Physical activity, cardiorespiratory fitness and the incidence of type 2 diabetes in a prospective study of men

Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies

OBJECTIVE

To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults.

DESIGN

Overview of systematic reviews.

DATA SOURCE

Five bibliographic databases were searched from January 2002 to March 2024.

RESULTS

From the 9062 papers identified, we included 26 systematic reviews. We found eight meta-analyses that described five unique mortality outcomes among general populations. CRF had the largest risk reduction for all-cause mortality when comparing high versus low CRF (HR=0.47; 95% CI 0.39 to 0.56). A dose-response relationship for every 1-metabolic equivalent of task (MET) higher level of CRF was associated with a 11%-17% reduction in all-cause mortality (HR=0.89; 95% CI 0.86 to 0.92, and HR=0.83; 95% CI 0.78 to 0.88). For incident outcomes, nine meta-analyses described 12 unique outcomes. CRF was associated with the largest risk reduction in incident heart failure when comparing high versus low CRF (HR=0.31; 95% CI 0.19 to 0.49). A dose-response relationship for every 1-MET higher level of CRF was associated with a 18% reduction in heart failure (HR=0.82; 95% CI 0.79 to 0.84). Among those living with chronic conditions, nine meta-analyses described four unique outcomes in nine patient groups. CRF was associated with the largest risk reduction for cardiovascular mortality among those living with cardiovascular disease when comparing high versus low CRF (HR=0.27; 95% CI 0.16 to 0.48). The certainty of the evidence across all studies ranged from very low-to-moderate according to Grading of Recommendations, Assessment, Development and Evaluations.

CONCLUSION

We found consistent evidence that high CRF is strongly associated with lower risk for a variety of mortality and incident chronic conditions in general and clinical populations.

Independent and joint associations of estimated cardiorespiratory fitness and its dynamic changes and obesity with the risk of hypertension: A prospective cohort

Our aim was to examine the independent and joint associations of estimated cardiorespiratory fitness (CRF) and its changes and obesity with risk of hypertension in a rural Chinese population. A prospective cohort including 9848 adults without hypertension at baseline was enrolled. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression models. Restricted cubic splines were used to model the dose-response relationship. During 6 years follow-up, 2,019 individuals developed hypertension. A negative association between estimated CRF and hypertension incidence was observed, with the risk being 0.87 (0.84-0.90) per MET increment. For estimated CRF change, the risks of hypertension were 1.50 (1.27-1.77) and 0.75 (0.59-0.97) for decreasers and increasers, respectively, compared to maintainers. Joint analyses showed individuals in the overweight/obesity-fourth quartile of estimated CRF had a 2.08 times higher risk of hypertension than those in the normal weight-first quartile (Pinteraction < 0.05). Those overweight/obesity-decreasers had the highest risk (OR: 2.19, 95%CI: 1.71-2.81; Pinteraction < 0.05) compared to the normal-maintainers. Similar results for abdominal obesity were also observed. Estimated CRF and its dynamic changes showed a negative association with hypertension incidence in the rural Chinese population.

Renal Rehabilitation: Present and Future Perspectives

Chronic kidney disease (CKD) is a global health problem. In patients with CKD, exercise endurance is decreased, especially as renal dysfunction advances. This is due to the combined effects of protein-energy wasting, uremic acidosis, and inflammatory cachexia, which lead to sarcopenia and are aggravated by a sedentary lifestyle, resulting in a progressive downward spiral of deconditioning. Renal rehabilitation (RR) is a coordinated, multifaceted intervention designed to optimize a patient's physical, psychological, and social functioning, as well as to stabilize, slow, or even reverse the progression of renal deterioration, improving exercise tolerance and preventing the onset and worsening of heart failure, thereby reducing morbidity and mortality. This review focused on the history and benefits of RR in patients with CKD. Based on current evidence, RR is an effective, feasible, and safe secondary prevention strategy in CKD. RR is a promising model for a new field of rehabilitation. Therefore, efforts to increase RR implementation rates are urgently needed.

Nonexercise machine learning models for maximal oxygen uptake prediction in national population surveys

OBJECTIVE

Nonexercise algorithms are cost-effective methods to estimate cardiorespiratory fitness (CRF), but the existing models have limitations in generalizability and predictive power. This study aims to improve the nonexercise algorithms using machine learning (ML) methods and data from US national population surveys.

