Body mass index-independent effect of fitness and physical activity for all-cause mortality

Skeletal muscle mass is a strong predictor of cardiorespiratory fitness in the Chinese population with obesity

BACKGROUND AND AIMS

Although skeletal muscle is well-known as physiologically related to VO₂max, the independent predictive value of skeletal muscle mass (SMM) VO₂max in people with obesity has not been studied. This study aims to determine the relationships between maximal oxygen uptake (VO₂max) and SMM in the Chinese population with obesity.

METHODS AND RESULTS

Overall, 409 participants with obesity were included in this cross-sectional study. A maximal and graded exercise testing measured VO₂max, and body compositions were measured by bioelectrical impedance analysis. Subsequently, correlation coefficients and stepwise multiple linear regression analyses were used to determine the relationships between VO₂max and body compositions. SMM was found to have a significant correlation with VO₂max (r = 0.290, P < 0.001) after adjusting for sex, age, body mass index (BMI), waist-to-hip ratio, and percent body fat (PBF). In previous studies, BMI was widely recognized as a strong predictor of VO₂max. This study revealed surprising results: after SMM was controlled, the correlation between BMI and VO₂max was reduced (from r = 0.381, P < 0.001 to r = 0.191, P < 0.001). SMM was found the most important independent predictor. In the regression model, the variance of VO₂max was explained by the SMM which accounted for 27.4%.

CONCLUSIONS

In summary, SMM is a stronger independent predictor of cardiorespiratory fitness in the Chinese population with obesity than sex, age, BMI, waist-to-hip ratio, and PBF.

Long-term effects on weight loss and maintenance by intensive start with diet and exercise

This 36-month study aimed to determine whether exercise intervention added to weight loss treatment in the beginning or at 6 months is effective for weight loss and long-term weight maintenance. A total of 120 obese adults (body mass index >30) were randomly assigned to intensified behavioral modification (iBM), iBM+ additional exercise from 0 to 3 months (CWT1), iBM+ additional exercise from 6 to 9 months (CWT2), and a control group (CON). Questionnaires and measurements were collected at baseline, 3, 9, 24, and 36 months. The intervention consisted of an 12 months intensified weight-loss period followed by a 24 months weight-maintenance period. Eighty (67%) subjects (mean age 46.0 years, BMI 36.2) completed the trial. Compared with the control group, all three intervention groups had significant weight loss during the 36-month intervention period (p < 0.001). The achieved weight loss remained significant at 36 months in the iBM (-6.8%, p < 0.001), the CWT1 (-5.8%, p < 0.001), and the CWT2 group (-3.9%, p < 0.001). The CWT1 group showed significant reduction in waist circumference at 9 months (-11.3 cm, p < 0.001), at 24 months (-8.8 cm, p < 0.001), and at 36 months (-8.7 cm, p < 0.001). Intensified behavioral modification alone and with exercise resulted in clinically significant weight loss and long-term weight maintenance. The addition of exercise at the onset promoted greater reductions in waist circumference. In the treatment of obesity, including severe obesity, more intensive lifestyle interventions with exercise should be incorporated.

Effects of a School-Based Physical Activity Intervention for Obesity, Health-Related Physical Fitness, and Blood Pressure in Children with Intellectual Disability: A Randomized Controlled Trial

Children with intellectual disability (ID) are more vulnerable to health conditions than their typically developing peers. Evidence of effective interventions is scarce. A randomized controlled trial was conducted in 30 overweight and obese children with intellectual disability (ID) in China to evaluate a 12-week school-based physical activity intervention for obesity, health-related physical fitness (HRPF), and blood pressure. The intervention consisted of 24 physical activity (PA) sessions (2 sessions/week, 60 min/session), with exercise intensity progressively increasing from a moderate level to a vigorous level. All participants were followed up for 12 weeks after the intervention period to evaluate sustained effects. Outcomes were repeatedly measured at baseline, after the intervention, and after follow-up. The intervention was effective in reducing some obesity-related outcomes (including weight and body mass index) and improving some HRPF-related outcomes (including the 6 min walk test and the 30 s sit-to-stand test), with the significant effects being sustained after the 12-week follow-up. No effect was observed on blood pressure. The findings of this study contribute to the development and implementation of PA interventions to reduce obesity and improve HRPF in children with ID.

Interventions for health-related physical fitness and overweight and obesity in children with intellectual disability: Systematic review and meta-analysis

BACKGROUND

Poor health-related physical fitness (HRPF) and overweight and obesity are common health problems for children with intellectual disability. This study aimed to review existing lifestyle intervention studies, and identify effective strategies for this population.

METHODS

A systematic search was undertaken in three databases. The random-effects model was used to pool the weighted results by inverse variance methods, and the I² statistic was applied to assess heterogeneity among the included studies.

RESULTS

Most of the identified interventions (27/29) adopted physical activity (PA). For obesity-related outcomes, the results showed no significant effect of PA studies on reducing obesity. For HRPF outcomes, significant effects were found on 6-min walk distance (51.86 m, 95% CI [16.49, 87.22], p < .05).

CONCLUSIONS

PA is the predominant intervention component adopted and may contribute to improving cardiopulmonary fitness; but the lack of research limits our ability to draw any confirmed conclusion on obesity-related outcomes and other HRPF outcomes.

Combatting Sedentary Behaviors by Delivering Remote Physical Exercise in Children and Adolescents with Obesity in the COVID-19 Era: A Narrative Review

The coexistence of childhood obesity (or its risk) and COVID-19 pandemic put children and adolescents in greater risk to develop respiratory and cardiovascular diseases. In fact, the restrictions introduced to limit the spread of the virus had detrimental effects on various lifestyle components, especially in young population. This resulted in augmented levels of physical inactivity and sedentary behaviors and a reduced time spent in play outdoors or sport practices. Contrariwise, the increased use of technology led clinicians, teachers, and trainers to maintain relations with obese children/adolescents so as to reduce sedentary behaviors and the associated health risks. This narrative review aims to describe the role of Telehealth and Tele-exercise as useful tools in the management of pediatric obesity during COVID-19 pandemic. Telehealth and Tele-exercise were effective in promoting self-monitoring and behavioral changes, including adherence to exercise training programs in children and adolescents. Moreover, tele-exercise platforms such as applications or exergames allowed flexible scheduling, limiting the infection risks.

Accelerometry-based physical activity, disability and quality of life before and after lumbar decompression surgery from a physiotherapeutic perspective: An observational cohort study

BACKGROUND

The effect of lumbar decompression on physical activity (PA) measures (measured as number of steps/day and as moderate to vigorous PA (MVPA)) is poorly understood. The aim of the current study was to compare PA in patients before and after lumbar decompression and to determine the association between change in steps/day and MVPA with change in disability, health-related quality of life (HRQOL) and pain.

METHODS

Patients undergoing lumbar decompression surgery were recruited. Steps/day and MVPA MVPA were recorded with an accelerometer. Oswestry Disability Index (ODI), HRQOL (Short Form 36 questionnaire (SF-36)) and pain levels (visual analogue scale (VAS)) were collected prior to surgery and six and twelve weeks postoperatively. Steps/day were compared to the lower bound of steps/day in healthy persons (7,000 steps per day), and the relationship between changes in steps/day, MVPA, ODI, SF-36, and VAS were calculated.

