Reduction in trunk fat predicts cardiovascular exercise training-related reductions in C-reactive protein

Long-term impact of adherence to muscle-strengthening guidelines on inflammation markers: a 17-year follow-up study with obesity parameters as mediators

Objective

To evaluate the relationship between adherence to muscle-strengthening guidelines in young adulthood and inflammation markers over a 17-year follow-up period. Additionally, it aims to examine whether body mass index (BMI) and waist circumference (WC) act as mediators in this relationship.

Methods

The study analysed data from young adults aged 18-26 years who participated in waves III (2001-2002), IV (2008-2009) and V (2016-2018) of the Add Health Study. Adherence to muscle-strengthening guidelines was self-reported, and participants were classified as adherent if they engaged in strength training ≥2 days per week across all waves. Venous blood samples were collected at participants' homes to measure high-sensitivity C reactive protein (hs-CRP) levels and various cytokine concentrations, including interleukin (IL)-6, IL-1beta, IL-8, IL-10 and tumour necrosis factor-alpha (TNF-α). A global inflammation score was also calculated using z-scores of these markers.

Results

A total of 2320 individuals participated (60.8% females). Participants adhering to muscle-strengthening guidelines exhibited significant reductions in hs-CRP, IL-6 and the inflammation z-score, with mean difference (MD) of -1.556 mg/L (95% CI BCa -2.312 to -0.799), -0.324 pg/mL (95% BCa CI -0.586 to -0.062), and -0.400 (95% BCa CI -0.785 to -0.035), respectively. Mediation analysis revealed that BMI and WC levels at wave V significantly mediated the relationship between strength training and inflammation z-score, with significant indirect effects of -0.142 (95% CI -0.231 to -0.055) for BMI and -0.210 (95% CI -0.308 to -0.124) for WC.

Conclusion

Adherence to muscle-strengthening guidelines alone may not be sufficient to achieve a notable decrease in inflammation without concurrent reductions in these obesity parameters.

Effects of different exercise modalities on inflammatory markers in the obese and overweight populations: unraveling the mystery of exercise and inflammation

In the realm of obesity and overweight, the risk of chronic diseases significantly escalates, closely intertwined with inflammatory factors. Research suggests that specific exercise interventions, particularly aerobic exercise and resistance exercise, can have beneficial effects on inflammation levels. However, debates persist regarding the actual impact of exercise in the obese and overweight population. We employed meta-analysis research methods and searched the China National Knowledge Infrastructure Wanfang Data, PubMed, and Web of Science databases to gather controlled experiments on the effects of resistance exercise or aerobic exercise on C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Two researchers independently conducted literature screening and data extraction. The quality of the literature was assessed according to the Cochrane Handbook standards, and subgroup analyses of CRP, IL-6, and TNF-α were performed using RevMan 5.4 software. Through quantitative synthesis of results from 22 selected studies encompassing a total of 1,135 research subjects, this study systematically explored the specific regulatory effects of different exercise modalities on inflammatory markers in the obese and overweight population. The findings indicate that both aerobic exercise and resistance exercise effectively reduce CRP levels in obese individuals, with aerobic exercise demonstrating a more pronounced effect. Aerobic exercise also significantly lowers IL-6 levels, while the impact of resistance exercise on IL-6 is relatively minor. However, in terms of reducing TNF-α levels, neither modality appears to exert a significant effect. Overall, exercise, especially aerobic exercise, emerges as a positive regulator of inflammatory markers in the context of obesity and overweight.

Sitting Less, Recovering Faster: Investigating the Relationship between Daily Sitting Time and Muscle Recovery following Intense Exercise: A Pilot Study

(1) There is growing concern surrounding the adverse effects of prolonged sitting on health, yet its impact on post-exercise recovery remains relatively unexplored. This study aimed to better understand the potential influence of habitual prolonged sitting on recovery time and the unfavorable impact prolonged sitting may have on time to recovery, as assessed by muscle damage and inflammatory markers and an isokinetic dynamometer. (2) Nine college-age men (mean age ± SD = 22.1 ± 3.1 years, body mass = 80.9 ± 15.7 kg, height = 171 ± 9.0 cm, Body Mass Index (BMI) = 27.6 ± 4.9 kg·m2) participated in an exhaustive exercise protocol. Creatine Kinase (CK), Myoglobin (Mb), C-Reactive Protein (CRP), White Blood Cell Count (WBC), Peak Torque (PT), and muscle soreness were measured at baseline and 0, 24, 48, and 72 h post-exercise. Dietary and exercise logs were maintained during the 5-day testing procedure. (3) No significant differences were observed in muscle damage markers (CK [p = 0.068] and Mb [p = 0.128]), inflammatory markers (CRP [p = 0.814] and WBC [p = 0.140]), or PT [p = 0.255]) at any time point. However, a significant positive correlation was found between daily sitting time and the percent increase in CK concentration from 0 h to 72 h (r = 0.738, p = 0.023). Strong correlations were also noted between prolonged sitting and percent change in Mb concentration at 48 h (r = 0.71, p = 0.033) and 72 h (r = 0.889, p = 0.001). There was a significant two-way interaction for time × velocity (p = 0.043) for PT with a simple main effect for time at 60°·s-1 (p = 0.038). No significant associations were detected between daily carbohydrate or protein intake and recovery markers (p > 0.05). (4) The findings suggest minimizing daily sitting time may expedite and potentially aid muscle recovery after an intense exercise bout, although further research is warranted to validate these findings.

