise per/week. mHealth patients significantly increased peak VO2 from 15.2 ± 4.3 to 18.0 ± 4.8 ml/kg/min (20.3 ± 26.4%; p ≤0.05), while usual care did not change from 14.3 ± 5.4 to 14.5 ± 5.7 ml/kg/min (1.0 ± 6.9%; NS). Comparison of these changes resulted in a significant difference between groups (p ≤0.05) for peak VO2. Claudication onset time significantly increased in mHealth (320 ± 226 to 525 ± 252 seconds; ≤ 0.05), while usual care demonstrated a worsening (252 ± 256 to 231 ± 196 seconds; NS). The comparison of these group changes resulted in a significant difference (p ≤0.05). Neither steps per day or minutes of activity reached significant differences between groups. In conclusion, a 12-week mHealth program in PAD patients with IC can improve peak VO2 and claudication onset time; and mHealth interventions represent a promising alternative therapy for those patients who cannot participate in supervised exercise.

Effects of Increasing Exercise Intensity and Dose on Multiple Measures of HDL (High-Density Lipoprotein) Function

Abstract: Objective— Measures of HDL (high-density lipoprotein) function are associated with cardiovascular disease. However, the effects of regular exercise on these measures is largely unknown. Thus, we examined the effects of different doses of exercise on 3 measures of HDL function in 2 randomized clinical exercise trials. Approach and Results— Radiolabeled and boron dipyrromethene difluoride–labeled cholesterol efflux capacity and HDL-apoA-I (apolipoprotein A-I) exchange were assessed before and after 6 months of exercise training in 2 cohorts: STRRIDE-PD (Studies of Targeted Risk Reduction Interventions through Defined Exercise, in individuals with Pre-Diabetes; n=106) and E-MECHANIC (Examination of Mechanisms of exercise-induced weight compensation; n=90). STRRIDE-PD, participants completed 1 of 4 exercise interventions differing in amount and intensity. E-MECHANIC participants were randomized into 1 of 2 exercise groups (8 or 20 kcal/kg per week) or a control group. HDL-C significantly increased in the high-amount/vigorous-intensity group (3±5 mg/dL; P =0.02) of STRRIDE-PD, whereas no changes in HDL-C were observed in E-MECHANIC. In STRRIDE-PD, global radiolabeled efflux capacity significantly increased 6.2% (SEM, 0.06) in the high-amount/vigorous-intensity group compared with all other STRRIDE-PD groups (range, −2.4 to −8.4%; SEM, 0.06). In E-MECHANIC, non-ABCA1 (ATP-binding cassette transporter A1) radiolabeled efflux significantly increased 5.7% (95% CI, 1.2–10.2%) in the 20 kcal/kg per week group compared with the control group, with no change in the 8 kcal/kg per week group (2.6%; 95% CI, −1.4 to 6.7%). This association was attenuated when adjusting for change in HDL-C. Exercise training did not affect BODIPY-labeled cholesterol efflux capacity or HDL-apoA-I exchange in either study. Conclusions— Regular prolonged vigorous exercise improves some but not all measures of HDL function. Future studies are warranted to investigate whether the effects of exercise on cardiovascular disease are mediated in part by improving HDL function. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00962962 and NCT01264406.

A coding and non-coding transcriptomic perspective on the genomics of human metabolic disease