MATERIALS AND METHODS

We used the 1999-2004 data from the National Health and Nutrition Examination Survey (NHANES). Maximal oxygen uptake (VO2 max), measured through a submaximal exercise test, served as the gold standard measure for CRF in this study. We applied multiple ML algorithms to build 2 models: a parsimonious model using commonly available interview and examination data, and an extended model additionally incorporating variables from Dual-Energy X-ray Absorptiometry (DEXA) and standard laboratory tests in clinical practice. Key predictors were identified using Shapley additive explanation (SHAP).

RESULTS

Among the 5668 NHANES participants in the study population, 49.9% were women and the mean (SD) age was 32.5 years (10.0). The light gradient boosting machine (LightGBM) had the best performance across multiple types of supervised ML algorithms. Compared with the best existing nonexercise algorithms that could be applied to the NHANES, the parsimonious LightGBM model (RMSE: 8.51 ml/kg/min [95% CI: 7.73-9.33]) and the extended LightGBM model (RMSE: 8.26 ml/kg/min [95% CI: 7.44-9.09]) significantly reduced the error by 15% and 12% (P < .001 for both), respectively.

DISCUSSION

The integration of ML and national data source presents a novel approach for estimating cardiovascular fitness. This method provides valuable insights for cardiovascular disease risk classification and clinical decision-making, ultimately leading to improved health outcomes.

CONCLUSION

Our nonexercise models provide improved accuracy in estimating VO2 max within NHANES data as compared to existing nonexercise algorithms.

Physical Activity Types, Physical Activity Levels and Risk of Diabetes in General Adults: The NHANES 2007-2018

BACKGROUND

Recreational activities show benefits for diabetes prevention, but work-related activity and the total amount of individual physical activity is rarely discussed.

PURPOSE

The purpose of this study was to evaluate the participation in five typical physical activities (vigorous work activity, vigorous recreational activities, moderate work activity, moderate recreational activities, and walk/bicycle for transportation), as well as the weekly distribution of total physical activity intensity, and to explore the relationships between physical activity types, physical activity levels, and risk of diabetes.

STUDY DESIGN

Cross-sectional study.

METHODS

The self-reported physical activity data on specific domains of physical activity were acquired from individuals in the 2007-2018 National Health and Nutrition Examination Survey (NHANES) using the Physical Activity Questionnaire (PAQ). Diabetes status was assessed by self-reported medical diagnosis or medication usage, or a fasting glucose concentration ≥ 126 mg/dL (fasting is defined as no caloric intake for at least 8 h) or HbA1c ≥ 6.5%. Weighted logistic regression was used to investigate the associations between physical activity types, physical activity levels, and risk of diabetes.

RESULTS

Diabetes was less prevalent in people who participated in physical activity and the risk of diabetes reduced progressively as total physical activity levels increased. Younger adults (20-44 years) and males reported a higher proportion of high-intensity physical activity participation.

CONCLUSIONS

Our findings highlight the importance of a physically active lifestyle for preventing diabetes. Distinct types of physical activity had different effects on the risk of diabetes. A greater total physical activity level was related to a substantial reduction in diabetes risk.

Restricted cafeteria feeding and treadmill exercise improved body composition, metabolic profile and exploratory behavior in obese male rats

The aim of this study was to evaluate, in male Long-Evans rats, whether a restricted-cafeteria diet (CAFR), based on a 30% calorie restriction vs continuous ad libitum cafeteria (CAF) fed animals, administered alone or in combination with moderate treadmill exercise (12 m/min, 35 min, 5 days/week for 8 weeks), was able to ameliorate obesity and the associated risk factors induced by CAF feeding for 18 weeks and to examine the changes in circadian locomotor activity, hypothalamic-pituitary-adrenal (HPA) axis functionality, and stress response elicited by this dietary pattern. In addition to the expected increase in body weight and adiposity, and the development of metabolic dysregulations compatible with Metabolic Syndrome, CAF intake resulted in a sedentary profile assessed by the home-cage activity test, reduced baseline HPA axis activity through decreased corticosterone levels, and boosted exploratory behavior. Both CAFR alone and in combination with exercise reduced abdominal adiposity and hypercholesterolemia compared to CAF. Exercise increased baseline locomotor activity in the home-cage in all dietary groups, boosted exploratory behavior in STD and CAF, partially decreased anxiety-like behavior in CAF and CAFR, but did not affect HPA axis-related parameters.

