Response of high-sensitivity C-reactive protein to exercise training in an at-risk population

Effect of Exercise Training on Some Anti-Inflammatory Adipokines, High Sensitivity C-Reactive Protein, and Clinical Outcomes in Sedentary Adults With Metabolic Syndrome

OBJECTIVE

This study aimed to investigate the effects of aerobic interval training and resistance training on anti-inflammatory adipokines, high sensitivity C-reactive protein, and clinical outcomes in sedentary men with metabolic syndrome.

METHODS

A total of 33 sedentary men with metabolic syndrome (age: 46.2 ± 4.6 years; body mass index: 35.4 ± 1.9 kg.m2) were randomly assigned to one of 3 groups: aerobic interval training (n = 12), resistance training (n = 10), or control (n = 11). Participants in the exercise groups completed a 12-week training program, 3 sessions per week, while those in the control group maintained their sedentary lifestyle. The levels of high sensitivity C-reactive protein (hs-CRP), omentin-1, adiponectin, lipid profiles, blood pressure, glucose metabolism, body composition, and peak oxygen uptake (VO2peak) were measured at baseline and after the intervention.

RESULTS

Both aerobic interval training and resistance training significantly improved the levels of omentin-1 and adiponectin, as well as reduced inflammation, as indicated by a decrease in hs-CRP levels. Exercise training also led to significant improvements in lipid profiles, blood pressure, glucose metabolism, and body composition. Specifically, the aerobic interval training group had significantly greater increases in high-density lipoprotein cholesterol and VO2peak, as well as greater reductions in low-density lipoprotein cholesterol, triglycerides, and total cholesterol compared to the resistance training group.

CONCLUSION

Exercise training, particularly aerobic interval training and resistance training, can be an effective non-pharmacological intervention for managing inflammation and improving cardiovascular health in metabolic syndrome patients.

Effects of 12-week moderate aerobic exercise on ROCK2 activity, hs-CRP and glycemic index in obese patients with impaired glucose tolerance

BACKGROUND

Obesity is a chronic low-grade inflammatory state that is related to prediabetes, increased Rhoassociated kinase 2 (ROCK2) activity and concentration of high-sensitivity C-reactive protein (hs-CRP). Therefore, the study was conducted to investigate the effects of 12-week moderate aerobic exercise on ROCK2 activity, hs-CRP, glycosylated hemoglobin A1C (HbA1c), and glycemic index in obese patients with impaired glucose tolerance.

METHODS

In a quasi-experimental design with pre and post-test, 42 obese men with prediabetes [mean±SD, age: 44.73 ± 3.30 years, body mass index (BMI): 33.22 ± 2.05 kg/m², HbA1c: 6.29 % ± 0.75] were allocated into two randomized homogeneous groups: Aerobic training group (AT, n=22) or control group (C, n=20). Exercise group performed a moderate aerobic exercise program three sessions per week, 60 minutes per session for 12 weeks. Body mass, BMI, maximal oxygen consumption (VO₂max), serum levels of fasting blood glucose (FBG), insulin, insulin resistance (HOMA-IR), homeostasis model assessment of β-cell function (HOMA-B); HbA1c, hs-CRP, or ROCK2 activity were measured before and after the study period. The data were analyzed using repeated measures ANOVA 2×2 and paired sample t test at a significant level of p < 0.05.

RESULTS

AT caused a significant reduction in body mass (p≤ 0.001), BMI (p= 0.04), HOMA-B (p=0.003), serum levels of FBG (p= 0.002), HbA1c (p= 0.039), hs-CRP (p≤ 0.0001), and ROCK2 activity (p= 0.001). In contrast, in the same group, a significant increase was observed in VO₂max (p= 0.04).

CONCLUSION

The results of this study showed that moderate aerobic exercise was an effective and safe method to prevent type 2 diabetes and cardiovascular diseases in obese men with prediabetes by improving glucose metabolism, reduction of body mass, ROCK2 activity and serum levels of hs-CRP.

Lifestyle and Food Habits Impact on Chronic Diseases: Roles of PPARs

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that exert important functions in mediating the pleiotropic effects of diverse exogenous factors such as physical exercise and food components. Particularly, PPARs act as transcription factors that control the expression of genes implicated in lipid and glucose metabolism, and cellular proliferation and differentiation. In this review, we aim to summarize the recent advancements reported on the effects of lifestyle and food habits on PPAR transcriptional activity in chronic disease.

Effects of 1 year of exercise training versus combined exercise training and weight loss on body composition, low-grade inflammation and lipids in overweight patients with coronary artery disease: a randomized trial

Background

Dyslipidaemia and low-grade inflammation are central in atherogenesis and linked to overweight and physical inactivity. Lifestyle changes are important in secondary prevention of coronary artery disease (CAD). We compared the effects of combined weight loss and interval training with interval training alone on physical fitness, body composition, dyslipidaemia and low-grade inflammation in overweight, sedentary participants with CAD.

Methods

Seventy CAD patients, BMI 28–40 kg/m² and age 45–75 years were randomised to (1) 12 weeks’ aerobic interval training (AIT) at 90% of peak heart rate three times/week followed by 40 weeks’ AIT twice weekly or (2) a low energy diet (LED) (800–1000 kcal/day) for 8–10 weeks followed by 40 weeks’ weight maintenance including AIT twice weekly and a high-protein/low-glycaemic load diet. Effects of the intervention were evaluated by physical fitness, body weight and composition. Dyslipidaemia was described using both biochemical analysis of lipid concentrations and lipoprotein particle subclass distribution determined by density profiling. Low-grade inflammation was determined by C-reactive protein, soluble urokinase-type plasminogen activator receptor and tumour necrosis factor α. Effects on continuous outcomes were tested by mixed-models analysis.

Results

Twenty-six (74%) AIT and 29 (83%) LED + AIT participants completed the study. At baseline subject included 43 (78%) men; subjects averages were: age 63 years (6.2), body weight 95.9 kg (12.2) and VO₂peak 20.7 mL O₂/kg/min (4.9). Forty-six (84%) had pre-diabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance). LED + AIT reduced body weight by 7.2 kg (− 8.4; − 6.1) and waist circumference by 6.6 cm (− 7.7; − 5.5) compared to 1.7 kg (− 0.7; − 2.6) and 3.3 cm (− 5.1; − 1.5) after AIT (within-group p < 0.001, between-group p < 0.001 and p = 0.018, respectively). Treatments caused similar changes in VO₂peak and lowering of total cholesterol, triglycerides, non-HDL cholesterol and low-grade inflammation. A shift toward larger HDL particles was seen following LED + AIT while AIT elicited no change.

Conclusions

Both interventions were feasible. Both groups obtained improvements in VO₂peak, serum-lipids and inflammation with superior weight loss and greater central fat loss following LED + AIT. Combined LED induced weight loss and exercise can be recommended to CAD patients.

Trial registration NCT01724567, November 12, 2012, retrospectively registered (enrolment ended in April 2013).