Abstract: Genome-wide association studies (GWAS), relying on hundreds of thousands of individuals, have revealed >200 genomic loci linked to metabolic disease (MD). Loss of insulin sensitivity (IS) is a key component of MD and we hypothesized that discovery of a robust IS transcriptome would help reveal the underlying genomic structure of MD. Using 1,012 human skeletal muscle samples, detailed physiology and a tissue-optimized approach for the quantification of coding (>18,000) and non-coding (>15,000) RNA (ncRNA), we identified 332 fasting IS-related genes (CORE-IS). Over 200 had a proven role in the biochemistry of insulin and/or metabolism or were located at GWAS MD loci. Over 50% of the CORE-IS genes responded to clinical treatment; 16 quantitatively tracking changes in IS across four independent studies (P = 0.0000053: negatively: AGL, G0S2, KPNA2, PGM2, RND3 and TSPAN9 and positively: ALDH6A1, DHTKD1, ECHDC3, MCCC1, OARD1, PCYT2, PRRX1, SGCG, SLC43A1 and SMIM8). A network of ncRNA positively related to IS and interacted with RNA coding for viral response proteins (P < 1 × 10-48), while reduced amino acid catabolic gene expression occurred without a change in expression of oxidative-phosphorylation genes. We illustrate that combining in-depth physiological phenotyping with robust RNA profiling methods, identifies molecular networks which are highly consistent with the genetics and biochemistry of human metabolic disease.

Relationship between baseline physical activity assessed by pedometer count and new-onset diabetes in the NAVIGATOR trial

Abstract: Objective Physical activity is related to clinical outcomes, even after adjusting for body mass, but is rarely assessed in randomized clinical trials. Research design and methods We conducted an observational analysis of data from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research trial, in which a total of 9306 people from 40 countries with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors were randomized to receive nateglinide or placebo, in a 2-by-2 factorial design with valsartan or placebo. All were asked to also participate in a detailed lifestyle modification programme and followed-up for a median of 6.4 years with progression to diabetes as a co-primary end point. Seven-day ambulatory activity was assessed at baseline using research-grade pedometers. We assessed whether the baseline amount of physical activity was related to subsequent development of diabetes in individuals with impaired glucose tolerance. Results Pedometer data were obtained on 7118 participants and 35.0% developed diabetes. In an unadjusted analysis each 2000-step increment in the average number of daily steps, up to 10 000, was associated with a 5.5% lower risk of progression to diabetes (HR 0.95, 95%CI 0.92 to 0.97), with >6% relative risk reduction after adjustment. Conclusions Physical activity should be measured objectively in pharmacologic trials as it is a significant but underappreciated contributor to diabetes outcomes. It should be a regular part of clinical practice as well.

A Genome-Wide Association Study of Idiopathic Dilated Cardiomyopathy in African Americans

Abstract: Idiopathic dilated cardiomyopathy (IDC) is the most common form of non-ischemic chronic heart failure. Despite the higher prevalence of IDC in African Americans, the genetics of IDC have been relatively understudied in this ethnic group. We performed a genome-wide association study to identify susceptibility genes for IDC in African Americans recruited from five sites in the U.S. (662 unrelated cases and 1167 controls). The heritability of IDC was calculated to be 33% (95% confidence interval: 19–47%; p = 6.4 × 10−7). We detected association of a variant in a novel intronic locus in the CACNB4 gene meeting genome-wide levels of significance (p = 4.1 × 10−8). The CACNB4 gene encodes a calcium channel subunit expressed in the heart that is important for cardiac muscle contraction. This variant has not previously been associated with IDC in any racial group. Pathway analysis, based on the 1000 genes most strongly associated with IDC, showed an enrichment for genes related to calcium signaling, growth factor signaling, neuronal/neuromuscular signaling, and various types of cellular level signaling, including gap junction and cAMP signaling. Our results suggest a novel locus for IDC in African Americans and provide additional insights into the genetic architecture and etiology.

Beet the Best

Abstract: Rationale: A primary goal of therapy for patients with peripheral artery disease (PAD) and intermittent claudication is increased ambulatory function. Supervised exercise rehabilitation was recentl...

Multi-ethnic comparisons of diabetes in heart failure with reduced ejection fraction: insights from the HF-ACTION trial and the ASIAN-HF registry.