RESULTS

Twenty-six patients aged 37 to 75 years met inclusion criteria and were included in the study. Lumbar decompressions were performed for stenosis and/or disc herniation. Preoperatively, patients took an average 5,073±2,621 (mean±standard deviation) steps/day. At 6 weeks postoperatively, patients took 6,131±2,343 steps/day. At 12 weeks postoperatively, patients took 5,683±2,128 steps/day. Postoperative MVPA minutes per week increased compared to preoperative MVPA (preoperative: 94.6±122.9; 6 weeks: 173.9±181.9; 12 weeks: 145.7±132.8). From preoperative to 12 weeks postoperative, change in steps correlated with MVPA (R=0.775; P<0.001), but not with ODI (R=0.069; P=0.739), SF-36 (R=0.138; P=0.371), VAS in the back (R=0.230; P=0.259) or VAS in the leg (R=-0.123; P=0.550).

CONCLUSIONS

During the first 12 postoperative weeks, daily steps did not reach the lower bound of normal step activity of 7,000 steps/day, however postoperative steps/day were higher than before surgery. Steps/day and MVPA appear to be independent of ODI and SF-36 and represent additional outcome parameters in patients undergoing lumbar decompression surgery and should be considered e.g., by physiotherapists especially from 6 to 12 weeks postoperatively.

LEVEL OF EVIDENCE

2, prospective cohort study.

Effects of a School-Based Physical Activity Intervention for Obesity and Health-Related Physical Fitness in Adolescents With Intellectual Disability: Protocol for a Randomized Controlled Trial

BACKGROUND

Childhood obesity accompanied by lower levels of health-related physical fitness (HRPF) is a major threat to public health both internationally and locally. Children with intellectual disability, especially adolescents, have a higher risk of being overweight/obese and having poor HRPF levels. Therefore, more interventions are needed to help this population attain their optimal health levels. However, there has been relatively limited research on this population compared with on their typically developing peers.

OBJECTIVE

The proposed study aims to fill this knowledge gap by developing and examining the success of a physical activity (PA) intervention for the target population.

METHODS

The proposed study will be a 12-week, school-based randomized controlled trial. The participants (N=48) will be recruited from special schools for students with mild intellectual disability and then randomly allocated to either the intervention group (IG) or the wait-list control group (CG). During the intervention period, the participants in the IG will receive a fun game-based moderate-to-vigorous PA (MVPA) training program (2 sessions/week, 60 minutes/session, for a total of 24 sessions). The intensity of the activities will increase in a progressive manner. Participants in the CG will receive no program during the study period, but the same PA program will be provided to them after the completion of the study. To observe and evaluate the sustaining effects of the intervention, follow-up testing will be scheduled for the participants 12 weeks after the intervention concludes. The study outcomes will include primary outcomes (obesity- and fitness-related outcomes) and a secondary outcome (blood pressure). All of the measurements will be taken at 3 time points. After the follow-up tests, the same PA training program will be provided to the participants in the CG.

RESULTS

This study is ongoing. The participants were recruited from October 2020 to November 2020. The total duration of the study is 13 months. Study results are expected at the end of 2021.

CONCLUSIONS

The proposed study is expected to reduce obesity and improve HRPF levels in children with intellectual disability. If proven effective, the intervention will be made accessible to more special schools and mainstream schools with students with intellectual disability. Furthermore, the study can serve as an example for international researchers, policy makers, and members of the public who are seeking to tackle the problem of obesity and poor HRPF among children with intellectual disability.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04554355; https://www.clinicaltrials.gov/ct2/show/NCT04554355.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/25838.

The Validity of the YMCA 3-Minute Step Test for Estimating Maximal Oxygen Uptake in Healthy Korean and Vietnamese Adults

Background

Cardiorespiratory fitness (CRF) is a fundamental component of physical fitness. While maximal oxygen uptake (VO₂max) is the gold standard for quantifying CRF, standard maximal exercise tests using direct measurements VO₂max are dependent on the availability of laboratory equipment, and thereby expensive and time consuming. Recently, an equation was formulated to indirectly estimate VO₂max using the YMCA 3-minute step test.

Methods

The study included 15 Korean (KR) and 15 Vietnamese (VN) healthy adults aged 19-35 years. All subjects completed a YMCA 3-minute step test (YMCA 3MST) and a maximal exercise treadmill test to predict VO₂max and VO₂max measures, respectively.

Results

There was a significant relationship between VO₂max predicted from the YMCA 3MST and actual VO₂max measurements from the treadmill test (r = 0.80, p < 0.0001; KR group: r = 0.81, p < 0.0001; VN group: r = 0.93, p < 0.0001). Bland-Altman analysis revealed statistical agreement between tests, although there was a systematic overestimation of 3.36 mL/kg/min for the KR group.

Conclusion

The equation for predicting VO₂max from the YMCA 3MST was validated among the study subjects. However, future research should explore the validity and reliability of the YMCA 3MST equation for estimating VO₂max in other populations.

Aerobic Training Associated with Arginine Supplementation Reduces Collagen-Induced Platelet Hyperaggregability in Rats under High Risk to Develop Metabolic Syndrome

BACKGROUND

Increased platelet response is seen in individuals with metabolic syndrome. Previous reports have shown that arginine supplementation and aerobic exercise training enhance vascular nitric oxide (NO) activity and inhibit platelet hyperaggregability; however, the effects of their association remain unknown.

AIM

To investigate whether arginine supplementation and aerobic exercise association may exert beneficial effects, reducing platelet hyperaggregability in rats under high risk to develop metabolic syndrome.

METHODS

Wistar rats were divided into two groups: control (C) and fructose (F - water with 10% of fructose). After two weeks, the F group was subdivided into four groups: F, the same as before; fructose + arginine (FA - 880 mg/kg/day of L-arginine by gavage); fructose + training (FT); and fructose + arginine + training (FTA). Treatment lasted for eight weeks.

RESULTS

The fructose administration was able to increase the collagen-induced platelet aggregation (27.4 ± 2.7%) when compared to the C group (8.0 ± 3.4%). Although the arginine supplementation (32.2 ± 6.3%) or aerobic training (23.8 ± 6.5%) did not promote any change in platelet collagen-induced hyperaggregability, the association of arginine supplementation and aerobic exercise promoted an inhibition of the platelet hyperaggregability induced by fructose administration (13.9 ± 4.4%) (P < 0.05). These effects were not observed when ADP was employed as an agonist. In addition, arginine supplementation associated with aerobic exercise promoted a decrease in interleukin-6 (IL-6) and interleukin-8 (IL-8) serum levels when compared to the fructose group, demonstrating an anti-inflammatory effect.

CONCLUSIONS

Our data indicate an important role of arginine supplementation associated with aerobic exercise, reducing platelet hyperaggregability and inflammatory biomarker levels in rats under high risk to develop metabolic syndrome.