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

Background

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.

Methods

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% VO_2reserve) separated by similar bouts of lower-intensity intervals (50–60% VO_2reserve). 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.

Results

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 (CD14^dim/CD16^bright) and intermediate (CD14^bright/CD16^positive) 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.

Conclusions

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.

Trial registration

ClinicalTrials.gov, NCT02528344. Registered on 19 August 2015.

Article Commentary: Serum C-Reactive Protein (CRP), Target for Therapy or Trouble?

High sensitivity serum C-reactive protein (hs-CRP) has come into clinical use as a marker of risk for cardiovascular disease (CVD). In addition to a role as a marker of disease, CRP has also been implicated in the pathogenesis of CVD. Specific small-molecule inhibitors of CRP have recently been developed with the intent of mitigating cardiac damage during acute myocardial infarction. However, the use of CRP, both as a risk marker and a disease target are controversial for several reasons. Serum hs-CRP concentrations can be elevated on the basis of genetics, female gender, and non-Caucasian ethnicity. It is not clear, in these contexts, that elevations of hs-CRP have any pathological significance. As a non-specific indicator of inflammation, CRP is also not a specific indicator of a single disease state such as cardiovascular disease but elevated concentrations can be seen in association with other comorbidities including obesity and pulmonary disease. In sharp contrast to the proposed inhibition of CRP for cardiovascular disease treatment, the infusion of CRP has been shown to have profound therapeutic benefits for autoimmune disease and septic shock. The balance between the risks and benefits of these competing views of the role of CRP in disease and disease therapy is reminiscent of the ongoing controversy regarding the use of non-steroidal anti-inflammatory drugs (NSAIDs) for musculoskeletal disease and their cardiovascular side effects. Soon, NSAIDs may not be the only agents about which Rheumatologists and Cardiologists may spar.

Effects of l-arginine supplementation associated with continuous or interval aerobic training on chronic heart failure rats

OBJECTIVE

Chronic heart failure (CHF) is related with exercise intolerance and impaired nitric oxide (NO) production, which can lead to several functional capacity alterations. Considering the possible superiority of aerobic interval training compared to continuous training and the capacity of l-arginine to restore the NO pathway, the aim of the present study was to investigate whether these treatments are beneficial to exercise capacity, muscle mass preservation and hemodynamic, inflammatory and oxidative stress parameters in CHF rats.

METHODS

Thirty-eight male Wistar rats post 6weeks of myocardial infarction (MI) surgery were randomly assigned into 6 CHF groups: sedentary (SED, n=6); SED+Arg (n=7); ACT (n=8); ACT+Arg (n=5); AIT (n=7); AIT+Arg (n=5). Exercise test capacity (ETC) was performed pre and post 8weeks of intervention. Supplemented rats received Arg (1g/kg) by oral gavage (7×/week). Exercise training was performed on a rat treadmill (5×/week). Hemodynamic variables, tissue collection, congestion, inflammatory cytokines, and oxidative parameters were evaluated at the end of protocols.

RESULTS

All trained groups showed a superior exercise capacity compared to SED groups on the post-intervention test (p<0.0001). Pulmonary congestion was attenuated in AIT and AIT+Arg compared with the SED group (p<0.05). Left ventricular end-diastolic pressure (LVEDP) was lower in ACT+Arg, AIT, and AIT+Arg groups than SED group (p<0.05). Association of AIT with Arg supplementation was able to improve hemodynamic responses (left ventricular systolic pressure (LVSP), systolic blood pressure (SBP), +dP/dt_max, and -dP/dt_max (p<0.05), likewise, decrease muscular and renal lipid peroxidation and tumor necrosis factor (TNF)-α, and increase interleukin (IL)-10/TNF-α plasmatic levels (p<0.01). Groups that associated aerobic exercise with Arg supplementation (ACT+Arg and AIT+Arg) revealed higher gastrocnemius mass compared to the SED group (p<0.01).

CONCLUSIONS

Both aerobic training protocols were capable to improve aerobic capacity, and the association with Arg supplementation was important to attenuate muscle loss. Moreover, interval training associated with Arg supplementation elicits greater improvements in hemodynamic parameters, contributing to reduction in pulmonary congestion, and demonstrated particular responses in the inflammatory profile and in the antioxidant status.

Neutrophil and Monocyte Bactericidal Responses to 10 Weeks of Low-Volume High-Intensity Interval or Moderate-Intensity Continuous Training in Sedentary Adults

Neutrophils and monocytes are key components of the innate immune system that undergo age-associated declines in function. This study compared the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on immune function in sedentary adults. Twenty-seven (43 ± 11 years) healthy sedentary adults were randomized into ten weeks of either a HIIT (>90% maximum heart rate) or MICT (70% maximum heart rate) group training program. Aerobic capacity (VO_2peak), neutrophil and monocyte bacterial phagocytosis and oxidative burst, cell surface receptor expression, and systemic inflammation were measured before and after the training. Total exercise time commitment was 57% less for HIIT compared to that for MICT while both significantly improved VO_2peak similarly. Neutrophil phagocytosis and oxidative burst and monocyte phagocytosis and percentage of monocytes producing an oxidative burst were improved by training similarly in both groups. Expression of monocyte but not neutrophil CD16, TLR2, and TLR4 was reduced by training similarly in both groups. No differences in systemic inflammation were observed for training; however, leptin was reduced in the MICT group only. With similar immune-enhancing effects for HIIT compared to those for MICT at 50% of the time commitment, our results support HIIT as a time efficient exercise option to improve neutrophil and monocyte function.

Association of the Composite Inflammatory Biomarker GlycA, with Exercise-Induced Changes in Body Habitus in Men and Women with Prediabetes

GlycA is a new composite measure of systemic inflammation and a predictor of many inflammatory diseases. GlycA is the nuclear magnetic resonance spectroscopy-derived signal arising from glucosamine residues on acute-phase proteins. This study aimed to evaluate how exercise-based lifestyle interventions modulate GlycA in persons at risk for type 2 diabetes. GlycA, fitness, and body habitus were measured in 169 sedentary adults (45–75 years) with prediabetes randomly assigned to one of four six-month exercise-based lifestyle interventions. Interventions included exercise prescription based on the amount (energy expenditure (kcal/kg weight/week (KKW)) and intensity (%VO_2peak). The groups were (1) low-amount/moderate-intensity (10KKW/50%) exercise; (2) high-amount/moderate-intensity (16KKW/50%) exercise; (3) high-amount/vigorous-intensity (16KKW/75%) exercise; and (4) a Clinical Lifestyle (combined diet plus low-amount/moderate-intensity exercise) intervention. Six months of exercise training and/or diet-reduced GlycA (mean Δ: −6.8 ± 29.2 μmol/L; p = 0.006) and increased VO_2peak (mean Δ: 1.98 ± 2.6 mL/kg/min; p < 0.001). Further, visceral (mean Δ: −21.1 ± 36.6 cm²) and subcutaneous fat (mean Δ: −24.3 ± 41.0 cm²) were reduced, while liver density (mean Δ: +2.3 ± 6.5HU) increased, all p < 0.001. When including individuals in all four interventions, GlycA reductions were associated with reductions in visceral adiposity (p < 0.03). Exercise-based lifestyle interventions reduced GlycA concentrations through mechanisms related to exercise-induced modulations of visceral adiposity. This trial is registered with Clinical Trial Registration Number NCT00962962.

