Cardiorespiratory fitness and C-reactive protein among a tri-ethnic sample of women

A Phenome-Wide Association Study (PheWAS) of Genetic Risk for C-Reactive Protein in Children of European Ancestry: Results From the ABCD Study

BACKGROUND

C-reactive protein (CRP) is a moderately heritable marker of systemic inflammation that is associated with adverse physical and mental health outcomes. Identifying factors associated with genetic liability to elevated CRP in childhood may inform our understanding of variability in CRP that could be targeted to prevent and/or delay the onset of related health outcomes.

METHODS

We conducted a phenome-wide association study (PheWAS) of genetic risk for elevated CRP (i.e. CRP polygenic risk score [PRS]) among children genetically similar to European ancestry reference populations (median analytic n = 5,509) from the Adolescent Brain and Cognitive Development℠ (ABCD) Study. Associations between CRP PRS and 2,377 psychosocial and neuroimaging phenotypes were estimated using independent mixed effects models. Post hoc analyses examined whether: (1) covarying for measured body mass index (BMI) or removing the shared genetic architecture between CRP and BMI altered phenotypic associations, (2) sex moderated CRP PRS associations, and (3) associations are unconfounded by assortative mating or passive gene-environment correlations (using a within-family analyses). Multiple testing was adjusted for using Bonferroni and false discovery rate (FDR) correction.

RESULTS

Nine phenotypes were positively associated with CRP PRS after multiple testing correction: five weight- and eating-related phenotypes (e.g. BMI, overeating), three phenotypes related to caregiver somatic problems (e.g. caregiver somatic complaints), as well as weekday video watching (all ps = 1.2 × 10-7 - 2.5 × 10-4, all p FDR s = 0.0002 - 0.05). No neuroimaging phenotypes were associated with CRP PRS (all ps = 0.0003 - 0.998; all p FDR s = 0.08 - 0.998) after correction for multiple testing. Eating and weight-related phenotypes remained associated with CRP PRS in within-family analyses. Covarying for BMI resulted in largely consistent results, and sex did not moderate any CRP PRS associations. Removing the shared genetic variance between CRP and BMI attenuated all relationships; associations with weekday video watching, caregiver somatic problems and caregiver report that the child is overweight remained significant while associations with waist circumference, weight, and caregiver report that child overeats did not.

DISCUSSION

Genetic liability to elevated CRP is associated with higher weight, eating, and weekday video watching during childhood as well as caregiver somatic problems. These associations were consistent with direct genetic effects (i.e., not solely due to confounding factors like passive gene-environment correlations) and were independent of measured BMI. The majority of associations with weight and eating phenotypes were attributable to shared genetic architecture between BMI and inflammation. The relationship between genetics and heightened inflammation in later life may be partially attributable to modifiable behaviors (e.g. weight and activity levels) that are expressed as early as childhood.

Using cardiorespiratory fitness to operationalize vitality: a path analysis on the hierarchical structure of intrinsic capacity

BACKGROUND

There is a lack of consensus about the operationalization of vitality, which is one of the intrinsic capacity (IC) domains. In particular, no study has investigated whether cardiorespiratory fitness (CRF) can be considered a vitality indicator.

OBJECTIVE

To examine whether vitality is the upstream domain of IC, and establish the validity of CRF as a vitality indicator, using maximal oxygen consumption (VO2 max) as a representative.

METHODS

561 older adults from a longitudinal cohort study were included. Variables under consideration were VO2 max, other IC domains, instrumental activities of daily living (IADL), and handgrip strength, which was considered an already validated indicator of vitality. Using handgrip strength as the reference point, path analyses were performed to examine whether VO2 max followed a similar hierarchical structure in predicting change in IADL difficulty through other IC domains.

RESULTS

The mean age of the participants was 75.5 years. The path model in which vitality was measured by VO2 max demonstrated adequate fit, which was similar to the model in which vitality was measured by handgrip strength. Regarding the path coefficients, the model using VO2 max demonstrated significant total and indirect effects. Notably, the indirect effect was due to the locomotor domain (standardized coefficient = -0.148, p < .001), but not the cognitive or psychological domain.

CONCLUSION

Vitality is the upstream domain of IC. VO2 max can be considered an indicator to operationalize the vitality concept.

Associations of cardiorespiratory fitness and body mass index with incident restrictive spirometry pattern

OBJECTIVES

Restrictive spirometry pattern (RSP) suggests an impairment of lung function associated with a significantly increased risk of premature mortality. We evaluated the independent and joint associations of cardiorespiratory fitness (CRF) and body mass index with incident RSP.

METHODS

Data from the Aerobics Centre Longitudinal Study included 12 360 participants (18-82 years). CRF was assessed by maximal treadmill test and categorised into five groups. Body mass index was categorised into normal weight (<25.0 kg/m²), overweight (25.0-29.9 kg/m²) or obesity (≥30.0 kg/m²). RSP was defined as the simultaneous occurrence of forced expiratory volume in 1 s/force vital capacity ≥lower limit of normal and forced vital capacity <lower limit of normal.

RESULTS

There were 900 (7.3%) cases of RSP (mean follow-up: 6.9 years). Compared with category 1 ('least fit'), HRs (95% CIs) of RSP were 0.78 (0.63 to 0.96), 0.68 (0.54 to 0.86), 0.70 (0.55 to 0.88) and 0.59 (0.45 to 0.77) in categories 2, 3, 4 and 5 (most fit), respectively, after adjusting for confounders including body mass index. Compared with normal weight, HRs (95% CIs) of RSP were 1.06 (0.91 to 1.23) and 1.30 (1.03 to 1.64) in overweight and obese, respectively. However, the association between obesity and RSP was attenuated when additionally adjusting for CRF (HR 1.08, 95% CI 0.84 to 1.39). Compared with the 'unfit and overweight/obese' group, HRs (95% CIs) for RSP were 1.35 (0.98 to 1.85), 0.77 (0.63 to 0.96) and 0.70 (0.56 to 0.87) in the 'unfit and normal weight,' 'fit and overweight/obese' and 'fit and normal weight' groups, respectively.

CONCLUSIONS

Low CRF was associated with a greater incidence of RSP, irrespective of body mass index. Future studies are needed to explore potential underlying mechanisms of this association and to prospectively evaluate if improving CRF reduces the risk of developing RSP.

The associations between exercise and lipid biomarkers

Cardiovascular diseases (CVD) remain the leading cause of death globally, and further efforts are being undertaken to understand and modify CVD risk factors, such as dyslipidemia (DLD), hypertension, and diabetes. The sedentary lifestyle of most individuals today contributes to the prevalence of these conditions. Uncontrolled dyslipidemia serves as a fertile ground for atherosclerotic plaque formation, while lipoproteins (Lp) act as cofactors for inflammatory processes that cause plaque destabilization leading to subsequent CVD events. As such, many health experts and institutions continue to emphasize the importance of cardiorespiratory fitness (CRF) and muscular strength (MusS) with the intent to reduce atherogenic lipoproteins and proprotein convertase subtilisin kexin type 9 (PCSK-9) expression. Concordantly, the two modes of exercise training (ET), such as aerobic ET (aET) and resistance ET (rET) have both demonstrated to improve CRF and MusS, respectively. Although both modes of ET were shown to independently reduce mortality, participation in both forms resulted in a more pronounced improvement in cholesterol levels and CVD-related mortality. Though reduction of adiposity is not a pre-requisite to achieve better control of DLD through increased CRF and MusS, the beneficial effects of physical activity on the inflammatory processes linked to atherosclerosis are almost always associated with a simultaneous decrease in overall adiposity. It is therefore essential to promote both aET and rET, including weight loss in order to attenuate the risks stemming from atherosclerosis and its proinflammatory components.