Predictors of Physical Activity in Middle Childhood. A Fixed-Effects Regression Approach

Background: Moderate-to-vigorous physical activity (MVPA) has a range of health benefits across the life span. Although many putative determinants of children's MVPA have been identified, their causal status is uncertain due to difficulties in adjusting for potential confounders. Objective: To inform promotion of children's MVPA we therefore aimed to examine well-known child-, family- and contextual predictors of MVPA in middle childhood, by applying a fixed effects regression approach, which rules out the influence of all unmeasured time-invariant confounders. Methods: Two birth cohorts of children living in the city of Trondheim, Norway were invited to participate (82.0% consented). The participants were followed-up biennially from age 6 to 10 years (n = 800) between 2009 and 2014. MVPA in children was recorded by accelerometers and child-, family- and contextual factors were obtained through interviews and questionnaires. Predictors included (i) child-level factors: the child's time outdoors, organized sports participation, athletic self-concept, self-reported screen time and objectively measured sedentariness; (ii) family factors: self-reported parental MVPA and actively transporting the child to school; and (iii) contextual factors: parental socio-economic status (SES), access to playgrounds and ballparks, traffic safety, and having a garden. A three-wave prospective study was conducted with a hybrid fixed effects regressions analysis adjusting for all time-invariant confounders to examine predictors of MVPA. Results: Children evidenced increased MVPA when they spent more time outside, spent less time being sedentary and when the family had a garden and lived in a traffic-safe area. Conclusion: Adjusting for measured time-varying and all unmeasured time-invariant confounders renders many previously identified child and family factors without impact on MVPA in children. However, several contextual factors may promote MVPA in middle childhood, and efforts to facilitate children being outside in environments that promote physical activity (e.g., being outside, in gardens, or otherwise traffic safe areas) may prove important.

Effects of Physical Exercise on Adiponectin, Leptin, and Inflammatory Markers in Childhood Obesity: Systematic Review and Meta-Analysis

BACKGROUND

New findings on adipose tissue physiology and obesity-associated inflammation status suggest that modification of the adipokine level can be relevant for the long-term prevention of obesity-associated chronic disease.

OBJECTIVES

The scope of the present study was to investigate the effectiveness of physical exercise in reducing the systemic inflammation related to obesity in children.

METHODS

We conducted a systematic review with meta-analysis of controlled randomized trials, identified through electronic database search, which investigated the effect of physical exercise, without concomitant dietary intervention, on adiponectin, leptin, and/or other inflammatory markers in children up to age 18 years with a body mass index greater than the 95th percentile for age and sex.

RESULTS

Seven trials were included in the meta-analysis, with a total of 250 participants. Compared with the control group without any lifestyle modification, the physical exercise resulted in a reduction in leptin [standardized mean difference (SMD) -1.13; 95% confidence interval (95%CI): -1.89 to -0.37; I² = 79.9%] and interleukin-6 (SMD -0.84; 95%CI: -1.45 to -0.23, I² = 0.9%) and an increase in adiponectin plasma concentration (SMD 0.69; 95%CI: 0.02-1.35; I² = 74.3%).

CONCLUSIONS

These results indicate that physical exercise improved the inflammatory state in children with obesity. It is unclear whether this effect can reduce the risk of cardiovascular and metabolic disease in adulthood. Clinical trials with a uniform intervention protocol and outcome measurements are required to put our knowledge on adipose tissue biology into a clinical perspective.

An assessment of the relationship of physical activity, obesity, and chronic diseases/conditions between active/obese and sedentary/ normal weight American women in a national sample

OBJECTIVE

Obesity and physical inactivity are associated with increased rates of chronic diseases and conditions. However, the 'fit but fat' theory posits that cardiopulmonary fitness (or physical activity) can mitigate risks to health associated with obesity. The purpose of this study was to compare chronic diseases and conditions of highly active/obese women with inactive/normal weight women.

STUDY DESIGN

This was a cross-sectional study of the 2015 Behavioral Risk Factor Surveillance System data.

METHODS

Weighted descriptive statistics were performed to describe the demographic characteristics of the two groups. We calculated odds ratios and adjusted odds ratios for chronic diseases and conditions comparing highly active/obese women with inactive/normal weight women.

RESULTS

Highly active/obese women were more likely to report risk factors (hypertension, high cholesterol, and diabetes) for coronary heart disease (CHD) and cardiovascular disease (CVD) than inactive/normal weight women; however, they did not have increased rates of CVD, CHD, or heart attack and had decreased risk for stroke. Highly active/obese women had increased risk for asthma, arthritis, and depression, but not for cancer, kidney disease, or chronic obstructive pulmonary disease.

CONCLUSIONS

Highly active/obese women appear to be staving off the actual development of CHD and CVD; however, further research is needed to understand the long-term health benefits of physical activity among obese women.

Fitness Is Independently Associated with Central Hemodynamics in Metabolic Syndrome

PURPOSE

Fit individuals with metabolic syndrome (MetS) have lower mortality risk compared with less fit counterparts, despite the presence of obesity as a component of the syndrome. To understand the importance of fitness in treating this condition, we examined the association of fitness and fatness with central hemodynamic indices that are known independent predictors of cardiovascular events.

METHODS

Sixty-eight individuals with MetS participated in this cross-sectional study. Central hemodynamics is calculated from radial applanation tonometry and comprised aortic reservoir pressure, backward pressure wave (Pb), reflection magnitude (RM), and augmentation index at 75 bpm (AIx75). Cardiorespiratory fitness (CRF) and body fat percentage (BF%) were determined via indirect calorimetry during maximal exercise testing and dual-energy x-ray absorptiometry, respectively.

RESULTS

CRF was inversely associated with aortic reservoir pressure (r = -0.29, P = 0.02), Pb (r = -0.42, P < 0.001), RM (r = -0.48, P < 0.001), and AIx75 (r = -0.65, P < 0.001). BF% was also correlated with AIx75 (r = 0.37, P < 0.05) and RM (r = 0.36, P < 0.005) but at a weaker association compared with CRF. Multiple regression analysis revealed CRF as a predictor of aortic reservoir pressure (β = -0.52, P = <0.01), Pb (β = -0.41, P < 0.03), and AIx75 (β = -0.45, P = 0.01), independent of BF% and other confounding factors.

CONCLUSIONS

CRF predicts central hemodynamics independent of BF% and other confounding factors. This suggests that CRF improvement may be a higher priority when compared with fat loss for lowering the risk of cardiovascular mortality in MetS individuals.

Cardiorespiratory Fitness and Adiposity as Determinants of Metabolic Health-Pooled Analysis of Two Twin Cohorts

CONTEXT

The joint effects of cardiorespiratory fitness (CRF) and body composition on metabolic health are not well known.

OBJECTIVE

To examine the associations of CRF, fat-free mass index (FFMI), and fat mass index (FMI) with metabolic health in individual twins and controlling for genetic and shared environmental effects by studying monozygotic intrapair differences.