The association of cardiorespiratory fitness and the risk of hypertension: a systematic review and dose-response meta-analysis

Established evidence has indicated a negative correlation between cardiorespiratory fitness (CRF) and hypertension risk. In this study, we performed a meta-analysis to investigate the categorical and dose-response relationship between CRF and hypertension risk and the effects of CRF changes on hypertension risk reduction. The PubMed, Web of Science, and Embase databases were searched for relevant studies. The summarized relative risk (RR) and 95% confidence interval (95% CI) were estimated using the DerSimonian and Laird random effect model, and the dose-response relationship between CRF and hypertension risk was characterized using generalized least-squares regression and restricted cubic splines. Nine cohorts describing 110,638 incident hypertension events among 1,618,067 participants were included in this study. Compared with the lowest category of CRF, the RR of hypertension was 0.63 (95% CI: 0.56-0.70) for the highest CRF category and 0.85 (95% CI: 0.80-0.91) for the moderate category of CRF. For a 1-metabolic equivalent increment in CRF, the pooled RR of hypertension was 0.92 (95% CI: 0.90-0.94) in the total population. The RR of hypertension was 0.71 (95% CI: 0.64-0.79) for participants with CRF increased compared with those whose CRF was decreased over time. In conclusion, our meta-analysis supports the widely held notion of a negative dose-dependent relationship between CRF and hypertension risk.

Independent and joint associations of non-exercise cardiorespiratory fitness and obesity with risk of type 2 diabetes mellitus in the Rural Chinese Cohort Study

BACKGROUND AND AIMS

An association between cardiorespiratory fitness (CRF) and type 2 diabetes mellitus (T2DM) has not been established in the Chinese population. This study aimed to estimate the independent and joint associations of CRF and obesity with T2DM incidence in the rural Chinese population.

METHODS AND RESULTS

We conducted a prospective study of 11,825 non-T2DM subjects among rural Chinese adults. Cox regression models were used to estimate the independent and joint associations between CRF and obesity exposure on T2DM. Restricted cubic splines were used to model the dose-response association. During a median follow-up of 6.01 years, 835 participants developed T2DM. In comparison to quartile 1 of CRF, the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) of quartiles 2, 3, 4 were 0.75 (0.61-0.91), 0.54 (0.43-0.68), and 0.42 (0.32-0.55), respectively. When stratified by sex, the results were similar. Joint analyses showed that overweight/obesity-unfit individuals had a 2.28 times higher risk of developing T2DM than the normal weight-fit referent (HR 2.28, 95% CI 1.84-2.83; P_interaction <0.001). The risk for the overweight/obesity-fit category (HR 1.61, 95% CI 1.21-2.15) was larger than for the normal weight-unfit category (HR 1.38, 95% CI 0.97-1.95) versus the normal weight-fit referent. Similar joint associations for waist circumference and CRF with T2DM were also observed.

CONCLUSION

A negative association was observed between CRF and risk of T2DM. Overweight/obese or abdominal obesity and unfit participants showed the highest risks of T2DM. It is therefore strongly recommended that fitness-enhancing be encouraged for the prevention of T2DM, especially among obesity participants.

Digital Support to Multimodal Community-Based Prehabilitation: Looking for Optimization of Health Value Generation

Prehabilitation has shown its potential for most intra-cavity surgery patients on enhancing preoperative functional capacity and postoperative outcomes. However, its large-scale implementation is limited by several constrictions, such as: i) unsolved practicalities of the service workflow, ii) challenges associated to change management in collaborative care; iii) insufficient access to prehabilitation; iv) relevant percentage of program drop-outs; v) need for program personalization; and, vi) economical sustainability. Transferability of prehabilitation programs from the hospital setting to the community would potentially provide a new scenario with greater accessibility, as well as offer an opportunity to effectively address the aforementioned issues and, thus, optimize healthcare value generation. A core aspect to take into account for an optimal management of prehabilitation programs is to use proper technological tools enabling: i) customizable and interoperable integrated care pathways facilitating personalization of the service and effective engagement among stakeholders; ii) remote monitoring (i.e. physical activity, physiological signs and patient-reported outcomes and experience measures) to support patient adherence to the program and empowerment for self-management; and, iii) use of health risk assessment supporting decision making for personalized service selection. The current manuscript details a proposal to bring digital innovation to community-based prehabilitation programs. Moreover, this approach has the potential to be adopted by programs supporting long-term management of cancer patients, chronic patients and prevention of multimorbidity in subjects at risk.

The Effect of Aerobic Training and Increasing Nonexercise Physical Activity on Cardiometabolic Risk Factors

PURPOSE

Epidemiological studies suggest that sedentary behavior is an independent risk factor for cardiovascular mortality independent of meeting physical activity guidelines. However, limited evidence of this relationship is available from prospective interventions. The purpose of the present study is to evaluate the combined effect of aerobic training and increasing non-exercise physical activity on body composition and cardiometabolic risk factors.