Effects of rope skipping exercise on physical, cardiovascular fitness and exercise tolerance in adolescent students with moderate intellectual disability

BACKGROUND

Adolescents with intellectual disabilities (ID) who live a sedentary lifestyle may lead to an increased risk of chronic cardiovascular disease in adulthood. The aim of this study is to investigate the effects of 8-week progressive rope skipping training on physical, cardiovascular fitness and exercise tolerance of high school students with moderate ID.

METHODS

Thirty-four senior high school with ID (aged 15-18 years old) were randomised into experimental group received progressive skipping rope exercise (RS, n = 17) and control group no rope skipping exercise intervention group (CON, n = 17). The RS group were received progressive rope skipping exercise for 50 min each time, three times a week, for 8 weeks. The control group was not allowed to participate in intervention activities during the study period. The physical fitness, body composition, arterial stiffness index (ASI) and blood pressure were measured before and after the 8-week intervention.

RESULTS

After the 8-week progressive skipping rope exercise intervention, the participants from the RS group increased in the 3-min step test, sit-up test, grip strength and sit and reach test, when compared to the baseline (P < 0.05). The RS group exhibited lower the area under curve of heart rate (HR) during post-exercise recovery (P < 0.05). The participants in the RS group showed significant decreases in systolic (SBP) and diastolic (DBP) blood pressure, mean arterial pressure (MAP) and HR when compared to the baseline (P < 0.05). Change SBP has moderate positive correlation with change ASI.

CONCLUSIONS

The results of this experiment suggest that progressive rope skipping exercise might improve physical fitness and promote cardiovascular health, as well as enhance exercise tolerance for adolescent students with moderate ID.

Long-term effects of different exercise training modes on cytokines and adipokines in individuals with overweight/obesity and cardiometabolic diseases: A systematic review, meta-analysis, and meta-regression of randomized controlled trials

The present study aimed to investigate the evidence on the effects of different long-term training interventions (aerobic [AeT], resistance [RT], and combined [COMB]) and spontaneous physical activity (PA) in modifying cytokines and adipokines in individuals with overweight or obesity with or without cardiometabolic diseases while considering potential confounders. Although exercise interventions have become a potentially effective tool for preventing and treating metabolic diseases, the evidence provided by previous systematic reviews is inconclusive since several potential confounders have yet to be addressed. Therefore, we conducted a systematic literature search in Medline, Cochrane, and Embase databases from January 2000 to July 2022 and performed a meta-analysis. Inclusion criteria retrieved 106 full texts comprising 8,642 individuals with a range BMI of 25.1-43.8 kg m^-2 . We found that independently of the training mode, exercise had a beneficial effect on diminishing Adiponectin, C-reactive protein (CRP), IL-6, IL-18, IL-20, Leptin, sICAM, and TNF-α levels circulating levels. Furthermore, by subsequent analysis, we detected differential effects of AeT, RT, and COMB, with sex, age, body composition, and trial length acting as moderators. The comparison of training modes revealed a difference favoring COMB over AeT for regulating the increase in CRP with no differences in the remaining biomarkers. Meta-regression analysis revealed an effect of change in maximal oxygen uptake (VO_2max ) on CRP, IL-6, and TNF-α, while IL-10 was influenced by the change in body fat. The results suggest that all interventions, except PA, are effective in lessening this population's inflammatory status, provided that exercise results in an increase of VO_2max .

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

Sprint interval training (SIT) reduces serum epidermal growth factor (EGF), but not other inflammatory cytokines in trained older men

Purpose

The present study aimed to investigate the effect of age on circulating pro- and anti-inflammatory cytokines and growth factors. A secondary aim was to investigate whether a novel sprint interval training (SIT) intervention (3 × 20 s ‘all out’ static sprints, twice a week for 8 weeks) would affect inflammatory markers in older men.

Methods

Nine older men [68 (1) years] and eleven younger men [28 (2) years] comprised the younger group. Aerobic fitness and inflammatory markers were taken at baseline for both groups and following the SIT intervention for the older group.