Abstract: AIM To describe differences in patient characteristics and outcomes by ethnicity in patients with diabetes mellitus (DM) and heart failure (HF) with reduced ejection fraction (HFrEF, ejection fraction ≤35%) in a multi-ethnic cohort. METHODS AND RESULTS Patient level data from two cohorts (HF-ACTION and ASIAN-HF) were combined, and patients grouped by self-reported ethnicity. DM was defined as the presence of a clinical diagnosis and/or receiving anti-diabetic therapy. A total of 6214 (1324 whites, 674 blacks, 1297 Chinese, 1510 Indians, 717 Malays, 692 Japanese/Koreans) patients were included. The overall prevalence of DM was 39.5% (n = 2454). The prevalence of DM was lowest in whites (29.3%), followed by Japanese/Koreans (34.1%), blacks (35.9%), Chinese (42.3%), Indians (44.2%), and highest in Malays (51.9%). The correlation between age, sex, body mass index, coronary artery disease, hypertension, atrial fibrillation, peripheral vascular disease and chronic kidney disease with DM differed significantly by ethnicity (P for interaction <0.05). The strongest correlations were seen in Malay women, whites with obesity, Indians with coronary artery disease and hypertension, and blacks with chronic kidney disease. On multivariable analyses, DM was significantly associated with the composite of 1-year overall mortality/HF hospitalization (hazard ratio 1.37, 95% confidence interval 1.19-1.57; P < 0.001), with no interaction by ethnicity (P for interaction =0.31). CONCLUSIONS There is marked heterogeneity in the prevalence and correlates of DM among different ethnic groups with HF worldwide. Subgroups particularly predisposed to DM warrant special attention, since DM increases the combined risk of morbidity and mortality in all ethnicities with HF.

Effects of aerobic training with and without weight loss on insulin sensitivity and lipids.

Abstract: Purpose The purpose of this study is to evaluate the effect of exercise training with modest or greater weight loss (≥3%) or not (<3%) on insulin sensitivity, lipoprotein concentrations, and lipoprotein particle size in overweight and obese participants. Methods Adults (N = 163, body mass index: 25–37 [kg/m2]) participated in 8 months of exercise training. Insulin sensitivity, lipid concentrations, lipid particle size and other cardiometabolic variables were measured at baseline and follow-up. Participants were categorized by whether they achieved at least modest weight loss (≥ 3%) or not (<3%) following the intervention. Results A greater improvement in insulin sensitivity was observed in adults performing exercise training with at least modest weight loss (2.2 mU·l-1 ·min -1, CI: 1.5 to 2.8) compared to those who did not (0.8 mU·l-1 ·min -1, CI: 0.5 to 1.2). Similar results were observed for acute insulin response, triglycerides, non-HDL cholesterol concentration, low density lipoprotein (LDL) particle size and high density lipoprotein (HDL) particle size (p<0.05), when all exercise groups were combined. No significant results across weight loss categories were observed for LDL, HDL, glucose, or insulin levels. Conclusion The present study suggests that aerobic exercise combined with at least modest weight loss leads to greater improvements in insulin sensitivity, triglycerides as well as other non-traditional lipid risk factors (non-HDL cholesterol, HDL/LDL particle size). Clinicians should advocate patients who are overweight/obese to exercise and obtain modest weight loss for improved cardiovascular benefits.

Pilot randomized trial of a couple-based physical activity videoconference intervention for sedentary cancer survivors