METHODS

Obese adults (N=45) were randomized to 6-months of aerobic training (AERO), aerobic training and increasing non-exercise physical activity (~3,000 steps above baseline levels) (AERO-PA), or a control group (CON). The AERO and AERO-PA groups performed supervised aerobic training (3-4 times per week). The AERO-PA group wore Fitbit One accelerometers and received behavioral coaching to increase non-exercise physical activity.

RESULTS

There was a larger increase in fitness in the AERO-PA group (0.27 L/min, 0.16 to 0.40) compared to the AERO group (0.09 L/min, CI: -0.04 to 0.22) and the CON (0.01, CI: -0.11 to 0.12) groups. While significant findings were not observed in the entire study sample, when the analysis was restricted to participants compliant to the intervention (N=33), we observed significant reductions in waist circumference, percent weight loss, body fat, 2-hr glucose and 2-hr insulin in comparison to the CON group (p<0.05), but not the AERO group. Further, linear regression models showed that change in steps was associated with 21% and 26% of the variation in percent weight loss and percent fat loss, respectively.

CONCLUSION

Increasing non-exercise physical activity with aerobic training may represent a viable strategy to augment the fitness response in comparison to aerobic training alone and has promise for other health indicators.

Impact of physical activity on redox status and nitric oxide bioavailability in nonoverweight and overweight/obese prepubertal children

Nutritional status might contribute to variations induced by physical activity (PA) in redox status biomarkers. We investigated the influence of PA on redox status and nitric oxide (NO) production/metabolism biomarkers in nonoverweight and overweight/obese prepubertal children. We performed a cross-sectional evaluation of 313 children aged 8-9 years (163 nonoverweight, 150 overweight/obese) followed since birth in a cohort study (Generation XXI, Porto, Portugal). Plasma total antioxidant status (P-TAS), plasma and urinary isoprostanes (P-Isop, U-Isop), urinary hydrogen peroxide (U-H₂O₂), myeloperoxidase (MPO) and plasma and urinary nitrates and nitrites (P-NOx, U-NOx) were assessed, as well as their association with variables of reported PA quantification (categories of PA frequency (>1x/week and ≤1x/week)and continuous PA index (obtained by the sum of points)) in a questionnaire with increasing ranks from sedentary to vigorous activity levels. U-NOx was significantly higher in children who presented higher PA index scores and higher PA frequency. Separately by BMI classes, U-NOx was significantly higher only in nonoverweight children who practiced PA more frequently (p = 0.037). In overweight/obese children, but not in nonoverweight, P-TAS was higher among children with higher PA frequency (p = 0.007). Homeostasis model assessment index (HOMA-IR) was significantly lower in more active overweight/obese children, but no differences were observed in nonoverweight children. In the fully adjusted multivariate linear regression models for P-TAS, in the overweight/obese group, children with higher PA frequency presented higher P-TAS. In the U-NOx models, U-NOx significantly increased with PA index, only in nonoverweight children. Our results provide additional evidence in support of a protective effect of physical activity, in nonoverweight by increasing NO bioavailability and in overweight/obese children by enhancing systemic antioxidant capacity and insulin sensitivity. These results highlight the importance of engaging in regular physical exercise, particularly among overweight/obese children, in which a positive association between oxidant status and cardiometabolic risk markers has been described.

Response of the oxygen uptake efficiency slope to exercise training in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) patients have poor cardiorespiratory fitness. Although cardiopulmonary exercise testing (CPET) is a universal assessment of cardiorespiratory fitness, values taken at 'peak' effort are strongly influenced by motivation and the choice of test endpoint. The oxygen uptake efficiency slope (OUES) integrates cardiovascular, musculoskeletal, and respiratory function into a single index to provide a more pragmatic and safer alternative to maximal testing. No research has explored whether exercise can improve the OUES in CKD patients.

METHODS

Thirty-two patients with non-dialysis CKD were recruited into a 12-week exercise program consisting of mixed aerobic and resistance training three times a week. CPET was conducted at baseline, and then, following a 6-week control period, at pre- and post-exercise intervention. Direct measurements of oxygen consumption (V̇O2) and ventilatory parameters were collected. The OUES was calculated as the relationship between V̇O2 and the log10 of minute ventilation (V̇E).