Very short/short-term benefit of inpatient/outpatient cardiac rehabilitation programs after coronary artery bypass grafting surgery

BACKGROUND

Exercise-based rehabilitation is an important part of treatment patients following coronary artery bypass graft (CABG) surgery.

HYPOTHESIS

To evaluate effect of very short/short-term exercise training on cardiopulmonary exercise testing (CPET) parameters.

METHODS

We studied 54 consecutive patients with myocardial infarction (MI) treated with CABG surgery referred for rehabilitation. The study population consisted of 50 men and 4 women (age 57.72 ± 7.61 years, left ventricular ejection fraction 55% ± 5.81%), who participated in a 3-week clinical and 6-month outpatient cardiac rehabilitation program. The Inpatient program consisted of cycling 7 times/week and daily walking for 45 minutes. The outpatient program consisted mainly of walking 5 times/week for 45 minutes and cycling 3 times/week. All patients performed symptom-limited CPET on a bicycle ergometer with a ramp protocol of 10 W/minute at the start, for 3 weeks, and for 6 months.

RESULTS

After 3 weeks of an exercise-based cardiac rehabilitation program, exercise tolerance improved as compared to baseline, as well as peak respiratory exchange ratio. Most importantly, peak VO₂ (16.35 ± 3.83 vs 17.88 ± 4.25 mL/kg/min, respectively, P < 0.05), peak VCO₂ (1.48 ± 0.40 vs 1.68 ± 0.43, respectively, P < 0.05), peak ventilatory exchange (44.52 ± 11.32 vs 52.56 ± 12.37 L/min, respectively, P < 0.05), and peak breathing reserve (52.00% ± 13.73% vs 45.75% ± 14.84%, respectively, P < 0.05) were also improved. The same improvement trend continued after 6 months (respectively, P < 0.001 and P < 0.0001). No major adverse cardiac events were noted during the rehabilitation program.

CONCLUSIONS

Very short/short-term exercise training in patients with MI treated with CABG surgery is safe and improves functional capacity.

Physical Activity and Obesity: Their Interaction and Implications for Disease Risk and the Role of Physical Activity in Healthy Weight Management

The prevalence of overweight and obesity is increasing at an epidemic rate. Increased adiposity, especially central or visceral adiposity, is predictive of cardiovascular disease/coronary heart disease, metabolic syndrome, and type 2 diabetes mellitus. The increased risk for cardiovascular disease/coronary heart disease and metabolic abnormalities associated with abdominal obesity may be mediated, at least in part, by increased systemic inflammation. Greater physical activity and/or fitness may reduce inflammation associated with greater visceral adiposity. Increased adiposity and low levels of physical activity and/or fitness are risk factors for atherosclerotic disease and type 2 diabetes, as well as the increased mortality associated with them. Increased physical activity/fitness reduces disease and mortality risk regardless of body mass index but does not completely abrogate the risks associated with obesity. Both moderate to vigorous physical activity and weight loss independently reduce the risk for type 2 diabetes and improve glucose/insulin metabolism via di ferent mechanisms. Physical activity on the order of 2500 to 2800 kcal/wk may be necessary to prevent weight gain or maintain weight loss. Strength training is recommended as an adjunct to regular aerobic exercise but not as the primary mode of exercise for weight loss. Individuals are strongly encouraged to engage in regular physical activity because of the known health benefits, regardless of whether that activity results in weight loss.

Effects of exercise on c-reactive protein in healthy patients and in patients with heart disease: A meta-analysis

Decreases in circulating hsCRP have been associated with increased physical activity and exercise training, although the ability of exercise interventions to reduce hsCRP and which individuals benefit the most remains unclear. This meta-analysis evaluates the ability of exercise to reduce hsCRP levels in healthy individuals and in individuals with heart disease. A systematic review and meta-analysis was conducted that included exercise interventions trials from 1995 to 2012. Forty-three studies were included in the final analysis for a total of 3575 participants. Exercise interventions significantly reduced hsCRP (standardized mean difference -0.53 mg/L; 95% CI, -0.74 to -0.33). Results of sub-analysis revealed no significant difference in reductions in hsCRP between healthy adults and those with heart disease (p = .20). Heterogeneity between studies could not be attributed to age, gender, intervention length, intervention type, or inclusion of diet modification. Exercise interventions reduced hsCRP levels in adults irrespective of the presence of heart disease.​.

A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity

BACKGROUND

Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR.

METHODS

To determine CR's feasibility, safety, and effects on predictors of longevity, disease risk factors, and quality of life in nonobese humans aged 21-51 years, 218 persons were randomized to a 2-year intervention designed to achieve 25% CR or to AL diet. Outcomes were change from baseline resting metabolic rate adjusted for weight change ("RMR residual") and core temperature (primary); plasma triiodothyronine (T3) and tumor necrosis factor-α (secondary); and exploratory physiological and psychological measures.

RESULTS

Body mass index averaged 25.1 (range: 21.9-28.0 kg/m(2)). Eighty-two percent of CR and 95% of AL participants completed the protocol. The CR group achieved 11.7±0.7 %CR (mean ± standard error) and maintained 10.4±0.4% weight loss. Weight change in AL was negligible. RMR residual decreased significantly more in CR than AL at 12 months (p = .04) but not 24 months (M24). Core temperature change differed little between groups. T3 decreased more in CR at M12 and M24 (p < .001), while tumor necrosis factor-α decreased significantly more only at M24 (p = .02). CR had larger decreases in cardiometabolic risk factors and in daily energy expenditure adjusted for weight change, without adverse effects on quality of life.

CONCLUSIONS

Sustained CR is feasible in nonobese humans. The effects of the achieved CR on correlates of human survival and disease risk factors suggest potential benefits for aging-related outcomes that could be elucidated by further human studies.

A pilot study to investigate if New Zealand men with prostate cancer benefit from a Mediterranean-style diet

Carcinoma of the prostate is the most commonly diagnosed malignancy and the third leading cause of mortality in New Zealand men, making it a significant health issue in this country. Global distribution patterns suggest that diet and lifestyle factors may be linked to the development and progression of this cancer. Twenty men with diagnosed prostate cancer adhered to a Mediterranean diet, with specific adaptations, for three months. Prostate-specific antigen, C-reactive protein and DNA damage were evaluated at baseline and after three months of following the diet. Dietary data were collated from diet diaries and an adaptation of a validated Mediterranean diet questionnaire. A significant reduction in DNA damage compared to baseline was apparent, with particular benefit noted for overall adherence to the diet (p = 0.013), increased intake of folate (p = 0.023), vitamin C (p = 0.007), legumes (p = 0.004) and green tea (p = 0.002). Higher intakes of red meat and dairy products were inversely associated with DNA damage (p = 0.003 and p = 0.008 respectively). The results from this small feasibility study suggest that a high-antioxidant diet, modelled on Mediterranean traditions, may be of benefit for men with prostate cancer. Protection against DNA damage appears to be associated with the diet implemented, ostensibly due to reduction in reactive oxidant species. These findings warrant further exploration in a longer trial, with a larger cohort.