Abstract: Objective Including partners in interventions to increase physical activity (PA) could promote better adherence and longer-term effects. In preparation for a future large-scale randomized controlled trial (RCT), this randomized pilot trial tested the acceptability of a novel couple-based PA intervention for breast and prostate cancer survivors and the feasibility of conducting an RCT testing the intervention. Method Twenty cancer survivors (70% female; mean age = 63.0 years, SD = 8.9) and their partners (35% female; mean age = 62.8 years, SD = 7.7) were randomized to either the intervention or waitlist control. Couples in the intervention received four videoconference sessions including training in communication and support skills and behavior change techniques. Measures of PA and partner support for exercise were collected from survivors and partners before randomization and postintervention. Survivors also completed a physical well-being measure, and intervention participants completed a treatment acceptability measure. Results Recruitment was challenging; approximately 18% of eligible survivors and their partners agreed to participate. Ninety-two percent of randomized participants completed postintervention surveys, and 78% of dyads randomized to the intervention arm completed all 4 sessions. Mean acceptability ratings were moderate to high. Mean difference scores suggested that participants in the intervention arm tended to report greater improvements in PA, partner support, and physical well-being than those in the control arm. Conclusions These preliminary findings suggest that the couple-based PA intervention was acceptable to survivors and their partners and that a large-scale RCT is likely to be feasible with modified recruitment strategies. Recommendations for improving recruitment and conducting a larger study are presented. (PsycINFO Database Record

Influence of Baseline Physical Activity Level on Exercise Training Response and Clinical Outcomes in Heart Failure: The HF-ACTION Trial.

Abstract: Objectives This study sought to evaluate the influence of baseline physical activity (PA) on responses to aerobic exercise training and clinical events in outpatients with chronic systolic heart failure (HF) from the multicenter HF-ACTION (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure) trial. Background The influence of baseline PA on exercise capacity, responses to exercise training and clinical outcomes in patients with chronic HF is unclear. Methods Of 2,130 participants who provided consent for this analysis, 1,494 patients (64%) had complete baseline PA data, using a modified version of the International Physical Activity Questionnaire–Short Form questionnaire and were included in the analysis; 742 received usual care and 752 were allocated to the exercise training group. Changes in exercise capacity, all-cause mortality and hospitalization, cardiovascular (CV) mortality and hospitalization, and CV mortality and HF hospitalization were evaluated as a function of baseline PA tertile. Results At baseline, the highest PA tertile showed greater peak oxygen uptake, cardiopulmonary exercise test duration, and 6-min walk test distance than the other 2 PA tertiles, as well as lower New York Heart Association functional class, lower Beck depression score, and lower atrial fibrillation prevalence than the lowest PA tertile. Compared to the lowest PA tertile, the middle tertile had 18% lower risk of CV death/CV hospitalizations, and the upper tertile showed 23% lower risk of CV death/HF hospitalizations. Exercise capacity and clinical outcome responses to training were similar and largely nonsignificant across baseline PA tertiles with significant benefit of training on exercise test duration for all tertiles. Conclusions In patients with chronic systolic HF, aerobic exercise training significantly improves exercise test duration to a similar extent across baseline PA tertiles. Although higher baseline PA was associated with lower risk of clinical events, no significant differences in event rates within each PA tertile were seen between subgroups randomized to exercise training versus usual care. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure [HF-ACTION]; NCT00047437 )

Short-term effects of fine particulate matter and ozone on the cardiac conduction system in patients undergoing cardiac catheterization

Abstract: Air pollution-induced changes in cardiac electrophysiological properties could be a pathway linking air pollution and cardiovascular events. The evidence of air pollution effects on the cardiac conduction system is incomplete yet. We investigated short-term effects of particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) and ozone (O3) on cardiac electrical impulse propagation and repolarization as recorded in surface electrocardiograms (ECG). We analyzed repeated 12-lead ECG measurements performed on 5,332 patients between 2001 and 2012. The participants came from the Duke CATHGEN Study who underwent cardiac catheterization and resided in North Carolina, United States (NC, U.S.). Daily concentrations of PM2.5 and O3 at each participant’s home address were predicted with a hybrid air quality exposure model. We used generalized additive mixed models to investigate the associations of PM2.5 and O3 with the PR interval, QRS interval, heart rate-corrected QT interval (QTc), and heart rate (HR). The temporal lag structures of the associations were examined using distributed-lag models. Elevated PM2.5 and O3 were associated with four-day lagged lengthening of the PR and QRS intervals, and with one-day lagged increases in HR. We observed immediate effects on the lengthening of the QTc interval for both PM2.5 and O3, as well as delayed effects for PM2.5 (lagged by 3 – 4 days). The associations of PM2.5 and O3 with the PR interval and the association of O3 with the QRS interval persisted until up to seven days after exposure. In patients undergoing cardiac catheterization, short-term exposure to air pollution was associated with increased HR and delays in atrioventricular conduction, ventricular depolarization and repolarization.