Results

Interleukin (IL)-8, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) were unchanged for the older and younger groups at baseline (IL-8, p = 0.819; MCP-1, p = 0.248; VEGF, p = 0.264). Epidermal growth factor (EGF) was greater in the older group compared to the younger group at baseline [142 (20) pg mL⁻¹ and 60 (12) pg mL⁻¹, respectively, p = 0.001, Cohen's d = 1.64]. Following SIT, older men decreased EGF to 100 (12) pg mL⁻¹ which was similar to that of young men who did not undergo training (p = 0.113, Cohen's d = 1.07).

Conclusion

Older aerobically trained men have greater serum EGF than younger aerobically trained men. A novel SIT intervention in older men can shift circulating EGF towards trained younger concentrations. As lower EGF has previously been associated with longevity in C. elegans, the manipulative effect of SIT on EGF in healthy ageing in the human may be of further interest.

Association among Adherence to the Mediterranean Diet, Cardiorespiratory Fitness, Cardiovascular, Obesity, and Anthropometric Variables of Overweight and Obese Middle-Aged and Older Adults

The aim of this study was to evaluate the independent and combined associations between adherence to the Mediterranean diet (AMedDiet), cardiorespiratory fitness (CRF), and different parameters of overweight and obese middle-aged and older adults. Sixty-two participants were enrolled in this cross-sectional study. Fat mass was measured with Dual energy X-ray absorptiometry. AMedDiet and physical activity (PA) were assessed with the PREDIMED and Global PA Questionnaire (GPAQ). Maximal aerobic power was assessed using the 6-min walk test. Systolic (SBP) and diastolic (DBP) blood pressure (BP) were measured with Omron M6, and double product (DP) and mean BP (MBP) were calculated. Kinanthropometry proportionality variables related to obesity were also calculated. Participants with a low CRF as an independent factor or together with a low AMedDiet obtained significantly higher BP, total and trunk fat mass, and proportionality variables (all p ˂ 0.0001). According to the multiple nonlinear regression analysis, Vo2max, AMedDiet, and sex explained 53.4% of SBP, with this formula: 238.611 − (3.63*Vo2max) + (0.044*Vo2max²) − (13.051*AMedDiet) + (0.68*AMedDiet²) + (12.887*sex). SBP and p rediction SBP with the new formula showed a correlation of 0.731 (p ˂ 0.0001); showing a difference between the values of −0.278 (p = 0.883). In conclusion, CRF as an independent factor and combined with AMedDiet can be associated with BP, body composition, and proportionality in overweight and obese middle-aged and older adults.

Dietary Weight Loss, Exercise, and Inflammation in Older Adults with Overweight or Obesity and Cardiometabolic Disease

OBJECTIVE

This study aimed to examine exercise modality during weight loss on change in inflammation among older adults with overweight or obesity and cardiometabolic disease.

METHODS

A total of 222 older adults with a mean (SD) age of 66.9 (4.7) years and a mean (SD) BMI of 33.5 (3.5) kg/m2 were randomized to weight loss (WL; n = 68), WL plus aerobic training (WL + AT; n = 79), or WL plus resistance training (WL + RT; n = 75) for 18 months. C-reactive protein (CRP) and interleukin-6 were measured at baseline, 6 months, and 18 months.

RESULTS

All groups lost significant weight from baseline to 18 months, with average adjusted changes of -5.5% for WL, -9.0% for WL + AT, and -10.1% for WL + RT. WL + RT and WL + AT lost significantly more weight than WL (P < 0.05). At 18 months, CRP values in WL + RT were significantly lower than WL (2.25 pg/mL vs. 3.38 pg/mL; P = 0.004). The only difference in interleukin-6 was that at 18 months, WL + RT was lower than WL + AT (2.32 pg/mL vs. 2.75 pg/mL; P = 0.03).

CONCLUSIONS

The addition of RT during WL was more effective at reducing levels of CRP than WL. Although results were in the expected direction, there was no difference in CRP between WL and WL + AT.

An anti-inflammatory phenotype in visceral adipose tissue of old lean mice, augmented by exercise

Visceral adipose tissue is an immunogenic tissue, which turns detrimental during obesity by activation of proinflammatory macrophages. During aging, chronic inflammation increases proportional to visceral adipose tissue (VAT) mass and associates with escalating morbidity and mortality. Here, we utilize a mouse model to investigate the inflammatory status of visceral adipose tissue in lean aging mice and assess the effects of exercise training interventions. We randomized adult (11 months; n = 21) and old (23 months; n = 27) mice to resistance training (RT) or endurance training (ET), or to a sedentary control group (S). Strikingly, we observed an anti-inflammatory phenotype in the old mice, consisting of higher accumulation of M2 macrophages and IL-10 expression, compared to the adult mice. In concordance, old mice also had less VAT mass and smaller adipocytes compared to adult mice. In both age groups, exercise training enhanced the anti-inflammatory phenotype and increased PGC1-α mRNA expression. Intriguingly, the brown adipose tissue marker UCP1 was modestly higher in old mice, while remained unchanged by the intervention. In conclusion, in the absence of obesity, visceral adipose tissue possesses a pronounced anti-inflammatory phenotype during aging which is further enhanced by exercise.