DESIGN, SETTING, AND PARTICIPANTS

Two cross-sectional samples of healthy adult monozygotic and dizygotic twins were drawn from population-based Danish and Finnish national twin registries (n = 996 and n = 309).

MAIN MEASURES

CRF was defined as VO2max divided by fat-free mass. Insulin sensitivity and acute insulin response indices were derived from an oral glucose tolerance test. A continuous metabolic syndrome score was calculated. Visceral and liver fat were measured in the Finnish sample. Associations were analyzed separately in both cohorts with multivariate linear regression and aggregated with meta-analytic methods.

RESULTS

Insulin sensitivity, acute insulin response, metabolic syndrome score, visceral, and liver fat amount had strong and statistically significant associations with FMI (|β| 0.53 to 0.79), whereas their associations with CRF and FFMI were at most weak (|β| 0.02 to 0.15). The results of the monozygotic intrapair differences analysis showed the same pattern.

CONCLUSIONS

Although FMI is strongly associated with worsening of metabolic health traits, even after controlling for genetic and shared environmental factors, there was little evidence for the effects of CRF or FFMI on metabolic health. This suggests that changing FMI rather than CRF or FFMI may affect metabolic health irrespective of genetic or early environmental determinants.

Validity of Submaximal Step Tests to Estimate Maximal Oxygen Uptake in Healthy Adults

BACKGROUND

Aerobic capacity (VO2max) is a strong predictor of health and fitness and is considered a key physiological measure in the healthy adult population. Submaximal step tests provide a safe, simple and ecologically valid means of assessing VO2max in both the general population and a rehabilitation setting. However, no studies have attempted to synthesize the existing knowledge regarding the validity of the multiple step-test protocols available to estimate VO2max in the healthy adult population.

OBJECTIVES

The objective of this study was to systematically review literature on the validity and reliability of submaximal step-test protocols to estimate VO2max in healthy adults (age 18-65 years).

DATA SOURCES AND STUDY SELECTION

A systematic literature search of the MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library databases was performed. The search returned 690 studies that underwent the initial screening process. To be included, the study had to (1) have participants deemed to be healthy and aged between 18 and 65 years; (2) assess VO2max by means of a submaximal step test against a graded exercise test (GXT) to volitional exhaustion; and (3) be available in English. Reference lists from included articles were screened for additional articles.

DATA ANALYSIS AND STUDY APPRAISAL METHODS

The primary outcome measures used were the validity statistics between the actual measured VO2max and predicted VO2max values, and the reported direction of the statistically significant difference between the measured VO2max and the predicted VO2max. The Quality Assessment Tool for Quantitative Studies was used to assess the risk of bias in each included study, and was adapted to the type of quantitative study design used.

RESULTS

The combined database search produced 690 studies, from which 644 were excluded during the screening process. Following full-text assessment, a further 39 studies were excluded based on the eligibility criteria detailed previously. Four additional studies were located via the reference lists of the included studies, leaving 11 studies that fulfilled the inclusion criteria and which compared eight different step-test protocols against a direct measure of VO2max incurred during a maximal GXT. Validity measures varied, with a broad range of correlation coefficients reported across the 11 studies (r = 0.469-0.95). Of the 11 studies, two reported reliability measures, demonstrating good test-retest reliability [mean -0.8 ± 3.7 mL kg(-1) min(-1) (±7.7 % of the mean measured VO2max)].

CONCLUSIONS

Considering the relationship between VO2max and various markers of health, the use of step tests as a measure of health in both the general adult population and rehabilitation settings is advocated. Step tests provide a simple, effective and ecologically valid method of submaximally assessing VO2max that can be implemented in a variety of situations within the general adult population. Future research is needed to assess the reliability of the majority of the step-test procedures reviewed. Based on the validity measures, submaximal step-test protocols are an acceptable means of estimating VO2max in the generally healthy adult population. For tracking changes in cardiorespiratory fitness, the Chester Step test appears to be an appropriate tool due to its high test-retest reliability.

Joint association of physical activity and overweight with subsequent psychotropic medication: a register-linked follow-up study among employees

Background

Physical activity level and overweight have shown associations with mental health problems but it is not known whether the risk of mental health problems due to overweight varies by physical activity. We examined joint association of physical activity and overweight with subsequent psychotropic medication among 40–60-year-old employees.

Methods

The questionnaire survey data were derived from Helsinki Health Study baseline postal questionnaires in 2000–02 among employees of the City of Helsinki aged 40–60 years (n = 8960, response rate 67 %). Baseline survey data were linked with prospective register data on prescribed psychotropic medication (ATC-codes N05 and N06, except N06D) among those with written consent (74 %) for such linkage. The analyses included 6169 responders (78 % women, corresponding to the target population). We divided participants into six groups according to their baseline self-reported body mass index and leisure-time physical activity using physically highly active normal-weight participants as a reference group. We used Cox regression analysis adjusted for age, gender, psychotropic medication prior to baseline, and socioeconomic position, marital status, working conditions, limiting long-standing illness, alcohol use, and smoking.

Results

At baseline, 49 % were overweight and 23 % were physically inactive. After adjusting for age and gender, inactive normal-weight (hazard ratio (HR) 1.3, 95 % CI 1.1–1.5), moderately active overweight (HR 1.3, 95 % CI 1.1–1.5) and inactive overweight (HR 1.4, 95 % CI 1.2–1.6) had higher risk for any psychotropic medication compared with group of highly active normal-weight. After adjusting for prior medication, only the inactive overweight group had higher risk (HR 1.4, 95 % CI 1.2–1.6). Other covariates made but a minor contribution to the examined associations. For antidepressants the associations were somewhat stronger than for sedatives.

Conclusions

Both normal-weight and physical activity help prevent psychotropic medication but physical activity dominates the association over normal-weight.

Association Between Leisure Time Physical Activity, Cardiopulmonary Fitness, Cardiovascular Risk Factors, and Cardiovascular Workload at Work in Firefighters

BACKGROUND

Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong.

METHODS

Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios.

RESULTS

Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities.

CONCLUSION

Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

Exercise-induced changes in inflammatory processes: Implications for thrombogenesis in cardiovascular disease

Sedentary lifestyle is a risk factor and a strong predictor for chronic disease and premature death. Low-grade inflammation has been proved a key player in the pathogenesis of cardiovascular disease. Inflammatory processes have been also involved in maintaining the balance between coagulation and fibrinolysis. In addition, an inverse linear dose-response relation between physical activity and mortality risks has also been reported. However, the favorable effects of structured exercise programs and the independent contribution of physical activity to cardiovascular risk are still under investigation. In response to heavy exercise, interleukin-6 (IL-6) is secreted by contracting skeletal muscles, followed by an acute reactant release of C-reactive protein (CRP). Both CRP and IL-6 can stimulate monocyte tissue factor production, provoke platelet hyperreactivity, promote fibrinogen biosynthesis, and enhance microparticle formation and erythrocyte aggregability, thus triggering prothrombotic state. By contrast, regular exercise and physical activity are protective against all-cause mortality through suppressing pro-inflammatory cytokine production, enhancing anti-inflammatory mediators and antioxidant development, and promoting fibrinolytic activity. Low-load resistance exercise also plays an advantageous role in thrombogenesis by reducing inflammatory processes and potentiating fibrinolytic features. In the present review article, we provide an overview of the impact of different modes and intensities of physical activity on vascular inflammation and thrombogenesis.