Effect of high-intensity interval training on muscle remodeling in rheumatoid arthritis compared to prediabetes.

Abstract: Sarcopenic obesity, associated with greater risk of cardiovascular disease (CVD) and mortality in rheumatoid arthritis (RA), may be related to dysregulated muscle remodeling. To determine whether exercise training could improve remodeling, we measured changes in inter-relationships of plasma galectin-3, skeletal muscle cytokines, and muscle myostatin in patients with RA and prediabetes before and after a high-intensity interval training (HIIT) program. Previously sedentary persons with either RA (n = 12) or prediabetes (n = 9) completed a 10-week supervised HIIT program. At baseline and after training, participants underwent body composition (Bod Pod®) and cardiopulmonary exercise testing, plasma collection, and vastus lateralis biopsies. Plasma galectin-3, muscle cytokines, muscle interleukin-1 beta (mIL-1β), mIL-6, mIL-8, muscle tumor necrosis factor-alpha (mTNF-α), mIL-10, and muscle myostatin were measured via enzyme-linked immunosorbent assays. An independent cohort of patients with RA (n = 47) and age-, gender-, and body mass index (BMI)-matched non-RA controls (n = 23) were used for additional analyses of galectin-3 inter-relationships. Exercise training did not reduce mean concentration of galectin-3, muscle cytokines, or muscle myostatin in persons with either RA or prediabetes. However, training-induced alterations varied among individuals and were associated with cardiorespiratory fitness and body composition changes. Improved cardiorespiratory fitness (increased absolute peak maximal oxygen consumption, or VO2) correlated with reductions in galectin-3 (r = −0.57, P = 0.05 in RA; r = −0.48, P = 0.23 in prediabetes). Training-induced improvements in body composition were related to reductions in muscle IL-6 and TNF-α (r < −0.60 and P <0.05 for all). However, the association between increased lean mass and decreased muscle IL-6 association was stronger in prediabetes compared with RA (Fisher r-to-z P = 0.0004); in prediabetes but not RA, lean mass increases occurred in conjunction with reductions in muscle myostatin (r = −0.92; P <0.05; Fisher r-to-z P = 0.026). Subjects who received TNF inhibitors (n = 4) or hydroxychloroquine (n = 4) did not improve body composition with exercise training. Exercise responses in muscle myostatin, cytokines, and body composition were significantly greater in prediabetes than in RA, consistent with impaired muscle remodeling in RA. To maximize physiologic improvements with exercise training in RA, a better understanding is needed of skeletal muscle and physiologic responses to exercise training and their modulation by RA disease–specific features or pharmacologic agents or both. ClinicalTrials.gov Identifier: NCT02528344 . Registered on August 19, 2015.

Associations Between Residential Proximity to Traffic and Vascular Disease in a Cardiac Catheterization Cohort.