Participant-reported priorities and preferences for developing a home-based physical activity telemonitoring program for persons with tetraplegia: a qualitative analysis

Study design

Focus group.

Objectives

The purpose of this qualitative study was to explore perceptions and priorities of persons with spinal cord injury (SCI) for physical activity and to incorporate their feedback to inform future development of a physical activity program delivered via a telemonitoring platform.

Setting

New York.

Methods

Qualitative data were collected from a purposive sample of adults with tetraplegia (N = 7). Two investigators led an audio-recorded focus group using a moderator's guide. Data were analyzed using a six-phase thematic analysis approach.

Results

The discussion focused on two major areas, which resulted in multiple derived themes and subthemes. The first theme centered on the daily life of persons with tetraplegia, including changes after SCI, gain of function prioritization, and identification of psychosocial support systems that facilitate community reintegration after injury. The second theme centered on participant perceptions and recommendations for a physical activity program delivered via a telemonitoring platform. Desired design features included variations in schedule, diverse activities, or exercises included in each class, and optional two-way video to enable social interactions with classmates.

Conclusions

Participants favorably viewed the concept of a physical activity program delivered via a telemonitoring platform and contributed program design ideas. Although this was a small sample size, challenges to obtaining physical activity expressed by participants were consistent with those identified previously in larger studies of persons with tetraplegia. Therefore, we expect these concepts and their recommendations to be relevant to the greater SCI community.

The effect of resistance exercise upon age-related systemic and local skeletal muscle inflammation

AIM

Chronic inflammation increases with age and is correlated positively to visceral fat mass, but inversely to muscle mass. We investigated the hypothesis that resistance training would increase muscle mass and strength together with a concomitant drop in local and systemic inflammation level independent of any changes in visceral fat tissue in elderly.

METHODS

25 subjects (mean 67, range 62-70 years) were randomized to 1 year of heavy resistance training (HRT) or control (CON), and tested at 0, 4 and 12 months for physical performance, body composition (DXA), vastus lateralis muscle area (MRI) local and systemic inflammation (blood and muscle). In addition, systemic and local muscle immunological responses to acute exercise was determined before and after the training period.

RESULTS

Increases in muscle mass (≈2%, p < 0.05), vastus lateralis area (≈9%. P < 0.05), isometric (≈15%) and dynamic (≈15%) muscle strength (p < 0.05) were found in the HRT group after 12 months training. HRT did not alter overall or visceral fat mass (p > 0.05). Blood C-Reactive Protein declined over time in both groups (p < 0.05), whereas muscle inflammation markers were unchanged to 1 year of HRT. Acute exercise increased plasma IL-6 and FGF-19 (p < 0.05), decreased FGF-21 (p < 0.05) and CCL-20 (p < 0.05), and increased GDNF in muscle (p < 0.001) similarly before and after 1 year in both groups.

CONCLUSION

Long term resistance training increased muscle strength and improved muscle mass, but did not alter visceral fat mass and did not show any specific effect upon resting or exercise induced markers of inflammation.

Effects of different menopausal hormone replacement regimens on body composition in Chinese women

PURPOSE

The aim of this study was to determine the effects of different menopausal hormone therapy regimens on body composition in healthy postmenopausal Chinese women.

MATERIALS AND METHODS

One hundred and twenty-three healthy postmenopausal Chinese women were randomly assigned to either group A (0.625 mg conjugated equine estrogens [CEE] plus 100 mg micronized progesterone [MP]), group B (0.3 mg CEE plus 100 mg MP), or group C (0.625 mg CEE plus 10 mg dydrogesterone). Body composition was assessed by dual-energy X-ray absorptiometry.

RESULTS

One hundred and two women completed the trial at 1 year. A small but significant gain in lean body mass (619 ± 1019 g, p = 0.002) and a decrease of fat mass in all separate regions was observed in group A. A significant shift from gynoid to android fat distribution was observed in group B and group C (android/gynoid fat percentage ratios increased by 0.06 ± 0.08, p = 0.000 and 0.03 ± 0.08, p = 0.018, respectively), whereas no significant change was observed in group A (0.02 ± 0.06, p = 0.103).

CONCLUSIONS

In healthy postmenopausal Chinese women, 0.625 mg of CEE combined with 100 mg of MP was associated with a more favorable fat distribution compared with 0.3 mg CEE plus 100 mg MP or 0.625 mg CEE plus 10 mg dydrogesterone.