The role of physical activity in the CKD setting

A sedentary lifestyle contributes to the development of cardiovascular disease, hypertension, diabetes and probably cancer in the general population; this cluster of disease may be defined the diseasome of physical inactivity. Also in CKD/ESRD patients physical activity is strikingly low. As a result of growing evidence suggestive of cardiovascular benefit among the CKD population with exercise, the National Kidney Foundation recommended counseling by nephrologists to increase patients' levels of physical activity in their guideline about management of cardiovascular disease. Therefore, to maintain the well-being and functional capacity of renal patients attention should be directed toward maintaining strength and aerobic fitness as well as focusing on renal function and anemia or other comorbidities. All CKD/ESRD patients should be counseled and regularly encouraged by nephrology and dialysis staff to increase their level of physical activity.

Benefit of physical fitness against inflammation in obesity: role of beta adrenergic receptors

Evidence shows that both poor physical fitness and obesity are linked to low-grade inflammation and inflammatory diseases. However, their relative roles on inflammation and underlying mechanisms remain unclear. Given the inhibitory effect of catecholamines on inflammatory cytokine production, we speculated that compromised responsiveness of immune cells' beta adrenergic receptors (β-ARs) to agonists may be associated with constitutively elevated levels of inflammatory cytokines. We examined circulating levels of inflammatory cytokines TNF, IL-1β, IL-6 and β-AR sensitivity of, 70 overweight or obese compared to 26 normal-weight, otherwise healthy individuals in order to investigate the associations among obesity, physical fitness, and low-grade inflammation and to examine the role of β-ARs in these relationships. Cardiorespiratory fitness was determined by VO2peak (ml/kg/min) via a treadmill exercise. Beta-AR sensitivity was evaluated by measuring the degree of inhibition in lipopolysaccharides-stimulated monocytic intracellular TNF production by isoproterenol. In all participants, BMI, which was initially a predictor of IL-1β and IL-6 levels independent of demographic characteristics, no longer significantly predicted them after controlling for fitness levels. Among the overweight or obese participants, greater cardiorespiratory fitness was a strong predictor of lower levels of TNF and IL-1β after controlling for the covariates. When β-AR sensitivity was controlled for, however, fitness was no longer a significant predictor of those cytokines. Monocytic β-AR sensitivity was negatively associated with inflammatory marker levels and diminished in obese individuals; however, when fitness was controlled for, the significant weight group differences in β-AR sensitivity disappeared. Our findings indicate that better cardiorespiratory fitness protects against obesity-related low-grade inflammation and β-AR desensitization. Given the significance of β-AR function in pathogenesis of various diseases, clinical implications of its role in the fitness-inflammation association among the obese are profound.

Physical activity versus sedentary behavior: associations with lipoprotein particle subclass concentrations in healthy adults

Background

Physical activity (PA) and sedentary behavior (SED) may have independent effects on health and disease. This might be due to PA and SED having distinct effects on lipoprotein metabolism. The aim of this study was to determine associations between lipoprotein subclass particle concentrations (-P) and accelerometer-measured SED and moderate-to-vigorous PA (MVPA) in a sample of healthy adult subjects.

Methods

Lipoprotein subclass particle concentrations were determined by proton nuclear magnetic resonance spectroscopy, whereas SED and MVPA were measured using Agtigraph GT1M and GT3X+ accelerometers. We obtained valid data in 73 subjects (30 men and 43 women, age 40.5 ± 10.6 years; body mass index 24.0 ± 2.8). Multiple regression analysis was used to determine associations (partial correlations) with lipoproteins.

Results

Positive associations were detected between SED and small VLDL-P, large LDL-P and TG (partial r = 0.24 to 0.25, p < .047). Corresponding associations were non-significant for MVPA (partial r = -0.12 to 0.04, p > .355). On the contrary, MVPA was positively associated with large HDL-P, average HDL size, Apo A1 and HDL-cholesterol (partial r = 0.28 to 0.50, p < .027), whereas SED was not (partial r = -0.06 to 0.07, p > .607).

Conclusion

There might be a specific effect of SED versus MVPA on lipoprotein metabolism. However, our results must be interpreted carefully due to possible effect-modification by gender and a low sample size. Thus, our findings should be viewed as preliminary.

Leptin signaling in skeletal muscle after bed rest in healthy humans

PURPOSE

This study aimed at determining the effects of bed rest on the skeletal muscle leptin signaling system.

METHODS

Deltoid and vastus lateralis muscle biopsies and blood samples were obtained from 12 healthy young men (mean ± SD, BMI 22.8 ± 2.7 kg/m(2)) before and after 7 days of bed rest. Leptin receptor isoforms (OB-Rs), suppressor of cytokine signaling 3 (SOCS3) and protein tyrosine phosphatase 1B (PTP1B) protein expression and signal transducer and activator of transcription 3 (STAT3) phosphorylation were analyzed by Western blot.

RESULTS

After bed rest basal insulin concentration was increased by 53% (P < 0.05), the homeostasis model assessment (HOMA) by 40% (P < 0.05), and serum leptin concentration by 35% (P < 0.05) with no changes in body fat mass. Although the soluble isoform of the leptin receptor (s-OBR) remained unchanged, the molar excess of leptin over sOB-R was increased by 1.4-fold after bed rest (P < 0.05). OB-Rs and SOCS3 protein expression, and STAT3 phosphorylation level remained unaffected in deltoid and vastus lateralis by bed rest, as PTP1B in the deltoid. PTP1B was increased by 90% with bed rest in the vastus lateralis (P < 0.05). There was a linear relationship between the increase in vastus lateralis PTP1B and the increase in both basal insulin concentrations (r = 0.66, P < 0.05) and HOMA (r = 0.68, P < 0.05) with bed rest.

CONCLUSIONS

One week of bed rest is associated with increased leptin levels without augmenting STAT3 phosphorylation indicating some degree of leptin resistance in skeletal muscle, which can be explained, at least in part, by an elevation of PTP1B protein content in the vastus lateralis muscle.

At cancer diagnosis: a 'window of opportunity' for behavioural change towards physical activity. A randomised feasibility study in patients with colon and breast cancer

INTRODUCTION

Challenges exist in identifying, recruiting and motivating sedentary patients with cancer to initiate physical activity towards recommended levels. We hypothesise that the onset period of adjuvant chemotherapy can be 'the open window of opportunity' to identify and motivate sedentary patients with breast and colon cancers, at risk for developing coronary heart disease, to initiate and sustain lifestyle changes.

AIMS

To investigate the feasibility of oncologists/nurses screening for physical inactivity, in order to identify and recruit an at-risk population of sedentary patients with breast or colon cancer at the onset of adjuvant chemotherapy. Furthermore, the study will examine the adherence to one of two multimodal exercise interventions lasting 12 weeks; (1) hospital-based, high intensity, group exercise intervention (2) home-based, low intensity, individual, pedometer intervention. Both arms will be compared with a control group.