Cardiorespiratory Fitness in Adults Aged 18 to 34 Years and Long-Term Pericardial Adipose Tissue (from the Coronary Artery Risk Development in Young Adults Study)

Pericardial adipose tissue (PAT), an ectopic adipose depot surrounding the coronary arteries, is a pathogenic risk marker for cardiometabolic disease; however, the association between cardiorespiratory fitness (CRF) and PAT is unclear. Young adults (n = 2,614, mean age 25.1 years, 55.8% women, and 43.8% Black at baseline [1985 to 1986]) from the Coronary Artery Risk Development in Young Adults study were included. Maximal CRF was estimated at baseline, examination year 7 (1992 to 1993) and year 20 (2005 to 2006), using a symptom-limited maximal treadmill exercise test (duration in minutes) among those achieving ≥85% of age-predicted maximal heart rate. PAT volume (ml) was quantified at examination year 15 (2000 to 2001) and year 25 (2010 to 2011) using computed tomography. Multivariable linear and linear mixed regressions with covariates (sociodemographics, cardiovascular disease risk factors, inflammation, waist circumference) from baseline, year 7, and/or year 20 were used. Separate multivariable regression models revealed inverse associations of CRF at baseline, year 7, or year 20 with PAT at year 25 in fully adjusted models (all p <0.001). The linear mixed model showed that a 1-minute increase in treadmill exercise test duration over 20 years was associated with 1.49 ml lower subsequent PAT volume (p <0.001). In conclusion, findings suggest that higher CRF is inversely associated with subsequent PAT volume. Strategies to optimize CRF may be preventive against excessive PAT accumulation with age.

Current state of unhealthy living characteristics in White, African American and Latinx populations

The United States (US) is similar to most industrialized countries in that it falls short on many of the basic metrics related to cardiovascular and overall health. These metrics include nutritional patterns, levels of physical activity (PA), cardiorespiratory fitness (CRF), and prevalence of overweight and obesity. These issues are even more apparent in underserved communities, among whom unhealthy living characteristics cluster and contribute to a disproportionate chronic disease burden. The reasons for these inequities are complex and include social and economic factors as well as reduced access to health care. CRF has been demonstrated to be a critically important risk factor that tends to be lower in disadvantaged groups. In this article we discuss the current state of health & lifestyle characteristics in the US, the impact of social inequality on health, and the particular role that CRF and PA patterns play in the current state of unhealthy living characteristics as they relate to underserved populations.

The Effects of Exercise on Lipid Biomarkers

The World Health Organization has declared obesity to be a global epidemic that increases cardiovascular disease (CVD) mortality risk factors, such as hypertension, diabetes, dyslipidemia, and atherosclerosis. The increasing ratio of time spent in sedentary activities to that spent performing physically demanding tasks increases the trends to obesity and susceptibility to these risk factors. Dyslipidemia is the foundation of atherosclerotic buildup and lipoproteins serve as cofactors to the inflammatory processes that destabilize plaques. Increasing cardiorespiratory fitness and muscular strength helps attenuate concentrations of low-density lipoproteins (LDLs), such as LDL cholesterol, and increase levels of high-density lipoprotein cholesterol, as well as reduce proprotein convertase subtilisin kexin type 9 expression. Effects of physical activity on the inflammatory pathways of atherosclerosis, specifically C-reactive protein, are more closely related to reducing the levels of adiposity in tandem with increasing fitness, than with exercise training alone. The purpose of this review is to describe the physiology of dyslipidemia and relate it to CVD and exercise therapies.

Association between Cardiorespiratory Fitness and Circulating Proteins in 50-Year-Old Swedish Men and Women: a Cross-Sectional Study

BACKGROUND AND AIMS

A strong cardiorespiratory fitness is suggested to have beneficial effects on cardiovascular risk; the exact mechanisms underlying the cardioprotective effects of fitness remain uncertain. Our aim was to investigate associations between cardiorespiratory fitness and multiple plasma proteins, in order to obtain insights about physiological pathways associated with the effects of exercise on cardiovascular health.

METHODS

In the Prospective investigation of Obesity, Energy and Metabolism (POEM) study (n=444 adults aged 50 years, 50% women), cardiorespiratory fitness was measured by a maximal exercise test on bicycle ergometer with gas exchange (VO₂peak) normalized for body lean mass (dual-energy X-ray absorptiometry (DXA)). We measured 82 cardiovascular proteins associated with cardiovascular pathology and inflammation in plasma samples with a proximity extension assay.

RESULTS

In sex-adjusted linear regression, VO₂peak was associated with 18 proteins after Bonferroni correction for multiple testing (p<0.0006). Following additional adjustment for fat mass (DXA), fasting glucose (mmol/L), low-density lipoprotein (LDL, mmol/L), smoking status, waist/hip ratio, blood pressure (mmHg), education level, and lpnr (lab sequence number), higher VO₂peak was significantly associated with lower levels of 6 proteins: fatty-acid binding protein-4 (FABP4), interleukin-6 (IL-6), leptin, cystatin-B (CSTB), interleukin-1 receptor antagonist (IL-1RA), and growth differentiation factor 15 (GDF-15), and higher levels of 3 proteins: galanin, kallikrein-6 (KLK6), and heparin-binding EGF-like growth factor (HB-EGF), at nominal p-values (p<0.05).

CONCLUSIONS

We identified multiple novel associations between cardiorespiratory fitness and plasma proteins involved in several atherosclerotic processes and key cellular mechanisms such as inflammation, energy homeostasis, and protease activity, which shed new light on how exercise asserts its beneficial effects on cardiovascular health. Our findings encourage additional studies in order to understand the underlying causal mechanisms for these associations.

Association between Cardiorespiratory Fitness and Bronchiectasis at CT: A Long-term Population-based Study of Healthy Young Adults Aged 18-30 Years in the CARDIA Study

Background Protective factors against the risk of bronchiectasis are unknown. A high level of cardiorespiratory fitness is associated with a lower risk of chronic obstructive pulmonary disease. But whether fitness relates to bronchiectasis remains, to the knowledge of the authors, unknown. Purpose To examine the association between cardiorespiratory fitness and bronchiectasis. Materials and Methods This was a secondary analysis of a prospective observational study: the Coronary Artery Risk Development in Young Adults cohort (from 1985-1986 [year 0] to 2015-2016 [year 30]). During a 30-year period, healthy participants (age at enrollment 18-30 years) underwent treadmill exercise testing at year 0 and year 20 visits. Cardiorespiratory fitness was determined according to the treadmill exercise duration. The 20-year difference in cardiorespiratory fitness was used as the fitness measurement. At year 25, chest CT was performed to assess bronchiectasis and was used as the primary outcome. Multivariable logistic models were performed to determine the association between cardiorespiratory fitness changes and bronchiectasis. Results Of 2177 selected participants (at year 0: mean age, 25 years ± 4 [standard deviation]; 1224 women), 209 (9.6%) had bronchiectasis at year 25. After adjusting for age, race-sex group, study site, body mass index, pack-years smoked, history of tuberculosis, pneumonia, asthma and myocardial infarction, peak lung function, and cardiorespiratory fitness at baseline, preservation of cardiorespiratory fitness was associated with lower odds of bronchiectasis at CT at year 25 (per 1-minute-longer treadmill duration from year 0 to year 20: odds ratio [OR], 0.88; 95% CI: 0.80, 0.98; P = .02). A consistent strong association was found when cough and phlegm were included in bronchiectasis (OR, 0.72; 95% CI: 0.59, 0.87; P < .001). Conclusion In a long-term follow-up, the preservation of cardiorespiratory fitness was associated with lower odds of bronchiectasis at CT. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Stojanovska in this issue.