The Effects of Resistance Exercise on Biomarkers of Breast Cancer Prognosis: A Pooled Analysis of Three Randomized Trials

Background: Using a secondary data analysis from randomized controlled trials comparing one year of resistance exercise (n = 109) to a placebo control condition (n = 106) in postmenopausal, posttreatment breast cancer survivors, we investigated the influence of resistance training and changes in body composition on markers associated with cancer progression.Methods: Measures included serum levels of insulin, IGF-1, IGFBP1-3, leptin, serum amyloid A (SAA), adiponectin, C-reactive protein (CRP), IL1β, TNFα, IL6, and IL8, and body composition (total, lean and fat mass in kg) by DXA at baseline, 6, and 12 months. Linear mixed effects models were used to examine the association between group, biomarkers, and body composition and whether or not changes in muscle strength or body composition influenced the effect of exercise on biomarkers.Results: CRP decreased over time among women participating in resistance training compared with increases in controls (P = 0.045). In stratified analyses and compared with increases in controls, women who gained strength reduced CRP (P = 0.003) and maintained levels of IL1β and IL6. Among exercisers who lost weight (≥2 kg), CRP (P = 0.045), leptin (P < 0.01), and SAA (P = 0.029) decreased, whereas IGF-BP1 (P = 0.036) increased compared with controls.Conclusions: Resistance training may lower inflammation and improve insulin pathway profiles, but the magnitude and degree of benefit from exercise may depend upon whether or not women gained strength, a possible marker of compliance with training, and/or lost weight during exercise.Impact: Future resistance training trials should consider these potential influencing factors as they may determine how well exercise can slow cancer progression and prevent disease recurrence. Cancer Epidemiol Biomarkers Prev; 27(2); 146-53. ©2017 AACR.

Exercise and Estrogen Make Fat Cells "Fit"

Adipose tissue inflammation links obesity and metabolic disease. Both exercise and estrogen improve metabolic health, enhance mitochondrial function, and have antiinflammatory effects. We hypothesize that there is an inverse relationship between mitochondrial function and inflammation in adipose tissue and that exercise acts as an estrogen "mimetic." Explicitly, exercise may improve adipose tissue "immunometabolism" by improving mitochondrial function and reducing inflammation.

Aerobic exercises alleviate symptoms of fatigue related to inflammatory cytokines in obese patients with type 2 diabetes

BACKGROUND

Non-insulin dependent diabetic patients frequently suffer from fatigue symptoms that result from chronic systemic inflammation. Aerobic exercise was proved to modulate systemic inflammation.

OBJECTIVE

This study was an attempt to measure the impact of aerobic exercises on fatigue symptoms related to systemic inflammation in obese patients with type 2 diabetes.

METHODS

Eighty obese patients with type 2 diabetes participated in the present study, their age ranged from 40-58 years and their BMI ranged from 31-36 kg/m2 and were assigned to two subgroups; group (A) received aerobic exercise training for 12 weeks and group (B) received no exercise training for 3 months. Measurements of fatigue symptoms and markers of systemic inflammation were assessed before and at the end of the study for all participants in both groups.

RESULTS

The mean values of inflammatory markers (IL-6 and TNF-α) and Multidimensional Fatigue Inventory (MFI) was significantly decreased in group (A), while changes were not significant in group (B). Moreover, there were significant differences between mean levels of the investigated parameters in group (A) and group (B) at the end of the study.

CONCLUSION

Treadmill walking exercise training is an effective treatment policy to improve symptoms of fatigue related to inflammatory cytokines in obese patients with type 2 diabetes.

Exercise and the Regulation of Inflammatory Responses

Exercise initiates a cascade of inflammatory events, which ultimately lead to long-term effects on human health. During and after acute exercise in skeletal muscle, interactions between immune cells, cytokines, and other intracellular components, create an inflammatory milieu responsible for the recovery and adaption from an exercise bout. In the systemic circulation, cytokines released from muscle (myokines) mediate metabolic and inflammatory processes. Moderate exercise training results in improvements in systemic inflammation, evident by reductions in acute phase proteins. The anti-inflammatory effects of regular exercise include actions dependent and independent of changes in adipose tissue mass. Future research should encompass approaches, which attempt to integrate other, less-recognized physiological processes with acute and long-term inflammatory changes. This will include investigation into metabolic, endocrine, and immune components of various tissues and organs.

Effects of an education and home-based pedometer walking program on ischemic heart disease risk factors in people infected with HIV: a randomized trial

OBJECTIVE

People infected with the human immunodeficiency virus are at an increased risk of developing ischemic heart disease (IHD); however, the effects of an education and home-based pedometer walking program on risk factors of IHD are not known.

METHODS

We conducted a 12-month randomized study of an education and home-based pedometer walking program in 84 human immunodeficiency virus-infected individuals with risk factors of IHD.