METHODS AND ANALYSES

All newly referred patients will be screened for sedentary behaviour, using national recommendations. Testing at baseline, 6, 12 and 39 weeks will include; (1) physiological testing (VO2-peak, one repetition maximum muscle strength and lung function (2) fasting full body dual-energy X-ray absorptiometry scan (3) fasting blood glucose, insulin, lipids and cholesterols, (4) psychometric questionnaires (general well-being, quality of life, anxiety and depression, motivational readiness). The randomised controlled trial feasibility design is selected in order to examine barriers for recruitment, programme adherence, safety aspects and potential efficacy to the interventions during adjuvant chemotherapy.

ETHICS AND DISSEMINATION

The Scientific Committee of the Capital Region (case No. H-1-2011-131) and the Danish Data Protection Agency (j. No. 2011-41-6349) approved the study. Data will be entered and locked into a database hosted by the Copenhagen Trial Unit, Rigshosptialet. Data will be available for analyses to project members and the trial statistician after the 45 included patients have completed the 12-week test. Results will be published in peer-reviewed scientific journals.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN24901641.

Fitness vs. fatness on all-cause mortality: a meta-analysis

The purpose of this study was to quantify the joint association of cardiorespiratory fitness (CRF) and weight status on mortality from all causes using meta-analytical methodology. Studies were included if they were (1) prospective, (2) objectively measured CRF and body mass index (BMI), and (3) jointly assessed CRF and BMI with all-cause mortality. Ten articles were included in the final analysis. Pooled hazard ratios were assessed for each comparison group (i.e. normal weight-unfit, overweight-unfit and -fit, and obese-unfit and -fit) using a random-effects model. Compared to normal weight-fit individuals, unfit individuals had twice the risk of mortality regardless of BMI. Overweight and obese-fit individuals had similar mortality risks as normal weight-fit individuals. Furthermore, the obesity paradox may not influence fit individuals. Researchers, clinicians, and public health officials should focus on physical activity and fitness-based interventions rather than weight-loss driven approaches to reduce mortality risk.

Evidence that aerobic fitness is more salient than weight status in predicting standardized math and reading outcomes in fourth- through eighth-grade students

OBJECTIVE

To determine whether aerobic fitness is more salient than weight status in predicting performance on standardized math and reading tests in fourth- to eighth-grade students.

STUDY DESIGN

A cross-sectional study of data abstracted from 11,743 students in 47 public schools. Aerobic fitness was defined by entering the healthy fitness zone of Fitnessgram's Progressive Aerobic Cardiovascular Endurance Run, which has been shown to correlate highly with maximum oxygen consumption. Mixed-effects logistic regression analyses were conducted to model the student-level effect of aerobic fitness status on passing the Nebraska State Accountability (NeSA) math and reading tests after adjusting for body mass index (BMI) percentile, free/reduced lunch status, sex, race, grade level, and school type.

RESULTS

After adjustment, aerobically fit students had greater odds of passing the NeSA math and reading tests compared with aerobically unfit students regardless of whether the students received free/reduced lunch; however, the effect of being aerobically fit on the standardized test scores was significantly greater for students not receiving free/reduced lunch. Weight status, as measured by BMI percentile, was not a significant predictor of passing the NeSA math or reading test after including free/reduced lunch status in the model.

CONCLUSIONS

Aerobic fitness was a significant predictor of academic performance; weight status was not. Although decreasing BMI for an overweight or obese child undoubtedly improves overall health, results indicated all students benefit academically from being aerobically fit regardless of weight or free/reduced lunch status. Therefore, to improve academic performance, school systems should focus on the aerobic fitness of every student.

Physical activity, measures of obesity, and cardiometabolic risk: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The influence of higher physical activity on the relationship between adiposity and cardiometabolic risk is not completely understood.

METHODS

Between 2000-2002, data were collected on 6795 Multi-Ethnic Study of Atherosclerosis (MESA) participants. Self-reported intentional physical activity in the lowest quartile (0-105 MET-minutes/week) was categorized as inactive and the upper three quartiles (123-37,260 MET-minutes/week) as active. Associations of body mass index (BMI) and waist circumference categories, stratified by physical activity status (inactive or active) with cardiometabolic risk factors (dyslipidemia, hypertension, upper quartile of homeostasis model assessment of insulin resistance [HOMA-IR] for population, and impaired fasting glucose or diabetes) were assessed using logistic regression analysis adjusting for age, gender, race/ethnicity, and current smoking.

RESULTS

Among obese participants, those who were physically active had reduced odds of insulin resistance (47% lower; P < .001) and impaired fasting glucose/diabetes (23% lower; P = .04). These associations were weaker for central obesity. However, among participants with a normal waist circumference, those who were inactive were 63% more likely to have insulin resistance (OR [95% CI] 1.63 [1.24-2.15]) compared with the active reference group.

CONCLUSIONS

Physical activity was inversely related to the cardiometabolic risk associated with obesity and central obesity.

Low levels of physical activity in patients with severe mental illness

BACKGROUND

Physical inactivity is an independent risk factor for cardiovascular diseases and Type 2 diabetes, both being highly prevalent in patients with severe mental illness. Though physical activity has become an important issue in psychiatric treatment and rehabilitation in the past decade, systematic evaluations of physical activity level in psychiatric populations could be more disseminated.

AIM

The primary aim of the study was to investigate the physical activity level of psychiatric patients in comparison with healthy controls.

METHODS

Patients with severe mental illness (n =47) and a group of healthy controls (n =28) matched on sex and age reported their physical activity level using the Physical Activity Scale (PAS). PAS was administered as an interview in relation to patients and as a questionnaire in relation to healthy controls.

RESULTS

Patients had statistically significant lower levels of physical activity compared with healthy controls (P <0.0001) and the level of physical activity among patients was hazardously low.

CONCLUSION

The study confirmed previous studies and clinical experience that patients with severe mental illness are physically inactive and emphasize the importance of physical activity in psychiatric treatment and rehabilitation. The PAS is an applicable and relevant method for evaluating physical activity levels in psychiatric patients.

Complementary medicine, exercise, meditation, diet, and lifestyle modification for anxiety disorders: a review of current evidence

Use of complementary medicines and therapies (CAM) and modification of lifestyle factors such as physical activity, exercise, and diet are being increasingly considered as potential therapeutic options for anxiety disorders. The objective of this metareview was to examine evidence across a broad range of CAM and lifestyle interventions in the treatment of anxiety disorders. In early 2012 we conducted a literature search of PubMed, Scopus, CINAHL, Web of Science, PsycInfo, and the Cochrane Library, for key studies, systematic reviews, and metaanalyses in the area. Our paper found that in respect to treatment of generalized anxiety or specific disorders, CAM evidence revealed current support for the herbal medicine Kava. One isolated study shows benefit for naturopathic medicine, whereas acupuncture, yoga, and Tai chi have tentative supportive evidence, which is hampered by overall poor methodology. The breadth of evidence does not support homeopathy for treating anxiety. Strong support exists for lifestyle modifications including adoption of moderate exercise and mindfulness meditation, whereas dietary improvement, avoidance of caffeine, alcohol, and nicotine offer encouraging preliminary data. In conclusion, certain lifestyle modifications and some CAMs may provide a beneficial role in the treatment of anxiety disorders.