Aerobic exercise and weight loss reduce vascular markers of inflammation and improve insulin sensitivity in obese women

OBJECTIVES

To examine the relationships between plasma and tissue markers of systemic and vascular inflammation and obesity and insulin resistance and determine the effects of aerobic exercise training plus weight loss (AEX+WL) and weight loss (WL) alone on these biomarkers.

DESIGN

Prospective controlled study.

SETTING

Veterans Affairs Medical Center and University research setting.

PARTICIPANTS

Overweight and obese sedentary postmenopausal women (N = 77).

INTERVENTIONS

Six months, 3 d/wk AEX+WL (n = 37) or WL (n = 40).

MEASUREMENTS

Total-body dual-energy X-ray absorptiometry, abdominal computed tomography, hyperinsulinemic-euglycemic clamps (a criterion standard method of assessing insulin sensitivity), adipose tissue biopsies (n = 28), and blood for homeostasis model assessment-insulin resistance, and soluble forms of intracellular adhesion molecule 1 (sICAM-1) and vascular cell adhesion molecule 1 (sVCAM-1), C-reactive protein (CRP), and serum amyloid A (SAA).

RESULTS

Body weight (P < .001), percentage of fat (P < .001), visceral fat (P < .005), triglyceride levels (P < .001), and systolic blood pressure decreased comparably after WL and AEX+WL (P = .04). Maximal oxygen consumption increased 16% after AEX+WL (P < .001). Insulin resistance decreased in both groups (P = .005). Glucose utilization according to the clamp increased 10% (P = .04) with AEX+WL and 8% with WL (P = .07). AEX+WL decreased CRP by 29% (P < .001) and WL by 21% (P = .02). SAA levels decreased twice as much after AEX+WL (-19%, P = .02) as after WL (-9%, P = .08). Plasma sICAM-1 and sVCAM-1 levels did not change, but women with the greatest reduction in plasma sICAM-1 levels had the greatest reductions in fasting glucose (P = .02), insulin (P = .02), and insulin resistance (P = .004). Gluteal ICAM messenger ribonucleic acid levels decreased 27% after AEX+WL (P = .02) and did not change after WL.

CONCLUSION

Obesity and insulin resistance worsen markers of systemic and vascular inflammation. A reduction in plasma sICAM-1 is important to improve insulin sensitivity. CRP, SAA, and tissue ICAM decrease with exercise and weight loss, suggesting that exercise training is a necessary component of lifestyle modification in obese postmenopausal women.

The effects of exercise on cardiovascular biomarkers in patients with chronic heart failure

BACKGROUND

Exercise training is recommended for chronic heart failure (HF) patients to improve functional status and reduce risk of adverse outcomes. Elevated plasma levels of amino-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), and cardiac troponin T (cTnT) are associated with increased risk of adverse outcomes in this patient population. Whether exercise training leads to improvements in biomarkers and how such improvements relate to clinical outcomes are unclear.

METHODS AND RESULTS

Amino-terminal pro-brain natriuretic peptide, hs-CRP, and cTnT levels were assessed at baseline and 3 months in a cohort of 928 subjects from the HF-ACTION study, a randomized clinical trial of exercise training versus usual care in chronic HF patients with reduced left ventricular ejection fraction (<35%). Linear and logistic regressions were used to assess 3-month biomarker levels as a function of baseline value, treatment assignment (exercise training vs usual care), and volume of exercise. Linear regression and Cox proportional hazard modeling were used to evaluate the relations between changes in biomarker levels and clinical outcomes of interest that included change in peak oxygen consumption (peak VO2), hospitalizations, and mortality. Exercise training was not associated with significant changes in levels of NT-proBNP (P = .10), hs-CRP (P = .80), or detectable cTnT levels (P = .83) at 3 months. Controlling for baseline biomarker levels or volume of exercise did not alter these findings. Decreases in plasma concentrations of NT-proBNP, but not hs-CRP or cTnT, were associated with increases in peak VO2 (P < .001) at 3 months and decreased risk of hospitalizations or mortality (P ≤ .04), even after adjustment for a comprehensive set of known predictors.

CONCLUSIONS

Exercise training did not lead to meaningful changes in biomarkers of myocardial stress, inflammation, or necrosis in patients with chronic HF. Only improvements in NT-proBNP translated to reductions in peak VO2 and reduced risk of clinical events.

Rapid upregulation and clearance of distinct circulating microRNAs after prolonged aerobic exercise

Short nonprotein coding RNA molecules, known as microRNAs (miRNAs), are intracellular mediators of adaptive processes, including muscle hypertrophy, contractile force generation, and inflammation. During basal conditions and tissue injury, miRNAs are released into the bloodstream as "circulating" miRNAs (c-miRNAs). To date, the impact of extended-duration, submaximal aerobic exercise on plasma concentrations of c-miRNAs remains incompletely characterized. We hypothesized that specific c-miRNAs are differentially upregulated following prolonged aerobic exercise. To test this hypothesis, we measured concentrations of c-miRNAs enriched in muscle (miR-1, miR-133a, miR-499-5p), cardiac tissue (miR-208a), and the vascular endothelium (miR-126), as well as those important in inflammation (miR-146a) in healthy male marathon runners (N = 21) at rest, immediately after a marathon (42-km foot race), and 24 h after the race. In addition, we compared c-miRNA profiles to those of conventional protein biomarkers reflective of skeletal muscle damage, cardiac stress and necrosis, and systemic inflammation. Candidate c-miRNAs increased immediately after the marathon and declined to prerace levels or lower after 24 h of race completion. However, the magnitude of change for each c-miRNA differed, even when originating from the same tissue type. In contrast, traditional biomarkers increased after exercise but remained elevated 24 h postexercise. Thus c-miRNAs respond differentially to prolonged exercise, suggesting the existence of specific mechanisms of c-miRNA release and clearance not fully explained by generalized cellular injury. Furthermore, c-miRNA expression patterns differ in a temporal fashion from corollary conventional tissue-specific biomarkers, emphasizing the potential of c-miRNAs as unique, real-time markers of exercise-induced tissue adaptation.