RESULTS

No changes were observed in any variable during the control period, although modest increases in V̇O2peak were observed. No meaningful changes were observed as a result of exercise in any cardiorespiratory value obtained. The OUES calculated at 100%, 90%, 75%, and 50% of exercise duration did not change significantly after 12 weeks of exercise training.

CONCLUSION

Our results show that 12 weeks of exercise training had no beneficial effects on the OUES, which supports the modest change observed in V̇O2peak. The lack of change in the OUES and other parameters could indicate a dysfunctional cardiorespiratory response to exercise in patients with CKD, likely mediated by dysfunctional peripheral metabolic mechanisms.

Impact of unhealthy lifestyle on cardiorespiratory fitness and heart rate recovery of medical science students

Background

Medical science students represent valuable labour resources for better future medicine and medical technology. However, little attention was given to the health and well-being of these early career medical science professionals. The aim of this study is to investigate the impact of lifestyle components on cardiorespiratory fitness and heart rate recovery measured after moderate exercise in this population.

Methods

Volunteers without documented medical condition were recruited randomly and continuously from the first-year medical science students during 2011–2014 at the University of Surrey, UK. Demographics and lifestyle components (the levels of smoking, alcohol intake, exercise, weekend outdoor activity and screen-time, daily sleep period, and self-assessment of fitness) were gathered through pre-exercise questionnaire. Cardiorespiratory fitness (VO₂max) and heart rate recovery were determined using Åstrand–Rhyming submaximal cycle ergometry test. Data were analysed using SPSS version 25.

Results

Among 614 volunteers, 124 had completed both lifestyle questionnaire and the fitness test and were included for this study. Within 124 participants (20.6 ± 4 years), 46.8% were male and 53.2% were female, 11.3% were overweight and 8.9% were underweight, 8.9% were current smokers and 33.1% consumed alcohol beyond the UK recommendation. There were 34.7% of participants admitted to have < 3 h/week of moderate physical activity assessed according to UK Government National Physical Activity Guidelines and physically not fit (feeling tiredness). Fitness test showed that VO₂max distribution was inversely associated with heart rate recovery at 3 min and both values were significantly correlated with the levels of exercise, self-assessed fitness and BMI. Participants who had < 3 h/week exercise, or felt not fit or were overweight had significantly lower VO₂max and heart rate recovery than their peers.

Conclusion

One in three new medical science students were physically inactive along with compromised cardiorespiratory fitness and heart rate recovery, which put them at risk of cardiometabolic diseases. Promoting healthy lifestyle at the beginning of career is crucial in keeping medical science professionals healthy.

Long-term effects of group exercise intervention on maximal step-up height in middle-aged female primary care patients with obesity and other cardio-metabolic risk factors

Background

Low physical performance is a predictor of morbidity and mortality. This study looks at long-term effects of an exercise intervention on maximal step-up height (MSH) in individuals with low physical function. Factors associated with changes in MSH was studied.

Methods

Female patients (n = 101), mean (SD) age of 52 (11) years, were recruited for a 3-month group exercise intervention including 2–3 sessions/week of mixed aerobic fitness and strength training. MSH, weight, body mass index (BMI), waist circumference, maximal oxygen consumption (VO₂-max), self-reported health (SF-36) and physical activity (PA) were measured at baseline (T0), after 3 months (T1) and after 14–30 (mean 22) months (T2). Relationships between changes in MSH (cm) and age, baseline MSH, time to follow-up, changes in anthropometric measurements, VO₂-max, SF-36 and PA were studied with regression analyses.

Results

MSH, significantly, increased from T0 to T1, 27.2 (5.7) to 29.0 (5.5) cm and decreased to 25.2 (5.5) cm at T2. Time to follow-up (B = − 0.42, p < 0.001) and change in BMI (B = − 0.29, p = 0.012) correlated significantly to changes in MSH. Waist circumference, VO₂-max, PF and exercise/physical activity levels were significantly improved at T2, while BMI did not change. In a univariate logistic regression model, maintenance of MSH correlated to the extent of mixed training (OR 3.33, 95% CI 1.25–8.89). In a multivariate logistic regression model adjusted for important factors the correlation was not significant. However, MSH was significantly higher in individuals participating in 2–3 session per week compared to one session.

Conclusions

A 3-month group exercise intervention increased MSH, improved fitness, decreased risk in female patients with elevated cardio-metabolic risk. After an average of 22 months MSH was reduced while positive effects remained for waist circumference, VO₂-max, physical function and physical activity. However, regular group exercise 2–3 times per week with mixed aerobic fitness and strength training was associated with maintenance of MSH in a subgroup of patients. We suggest that such an intervention including regular support from healthcare professionals is a successful approach for maintaining improved leg-muscle strength among primary care patients.