RESULTS

Pedometer step count of the control and intervention groups improved significantly (P = 0.03 for both groups) at 6 months but was not significant at 12 months (P = 0.33 and 0.21, respectively). Significant between-group effects were observed in 6-minute walk test distance (P = 0.01), waist to hip ratio (P = 0.00), glucose (P = 0.00), and high-density lipoprotein (P = 0.01) over the 12-month period. The program did not result in change in high-sensitivity C-reactive protein as it was associated with perceived stress (r = 0.23; P = 0.03), weight (r = 0.28; P = 0.01), body mass index (r = 0.35; P < 0.00), waist (r = 0.28; P = 0.01) and hip circumference (r = 0.28; P = 0.01). Multivariate generalized estimation equation analysis demonstrated an inverse association between interaction and perceived stress (logB = -0.01; 95% confidence interval: -0.02 to -0.01; P <0.00) and body mass index (logB = -0.02; 95% confidence interval: -0.03 to -0.002; P = 0.02) at group level.

CONCLUSION

An education and home-based pedometer walking program improves physical activity levels, and beneficial changes in other IHD risk factors were noted.

Objectively assessed physical activity, adiposity, and inflammatory markers in people with type 2 diabetes

OBJECTIVE

Inflammatory processes may play an important role in the development of acute coronary syndromes in people with type 2 diabetes; thus, strategies to control inflammation are of clinical importance. We examined the cross-sectional association between objectively assessed physical activity and inflammatory markers in a sample of people with type 2 diabetes.

METHODS

Participants were 71 men and 41 women (mean age=63.9±7 years), without a history of cardiovascular disease, drawn from primary care clinics. Physical activity was objectively measured using waist-worn accelerometers (Actigraph GT3X) during waking hours for seven consecutive days.

RESULTS

We observed inverse associations between moderate-to-vigorous physical activity (per 10 min) with plasma interleukin-6 (B=-0.035, 95% CI -0.056 to -0.015), interleukin-1ra (B=-0.033, 95% CI -0.051 to -0.015), and monocyte chemotactic protein-1 (B=-0.011, 95% CI -0.021 to 0.000). These associations largely persisted in multivariable adjusted models, although body mass index considerably attenuated the effect estimate.

CONCLUSIONS

These data demonstrate an inverse association between physical activity and inflammatory markers in people with type 2 diabetes.

Life-long endurance exercise in humans: circulating levels of inflammatory markers and leg muscle size

Human aging is associated with a loss of skeletal muscle and an increase in circulating inflammatory markers. It is unknown whether endurance training (Tr) can prevent these changes. Therefore we studied 15 old trained (O-Tr) healthy males and, for comparison, 12 old untrained (O-Un), 10 Young-Tr (Y-Tr) and 12 Young-Un (Y-Un). Quadriceps size, VO2 peak, CRP, IL-6, TNF-α and its receptors, suPAR, lipid profile, leucocytes and glucose homeostasis were measured. Tr was associated with an improved insulin profile (p<0.05), and lower leucocyte (p<0.05) and triglyceride levels (p<0.05), independent of age. Aging was associated with poorer glucose control (p<0.05), independent of training. The age-related changes in waist circumference, VO2 peak, cholesterol, LDL, leg muscle size, CRP and IL-6 were counteracted by physical activity (p<0.05). A significant increase in suPAR with age was observed (p<0.05). Most importantly, life-long endurance exercise was associated with a lower level of the inflammatory markers CRP and IL-6 (p<0.05), and with a greater thigh muscle area (p<0.05), compared to age-matched untrained counterparts. These findings in a limited group of individuals suggest that regular physical endurance activity may play a role in reducing some markers of systemic inflammation, even within the normal range, and in maintaining muscle mass with aging.

Forced treadmill exercise training exacerbates inflammation and causes mortality while voluntary wheel training is protective in a mouse model of colitis

The purpose of this study was to examine whether exercise training reduced inflammation and symptomology in a mouse model of colitis. We hypothesized that moderate forced treadmill running (FTR) or voluntary wheel running (VWR) would reduce colitis symptoms and colon inflammation in response to dextran sodium sulfate (DSS). Male C57Bl/6J mice were randomized to sedentary, moderate intensity FTR (8-12 m/min, 40 min, 6 weeks, 5x/week), or VWR (30 days access to wheels). DSS was given at 2% (w/v) in drinking water over 5 days. Mice discontinued exercise 24 h prior to and during DSS treatment. Colons were harvested on Days 6, 8 and 12 in FTR and Day 8 post-DSS in VWR experiments. Contrary to our hypothesis, we found that moderate FTR exacerbated colitis symptomology and inflammation as measured by significant (p<0.05) increases in diarrhea and IL-6, IL-1β, IL-17 colon gene expression. We also observed higher mortality (3/10 died vs. 0/10, p=0.07) in the FTR/DSS group. In contrast, VWR alleviated colitis symptoms and reduced inflammatory gene expression in the colons of DSS-treated mice (p<0.05). While DSS treatment reduced food/fluid intake and body weight, there was a tendency for FTR to exacerbate, and for VWR to attenuate, this effect. FTR (in the absence of DSS) increased gene expression of the chemokine and antibacterial protein CCL6 suggesting that FTR altered gut homeostasis that may be related to the exaggerated response to DSS. In conclusion, we found that FTR exacerbated, whereas VWR attenuated, symptoms and inflammation in response to DSS.