Acute exercise and training alter blood lipid and lipoprotein profiles differently in overweight and obese men and women

Our purpose was to elucidate effects of acute exercise and training on blood lipids-lipoproteins, and high-sensitivity C-reactive protein (hsCRP) in overweight/obese men (n = 10) and women (n = 8); age, BMI, body fat percentage, and VO(2)max were (mean ± SEM): 45 ± 2.5 years, 31.9 ± 1.4 kg·m(-2), 41.1 ± 1.5%, and 25.2 ± 1.3 mlO(2)·kg(-1)·min(-1). Before exercise training subjects performed an acute exercise session on a treadmill (70% VO(2)max, 400 kcal energy expenditure), followed by 12 weeks of endurance exercise training (land-based or aquatic-based treadmill): 3 sessions·week(-1), progressing to 500 kcal·session(-1) during which subjects maintained accustomed dietary habits. After training, the acute exercise session was repeated. Blood samples, obtained immediately before and 24 h after acute exercise sessions, were analyzed for serum lipids, lipoproteins, and hsCRP adjusted for plasma volume shifts. Exercise training increased VO(2)max (+3.67 mlO(2)·kg(-1)·min(-1), P < 0.001) and reduced body weight (-2.7 kg, P < 0.01). Training increased high-density lipoprotein (HDL) and HDL(2b)-cholesterol (HDL-C) concentrations (+3.7 and +2.4 mg·dl(-1), P < 0.05) and particle numbers (+588 and +206 nmol·l(-1), P < 0.05) in men. In women despite no change in total HDL-C, subfractions shifted from HDL(3)-C (-3.2, P < 0.01) to HDL(2b)-C (+3.5, P < 0.05) and HDL(2a)-C (+2.2 mg·dl(-1), P < 0.05), with increased HDL(2b) particle number (+313 nmol·l(-1), P < 0.05). Training reduced LDL(3) concentration and particle number in women (-1.6 mg·dl(-1) and -16 nmol·l(-1), P < 0.05). Acute exercise reduced the total cholesterol (TC): HDL-C ratio in men (-0.16, P < 0.01) and increased hsCRP in all subjects (+0.05 mg·dl(-1), P < 0.05), regardless of training. Training did not affect acute exercise responses. Our data support the efficacy of endurance training, without dietary intervention, to elicit beneficial changes in blood lipids-lipoproteins in obese men and women.

Inflammation, aging, and adiposity: implications for physical therapists

BACKGROUND

Physical therapists treat older individuals, characterized as both a needy and expanding population. Frailty, a predisability condition with links to chronic inflammatory conditions, is estimated to affect 7% of individuals older than 60 years and 40% of people older than 80 years. Chronic inflammation is one of the most important physiologic correlates of the frailty syndrome and high levels of proinflammatory cytokines, related to both aging and increasing adiposity in older individuals are related to an increased risk of mortality, sarcopenia, reduced muscle strength and decreased mobility.

PURPOSE

The purpose of this narrative review is to inform the physical therapist of the effects of aging and increasing adiposity on chronic inflammation and the association of inflammation with muscle loss, strength, and mobility impairments in older adults; and to review the current evidence to provide clinical recommendations on physical activity and exercise regimes that may mitigate chronic inflammation in older adults.

DISCUSSION

As physical therapists help manage and treat an increasingly older population, understanding how the inflammatory milieu changes with aging and increasing adiposity and how these changes can be impacted by physical therapists via exercise and physical activity is critical.

CONCLUSION

Exercise is a potent preventive intervention strategy and countermeasure for chronic inflammation and adiposity. Exercise can also benefit the frail older individual by combating the negative effects of chronic inflammation and optimally balancing the production of pro and anti-inflammatory cytokines. In addition to providing an anti-inflammatory environment within muscle to mitigate the effects of chronic inflammation, exercise has the added benefit of improving muscle mass and function and decreasing adiposity in older adults.

Effects of physical activity on cardiovascular disease

Much attention has been directed toward lifestyle modifications as effective means of reducing cardiovascular disease risk. In particular, physical activity has been heavily studied because of its well-known effects on metabolic syndrome, insulin sensitivity, cardiovascular disease risk, and all-cause mortality. However, data regarding the effects of exercise on various stages of the atherosclerosis pathway remain conflicting. The investigators review previously published reports for recent observational and interventional trials investigating the effects of physical activity on markers of (or causal factors for) atherosclerotic burden and vascular disease, including serum lipoproteins, systemic inflammation, thrombosis, coronary artery calcium, and carotid intima-media thickness. In conclusion, the data show a correlation between physical activity and triglyceride reduction, apolipoprotein B reduction, high-density lipoprotein increase, change in low-density lipoprotein particle size, increase in tissue plasminogen activator activity, and decrease in coronary artery calcium. Further research is needed to elucidate the effect of physical activity on inflammatory markers and intima-media thickness.

Impact of physical activity, cardiorespiratory fitness, and exercise training on markers of inflammation

Physical activity and exercise training (ET) enhance overall cardiorespiratory fitness (ie, fitness), thus producing many benefits in the primary and secondary prevention of cardiovascular diseases. Substantial evidence also indicates that acute and chronic inflammation is involved in the development and progression of atherosclerosis and major cardiovascular events. The most commonly utilized marker of inflammation is C-reactive protein (CRP). In this review, we discuss the importance of inflammation, especially CRP, as a cardiovascular risk marker by reviewing an abundant cross-sectional and clinical intervention literature providing evidence that physical activity, enhanced fitness, and ET are inversely associated with CRP and that being overweight or obese is directly related with inflammation/CRP. Although we discuss the controversy regarding whether or not ET reduces CRP independent of weight loss, clearly physical activity, improved fitness, and ET are associated with reductions in inflammation and overall cardiovascular risk in both primary and secondary prevention.

Sixteen weeks of exercise reduces C-reactive protein levels in young women

PURPOSE

Regular exercise has been shown to protect against breast cancer risk, and one possible mechanism is through a reduction in inflammation. The purpose of this study was to examine the effects of 16 wk of aerobic exercise training on adipokines and inflammatory markers in healthy young women.

METHODS

Participants were 319 sedentary women aged 18-30 yr, with body mass index of 18-40 kg · m, randomized to an exercise intervention or no exercise for approximately 16 wk. Adiponectin, leptin, C-reactive protein (CRP), and amyloid A (AA) were measured at baseline and after 16 wk. Adiponectin was measured by enzyme-linked immunosorbent assay, and AA, CRP, and leptin were measured by multiplex bead array assays.

RESULTS

Exercise significantly decreased CRP levels in the exercise group compared with the control group (-1.41 mg · L in exercisers vs -0.005 mg · L in controls, P = 0.040), and this effect was largely driven by changes in CRP that occurred in the obese exercisers. There was no effect of exercise on levels of SAA, adiponectin, or leptin. There was also no effect of exercise on stress and depression scores. Neither change in percent body fat nor change in fitness influenced the effects of exercise on these inflammatory markers.

CONCLUSIONS

This study demonstrated that a 16-wk aerobic exercise program significantly decreased levels of CRP in young women, especially in those who were obese. There was no evidence that this effect was mediated by changes in perceived stress, percent body fat, or fitness. These findings suggest that adopting an exercise routine early in life may decrease future risk of breast cancer and other chronic diseases in obese women.