Abstract: Objective— Exposure to mobile source emissions is nearly ubiquitous in developed nations and is associated with multiple adverse health outcomes. There is an ongoing need to understand the specificity of traffic exposure associations with vascular outcomes, particularly in individuals with cardiovascular disease. Approach and Results— We performed a cross-sectional study using 2124 individuals residing in North Carolina, United States, who received a cardiac catheterization at the Duke University Medical Center. Traffic-related exposure was assessed via 2 metrics: (1) the distance between the primary residence and the nearest major roadway; and (2) location of the primary residence in regions defined based on local traffic patterns. We examined 4 cardiovascular disease outcomes: hypertension, peripheral arterial disease, the number of diseased coronary vessels, and recent myocardial infarction. Statistical models were adjusted for race, sex, smoking, type 2 diabetes mellitus, body mass index, hyperlipidemia, and home value. Results are expressed in terms of the odds ratio (OR). A 23% decrease in residential distance to major roadways was associated with higher prevalence of peripheral arterial disease (OR=1.29; 95% confidence interval, 1.08–1.55) and hypertension (OR=1.15; 95% confidence interval, 1.01–1.31). Associations with peripheral arterial disease were strongest in men (OR=1.42; 95% confidence interval, 1.17–1.74) while associations with hypertension were strongest in women (OR=1.21; 95% confidence interval, 0.99–1.49). Neither myocardial infarction nor the number of diseased coronary vessels were associated with traffic exposure. Conclusions— Traffic-related exposure is associated with peripheral arterial disease and hypertension while no associations are observed for 2 coronary-specific vascular outcomes.

Combined Inflammation and Metabolism Biomarker Indices of Robust and Impaired Physical Function in Older Adults.

Abstract: Objectives To determine whether combinations of inflammatory markers are related to physical function. Design and subjects secondary analysis of baseline of three observational studies of community‐dwelling older adults Measurements The baseline data from 3 cohorts of older adults with different health and disease status were employed. Twenty markers of inflammation and metabolism were individually assessed for correlation with usual gait speed and were separated into robust and impairment quartiles. For the robustness and impairment indices, individual markers were selected using step‐wise regression over bootstrapping iterations, and regression coefficients were estimated for the markers individually and collectively as an additive score. Results We developed a robustness index involving 6 markers and an impairment index involving 8 markers corresponding positively and negatively with gait speed. Two markers, glycine and tumor necrosis factor receptor 1 (TNFR1), appeared only in the robustness index, and TNFR2; regulated on activation, normal T‐cell expressed and secreted; the amino acid factor; and matrix metallopeptidase 3; appeared only in the impairment index. Conclusion Indices of biomarkers were associated with robust and impaired physical performance but differ, in composition suggesting potential biological differences that may contribute to robustness and impairment.

Genetic Variation in Acid Ceramidase Predicts Non-completion of an Exercise Intervention.

Abstract: Genetic variation is associated with a number of lifestyle behaviours; it may be associated with adherence and individual responses to exercise training. We tested single nucleotide polymorphisms (SNPs) in the acid ceramidase gene (ASAH1) for association with subject adherence and physiologic benefit with exercise training in two well-characterised randomised, controlled 8-month exercise interventions: STRRIDE I (n = 239) and STRRIDE II (n = 246). Three ASAH1 non-coding SNPs in a linkage disequilibrium block were associated with non-completion: rs2898458(G/T), rs7508(A/G), and rs3810(A/G) were associated with non-completion in both additive (OR = 1.8, 1.8, 2.0; P < 0.05 all) and dominant (OR = 2.5, 2.6, 3.5; P < 0.05 all) models; with less skeletal muscle ASAH expression (p < 0.01) in a subset (N = 60); and poorer training response in cardiorespiratory fitness (peak VO2 change rs3810 r2 = 0.29, P = 0.04; rs2898458 r2 = 0.29, P = 0.08; rs7508 r2 = 0.28, p = 0.09); and similar in direction and magnitude in both independent exploratory and replication studies. Adherence to exercise may be partly biologically and genetically moderated through metabolic regulatory pathways participating in skeletal muscle adaptation to exercise training.