Changes in physical fitness predict improvements in modifiable cardiovascular risk factors independently of body weight loss in subjects with type 2 diabetes participating in the Italian Diabetes and Exercise Study (IDES)

OBJECTIVE

Physical fitness is inversely related to mortality in the general population and in subjects with type 2 diabetes. Here, we present data concerning the relationship between changes in physical fitness and modifiable cardiovascular risk factors in subjects with type 2 diabetes from the Italian Diabetes and Exercise Study.

RESEARCH DESIGN AND METHODS

Sedentary patients with type 2 diabetes (n = 606) were enrolled in 22 outpatient diabetes clinics and randomized to twice-a-week supervised aerobic and resistance training plus exercise counseling versus counseling alone for 12 months. Baseline to end-of-study changes in cardiorespiratory fitness, strength, and flexibility, as assessed by Vo(2max) estimation, a 5-8 maximal repetition test, and a hip/trunk flexibility test, respectively, were calculated in the whole cohort, and multiple regression analyses were applied to assess the relationship with cardiovascular risk factors.

RESULTS

Changes in Vo(2max), upper and lower body strength, and flexibility were significantly associated with the variation in the volume of physical activity, HbA(1c), BMI, waist circumference, high-sensitivity C-reactive protein (hs-CRP), coronary heart disease (CHD) risk score, and inversely, HDL cholesterol. Changes in fitness predicted improvements in HbA(1c), waist circumference, HDL cholesterol, hs-CRP, and CHD risk score, independent of study arm, BMI, and in case of strength, also waist circumference.

CONCLUSIONS

Physical activity/exercise-induced increases in fitness, particularly muscular, predict improvements in cardiovascular risk factors in subjects with type 2 diabetes independently of weight loss, thus indicating the need for targeting fitness in these individuals, particularly in subjects who struggle to lose weight.

Firefighters' physical activity: relation to fitness and cardiovascular disease risk

PURPOSE

Cardiovascular disease (CVD) accounts for 44% of on-duty deaths among US firefighters with a markedly higher event risk during strenuous duties compared with nonemergencies. Sedentary persons are most susceptible to such CVD "event-triggering" due to irregular bouts of vigorous physical activity (PA). Conversely, regular PA and increased levels of cardiorespiratory fitness (CRF) protect against CVD triggering. Therefore, the present study evaluates PA measures in structural firefighters and their relationship to CRF and CVD risk factors.

METHODS

Cross-sectional cohort study of 527 Midwestern career firefighters. PA frequency, duration, and intensity measures from a questionnaire along with total weekly aerobic exercise were analyzed. CRF was measured by maximal exercise tolerance testing. CVD risk parameters included body composition, blood pressure, and metabolic profiles. Group differences were compared using general linear models.

RESULTS

Measures of increasing frequency, duration, intensity of PA, and total weekly exercise (min) were significantly associated with higher CRF (P < 0.001) after adjustment for age, body mass index (BMI), and smoking status. After multivariate adjustment, increasing PA frequency was significantly associated with reduced total cholesterol-HDL ratio, triglycerides, and glucose, as well as HDL increments. Increasing BMI category was associated with significant decrements in CRF and unfavorable dose-response trends in CVD risk factors (P < 0.001), even for those reporting very frequent, sustained, and intense PA.

CONCLUSIONS

Increasing PA has beneficial independent effects on CRF, and PA frequency has similar favorable effects on CVD risk profiles. Whereas PA was beneficial regardless of BMI category, increasing BMI category had strong independent unfavorable effects. PA should be strongly encouraged for all firefighters with the highest priority given to PA frequency, followed by PA duration and intensity.

Cardiorespiratory fitness predicts cardiovascular risk profiles in career firefighters

OBJECTIVE

Evaluate the association between cardiovascular disease (CVD) risk factors and cardiorespiratory fitness (CRF) in firefighters.

METHODS

Cross-sectional study of 968 male career firefighters. Cardiorespiratory fitness was measured by maximal exercise tolerance tests. Cardiovascular disease risk parameters included body composition, resting vital signs, and metabolic profiles. Group comparisons were performed using χ test, analysis of variance, and general linear regression with/without adjustment for age and body mass index (BMI).

RESULTS

Higher metabolic equivalents categories were significantly associated with lower diastolic blood pressure, body fat, triglycerides, low-density lipoprotein cholesterol and total/high-density cholesterol ratio, and higher high-density lipoprotein (P ≤ 0.0272, age and BMI adjusted).

CONCLUSIONS

Increasing CRF has beneficial independent effects on CVD risk factor profiles among firefighters. Higher CRF was beneficial regardless of BMI; nevertheless, increasing BMI had strong independent unfavorable effects. Firefighters should be encouraged to increase their CRF to decrease their future risk of CVD.

Exercise and the treatment of diabetes and obesity

An active lifestyle increases general health and is protects from a number of different conditions, including exercise and obesity. There is emerging evidence that exercise by itself exerts clinically beneficial effects in both lean and obese subjects, even in the absence of effects on weight.1 Recent results have brought an increasing understanding of the molecular mechanisms underlying the beneficial effects of exercise at the level of metabolism and changes in gene expression. There is a significant dose-response to the effect of exercise, and the current guidelines regarding exercise amount may need to be revised upwards. Furthermore, this treatment option should not be overlooked.

Exercise-induced myokines and their role in chronic diseases

Physical inactivity has recently been identified as a major and independent risk factor for the development of dementia and cognitive decline. In addition to the effect of exercise with regard to protection against neurodegenerative diseases, it is well-established that physical inactivity increases the risk of type 2 diabetes, cardiovascular diseases (CVD), colon cancer and postmenopausal breast cancer. These diseases constitute a network of related diseases, also called "the diseasome of physical inactivity". In this review, physical inactivity is given the central role as an independent and strong risk factor for accumulation of visceral fat and consequently the activation of a network of systemic inflammatory pathways, which promote development of neurodegeneration as well as insulin resistance, atherosclerosis, and tumour growth. The recent finding that muscles produce and release myokines provides a conceptual basis for understanding some of the molecular mechanisms underlying organ cross talk, including muscle-fat cross talk. Accumulating data suggest that contracting skeletal muscles release myokines, which may work in a hormone-like fashion, exerting specific endocrine effects on visceral fat or mediating direct anti-inflammatory effects. Other myokines work locally within the muscle via paracrine mechanisms, exerting their effects on signalling pathways involved in fat oxidation.