Effects of different doses of physical activity on C-reactive protein among women

Elevated C-reactive protein (CRP) is associated with an increased risk of cardiovascular disease. Physical activity has been inversely associated with CRP. However, the clinical trials examining the effect of exercise training have produced conflicting results.

PURPOSE

The purpose of this study was to examine the influence an exercise training program on CRP in postmenopausal women.

METHODS

Sedentary, overweight, or obese postmenopausal women with elevated systolic blood pressure (120-160 mm Hg; n = 464) were randomized into one of four groups: a nonexercise control or one of three aerobic exercise groups; exercise energy expenditure of 4, 8, or 12 kcal·kg(-1)·wk(-1) (KKW) for 6 months at a training intensity of 50% of peak VO2.

RESULTS

Complete data for 421 participants were available, and mean (SD) baseline CRP was 5.7 (5.5) mg·L(-1), with no significant differences across groups. Although VO2 increased in a dose-response manner, there were no significant changes in CRP in any of the exercise intervention groups compared with the control group. Change in fitness was not associated with change in CRP, whereas change in weight was significantly associated with change in CRP.

CONCLUSIONS

Despite increasing fitness, 6 months of aerobic exercise training did not improve CRP. However, improvements in CRP were associated with reductions in weight.

Obesity paradox in elderly patients with cardiovascular diseases

Many elderly people are affected by cardiovascular diseases (CVD) and the majority of CVD patients are elderly people. For both patient populations, studies have shown that a high body mass index (BMI) is associated with lower mortality when compared to normal weight subjects, a fact commonly known as the "obesity paradox". Whether the correlation between obesity and better survival is based on methodological influences and other non-causal factors alone, or whether there is a causal link between obesity and a better survival in these subjects remains widely unexplored. The interrelation between aging, obesity, CVD, frailty and inflammation is a current issue of intensive research. For the elderly, parameters which include measures of body composition, fat and fat-free mass are of greater importance than BMI. Weight management in elderly people with cardiovascular diseases should aim at improvement and maintenance of physical function and quality of life rather than prevention of medical problems associated with obesity in younger and middle aged patients. Although many studies have shown that weight loss in elderly patients is associated with a poor prognosis, recent data demonstrate that intentional weight reduction in obese elderly people ameliorates the cardiovascular risk profile, reduces chronic inflammation and is correlated with an improved quality of life. An individual approach to weight management that includes the participation of the patient, co-morbidity, functional status, and social support should be aspired.

Time course of changes in inflammatory markers during a 6-mo exercise intervention in sedentary middle-aged men: a randomized-controlled trial

Regular exercise may improve systemic markers of chronic inflammation, but direct evidence and dose-response information is lacking. The objective of this study was to examine the effect and time course of changes in markers of chronic inflammation in response to progressive exercise training (and subsequent detraining). Forty-one sedentary men 45-64 yr of age completed either a progressive 24-wk exercise intervention or control followed by short-term removal of the intervention (2-wk detraining). Serum IL-6 fell by -0.4 pg/ml (SD 0.6) after 12 wk and responded to moderate-intensity exercise. Serum alanine aminotransferase (ALT) activity fell -7 U/l (SD 11) at 24 wk although there was no evidence of any change by week 12 (and therefore ALT required more vigorous-intensity activity and/or a more prolonged intervention). The effect on IL-6 was lost after 2-wk detraining whereas the change in ALT was retained. The temporal fall and rise in IL-6 with training and subsequent detraining in men with high IL-6 at baseline provided a retrospective opportunity to examine parallel genomic changes in peripheral mononuclear cells. A subset of 53 probes was differentially regulated by at least twofold after training with 31 of these changes being lost after detraining (n = 6). IL-6 responded quickly to the carefully monitored exercise intervention (within weeks) and required only moderate-intensity exercise, whereas ALT took longer to change and/or required more vigorous-intensity exercise. Further work is required to determine whether any of the genes that temporally changed in parallel with changes in IL-6 are a cause or consequence of this response.

The influence of cardiac rehabilitation on inflammation and metabolic syndrome in women with coronary heart disease

BACKGROUND

Metabolic syndrome (MetS) and increased inflammatory markers, both predictors of future cardiovascular events, are more prevalent in women with coronary heart disease (CHD). The influence of cardiac rehabilitation (CR) on MetS and inflammatory biomarkers is not well characterized for women.

PURPOSE

: The purpose of this article was to examine the effects of a 12-week behaviorally enhanced CR exclusively for women compared with traditional CR on components of the MetS and inflammatory markers in women with CHD.

METHODS

The randomized clinical trial used 2 treatment groups, both receiving a comprehensive 12-week CR program, with 1 group receiving a motivationally enhanced intervention exclusively for women. A subset of 91 women (mean age, 61.6 years) from the parent study provided serum samples to examine the effects of CR on high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and intercellular adhesion molecule-1 (ICAM-1).

RESULTS

After CR, the total sample of women demonstrated significant reductions in hsCRP (P =.002), IL-6 (P <.001), TNF-alpha (P =.010), and ICAM-1 (P =.016). Women in the gender-tailored CR program significantly improved all biomarker levels compared with baseline (P <.05 for all), whereas those in the traditional group improved only hsCRP (P <.05) and IL-6 (P <.05) levels. The combined study group demonstrated improvements in several components of MetS (triglycerides, waist circumference, and systolic blood pressure) but not in others (high-density lipoprotein cholesterol, fasting glucose, and diastolic blood pressure).

CONCLUSION

Cardiac rehabilitation promotes greater improvements in inflammatory biomarkers than in components of MetS for women with CHD. Improvements in body composition or weight may not be a precondition for the benefits of exercise because of loss of abdominal fat. Examining components of MetS as continuous variables is recommended to prevent lost information inherent in dichotomization.

Cardiorespiratory fitness and metabolic risk factors in obesity

PURPOSE OF REVIEW

An increase in cardiorespiratory fitness (CRF) through exercise training appears to partly ameliorate the health hazards of obesity and a number of mechanisms might explain the potential benefits. We review recent evidence about the relationships between CRF, exercise training and metabolic risk factors in obesity.

RECENT FINDINGS

Epidemiological data have shown that the anti-inflammatory effects of exercise could be an important mechanism in explaining cardio-protective effects of physical activity. Emerging evidence suggests that exercise training reduces markers of inflammation and improves glucose control in obesity, independent of weight loss. Novel mechanisms appear to involve exercise-induced changes in CD14+CD16+ cell populations, expression of toll-like receptors, and key changes in the metabolic regulation of visceral white adipose tissue. Other promising recent research has focused on exercise-induced signalling pathways governing glucose metabolism, such as insulin receptor substrate and Akt substrate. Using novel imaging techniques, studies have demonstrated exercise-induced improvements in lipoprotein subfraction particle size, and reduction in visceral adipose tissue and liver fat, independent of weight loss. These effects appear to be mostly restricted to interventions consisting of relatively high doses of exercise or exercise combined with calorie restriction, although further work is required to elucidate the dose-response relationships.