U-Shaped Association between Sleep Duration, C-Reactive Protein, and Uric Acid in Korean Women

Serum high-sensitivity C-reactive protein (hsCRP) and serum uric acid (SUA) are biomarkers that predict chronic inflammation and cardiovascular dysfunction. Therefore, we aimed to investigate the association between sleep duration, hsCRP, and SUA in Korean women. Cross-sectional data from the Seventh Korea National Health and Nutrition Examination Survey was analyzed. The odds ratio (OR) and 95% confidence intervals (CIs) for an association between higher hsCRP (>2.0 mg/L) or higher SUA (>5.6 mg/dL) and sleep duration were calculated using multiple logistic regression analyses after adjusting for potential confounders. In total, 6151 women were included in the analysis. There was a U-shaped relationship between continuous sleep duration, hsCRP, and SUA. Compared to those who slept for 7-8 h, the ORs (95% CIs) for higher hsCRP were 1.43 (0.95-2.16) in short sleepers and 1.64 (1.09-2.48) in long sleepers after adjusting for confounders. Compared with those who slept for 7-8 h, the ORs (95% CIs) for higher SUA were 1.54 (1.04-2.26) in short sleepers and 1.94 (1.27-2.96) in long sleepers after adjusting for confounders. We found a U-shaped association between sleep duration, hsCRP, and SUA in Korean women. 7-8 h sleep was associated with lower level of hsCRP and SUA in Korean women.

Oxidative Stress and Inflammation, Key Targets of Atherosclerotic Plaque Progression and Vulnerability: Potential Impact of Physical Activity

Atherosclerosis, a complex cardiovascular disease, is a leading cause of mortality and morbidity worldwide. Oxidative stress and inflammation are both involved in the development of atherosclerotic plaque as they increase the biological processes associated with this pathology, such as endothelial dysfunction and macrophage recruitment and adhesion. Atherosclerotic plaque rupture leading to major ischemic events is the result of vulnerable plaque progression, which is a result of the detrimental effect of oxidative stress and inflammation on risk factors for atherosclerotic plaque rupture, such as intraplaque hemorrhage, neovascularization, and fibrous cap thickness. Thus, both are key targets for primary and secondary interventions. It is well recognized that chronic physical activity attenuates oxidative stress in healthy subjects via the improvement of antioxidant enzyme capacities and inflammation via the enhancement of anti-inflammatory molecules. Moreover, it was recently shown that chronic physical activity could decrease oxidative stress and inflammation in atherosclerotic patients. The aim of this review is to summarize the role of oxidative stress and inflammation in atherosclerosis and the results of therapeutic interventions targeting them in both preclinical and clinical studies. The effects of chronic physical activity on these two key processes are then reviewed in vulnerable atherosclerotic plaques in both coronary and carotid arteries.

Circulating microRNAs and endothelial cell migration rate are associated with metabolic syndrome and fitness level in postmenopausal African American women

Postmenopausal African American women are at elevated risk for metabolic syndrome (MetS), which predisposes them to cardiovascular disease and other chronic diseases. Circulating microRNAs (ci-miR) are potential mediators of cardiometabolic diseases also impacted by cardiorespiratory fitness (CRF) level. Using real-time quantitative PCR, we compared the expression of vascular-related ci-miRs (miR-21-5p, miR-92a-3p, miR-126-5p, miR-146a-5p, miR-150-5p, miR-221-3p) in sedentary, overweight/obese, postmenopausal African American women based on 1) presence (n = 31) or absence (n = 42) of MetS and 2) CRF level (VO2peak ) (Very Low < 18.0 mL·kg-1 ·min-1 [n = 31], Low = 18.0-22.0 mL·kg-1 ·min-1 [n = 24], or Moderate >22.0 mL·kg-1 ·min-1 [n = 18]). Endothelial migration rate in response to subjects' serum was assessed to determine the effect of circulating blood-borne factors on endothelial repair. Ci-miR-21-5p was the only ci-miR that differed between women with MetS compared to those without MetS (0.93 ± 0.43 vs. 1.28 ± 0.71, P = 0.03). There were borderline significant differences (P = 0.06-0.09) in ci-miR-21-5p, 126-5p, and 221-3p levels between the CRF groups, and these three ci-miRs correlated with VO2peak (r = -0.25 to -0.28, P < 0.05). Endothelial migration rate was impaired in response to serum from women with MetS compared to those without after 16-24 h. Serum from women with Moderate CRF induced greater endothelial migration than the Very Low and Low CRF groups after 4 and 16-24 h, that was also not different from a young, healthy reference group. Ci-miR-21-5p is lower in postmenopausal African American women with MetS, while ci-miRs-21-5p, 126-5p, and 221-3p are associated with CRF. Factors which impair endothelial cell migration rate are present in serum of women with MetS, though having Moderate CRF may be protective.

Blood inflammatory and endothelial markers in women with von Willebrand disease

Introduction

VWD-affected females often experience menorrhagia. Periodical fluctuations of the sex steroids during the menstrual cycle cause changes both in the coagulation and immune system. The aim of the current study was to assess the changes in selected inflammatory and endothelial markers in women with VWD during two phases of the menstrual cycle (follicular and luteal) and to compare it with corresponding data from healthy controls.

Materials and methods

The study group included 12 VWD-affected females with regular menstrual cycle, with none of them being prescribed hormone treatment. They were not pregnant or breastfeeding. The control group consisted of 102 healthy females, matched for age and BMI.

Results

Within the VWD group, endostatin was higher during the follicular phase, compared to the luteal phase, although the difference was not significant (p = 0.062). sICAM-1 and IL-6 were higher in VWD-affected females, compared to the controls, sVCAM-1, cathepsin S and sP-selectin were lower (p<0.003 for all cases). The pattern was constant throughout the menstrual cycle.

Conclusions

Higher levels of endostatin during early follicular phase could potentially predispose women with VWD to the development of heavy menstrual bleeding, due to antiangiogenic properties and ability to suppress several coagulation factors. Lower p-selectin levels in VWD group, compared to controls, may also contribute to the bleeding tendency. Changes in other proteins, involved in angiogenesis are hypothetically related to the formation of angiodysplasia—common complication of VWF deficiency. The latter statement requires confirmation in larger studies.

Low cardiorespiratory fitness is associated with higher extracellular vesicle counts in obese adults

Low cardiorespiratory fitness (CRF) is associated with cardiovascular disease (CVD) independent of obesity. Extracellular vesicles (EVs) are a novel target of CVD, however, it remains unknown if obese individuals with very poor fitness (VPF) have elevated EVs versus people with poor fitness (PF). Thus, we tested whether VPF was associated with greater EV subtypes in obese adults. Subjects with VPF (n = 13, VO2 peak: 15.4 ± 0.6 mL/kg/min, BMI: 34.1 ± 1.7 kg/m2 ) and PF (n = 13, VO2 peak: 25.9 ± 3.0 mL/kg/min, BMI: 32.1 ± 1.2 kg/m2 ) were compared in this cross-sectional study. After an overnight fast, AnnexinV (AV) +/- platelet (CD31+ /CD41+ ), leukocyte (CD45+ /CD41- ), and endothelial EVs (CD105+ , CD31+ /CD41- ) were analyzed from fresh platelet poor plasma via imaging flow cytometry. Body fat, blood pressure (BP), and glucose tolerance (OGTT) were also tested. Body weight, BP, and circulating glucose were similar between groups, although VPF subjects were older than PF (64.0 ± 2.1 vs. 49.8 ± 4.2 year; P < 0.05). People with VPF, compared with PF, had higher total AV- EVs (P = 0.04), AV- platelet EVs (CD31+ /CD41+ ; P = 0.006), and AV- endothelial EVs (CD31+ /CD41- ; P = 0.005) independent of age and body fat. Higher AV- platelet and endothelial EVs were associated with lower VO2 peak (r = -0.56, P = 0.006 and r = -0.55, P = 0.005, respectively). Endothelial-derived AV- /CD31+ /CD41- EVs were also related to pulse pressure (r = 0.45, P = 0.03), whereas AV- /CD105 was linked to postprandial glucose (r = 0.41, P = 0.04). VPF is associated with higher AnnexinV- total, endothelial, and platelet EVs in obese adults, suggesting that subtle differences in fitness may reduce type 2 diabetes and CVD risk through an EV-related mechanism.