Lack of Association of a Functional Polymorphism in the Serotonin Receptor Gene With Body Mass Index and Depressive Symptoms in a Large Meta-Analysis of Population Based Studies

Abstract: The serotonin receptor 5-HTR2C is thought to be involved in the function of multiple brain structures. Consequently, the HTR2C gene has been studied extensively with respect to its association with a variety of phenotypes. One coding variant in the HTR2C gene, Cys23Ser (rs6318), has been associated with depressive symptoms. and adiposity; however, these findings have been inconsistent. The reasons for this mixed picture may be due to low statistical power or due to other factors such as failure to account for possible interacting environmental factors, such as psychosocial stress. Further, the literature around this polymorphism is marked by limited inclusion of persons of African ancestry. The present study sought to overcome these limitations and definitively determine the relationship of this polymorphism with depressive and obesity phenotypes in a large sample meta-analysis. Thus, we harmonized individual level data from 10 studies including the Women's Health Initiative, CARDIA, ARIC, Framingham Offspring, and the Jackson Heart Study, resulting in a sample of 27,161 individuals (10,457 Black women, 2,819 Black men, 7,419 White women, and 6,466 White men). We conducted a random effects meta-analysis using individual level data to examine whether the Cys23Ser variant-either directly, or conditionally depending on the level of psychosocial stress-was associated with depressive symptoms and body mass index (BMI). We found that psychosocial stress was associated with both depression and BMI, but that Cys23Ser was not directly associated with, nor did it modify the associations of psychosocial stress with depression or BMI. Thus, in the largest study of this polymorphism, we have determined that rs6318 is not associated with depression, or BMI.

Personalized Lifestyle Medicine

Abstract: Lifestyle medicine is the application of exercise, nutrition, and other lifestyle habits to maintain and improve human health. It is becoming clear that the typical elements of pharmacologic medicine apply to lifestyle medicine. These include the following principles: dosing is important; not every agent works identically in all individuals; variations in response are partly related to genetic factors. An equally important concept is apparent: the interaction between pharmacologic therapy and lifestyle approaches is just now becoming important in the application of the principles of personalized lifestyle medicine in clinical practice. Also, the principles of personalized or precision medicine apply to lifestyle medicine—the goal is the right therapy, for the right person, for the right condition, at the right time. Predicting who will respond in what manner to what lifestyle intervention in the presence or absence of pharmacologic therapy will enable precision lifestyle medicine in the future.

Relations of established aging biomarkers (IL-6, D-dimer, s-VCAM) to glomerular filtration rate and mortality in community-dwelling elderly adults.

Abstract: Background Biomarkers improving risk prediction for elderly populations with chronic kidney disease (CKD), an independent predictor of mortality, could be particularly useful. We previously observed that interleukin-6 (IL-6), D-dimer and soluble vascular adhesion molecule (s-VCAM) were independent biomarkers of mortality in elderly individuals. Therefore, we investigated whether these established biomarkers were independently associated with both estimated glomerular filtration rate (eGFR) and mortality. Methods The Established Populations for Epidemiologic Studies of the Elderly (EPESE) is a longitudinal cohort of community-dwelling elderly individuals. We investigated the association among eGFR, the biomarkers (IL-6, D-dimer and s-VCAM) and 4-year all-cause mortality using restricted cubic splines within Cox proportional hazards models. Results Among 1907 participants in EPESE, 1342 had available creatinine and biomarker measures. Incidence of all-cause mortality was 21.6%. eGFR was associated with all-cause mortality (P < 0.01); individuals at the lowest (<30 mL/min/1.73 m2) levels had the highest mortality rates. D-dimer and s-VCAM were associated (P < 0.01) with mortality, and after adjustment for IL-6, D-dimer and s-VCAM, the mortality risk varied by eGFR level. Conclusions In community-dwelling elderly individuals, we observed an association among eGFR, 4-year mortality and IL-6, D-dimer and s-VCAM. eGFR was independently associated with mortality, and the relation between eGFR and mortality was modified by IL-6, D-dimer and s-VCAM, which was most notable in individuals with severely reduced eGFR. These findings suggest that IL-6, D-dimer and s-VCAM may be useful biomarkers for improving risk prediction, but further studies are needed examining the role of these biomarkers in elderly individuals with CKD.