SUMMARY

Physical activity and the pursuit of physical fitness are important in the treatment of obesity because exercise training can improve a number of metabolic risk factors independent of weight loss. Thus exercise can provide important health benefits irrespective of weight loss in obese and overweight individuals.

Changes in C-reactive protein from low-fat diet and/or physical activity in men and women with and without metabolic syndrome

Change in high-sensitivity C-reactive protein (CRP) from low-fat diet (diet) and physical activity (PA) interventions is relatively unknown for adults with metabolic syndrome. The objective of the study was to assess CRP change (DeltaCRP) with diet and/or PA in men and women with and without metabolic syndrome. Men (n = 149) and postmenopausal women (n = 125) with elevated low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol were recruited into a 1-year randomized controlled trial. Treatment groups were as follows: control, diet (reduced total fat, saturated fat, and cholesterol intake), PA (45-60 minutes at 60%-85% maximum heart rate), or diet + PA. Weight loss was not an intervention focus. Metabolic syndrome was defined using the American Heart Association/National Heart, Lung, and Blood Institute criteria. Stored plasma samples were analyzed for CRP. Change in CRP was compared between treatments, within sex and metabolic syndrome status, using analysis of covariance, including covariates for baseline CRP and body fat change. For women with metabolic syndrome (n = 39), DeltaCRP was greater in diet vs control (-1.2 +/- 0.4, P = .009), diet + PA vs control (-1.3 +/- 0.4, P = .006), and diet + PA vs PA (-1.1 +/- 0.4, P = .02). Women with metabolic syndrome receiving the diet component (diet or diet + PA) had greater DeltaCRP compared with those who did not (control or PA) (P = .001). Change in CRP was not significantly different between intervention groups in men overall, women overall, men with (n = 47) or without metabolic syndrome (n = 102), or women without metabolic syndrome (n = 86). Low-fat diet may be the most effective treatment for reducing CRP in women with metabolic syndrome.

Is exercise training an effective therapy targeting endothelial dysfunction and vascular wall inflammation?

There is an increasing evidence that endothelial dysfunction and vascular wall inflammation are present in all stages of atherosclerosis. Atherosclerosis does not have to necessarily progress to an acute clinical event. Several therapeutic strategies exist, such as exercise training, which mitigates endothelial dysfunction and inflammation. Exercise training consistently improves the nitric oxide bioavailability, and the number of endothelial progenitor cells, and also diminishes the level of inflammatory markers, namely pro-inflammatory cytokines and C-reactive protein. However, the mechanisms by which exercise improves endothelial function in coronary artery disease patients are not fully clarified. Several mechanisms have been proposed to explain the positive effect of exercise on the disease progression. They include the decrease in cytokine production by the adipose tissue, skeletal muscles, endothelial cells, and blood mononuclear cells, and also, the increase in the bioavailability of nitric oxide, antioxidant defences, and regenerative capacity of endothelium. This study aims to provide a critical review of the literature linking exercise, inflammation, and endothelial dysfunction in coronary artery patients, and to discuss the potential mechanisms behind the exercise-training improvement of endothelial function and inflammatory status.

Prospective study of physical fitness, adiposity, and inflammatory markers in healthy middle-aged men and women

BACKGROUND

Physical fitness may provide cardiovascular benefits in the obese.

OBJECTIVE

We prospectively examined the associations between inflammatory markers and fitness, body mass index, and central adiposity.

DESIGN

Healthy men and women (n = 176) were recruited from the Whitehall II epidemiologic cohort. At baseline we measured physical fitness and adiposity, and blood was drawn for the assessment of inflammatory markers [C-reactive protein (CRP) and interleukin-6 (IL-6)]. We subsequently assessed inflammatory markers and adiposity at the 3-y follow-up visit.

RESULTS

Body mass index, but not physical fitness, was independently associated with IL-6 and CRP at follow-up. Weight gain was also associated with CRP at follow-up. Compared with fit-lean participants, the unfit-overweight participants had significantly higher concentrations of CRP (adjusted beta: 0.67; 95% CI, 0.31, 1.00) and IL-6 (adjusted beta: 0.28; 95% CI: -0.06, 0.49) at follow-up. In contrast, the fit-overweight and unfit-lean participants did not differ significantly from the fit-lean participants after adjustments for age, sex, smoking, employment grade, and baseline inflammation.

CONCLUSIONS

In participants followed up for 3 y, changes in low-grade inflammation were positively associated with adiposity but not with fitness at baseline. Further attention should focus specifically on overweight-obese participants in relation to physical fitness and cardiovascular disease risk.

No reduction in C-reactive protein following a 12-month randomized controlled trial of exercise in men and women

Low-grade systemic inflammation is suggested to play a role in the development of several chronic diseases including cancer. Higher levels of physical activity and lower adiposity have been associated with reduced levels of markers of systemic inflammation, such as C-reactive protein (CRP); however, reductions in CRP have not been consistently observed in randomized controlled trials of exercise.

PURPOSE

To examine the effect of a 12-month aerobic exercise intervention on CRP levels in men and women.

METHODS

One hundred two men and 100 women, sedentary and of ages 40 to 75 years, with mean body mass index (BMI) of 29.9 and 28.7 kg/m(2), respectively, were randomly assigned to a 12-month moderate-to-vigorous aerobic exercise intervention (6 d/wk, 60 min/d, 60-85% maximum heart rate) or control group. Fasting blood samples were collected at baseline and at 12 months. CRP levels were measured by high-sensitivity latex-enhanced nephelometry.

RESULTS

At baseline, CRP was 1.16 and 2.11 mg/L for men and women, respectively, and CRP was correlated with percent body fat (r = 0.48, P < or =0.001), BMI (r = 0.37, P < or = 0.001), and aerobic fitness (r = -0.49, P < or = 0.001). No intervention effects were observed for CRP in men or women, or when stratified by baseline BMI (<30 versus > or =30 kg/m(2)), baseline CRP (<3 versus > or =3 mg/L), or change in body weight, body composition, or aerobic fitness.

CONCLUSION

A 12-month moderate-to-vigorous aerobic exercise intervention did not affect CRP levels in previously sedentary men or women with average-risk CRP values at baseline.