Evaluation of the convergent validity of an estimated cardiorespiratory fitness algorithm

PURPOSE

Examine the convergent validity of a cardiorespiratory fitness (CRF) algorithm when compared to treadmill-assessed CRF.

METHODS

Data from the 1999-2004 NHANES were used (N = 3259 adults 20-49 years). Cardiorespiratory fitness was estimated from an algorithm. Participants completed a submaximal treadmill-based protocol. We (1) evaluated the pairwise association (and ICC) between estimated and measured cardiorespiratory fitness, (2) employed a paired samples t test to examine potential mean differences between estimated and measured cardiorespiratory fitness, (3) constructed a Bland-Altman plot and 95% limits of agreement (LoA) to explore systematic differences and random error between estimated and measured cardiorespiratory fitness, and (4) examined the association (via linear regression) of estimated and measured cardiorespiratory fitness with chronic disease prevalence and C-reactive protein (CRP).

RESULTS

Mean estimated CRF (10.68 METs) was lower than the mean measured CRF of 11.37 METs (p < 0.0001). The calculated pairwise correlation was of a moderate strength, r = 0.43 (p < 0.0001), with an ICC of 0.40 (p < 0.001). Calculated LoA indicated that estimated CRF may differ from measured CRF by 40% below to 48% above. Regression analyses yielded statistically significant inverse associations of estimated (unstandardized coefficient = - 0.026; p < 0.001) and measured (unstandardized coefficient = - 0.007; p = 0.002) CRF with chronic disease and estimated (unstandardized coefficient = - 0.08; p < 0.001) and measured (unstandardized coefficient = - 0.03; p < 0.001) CRF with CRP.

CONCLUSION

Measured and estimated CRF were moderately correlated. However, estimated and measured CRF were statistically significant different from one another with noteworthy scatter around the average difference. As such, when feasible, objective measurements of CRF should be taken.

Responses of inflammatory cytokines following moderate intensity walking exercise in overweight or obese individuals

This study investigated the effects of a 4-week moderate intensity walking exercise on the levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and adiponectin in overweight or obese individuals. Twenty-seven (13 men and 14 women) physically inactive, over-weight or obese (body mass index>25.0 kg/m²) individuals participated in the study. Each participant was randomly assigned to either exercise (EX; n=15) or control (CON; n=12) group. The EX group performed moderate intensity walking exercise on a treadmill for 60 min at 70% of maximal heart rate for 4 weeks (3 days/wk). Overnight fasting blood samples were collected before and after the study period (Pre and Post) to analyze the levels of pro-/anti-inflammatory cytokines such as CRP, TNF-α, and adiponectin. CRP and adiponectin as well as body weight and body composition were not significantly altered following the 4-week exercise intervention. However, there was a significant group×time interaction for TNF-α. The post hoc test revealed that the level of TNF-α significantly decreased only in EX (EX: mean±standard deviation, Pre 55.18±6.57 pg/mL, Post 50.31±6.22, P=0.018 vs. CON: Pre 55.5±5.88, Post 58.19±6.48, P=0.25). EX Post was also significantly lower as compared to CON Post (P=0.0074). Although there was no change in body weight or fat mass, the 4-week aerobic exercise training was long enough to decrease the level of TNF-α, indicating physical activity may improve level of inflammation independently from the change in fat mass. The current study also confirmed previous research suggesting that longer period of exercise training accompanied by weight loss may be required to induce significant changes in CRP and adiponectin.

Association between Cardiorespiratory Fitness and Lung Health from Young Adulthood to Middle Age

RATIONALE

Beyond the risks of smoking, there are limited data on factors associated with change in lung function over time.

OBJECTIVES

To determine whether cardiorespiratory fitness was longitudinally associated with preservation of lung health.

METHODS

Prospective data were collected from 3,332 participants in the Coronary Artery Risk Development in Young Adults study aged 18-30 in 1985 who underwent treadmill exercise testing at baseline visit, and 2,735 participants with a second treadmill test 20 years later. The association between cardiorespiratory fitness and covariate adjusted decline in lung function was evaluated.

MEASUREMENTS AND MAIN RESULTS

Higher baseline fitness was associated with less decline in lung function. When adjusted for age, height, race-sex group, peak lung function, and years from peak lung function, each additional minute of treadmill duration was associated with 1.00 ml/yr less decline in FEV1 (P < 0.001) and 1.55 ml/yr less decline in FVC (P < 0.001). Greater decline in fitness was associated with greater annual decline in lung function. Each 1-minute decline in treadmill duration between baseline and Year 20 was associated with 2.54 ml/yr greater decline in FEV1 (P < 0.001) and 3.27 ml/yr greater decline in FVC (P < 0.001). Both sustaining higher and achieving relatively increased levels of fitness over 20 years were associated with preservation of lung health.

CONCLUSIONS

Greater cardiopulmonary fitness in young adulthood, less decline in fitness from young adulthood to middle age, and achieving increased fitness from young adulthood to middle age are associated with less decline in lung health over time. Clinical trial registered with www.clinicaltrials.gov (NCT 00005130).

The Anti-Inflammatory Actions of Exercise Training

The list of diseases with a known inflammatory etiology is growing. Cardiovascular disease, osteoporosis, diabetes, geriatric cachexia, and Alzheimer's disease have all been shown to be linked to or exacerbated by aberrantly regulated inflammatory processes. Nevertheless, there is mounting evidence that those who are physically active, or who become physically active, have a reduction in biomarkers associated with chronic inflammation. There was strong early consensus that exercise-induced reductions in inflammation were explained by body mass index or body fatness, but recent studies provide support for the contention that exercise has body fat-independent anti-inflammatory effects. With few exceptions, the anti-inflammatory effects of exercise appear to occur regardless of age or the presence of chronic diseases. What remains unclear are the mechanisms by which exercise training induces these anti-inflammatory effects, but there are several intriguing possibilities, including release of endogenous products, such as heat shock proteins; selective reduction of visceral adipose tissue mass or reducing infiltration of adipocytes by macrophages; shift in immune cell phenotype; cross-tolerizing effects; or exercise-induced shifts in accessory proteins of toll-like receptor signaling. However, future research endeavors are likely to uncover additional potential mechanisms, and it could be some time before functional mechanisms are made clear. In summary, the potential anti-inflammatory influences of exercise training may provide a low-cost, readily available, and effective treatment for low-grade systemic inflammation and could contribute significantly to the positive effects of exercise training on chronic disease.

A Systematic Review of the Acute Effects of Exercise on Immune and Inflammatory Indices in Untrained Adults

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of global mortality. Although the incidence may be reduced with regular exercise, the health benefits of a single bout of exercise on selected CVD risk factors are not well understood. The primary objective of this review is to consider the transient effects of exercise on immune (neutrophil count) and inflammatory (interleukin-6 [IL-6], C-reactive protein [CRP]) markers in untrained adults.

METHODS

MEDLINE, EMBASE, CINAHL, Sports Discus and Cochrane were searched for relevant studies published from January 1946 to May 2013. Randomised controlled or crossover studies which measured any of these parameters in untrained but otherwise healthy participants in the 48 h following about of exercise, less than 1 h in duration were included.

RESULTS

Ten studies met the inclusion criteria. The results indicate a single bout of aerobic or resistance exercise of moderate to high intensity promotes an increase in IL-6 (145 %) and neutrophil counts (51 %). It appears that 30-60 min of moderate to high intensity exercise is necessary to elicit such changes although variables such as the mode, intensity and pattern of exercise also affect the response. The acute response of CRP within the included studies is equivocal.

CONCLUSIONS

Although responses to CRP are inconsistent, a single bout of exercise can increase the activity of both circulating IL-6 and neutrophil counts in untrained adults. These immune and inflammatory responses to a single bout of exercise may be linked to a range of health benefits.