Television viewing, C-reactive protein, and depressive symptoms in older adults

There is emerging evidence for a link between sedentary behavior and mental health, although the mechanisms remain unknown. We tested if an underlying inflammatory process explains the association between sedentary behavior and depressive symptoms. We conducted a two year follow-up of 4964 (aged 64.5±8.9 years) men and women from the English Longitudinal Study of Ageing, a cohort of community dwelling older adults. Self-reported TV viewing time was assessed at baseline as a marker of leisure time sedentary behavior. The eight-item Centre of Epidemiological Studies Depression (CES-D) scale was administered to measure depressive symptoms at follow-up. At baseline, TV time was associated with C-reactive protein (CRP), adjusted geometric mean CRP values were 2.94 mg/L (<2 h/d TV); 3.04 mg/L (2-4 h/d TV); 3.29 mg/L (4-6 h/d TV); 3.23 mg/L (>6 h/d TV). We observed both a direct association of TV time on CES-D score at follow-up (B=0.08, 95% CI, 0.05, 0.10) and indirect effects (B=0.07, 95% CI, 0.05, 0.08). The indirect effects were largely explained through lack of physical activity, smoking, and alcohol, but not by CRP or body mass index.

Resistance training reduces subclinical inflammation in obese, postmenopausal women

PURPOSE

Aerobic exercise is frequently prescribed to reduce inflammatory-related disease (cardiovascular disease and diabetes) risk. Resistance training (RT), however, may be key to maximizing anti-inflammatory benefits of consistent exercise. We examined the influence of RT on inflammatory biomarkers in obese, postmenopausal women.

METHODS

Twenty-three women (65.6 ± 2.6 yr; body mass index, 33 kg·m) underwent 12 wk of RT (3 sets, 10 exercises, 3× per week, 8-12 repetition maximum (RM), resistance exercise (EX), N = 11) or social interaction intervention (SI, stretching, knitting, health lectures, 2× per week, control group (CON), N = 12). Both before (BT) and after (AT) RT or SI, blood was collected before (PR), immediately (PO), 2 h (2H), and 24 h (24H) after a single resistance exercise bout (RE) in EX and at the same time points in nonexercise, resting CON. For all time points, blood was analyzed for IL-6, leptin, and lipopolysaccharide (LPS)-stimulated tumor necrosis factor-α (TNF-α) (LPS-TNF) and IL-10 (LPS-IL10). PR samples were also examined for C-reactive protein, TNF-α, and adiponectin, and mRNA expression of toll-like receptor 4 (TLR4) and MC1R. Subcutaneous adipose tissue was extracted BT and AT and analyzed for mRNA expression of monocyte chemotactic protein-1, leptin, CD68, and TLR4.

RESULTS

RT improved strength (44%) and reduced circulating C-reactive protein (-33%), leptin (-18%) and TNF-α (-29%) with no change in body composition. IL-6 decreased after SI in CON (-17%). LPS-TNF increased after SI or RT (CON +26%, EX +67%, respectively), whereas LPS-IL10 decreased in CON (-28%) but increased in EX (+20%). RT did not influence inflammatory biomarker gene expression in whole blood or subcutaneous adipose tissue. A single RE bout augmented LPS-TNF and LPS-IL10 at 24H in EX, particularly AT.

CONCLUSION

RT reduced markers of subclinical inflammation in circulation in obese, postmenopausal women in the absence of changes in body composition. Chronic RT also enhanced response to endotoxin challenge both at rest (PR) and 24 h after an acute RE bout (24H).

Relationship between systemic inflammation and delayed-type hypersensitivity response to Candida antigen in older adults

Research has shown that aging is associated with increased systemic inflammation as well as a reduction in the strength of immune responses. However, little evidence exists linking the decrease in cell-mediated immunity in older adults with other health parameters. We sought to examine the relationship between cell-mediated immunity as measured in vivo by the delayed-type hypersensitivity (DTH) response to candida antigen and demographic and physiological variables in older (65–80 y.o.) adults. Candida antigen response was not related to gender or obesity, or to a number of other physiological variables including fitness and body composition. However, positive responders had significantly lower serum C-reactive protein levels (CRP, p<0.05) vs. non-responders. Furthermore, subjects with CRP<4.75 mg•L⁻¹ had greater odds of developing a positive response compared to those with CRP>4.75 mg•L⁻¹. Therefore, positive responses to candida antigen in older adults appears to be related to lower levels of systemic inflammation.