Trial registration

ISRCTN21220201 September 18, 2019, retrospectively registered.

A Randomized Community-based Exercise Training Trial in African American Men: Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men

PURPOSE

To examine the impact of a community-based exercise training intervention on cardiometabolic outcomes in African American men who have a family history of type 2 diabetes.

METHODS

The Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men (ARTIIS) study randomized participants into either an exercise training intervention or an information only control group for 5 months. The exercise training intervention consisted of 150 min of moderate intensity aerobic activity and 2 d of resistance training per week, consistent with the current federal physical activity guidelines. Participants in the control group received monthly newsletters featuring topics focused heavily on type 2 diabetes education and prevention. Outcome data were analyzed using repeated-measures ANCOVA models and incorporating both intention-to-treat and per-protocol principles.

RESULTS

Adherence to the aerobic and resistance training prescriptions were between 77% and 79%. Despite significant within group improvements in glucose and insulin levels (fasting, 2 h, 2 h minus baseline) and Homeostatic Model 2-Insulin Resistance, there were not significant between group differences. There was a marginally significant between group difference for Homeostatic Model 2-Beta (P < 0.06), and significant between group differences in peak cardiorespiratory fitness (P < 0.001) and waist circumference (P = 0.03).

CONCLUSIONS

These findings suggest that exercise training in accordance with the current national recommendations is effective in improving some health parameters in middle-age African American men who have a family history of type 2 diabetes, but did not have a significant impact on glycemic status.

Cardiorespiratory fitness, muscular strength and risk of type 2 diabetes: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The study aimed to quantitatively summarise the dose-response relationships between cardiorespiratory fitness and muscular strength on the one hand and risk of type 2 diabetes on the other and estimate the hypothetical benefits associated with population-wide changes in the distribution of fitness.

METHODS

We performed a systematic review with meta-analysis. The PubMed and EMBASE electronic databases were searched from inception dates to 12 December 2018 for cohort studies examining the association of cardiorespiratory fitness or muscular strength with risk of incident type 2 diabetes in adults. The quality of included studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Twenty-two studies of cardiorespiratory fitness and 13 studies of muscular strength were included in the systematic review with both exposures having ten estimates available for the primary adiposity- or body size-controlled meta-analysis. In random-effects meta-analysis including 40,286 incident cases of type 2 diabetes in 1,601,490 participants, each 1 metabolic equivalent (MET) higher cardiorespiratory fitness was associated with an 8% (95% CI 6%, 10%) lower RR of type 2 diabetes. The association was linear throughout the examined spectrum of cardiorespiratory fitness. In 39,233 cases and 1,713,468 participants each 1 SD higher muscular strength was associated with a 13% (95% CI 6%, 19%) lower RR of type 2 diabetes. We estimated that 4% to 21% of new annual cases of type 2 diabetes among 45-64-year-olds could be prevented by feasible and plausible population cardiorespiratory fitness changes.

CONCLUSIONS/INTERPRETATION

Relatively small increments in cardiorespiratory fitness and muscle strength were associated with clinically meaningful reductions in type 2 diabetes risk with indication of a linear dose-response relationship for cardiorespiratory fitness.

REGISTRATION

PROSPERO (CRD42017064526).

[Correlation between the six-minute walk test and maximal exercise test in patients with type ii diabetes mellitus]

INTRODUCTION

The 6-minute walk test is an exercise test that has been used in diabetic patients to assess the effectiveness of exercise programmes and has been correlated with clinical parameters; however, the correlation with the maximum workload registered during stress testing has not been determined in diabetic patients.

OBJECTIVE

To establish the correlation between the 6-minute walk test and the maximum workload registered during a stress test in patients with type ii diabetes mellitus and its association with glycemic control.

MATERIALS AND METHODS

We included 42 patients with type ii diabetes mellitus and mean age of 61.1 years, who underwent physical examination, a 6-minute walk test, a treadmill stress test and laboratory studies.

RESULTS

The 6-minute walk test had high reproducibility in diabetic patients and showed a moderate-low correlation with maximum workload on the treadmill (r=49, p=0.001). A significant association was found between the 6-minute walk test and glycosylated haemoglobin A1C values (RP 1.57, χ² <0.05).

CONCLUSION

The 6-minute walk test is a highly reproducible test and has a significant correlation with maximum physical workload in the diabetic patients tested. Therefore, it can be used as a test for assessing functional capacity in this population.