Low cardiorespiratory fitness in African Americans: a health disparity risk factor?

Low cardiorespiratory fitness (CRF) is a well-established risk factor for all-cause and cardiovascular disease mortality. African Americans have higher rates of cardiovascular disease compared with their Caucasian counterparts. However, the extent to which lower CRF levels contribute to the excess risk in African Americans has not been fully explored. The purpose of this review is to: (i) explore the literature evaluating the relationship between CRF and mortality specifically in African American populations; and (ii) critically evaluate the studies which have compared CRF between African American and Caucasians in epidemiological studies and clinical trials. We have further discussed several potential mechanisms that may contribute to the observation of lower CRF levels in African American compared with Caucasian adults, including potential racial differences in physical activity levels, muscle fiber type distribution, and hemoglobin levels. If lower CRF is generally present in African Americans compared with Caucasians, and is of a clinically meaningful difference, this may represent an important public health concern.

Health Benefits of Exercise for People Living With HIV: A Review of the Literature

With life expectancy increasing and the symptomatology of HIV being altered since the advent of antiretroviral therapy (ART), we now have begun to see metabolic changes with negative implications among people living with HIV/AIDS (PLWHA). Some of these changes include increased blood lipids, central fat accumulation, lipodystrophy, and decreased aerobic capacity. All of which are known risk factors for cardiovascular disease, cancer, and all-cause mortality. A common practice among healthy and other clinical populations to help modify these risk factors is some form of aerobic exercise, resistance exercise, or a combination of both. It has been demonstrated that PLWHA could respond in a similar manner, which in turn may enhance life expectancy and/or quality of life. The purpose of this literature review was to examine the evidence of health benefits of routine exercise training among PLWHA since the advent of ART. Although limited in strength because of small sample sizes and limited intervention durations, there is overall consistency in the general findings. An overview of the findings would indicate that physical activity and exercise are both safe and effective in improving cardiorespiratory fitness, metabolic profile, and quality of life among PLWHA.

Predictors of improvement in endothelial function after exercise training in a diverse sample of postmenopausal women

BACKGROUND

Endothelial dysfunction measured via flow-mediated dilation (FMD) is associated with greater risk of future hypertension and cardiovascular events in postmenopausal women. Aerobic exercise training has been shown to improve endothelial function in Caucasian populations, but has not been evaluated specifically in African Americans. This has clinical importance due to the increased prevalence of cardiovascular disease in African Americans.

METHODS

In the present pilot study, 8 African American (age: 55.8±1.7 years, peak oxygen uptake [VO2 peak]: 21.0±3.9 mL/kg/minute, body mass index [BMI]: 30.1± 6.3 kg/m(2)) and 16 Caucasian (age: 57.2±5.9 years, VO2 peak: 21.8±3.7 mL/kg/minute, BMI: 29.3±5.2 kg/m(2)) sedentary postmenopausal women underwent brachial artery FMD measurements before and after 12 weeks of aerobic exercise training. FMD was quantified by comparing B-mode ultrasound images of the brachial artery at rest and following reactive hyperemia after 5 minutes of forearm occlusion. Participants performed aerobic exercise training 4 days per week for 12 weeks.

RESULTS

Despite improvements in fitness in both groups, aerobic exercise training did not significantly improve FMD in African American (5.8% to 5.7%, p=0.950) or Caucasian postmenopausal women (5.7% to 6.6%, p=0.267). In women with the greatest impairment in endothelial function at baseline (FMD<4.5%), a significant improvement in FMD was observed, independent of race, following exercise training (2.2% to 6.2%, p=0.007).

CONCLUSION

The benefits of aerobic exercise training on endothelial function in postmenopausal women are most pronounced in women with endothelial dysfunction prior to training and do not appear to be affected by race.

Effects of exercise training on chronic inflammation in obesity : current evidence and potential mechanisms

Chronic, systemic inflammation is an independent risk factor for several major clinical diseases. In obesity, circulating levels of inflammatory markers are elevated, possibly due to increased production of pro-inflammatory cytokines from several tissues/cells, including macrophages within adipose tissue, vascular endothelial cells and peripheral blood mononuclear cells. Recent evidence supports that adipose tissue hypoxia may be an important mechanism through which enlarged adipose tissue elicits local tissue inflammation and further contributes to systemic inflammation. Current evidence supports that exercise training, such as aerobic and resistance exercise, reduces chronic inflammation, especially in obese individuals with high levels of inflammatory biomarkers undergoing a longer-term intervention. Several studies have reported that this effect is independent of the exercise-induced weight loss. There are several mechanisms through which exercise training reduces chronic inflammation, including its effect on muscle tissue to generate muscle-derived, anti-inflammatory 'myokine', its effect on adipose tissue to improve hypoxia and reduce local adipose tissue inflammation, its effect on endothelial cells to reduce leukocyte adhesion and cytokine production systemically, and its effect on the immune system to lower the number of pro-inflammatory cells and reduce pro-inflammatory cytokine production per cell. Of these potential mechanisms, the effect of exercise training on adipose tissue oxygenation is worth further investigation, as it is very likely that exercise training stimulates adipose tissue angiogenesis and increases blood flow, thereby reducing hypoxia and the associated chronic inflammation in adipose tissue of obese individuals.

Inflammation and hypertension: are there regional differences?

Hypertension is a chronic disease with global prevalence and incidence rapidly increasing in low and medium income countries. The surveillance of cardiovascular risk factors, such as hypertension, is a global health priority in order to estimate the burden and trends, to appropriately direct resources, and to measure the effect of interventions. We propose here that the adoption of Western lifestyles in low and middle incomes countries has dramatically increased the prevalence of abdominal obesity, which is the main source of proinflammatory cytokines, and that the vascular systemic inflammation produced by adipose tissue contributes to the development of hypertension. The concentration of proinflammatory cytokines is higher in the Latin American population than that reported in developed countries, suggesting a higher susceptibility to develop systemic low-degree inflammation at a given level of abdominal obesity. These particularities are important to be considered when planning resources for health care programs. Moreover, studying these singularities may provide a better understanding of the causes of the burden of cardiovascular risk factors and the remarkable variability in the prevalence of these medical conditions within and between countries.

Racial differences in the response of cardiorespiratory fitness to aerobic exercise training in Caucasian and African American postmenopausal women

African American (AA) women have an elevated risk of cardiovascular disease and have been reported to have lower cardiorespiratory fitness (CRF) compared with Caucasian American (CA) women. However, little data exist that evaluate racial differences in the change in CRF following aerobic exercise training. CA (n = 264) and AA (n = 122) postmenopausal women from the Dose-Response to Exercise in Women study were randomized to 4, 8, and 12 kcal·kg body wt(-1)·wk(-13) (KKW) of aerobic training or the control group for 6 mo. CRF was evaluated using a cycle ergometer. A greater increase in relative CRF was observed in CA compared with AA women in the 4 (CA: 1.00 vs. AA: 0.35 ml O2·kg(-1)·min (-1), P = 0.034), 8 (CA: 1.59 vs. AA: 0.82 ml O2·kg(-1)·min (-1), P = 0.041), and 12 (CA: 1.98 vs. AA: 0.50 ml O2·kg(-1)·min (-1), P = 0.001) KKW groups. Similar effects were found in absolute CRF, with the exception of the 4-KKW (CA: 0.04 vs. AA: 0.02 l O2/min, P = 0.147) group. However, in categorical analyses, the percentages of women who improved in both relative (>0 ml O2·kg(-1)·min (-1)) and absolute (>0 l O2/min) CRF were not significantly different for CA and AA women in all exercise groups (all P > 0.05). AA postmenopausal women, in general, had an attenuated increase in CRF (both relative and absolute) following exercise training, but had similar response rates compared with CA women. Future studies should investigate the physiologic mechanisms responsible for this attenuated response.