Impact of hormone replacement therapy on exercise training-induced improvements in insulin action in sedentary overweight adults

Exercise training (ET) and hormone replacement therapy (HRT) are both recognized influences on insulin action, but the influence of HRT on responses to ET has not been examined. To determine if HRT use provided additive benefits for the response of insulin action to ET, we evaluated the impact of HRT use on changes in insulin during the course of a randomized, controlled, aerobic ET intervention. Subjects at baseline were sedentary, dyslipidemic, and overweight. These individuals were randomized to 6 months of one of 3 aerobic ET interventions or continued physical inactivity. In 206 subjects, an insulin sensitivity index (S(I)) was obtained with a frequently sampled intravenous glucose tolerance test pre- and post-ET. Baseline and postintervention fitness, regional adiposity, general adiposity, skeletal muscle biochemistry and histology, and serum lipoproteins were measured as other putative mediators influencing insulin action. Two-way analyses of variance were used to determine if sex or HRT use influenced responses to exercise training. Linear modeling was used to determine if predictors for response in S(I) differed by sex or HRT use(.) Women who used HRT (HRT+) demonstrated significantly greater improvements in S(I) with ET than women not using HRT (HRT-). In those HRT+ women, plasma triglyceride change best correlated with change in S(I). For HRT- women, capillary density change and, for men, subcutaneous adiposity change best correlated with change in S(I). In summary, in an ET intervention, HRT use appears to be associated with more robust responses in insulin action. Furthermore, relationships between ET-induced changes in insulin action and potential mediators of change in insulin action are different for men, and for women on or off HRT. These findings have implications for the relative utility of ET for improving insulin action in middle-aged men and women, particularly in the setting of differences in HRT use.

Association between mobility mode and C-reactive protein levels in men with chronic spinal cord injury

OBJECTIVE

To assess clinical determinants of systemic inflammation in persons with chronic spinal cord injury (SCI).

DESIGN

Cross-sectional survey.

SETTING

Veterans Affairs medical center.

PARTICIPANTS

As part of an epidemiologic study assessing SCI-related health conditions, 63 men with chronic SCI provided a blood sample and information regarding locomotive mode and personal habits.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Plasma high-sensitivity C-reactive protein (CRP).

RESULTS

The mean +/- standard deviation age was 56+/-14y, and participants were assessed 21+/-13y after injury. Adjusting for heart disease, hypertension, and body mass index (BMI), the mean CRP in 12 motorized wheelchair users (5.11mg/L) was not significantly greater than 23 participants who used a manual wheelchair (2.19mg/L) (P=.085) but was significantly greater than the 17 who walked with an assistive device (1.41mg/L) (P=.005) and the 12 who walked independently (1.63mg/L) (P=.027). CRP was significantly greater in participants with obesity but was not related to age, smoking, or SCI level and severity. CRP was elevated in participants reporting a urinary tract infection (UTI) or pressure ulcer within a year, but adjustment for this did not account for the elevated CRP in motorized wheelchair users.

CONCLUSIONS

These results suggest that CRP in chronic SCI is independently related to locomotive mode, BMI, and a history of pressure ulcers and UTI. It is suggested that future studies in SCI investigate whether modifying these factors influence systemic inflammation and cardiovascular health.

Relationships between adipose tissue and cytokine responses to a randomized controlled exercise training intervention

Adipose-derived cytokines play a prominent role in mediating the metabolic consequences of obesity and excess body fat. Given this, we hypothesized that alterations in adipose tissue stores incurred with exercise training would be reflected in changes in systemic cytokine concentrations. The Studies of Targeted Risk Reduction Intervention through Defined Exercise, where pronounced changes in adipose tissue stores were observed in the absence of significant changes in dietary intake, provided an ideal setting in which to test this hypothesis. Participants were randomized to 6 months of inactivity or one of 3 types of aerobic exercise training regimens: low-amount-moderate-intensity, low-amount-vigorous-intensity, and high-amount-vigorous-intensity. Plasma samples were collected at baseline and 2 weeks after cessation of 6 months of exercise training or inactivity. In 189 participants, concentrations of 17 cytokines were measured using Bio-Plex Cytokine Assays (Bio-Rad, Hercules, CA); 10 additional cytokines were measured in 60 of these subjects. Of all cytokines tested, the only concentration changes that approached statistical significance were those for granulocyte monocyte-colony stimulating factor and vascular endothelial growth factor, which appeared to increase with training in the low-amount-high-intensity group only (P < .05 for both cytokines). No response to exercise training was noted for any additional cytokine in any of the groups. No relationships were observed between changes in cytokine concentrations and changes in fat mass or other measures of body habitus. In contradiction to our hypothesis, despite significant alterations in body composition, exercise training produced limited cytokine responses.

Walking, vigorous physical activity, and markers of hemostasis and inflammation in healthy men and women

The impact of walking on cardiovascular health, as compared with vigorous physical activity, remains controversial. We performed a cross-sectional analysis including 185 healthy participants drawn from the Whitehall II epidemiological cohort to examine whether there is an independent association between walking and markers of hemostasis and inflammation after controlling for vigorous physical activity. Blood was drawn for the assessment of von Willebrand factor antigen (vWF), fibrinogen, interleukin (IL)-6, IL-1 receptor antagonist (IL-1ra), and tumor necrosis factor-alpha (TNF-alpha). Self-reported levels and types of physical activity were recorded, including time spent walking per week and frequency of participation in vigorous physical activity. Multiple linear regression analyses, adjusted for age, body mass index, blood pressure, gender, smoking, alcohol, grade of employment, and frequency of vigorous physical activity revealed that time spent walking was inversely related to vWF (beta=-0.13, P=0.086), fibrinogen (beta=-0.16, P=0.016), IL-6 (beta=-0.12, P=0.087), and TNF-alpha (beta=-0.16, P=0.039). In addition, vigorous activity was inversely associated with hemostatic markers but not with inflammatory cytokines. Regular walking is associated with lower levels of hemostatic and inflammatory markers independently of vigorous physical activity in healthy men and women.

Dietary carbohydrate intake and high-sensitivity C-reactive protein in at-risk women and men

BACKGROUND

The quality and quantity of dietary carbohydrate intake, measured as dietary glycemic load (GL), are associated with a number of cardiovascular disease (CVD) risk factors and, in healthy young women, are related to increased high-sensitivity C-reactive protein (hsCRP) concentrations. Our objective was to determine if GL is related to hsCRP and other measures of CVD risk in a population of sedentary, overweight, dyslipidemic middle-aged women and men enrolled in an exercise intervention trial (STRRIDE).

METHODS

This was a cross-sectional evaluation of the relationships between measures of dietary carbohydrate intake, calculated from food frequency questionnaire data, and CVD risk factors, including plasma hsCRP, measured in 171 subjects.

RESULTS

After adjusting for energy intake, GL and other measures of carbohydrate intake were not independently related to hsCRP (P > .05 for all). In the analyses performed separately for each sex, only the quantity of carbohydrate intake was independently related to hsCRP (R2 = 0.28, P < .04), and this relationship was present for women but not for men. The strongest relationship identified between GL and any CVD risk factor was for cardiorespiratory fitness (R2 = 0.12, P < .02); an elevated GL was associated with a lower level of fitness in all subjects, and this relationship persisted even when the findings were adjusted for energy intake and sex (R2 = 0.48, P < .03).

CONCLUSIONS

In middle-aged, sedentary, overweight to mildly obese, dyslipidemic individuals, consuming a diet with a low GL is associated with better cardiorespiratory fitness. Our findings suggest that the current literature relating carbohydrate intake and hsCRP should be viewed with skepticism, especially in the extension to at-risk populations that include men.