Association Between Cardiorespiratory Fitness and Risk of Type 2 Diabetes: A Meta-Analysis

OBJECTIVE

This meta-analysis aimed to (1) quantify the association of cardiorespiratory fitness (CRF) with type 2 diabetes risk in the general population and statin users and (2) investigate the joint effects of CRF and fatness with type 2 diabetes risk.

METHODS

Databases were searched for cohort studies reporting the association between CRF and type 2 diabetes risk. Summary hazard ratios (HRs) were obtained using random-effects models.

RESULTS

Fifteen studies were included. The HRs of type 2 diabetes for every 1-metabolic equivalent increase in CRF were 0.90 (95% CI: 0.86-0.94) for the general population and 0.92 (95% CI: 0.87-0.97) for statin users, and the HRs were linearly shaped (both P_nonlinearity  > 0.40). Compared with the nonstatin cohort, there was an increased risk of type 2 diabetes in statin users with the lowest and moderate CRF categories, but this was not present in the highest CRF category. The HR of type 2 diabetes for overweight/obesity-fit category versus normal weight-fit category was larger than that of the normal weight-unfit category versus the normal weight-fit category (P_interaction   = 0.004).

CONCLUSIONS

There was an inverse and dose-dependent association between CRF and type 2 diabetes risk. High CRF may eliminate the diabetogenic effect from statins, yet decreased body weight index seems superior in preventing type 2 diabetes.

The Relationship Between Cardiorespiratory Fitness and Arterial Stiffness in Middle-Aged Men with Abdominal Obesity

BACKGROUND

Abdominal obesity increases rapidly after middle age in Korean men, and there is an associated trend toward increasing levels of cardiovascular disease (CVD). The purpose of this study was to examine the effect of cardiorespiratory fitness (CRF) on arterial stiffness in men with abdominal obesity.

METHODS

A total of 387 middle-aged men (ages 42-59 years) with abdominal obesity participated in this cross-sectional study. Abdominal obesity was defined as a waist circumference ≥90 cm. Arterial stiffness was derived from brachial/ankle pulse wave velocity (baPWV). A treadmill exercise test was conducted to directly assess CRF using the peak oxygen uptake. Blood glucose, blood pressure, lipids, C-related protein (CRP), and baPWV were measured at rest.

RESULTS

CRF was inversely associated with baPWV (r = -0.340, P = 0.014) and CRP level (r = -0.325, P = 0.026). In addition, high CRF was associated with a lower triglyceride level (r = -0.219, P = 0.030) and a higher high-density lipoprotein cholesterol level (r = 0.317, P = 0.019).

CONCLUSIONS

These results demonstrated that high CRF was inversely associated with arterial stiffness in men with abdominal obesity. These results suggest that maintaining a high level of CRF can help middle-aged men with abdominal obesity to improve blood factors related to CVD.

Which is more important for cardiometabolic health: sedentary time, higher intensity physical activity or cardiorespiratory fitness? The Maastricht Study

AIMS/HYPOTHESES

Our aim was to examine the independent and combined (cross-sectional) associations of sedentary time (ST), higher intensity physical activity (HPA) and cardiorespiratory fitness (CRF) with metabolic syndrome and diabetes status.

METHODS

In 1933 adults (aged 40-75 years) ST and HPA (surrogate measure for moderate to vigorous physical activity) were measured with the activPAL3. CRF was assessed by submaximal cycle-ergometer testing. Metabolic syndrome was defined according to the Adult Treatment Panel (ATP) III guidelines. Diabetes status (normal, prediabetes [i.e. impaired glucose tolerance and/or impaired fasting glucose] or type 2 diabetes) was determined from OGTT. (Multinomial) logistic regression analyses were used to calculate likelihood for the metabolic syndrome, prediabetes and type 2 diabetes according to ST, HPA and CRF separately and combinations of ST-CRF and HPA-CRF.