The effect of prolonged whole-body cryostimulation treatment with different amounts of sessions on chosen pro- and anti-inflammatory cytokines levels in healthy men

Cryotherapy is used in the early treatment of acute injuries (sprains, strains, fractures) yet only a few papers discuss the possible influence of whole-body cryostimulation on inflammation mechanisms or immunology. It is postulated that cold exposure can have an immunostimulating effect related to enhanced noradrenaline response and can be connected with paracrine effects. The aim of this study was to examine the effect of different sequences of whole-body cryostimulations on the level of pro- and anti-inflammatory cytokines in healthy individuals. The research involved 45 healthy men divided into three groups. The groups were subjected to 5, 10 or 20, 3-minute long whole-body cryostimulations each day at -130°C. Blood was collected for analysis before the stimulations, after completion of the whole series, and 2 weeks after completion of the series, for the examination of any long-term effect. The analysis of results showed that in response to cryostimulation, the level of ani-inflammatory cytokines IL-6 and IL-10 increased while Il-1α cytokine level decreased. It seems that the most advantageous sequence was the series of 20 cryostimulations due to the longest lasting effects of stimulation after the completion of the whole series of treatments.

Muscles and their myokines

In the past, the role of physical activity as a life-style modulating factor has been considered as that of a tool to balance energy intake. Although it is important to avoid obesity, physical inactivity should be discussed in a much broader context. There is accumulating epidemiological evidence that a physically active life plays an independent role in the protection against type 2 diabetes, cardiovascular diseases, cancer, dementia and even depression. For most of the last century, researchers sought a link between muscle contraction and humoral changes in the form of an 'exercise factor', which could be released from skeletal muscle during contraction and mediate some of the exercise-induced metabolic changes in other organs such as the liver and the adipose tissue. We have suggested that cytokines or other peptides that are produced, expressed and released by muscle fibres and exert autocrine, paracrine or endocrine effects should be classified as 'myokines'. Given that skeletal muscle is the largest organ in the human body, our discovery that contracting skeletal muscle secretes proteins sets a novel paradigm: skeletal muscle is an endocrine organ producing and releasing myokines, which work in a hormone-like fashion, exerting specific endocrine effects on other organs. Other myokines work via paracrine mechanisms, exerting local effects on signalling pathways involved in muscle metabolism. It has been suggested that myokines may contribute to exercise-induced protection against several chronic diseases.

Impact of exercise on patients with depression and anxiety

BACKGROUND

Persons with common mental disorders are at risk of lowered physical activity.

AIMS

To investigate if patients with depressive and/or anxiety disorders can achieve a level of physical activity meeting public health recommendations, increase their physical fitness and quality of life (QoL) through participation in a physical exercise programme.

METHODS

In a non-blinded controlled study, 48 patients referred by private psychiatric clinics and private general practices were either treated in an intervention (n=27) or a control group (n=21). The intervention group took part in 20 weeks of group exercise consisting of aerobic training and non-aerobic weight-lifting. All participants were interviewed and tested at baseline, week 20 and at week 32.

RESULTS

The intervention group increased in physical activity (120 min/week) and VO(2)max (0.48 ml O(2)/min). The VO(2)max increase was maintained after a 12-week follow-up period. Findings should be conservatively interpreted because of high attrition rate.

CONCLUSIONS

Patients with anxiety and/or depressive disorders who participated in a structured, supervised exercise programme achieved in accordance with public health recommendations a higher level of physical activity and VO(2)max.

CLINICAL IMPLICATIONS

The clinical implications of the study may be a suggestion of offering physical exercise to milder and moderate severe cases of depression and anxiety.

Physical activity, fitness and fatness: relations to mortality, morbidity and disease risk factors. A systematic review

The purpose of this systematic review was to study the relative health risks of poor cardio-respiratory fitness (or physical inactivity) in normal-weight people vs. obesity in individuals with good cardio-respiratory fitness (or high physical activity). The core inclusion criteria were: publication year 1990 or later; adult participants; design prospective follow-up, case-control or cross-sectional; data on cardio-respiratory fitness and/or physical activity; data on BMI (body mass index), waist circumference or body composition; outcome data on all-cause mortality, cardiovascular disease mortality, cardiovascular disease incidence, type 2 diabetes or cardiovascular and type 2 diabetes risk factors. Thirty-six publications filled the criteria for inclusion. The data indicate that the risk for all-cause and cardiovascular mortality was lower in individuals with high BMI and good aerobic fitness, compared with individuals with normal BMI and poor fitness. In contrast, having high BMI even with high physical activity was a greater risk for the incidence of type 2 diabetes and the prevalence of cardiovascular and diabetes risk factors, compared with normal BMI with low physical activity. The conclusions of the present review may not be applicable to individuals with BMI > 35.

Relationships between Obesity, Cardiorespiratory Fitness, and Cardiovascular Function

Background. Obesity and low cardiorespiratory fitness (CRF) have been shown to independently increase the risk of CVD mortality. The aim of this study was to investigate the relationship between CRF, body fatness and markers of arterial function. Method and Results. Obese (9 male, 18 female; BMI 35.3 ± 0.9 kg·m(-2)) and lean (8 male, 18 female; BMI 22.5 ± 0.3 kg·m(-2)) volunteers were assessed for body composition (DXA), cardiorespiratory fitness (predicted V˙O2max), blood pressure (BP), endothelial vasodilatator function (FMD), and arterial compliance (AC) (via radial artery tonometry). The obese group had more whole body fat and abdominal fat (43.5 ± 1.2% versus 27.2 ± 1.6%; P < .001 and 48.6 ± 0.9% versus 28.9 ± 1.8%; P < .001, resp.), and lower FMD (3.2 ± 0.4% versus 5.7 ± 0.7%; P < .01) than the lean subjects, but there was no difference in AC. AC in large arteries was positively associated with CRF (R = 0.5; P < .01) but not with fatness. Conclusion. These results indicate distinct influences of obesity and CRF on blood vessel health. FMD was impaired with obesity, which may contribute to arterial and metabolic dysfunction. Low CRF was associated with reduced elasticity in large arteries, which could result in augmentation of aortic afterload.

The diseasome of physical inactivity--and the role of myokines in muscle--fat cross talk

Type 2 diabetes, cardiovascular diseases, colon cancer, breast cancer, dementia and depression constitute a cluster of diseases, which defines 'a diseasome of physical inactivity'. Both physical inactivity and abdominal adiposity, reflecting accumulation of visceral fat mass, are associated with the occurrence of the diseases within the diseasome. Physical inactivity appears to be an independent and strong risk factor for accumulation of visceral fat, which again is a source of systemic inflammation. Chronic inflammation is involved in the pathogenesis of insulin resistance, atherosclerosis, neurodegeneration and tumour growth. Evidence suggests that the protective effect of exercise may to some extent be ascribed to the anti-inflammatory effect of regular exercise, which can be mediated via a reduction in visceral fat mass and/or by induction of an anti-inflammatory environment with each bout of exercise. The finding that muscles produce and release myokines provides a conceptual basis to understand the mechanisms whereby exercise influences metabolism and exerts anti-inflammatory effects. According to our theory, contracting skeletal muscles release myokines, which work in a hormone-like fashion, exerting specific endocrine effects on visceral fat. Other myokines work locally within the muscle via paracrine mechanisms, exerting their effects on signalling pathways involved in fat oxidation.