Effects of 5 % weight loss through diet or diet plus exercise on cardiovascular parameters of obese: a randomized clinical trial

OBJECTIVE

To evaluate the effects of 5 % weight loss, through diet only or diet plus exercise, on lipid profile, inflammation and endothelial function in obese individuals.

METHODS

In this randomized clinical trial, 48 obese individuals were randomized to either a diet only group (DI) or a diet and exercise group (DI + EXE). Treatment was maintained until 5 % of the initial body weight was lost. At baseline and upon completion, the following parameters were analyzed: total cholesterol and fractions, triglycerides, fibrinogen, von Willebrand factor, high-sensitive C-reactive protein (hs-CRP) and endothelial function (brachial artery flow-mediated vasodilation-FMD).

RESULTS

Thirteen individuals dropped out before completing the weight loss intervention. The median time required for reduction of 5 % of initial body weight was 79.7 days for the DI group and 65.9 days for the DI + EXE group (P = 0.16). In both DI (n = 18) and DI + EXE (n = 17), total cholesterol (-15.8 ± 4.8 and -10.5 ± 4.9 mg/dL, respectively), triglycerides (-33.8 ± 10.0 and -39.4 ± 10.3 mg/dL, respectively) and hs-CRP (-1.35 ± 0.41 and -0.45 ± 0.43 mg/L, respectively) decreased significantly, and in a similar response (repeated measures ANOVA). Weight loss did not change significantly the fibrinogen and FMD in both groups.

CONCLUSION

A 5 % weight loss improves lipid profile and reduces inflammation in obese individuals. Endothelial function did not change significantly. Weight loss has a significant impact on these cardiovascular risk factors, and this is independent of physical training.

Physical activity and inflammation in a multiethnic cohort of women

PURPOSE

Many cross-sectional studies using data from a single time point have reported that higher levels of physical activity or fitness are associated with lower levels of inflammatory markers, but data examining change are limited, as are race/ethnicity-specific data. The purpose of this study was to examine the associations between physical activity and inflammation assessed at two time points among women of different race/ethnicities.

METHODS

A total of 1355 postmenopausal women (301 whites, 300 blacks, 300 Hispanics, 300 Asians/Pacific Islanders, and 154 American Indians) age 50-79 yr were studied. Participants were from 40 US cities and were free of cardiovascular disease and cancer. At baseline and year 3, women reported their recreational physical activities and provided blood samples, which were analyzed for several inflammatory markers.

RESULTS

In cross-sectional analyses, after adjusting for several potential confounders including body mass index, higher physical activity levels were generally related to lower inflammatory marker concentrations. For example, P values for a linear trend of lower C-reactive protein levels across physical activity tertiles at baseline were <0.0001 in all women and 0.94, 0.09, 0.002, 0.20, and 0.10, respectively, for the five race/ethnic groups listed above. For interleukin 6, the corresponding P values were <0.0001, 0.0007, 0.01, 0.03, 0.37, and 0.004, respectively, at baseline. Relationships at year 3 were similar to baseline. However, there was no relation between changes in physical activity and changes in inflammatory markers during the 3-yr period.

CONCLUSIONS

Among middle-age and older women overall, there were strong, inverse, cross-sectional associations between physical activity level and inflammatory markers. However, changes in inflammatory markers were unrelated to changes in physical activity. These data suggest a noncausal association between physical activity and inflammatory markers.

High-Sensitivity C-Reactive Protein in Japanese Patients with Type 2 Diabetes

OBJECTIVE

To assess the relationship between high-sensitivity (HS) C-reactive protein (CRP) and metabolic syndrome (MetS) or atherosclerosis and to assess effects of strict metabolic control on the degree of inflammation and MetS in patients with type 2 diabetes.

RESEARCH METHODS AND PROCEDURES

Four hundred thirteen patients with diabetes were enrolled in the cross-sectional study. Of these 413 patients, 161 patients were further admitted for 2.4 +/- 0.4 weeks (mean +/- SD) to investigate the change in HS-CRP or other parameters under strict metabolic control.

RESULTS

Log-transformed HS-CRP value (log HS-CRP) was strongly correlated with BMI (r = 0.448, p < 0.01). Log HS-CRP was also correlated with the presence of MetS or each component of MetS. Furthermore, a positive significant trend in HS-CRP levels was shown with an increasing number of MetS components (p < 0.05). Log HS-CRP showed a significant positive correlation with carotid artery intima-media thickness (IMT) (r = 0.152, p < 0.01). In multiple step-wise regression analysis, BMI, hemoglobin A(1c), right IMT, duration of diabetes, and triglyceride were selected as explanatory variables for log HS-CRP (R2 = 0.412). Under strict metabolic control, HS-CRP was significantly (p < 0.01) lower, together with lower levels of other markers for MetS. The change in HS-CRP was significantly correlated with the change in BMI (r = 0.161, p = 0.04).

DISCUSSION

In subjects with type 2 diabetes, HS-CRP levels are related to MetS and subclinical atherosclerosis. Strict weight management and metabolic control were associated with a reduction in HS-CRP levels, and changes in HS-CRP were related to changes in weight, supporting the hypothesis that lifestyle modification reduces inflammation and the risk of CHD.

Cardiovascular risk factors in football players

Cardiovascular disease is a leading cause of death in the United States. Football players represent a subpopulation that may have a unique risk profile pattern. Studies have suggested that football players may be at increased risk for cardiovascular disease. Paradoxically, there may be a cardioprotective effect associated with activity in general and, specifically, participation at higher levels of football. Our review will attempt to outline the pertinent evidence in regards to cardiovascular risk factors in football players. Specifically, hypertension, hypercholesterolemia, obesity, and sedentary lifestyle will be considered. In addition, we will discuss potential risk factors for investigation including C-reactive protein, homocysteine, insulin resistance, and sleep-disordered breathing. Studies at all levels of competition will be considered, including retired players whose findings may represent lifelong changes that occur as a result of participation in football. Further investigation will be needed to help clarify the relationship between football participation and cardiovascular risk.

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.

Low serum IL-6 is associated with high 6-minute walking performance in asymptomatic women aged 20 to 70years

Cross-sectional associations between low physical performance and inflammatory biomarkers have been reported in healthy subjects and in persons with specific disease conditions. In asymptomatic subjects, whether the inverse association between physical fitness and inflammatory biomarkers is dependent or is independent of fat mass, a significant source of inflammatory cytokines, and is independent of age, muscle mass and strength, endocrine, metabolic, and lifestyle factors is not known. Two hundred and twenty asymptomatic women aged 20 to 72years with a C-reactive protein <5mg/L were assessed for their mean speed over the 6-minute walking test (6MWS) and their serum IL-6, as well as body height, body weight, body lean and fat mass (measured by DXA), waist-to-hip ratio, grip and knee extension strength, physical activities (quantified by the QUANTAP questionnaire), tobacco consumption, serum 25(OH) vitamin D, parathyroid hormone (PTH), estradiol (E2), free testosterone, dehydroepiandrosterone sulfate (DHEAS), insulin-like growth factor (IGF-I), sex hormone-binding globulin (SHBG), calcium, albumin, and creatinine. In the stepwise multiple linear regression model, a 6MWS in the highest quartile (over 1.4m/s) was associated with lower values of serum IL-6 (p=0.02) and with higher values of grip strength (p=0.04) and creatinine (p=0.04). In conclusion, present results demonstrate that the relationship between lower levels of serum IL-6 and higher values of physical fitness in asymptomatic women is independent of age, body composition, and lifestyle, endocrine and metabolic confounders. It remains to be determined whether the inverse relationship between IL-6 and fitness reflects the presence of preclinical inflammatory diseases that could potentially influence fitness in asymptomatic women.