The associations of adiposity, physical activity and inflammation with fatigue in older adults

Persistent feelings of fatigue are a widespread complaint reported by older adults, and are associated with detriments in health and quality of life. The aim of this study was to determine the influence of weight status, habitual physical activity and inflammation, after controlling for common psychosocial variables such as depression, on perceptions of fatigue in relatively healthy older adults. Older men and women (N=182, age=69.2±6.7 years, 98 men) were assessed for adiposity via dual-energy X-ray absorptiometry, physical activity (PA) using accelerometers, systemic inflammation [serum C-reactive protein (CRP), interleukin-6 (IL-6), sIL-6R and WBC count], fatigue according to the Multidimensional Fatigue Inventory (MFI), sleep using the Pittsburgh Sleep Quality Index (PSQI) and depression via the Geriatric Depression Scale (GDS). Men and women reported similar levels of fatigue in all dimensions (p>0.05) except women reported higher levels of mental fatigue than men (p=0.049). With the exception of mental fatigue, adiposity was positively, and physical activity was inversely associated with all other dimension of fatigue (r range=0.20-0.42, and -0.18 to -0.37, respectively). CRP, IL-6 and WBC were also related to several dimensions of fatigue (r range=0.15-0.26). Regression analyses revealed that after controlling for other factors, including depression and sleep quality, adiposity independently explained a significant amount of the variance in general and physical fatigue. In addition to depression and sleep quality, adiposity may represent a potential target for reducing fatigue in older adults.

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.

Exercise Training and Immunosenescence

During the aging process, a decrease in the ability of the immune system to control infection, known as immunosenescence, takes place. Paradoxically, aging also results in chronic low-level inflammation and exaggerated inflammatory responses. A number of studies have investigated the effects of a variety of exercise training interventions on the immune system both in humans and using animal models of aging. Cross-sectional studies that compared masters athletes to untrained, age-matched controls found that the athletes had significantly better immune function, but these studies suffered because of the difficulty in generalizing results from highly trained athletes to a general population of physically active older adults. Prospective studies in humans have attempted to address this, but these studies have resulted in sometimes equivocal findings, possibly as a result of the differences in exercise training programs used. Finally, animal studies, both observational and mechanistic, have almost universally supported the exercise effect on enhancing immune status in the aged. More research is needed to determine the mechanism by which exercise influences immunity in the aged and to identify exercise training programs for use in this population. It is clear, however, that exercise is likely to be effective at boosting immunity in the older people when undertaken regularly.

Recalibrating America’s Activity Habits: The Saga Continues

This review discusses the 2008 Physical Activity Guidelines for Americans and other continuing efforts to nudge the public toward more active living. Future directions for inquiry and empirically driven public policy initiatives also are addressed.

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.

Effects of exercise and low-fat diet on adipose tissue inflammation and metabolic complications in obese mice

Adipose tissue inflammation causes metabolic disturbances, including insulin resistance and hepatic steatosis. Exercise training (EX) may decrease adipose tissue inflammation, thereby ameliorating such disturbances, even in the absence of fat loss. The purpose of this study was to 1) compare the effects of low-fat diet (LFD), EX, and their combination on inflammation, insulin resistance, and hepatic steatosis in high-fat diet-induced obese mice and 2) determine the effect of intervention duration (i.e., 6 vs. 12 wk). C57BL/6 mice (n = 109) fed a 45% fat diet (HFD) for 6 wk were randomly assigned to an EX (treadmill: 5 days/wk, 6 or 12 wk, 40 min/day, 65-70% Vo(2max)) or sedentary (SED) group. Mice remained on HFD or were placed on a 10% fat diet (LFD) for 6 or 12 wk. Following interventions, fat pads were weighed and expressed relative to body weight; hepatic steatosis was assessed by total liver triglyceride and insulin resistance by HOMA-IR and glucose AUC. RT-PCR was used to determine adipose gene expression of MCP-1, F4/80, TNF-alpha, and leptin. By 12 wk, MCP-1, F4/80, and TNF-alpha mRNA were reduced by EX and LFD. Exercise (P = 0.02), adiposity (P = 0.03), and adipose F4/80 (P = 0.02) predicted reductions in HOMA-IR (r(2) = 0.75, P < 0.001); only adiposity (P = 0.04) predicted improvements in hepatic steatosis (r(2) = 0.51, P < 0.001). Compared with LFD, EX attenuated increases in adiposity, hepatic steatosis, and adipose MCP-1 expression from 6 to 12 wk. There are unique metabolic consequences of a sedentary lifestyle and HFD that are most evident long term, highlighting the importance of both EX and LFD in preventing obesity-related metabolic disturbances.