Increased systemic elastase and C-reactive protein in aggressive periodontitis (CLOI-D-00160R2)

The inflammatory mediators, serum elastase and C-reactive protein (CRP), are associated with an increased risk for coronary heart disease. Thus, the aim of this study is to compare systemic inflammatory mediators in periodontally healthy controls (C), patients with untreated aggressive (AgP) and chronic (ChP) periodontitis. C [periodontal pocket probing depth (PPD)  <3.6 or <5 mm without bleeding (BOP), BOP < 10%], ChP (PDD ≥ 3.6 mm and probing attachment loss ≥5 mm at >30% of sites; age >35 years), and AgP (clinically healthy; PDD ≥ 3.6 mm at >30% of sites, bone loss ≥50% at ≥2 teeth; age ≤35 years) were examined clinically, and the body mass index was assessed. Blood was sampled for assessment of serum levels of elastase, CRP, lipopolysaccharide binding protein (LBP), interleukin (IL) 6, 8, and leukocyte counts. Thirty C, 31 ChP, and 29 AgP were analyzed. Elastase, CRP, LBP, and IL-6 levels were elevated in AgP compared to C (p < 0.013), whereas leukocyte counts and IL-8 were similar. Multiple regression analysis identified AgP (p < 0.001) and education level (p < 0.001) to explain 47% of the variation of elastase. AgP (p = 0.003), African origin (p = 0.006), female sex (p = 0.002), and BMI (p < 0.001) explained 39% of the variation of CRP. Serum elastase and CRP are significantly elevated in AgP compared to C. AgP patients exhibit a stronger systemic inflammatory burden than C patients.

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.

Cardiovascular disease, SCI and exercise: unique risks and focused countermeasures

PURPOSE

To summarise the spinal cord injury (SCI) specific profile of three cardiovascular disease risk factors (CVD): fasting dyslipidaemia, postprandial lipidaemia and vascular inflammation and to summarise exercise prescriptions that may attenuate each.

METHOD

NA.

RESULTS

NA.

CONCLUSIONS

At least three CVD risk factors have unique profiles in the SCI population. Fasting dyslipidaemia is characterised in the SCI population by depressed HDL cholesterol and normal or low total cholesterol. In the post-prandial state, persons with SCI exhibit an exaggerated triglyceride rise and delayed clearance compared to non-disabled persons. Finally, vascular inflammation, as indexed by C-reactive protein, is markedly elevated in SCI. Exercise may improve each, although the specific prescriptions differs. Fasting dyslipidaemia responds to 8 weeks of moderate intensity aerobic exercise performed 5 days weekly for 30 min daily. Post-prandial lipaemia treatment requires daily moderate or vigorous aerobic exercise, as the effect dissipates day by day. The daily exercise duration is proportional to fitness level, with total caloric expenditure emphasised rather than time. Finally, attenuating vascular inflammation in non-disabled persons requires moderate or vigorous exercise performed for ≥12 months, 5 days weekly for ≥45 min; with aerobic exercise plus resistance training more effective than aerobic exercise alone.

Circulating inflammatory and endothelial markers and risk of hypertension in white and black postmenopausal women

BACKGROUND

Systemic inflammation and endothelial activation are implicated in the development of hypertension. However, epidemiologic studies have yet to compare multiple corresponding biomarkers in relation to risk of hypertension, particularly in multiethnic populations.

METHODS

We identified 800 individuals with incident hypertension and 800 matched controls, each group with equal numbers of white and black women, in a nested case-control study within the Women's Health Initiative Observational Study. We measured markers of inflammation [high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1β, tumor necrosis factor receptor 2 (TNF-r2)] and endothelial activation [soluble intercellular adhesion molecule-1 (sICAM-1)] in baseline blood samples.

RESULTS

Before adjustment for measures of adiposity, higher hsCRP and IL-6 concentrations were associated with increased risk of hypertension in both white and black women, higher TNF-r2 was associated with increased risk of hypertension in black women only, and IL-1β and sICAM-1 were not associated with risk of hypertension. All the positive associations were attenuated after adjustment for body mass index. The resulting multivariable-adjusted relative risks (95% CI) of hypertension comparing the highest vs lowest quartile were 1.52 (0.94-2.48) and 1.23 (0.76-1.97) for hsCRP and IL-6 in white women and 1.30 (0.81-2.07), 1.58 (0.96-2.59), and 1.49 (0.94-2.36) for hsCRP, IL-6, and TNF-r2 in black women. The results after adjustment for waist circumference were similar.

CONCLUSIONS

After adjustment for measures of adiposity, there was no significant association of hsCRP, IL-6, IL-1β, TNF-r2, or sICAM-1 with incident hypertension in either white or black women. The interrelationships between inflammation and adiposity in development of hypertension need further investigation.

Relationship between obesity and physical fitness and periodontitis

BACKGROUND

Obesity and exercise are important elements associated with lifestyle-related diseases, and studies suggested that these factors may also be related to periodontitis. This study investigates the relationship between obesity and physical fitness and periodontitis.

METHODS

One thousand, one hundred and sixty Japanese subjects, aged 20 to 77 years, who participated in health examinations at Fukuoka Health Promotion Center were analyzed. Periodontal conditions were evaluated using the Community Periodontal Index (CPI), and subjects with > or =3 sextants of CPI code 3 or 4 were defined as having severe periodontitis. We used the body mass index (BMI) and percentage of body fat as indicators of obesity and estimated the maximal oxygen consumption (VO(2max)) during exercise as an indicator of physical fitness. We divided these variables into quintiles. We examined the single effect and interactions of the obesity index and VO(2max) on severe periodontitis.

RESULTS

The lowest quintile in BMI and the highest quintile in VO(2max) were inversely associated with severe periodontitis, singly, in multivariate logistic regression analyses. Subjects with the combined lowest quintile in BMI and the highest quintile in VO(2max) had a significantly lower risk of severe periodontitis compared to subjects with other combined quintiles in BMI and in VO(2max) (odds ratio: 0.17; 95% confidence interval: 0.05 to 0.55).

CONCLUSION

This study suggests that obesity and physical fitness may have some interactive effect on periodontal health status.

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.

Diagnostic criteria for metabolic syndrome: caucasians versus African-Americans

BACKGROUND

Metabolic syndrome is a constellation of risk factors used to identify individuals at greatest risk for developing cardiovascular disease (CVD). Early diagnosis of CVD would benefit African-Americans (AA), who have a higher prevalence of and mortality rate from CVD compared to Caucasians (CA). Two definitions for metabolic syndrome were used to classify healthy CA and AA, and evaluate how other CVD risk factors [C-reactive protein (CRP), percent body fat, fitness level, insulin resistance, and non-high-density lipoprotein cholesterol (HDL-C)] changed metabolic syndrome classification.

METHODS

Healthy AA (n = 97) and CA (n = 51) ranging from normal weight to obese, 18-45 years of age, with neither hypertension nor diabetes, were evaluated for cardiorespiratory fitness, height, weight, percent body fat, hip and waist circumference, blood pressure (BP), and fasting blood glucose, insulin, triglycerides, HDL, non-HDL-C, and CRP. Participants were classified as meeting the criteria for metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III 2004 (NCEP ATP III) and the International Diabetes Federation (IDF) definitions.

RESULTS

Significant ethnic differences (P < 0.01) in classification were noted for both metabolic syndrome definitions (NCEP ATP III, CA = 16.7% vs. AA = 5.7%; IDF, CA = 23.5% vs. AA = 8.2%). Ethnic differences were eliminated when fitness level or percent body fat was included as a criterion.

CONCLUSIONS

If diagnosis of metabolic syndrome is intended for early recognition of CVD risk and slowing CVD development, current definitions for metabolic syndrome will not capture healthy AA. Health-care providers may consider assessing percent body fat and participation in regular exercise, because these criteria would help identify AA at risk.

Cardiovascular fitness and risk factors of healthy African Americans and Caucasians

BACKGROUND

African Americans have a higher prevalence of and mortality rates from cardiovascular disease than Caucasians. One important risk factor for cardiovascular disease is poor cardiovascular fitness. We quantified associations between fitness and related primary risk factors for cardiovascular disease in healthy African Americans and Caucasians.

METHODS AND RESULTS

Participants included African American (n = 91) and Caucasian (n = 51) men and women aged 18 to 45 years with a body mass index less than 38 kg/m2, fasting blood glucose less than 126 mg/dL, and blood pressure less than 140/90 mm Hg. Fitness, waist and hip circumference, percent body fat, fasting blood glucose, insulin, lipid profiles, and C-reactive protein (CRP) were measured. The majority of African Americans (57.1%) were low-fair fitness (Caucasians, 31.4%), and only 20.8% were good/high fitness (Caucasians, 39.2%). The number of cardiovascular disease risk factors increased with decreasing fitness, and CRP was negatively associated with fitness in both groups.

CONCLUSIONS

Low fitness may characterize apparently healthy African Americans as at risk for cardiovascular disease. Including fitness as a risk factor may improve early identification of at-risk African Americans. Importantly, prescribing exercise as medicine and promoting regular physical activity to improve fitness is essential among African Americans.

A yearlong exercise intervention decreases CRP among obese postmenopausal women

PURPOSE

To investigate the effect of a yearlong moderate-intensity aerobic exercise intervention on C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) among overweight or obese postmenopausal women.

METHODS

In a randomized controlled trial, 115 postmenopausal, overweight or obese, sedentary women, aged 50-75 yr were randomized to an aerobic exercise intervention of moderate-intensity (60%-75% observed maximal HR), for > or = 45 min x d(-1), 5 d x wk (n = 53), or to a 1-d x wk(-1) stretching control (n = 62), on an intent-to-treat basis. CRP, SAA, and IL-6 were measured at baseline, at 3 months, and at 12 months.

RESULTS

From baseline to 12 months, CRP decreased 10% in exercisers and increased 12% in controls (P = 0.01); no effects were observed for SAA and IL-6. Among participants at baseline who were obese (body mass index (BMI) > or = 30 kg x m(-2)) or had abdominal obesity (waist circumference (WC) > or = 88 cm), exercise resulted in a more pronounced reduction in CRP (BMI > or = 30 kg x m(-2), P = 0.002; WC > or = 88 cm, P < 0.0001), borderline for SAA (BMI > or = 30 kg x m(-2), P = 0.08; WC > or = 88 cm, P = 0.04); no intervention effects were observed among women who did not have these characteristics. Overall, weight loss was minimal in the exercise intervention ( approximately 1.8 kg). Linear trends were observed between CRP and 12-month changes in aerobic fitness (Ptrend = 0.006), exercise adherence (Ptrend = 0.004), percentage body fat (Ptrend = 0.002), body weight (Ptrend = 0.002), WC (Ptrend = 0.02), and intra-abdominal fat (Ptrend = 0.03).

CONCLUSIONS

A moderate-intensity exercise intervention reduced CRP for 12 months among women who were obese at baseline. These findings support the role of exercise in modulating inflammatory processes that are related to increased risk of chronic disease among obese women.

Serum IGF-I and C-reactive protein in healthy black and white young men: the CARDIA male hormone study

OBJECTIVE

Animal and human studies suggest that C-reactive protein (CRP) may be inversely associated with serum insulin-like growth factor-I (IGF-I) concentrations. However, most human studies have not controlled adequately for confounding factors, particularly nutritional intake. This population-based study examined whether CRP is inversely associated with IGF-I and IGFBP-3 concentrations.

METHODS

In cross-sectional analysis, multivariable linear regression with adjustment for age, BMI, smoking status, alcohol intake, and nutritional factors was used to relate log CRP, the independent variable, to IGF-I and IGFBP-3 in a sample of black (n=364) and white men (n=486) separately by race.

RESULTS

Only black men had positive findings: log CRP was significantly associated with IGF-I (beta=-13.1 ng/ml, p=0.02) and the difference in mean IGF-I concentrations between the highest and lowest quartiles of CRP was 26 ng/ml. There was a statistically significant interaction between log CRP and smoking status (p=0.02); the regression coefficient for IGF-I predicted from log CRP was significant in smokers (beta=-39.8 ng/ml, p=0.0001), but not in non-smokers. The difference in mean IGF-I concentrations between highest and lowest quartiles of CRP was 100 ng/ml for black smokers. There were no associations for IGFBP-3.

CONCLUSIONS

In our study, CRP levels are inversely associated with IGF-I concentrations in black male smokers; however, the causal nature of the association is unclear and should be studied further.

Evaluation of iron deficiency as a nutritional adaptation to infectious disease: an evolutionary medicine perspective

An evolutionary perspective suggests that iron deficiency may have opposing effects on infectious disease risk, decreasing susceptibility by restricting iron availability to pathogens, and increasing susceptibility by compromising cellular immunocompetence. In some environments, the trade-off between these effects may result in optimal iron intake that is inadequate to fully meet body iron needs. Thus, it has been suggested that moderate iron deficiency may protect against acute infection, and may represent a nutritional adaptation to endemic infectious disease stress. To test this assertion, we examined the association between infection, reflected by C-reactive protein, a biomarker of inflammation, and iron status, reflected by transferrin receptor (TfR) and zinc protoporphyrin to heme ratio (ZPP:H), among school-age Kenyan children, and evaluated the hypothesis that moderate iron deficiency is associated with lower odds of infectious disease. TfR > 5.0 mg/l, with sensitivity and specificity for iron deficiency (ZPP:H > 80 micromol/mol) of 0.807 and 0.815, was selected as the TfR definition of iron deficiency. Controlling for age and triceps skinfold thickness (TSF), the odds ratio (OR) for acute viral or bacterial infection associated with iron deficiency (compared to normal/replete) was 0.50 (P = 0.11). Controlling for age and TSF, the OR for infection associated with an unequivocally iron replete state (compared to all others) was 2.9 (P = 0.01). We conclude that iron deficiency may protect against acute infection in children.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

Correlates of circulating C-reactive protein and serum amyloid A concentrations in breast cancer survivors

INTRODUCTION

Inflammatory status may be an important prognostic factor for breast cancer. Correlates of markers of inflammation in breast cancer survivors have not been thoroughly evaluated.

METHODS

Using data from, the Health, Eating, Activity, and Lifestyle (HEAL) Study (a population-based, multiethnic prospective cohort study of female breast cancer patients) we evaluated the associations between circulating markers of inflammation (C-reactive protein [CRP] and serum amyloid A [SAA], measured approximately 31 months after diagnosis) and several demographic, lifestyle, and clinical characteristics in 741 disease-free breast cancer survivors. Analysis of variance and regression methods were used for statistical analyses of log-transformed values of CRP and SAA.

RESULTS

After adjusting for age, BMI, ethnicity, and study site, higher concentrations of CRP were associated with increasing concentration of SAA (P-trend < 0.0001), increasing age (P-trend < 0.0001), increasing BMI (P-trend < 0.0001), increasing waist circumference (P-trend < 0.0001), positive history of heart failure (P = 0.0007), decreasing physical activity (P-trend = 0.005), Hispanic ethnicity (P = 0.05 vs. non-Hispanic white), and current smoking (P = 0.03 vs. never smoking). Vitamin E supplementation (P = 0.0005), tamoxifen use (P = 0.008), and radiation treatment (compared to no chemotherapy or radiation; P = 0.04) were associated with reduced CRP. Associations of CRP with clinical characteristics were not significant in the adjusted models. In a multivariate analysis, CRP showed significant associations with waist circumference, BMI, age, history of heart failure, tamoxifen use, and vitamin E supplementation (R (2) = 0.35). Similar, yet fewer, associations were observed for SAA (R (2) = 0.19).

CONCLUSIONS

This study highlights important correlates of inflammatory status in breast cancer patients. Our results are consistent with those from similar studies of healthy women.

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.