RESULTS

Higher ST, lower HPA and lower CRF were associated with greater odds for the metabolic syndrome and type 2 diabetes independently of each other. Compared with individuals with high CRF and high HPA (CRFhigh-HPAhigh), odds for the metabolic syndrome and type 2 diabetes were higher in groups with a lower CRF regardless of HPA. Individuals with low CRF and low HPA (CRFlow-HPAlow) had a particularly high odds for the metabolic syndrome (OR 5.73 [95% CI 3.84, 8.56]) and type 2 diabetes (OR 6.42 [95% CI 3.95, 10.45]). Similarly, compared with those with high CRF and low ST (CRFhigh-STlow), those with medium or low CRF had higher odds for the metabolic syndrome, prediabetes and type 2 diabetes, irrespective of ST. In those with high CRF, high ST was associated with significantly high odds for the metabolic syndrome (OR 2.93 [95% CI 1.72, 4.99]) and type 2 diabetes (OR 2.21 [95% CI 1.17, 4.17]). The highest odds for the metabolic syndrome and type 2 diabetes were observed in individuals with low CRF and high ST (CRFlow-SThigh) (OR [95% CI]: the metabolic syndrome, 9.22 [5.74, 14.80]; type 2 diabetes, 8.38 [4.83, 14.55]).

CONCLUSIONS/INTERPRETATION

These data suggest that ST, HPA and CRF should all be targeted in order to optimally reduce the risk for the metabolic syndrome and type 2 diabetes.

Alignment of diet prescription to genotype does not promote greater weight loss success in women with obesity participating in an exercise and weight loss program

OBJECTIVE

Genetics contribute to variability in individual response to weight-loss interventions. The objective of this study was to determine the efficacy of a commercially available exercise and weight-loss program and whether alignment of diet to genotype related to lipid metabolism promotes greater success.

DESIGN

Sedentary women with obesity (n = 63) had genotype (FABP2rs1799883, PPARG2rs1801282, ADRB3rs4994C3, ADRB2rs1042713, rs1042714) determined using a direct-to-consumer genetic screening kit purported to promote greater weight-loss success through dietary recommendations based on these genes. Participants were randomly assigned to follow a moderate carbohydrate (MC) or lower carbohydrate (LC) hypo-energetic diet that aligned (A) or did not align (NA) with genotype for 24 weeks while participating in a resistance training and walking program. Data were analysed by general linear model repeated measures adjusted for baseline variables and are presented as mean (95% confidence interval) changes from baseline.

RESULTS

Participants in the LC group experienced greater improvements (p = 0.051, ηp 2 = 0.025) in per cent changes in body composition (weight: MC -3.32 [-1.4, -5.2], LC -5.82 [-4.1, -7.6]; fat mass: MC -7.25 [-3.2, -11.2], LC -10.93 [-7.3, -14.5]; fat-free mass: MC -0.32 [1.4, -2.0], LC -1.48 [0.7, -3.0]; and body fat percentage: MC -4.19 [-1.6, -6.8], LC -5.60 [-3.3, -7.9] %). No significant differences were observed between genotype groups (weight: A -5.00 [-3.3, -6.7], NA -4.14 [-2.2, -6.1]; fat mass: A -10.15 [-7.0, -13.6], NA -8.02 [-4.0, -12.0]; fat-free mass: A -1.23 [0.3, -2.8], NA -0.56 [1.12, -2.3]; and body fat: A -5.28 [-3.0, -7.6], NA -4.51 [-1.9, -7.1] %).

CONCLUSIONS

Adherence to this exercise and weight-loss program promoted improvements in body composition and health outcomes. While individuals following the LC diet experienced greater benefits, alignment of these diets to this genetic profile did not promote greater health outcomes.

A Church-Based Weight Loss Intervention in African American Adults using Text Messages (LEAN Study): Cluster Randomized Controlled Trial

Background

African American adults experience a high prevalence of obesity and its associated comorbidities, including diabetes. Church-based interventions have been shown to be effective in decreasing weight in this population. mHealth interventions can address two needs for obesity treatment in this community, including enhancing weight loss and providing wide dissemination.

Objective

This study aimed to assess the feasibility and efficacy of a church-based weight loss intervention that incorporates mHealth technology.

Methods

In this study, 8 churches (n=97) were randomly assigned to the intervention or delayed intervention condition (control group). We recruited participants through their respective church. Volunteer church members were trained by study staff to deliver the 10-session, 6-month intervention. Participants in the intervention group attended group sessions and received automated short message service (SMS) text messages designed to reinforce behavioral strategies. Conversely, participants in the delayed intervention condition received SMS text messages related to health conditions relevant for African American adults. We obtained measures of body composition, blood pressure, blood glucose, and cholesterol.

Results

We successfully recruited 97 African American adults, with a mean age of 56.0 (SE 10.3) years and a mean body mass index of 38.6 (SE 6.4) kg/m2 (89/97, 91.8% females), who attended the churches that were randomized to the intervention (n=68) or control (n=29) condition. Of these, 74.2% (72/97) of the participants (47/68, 69.1% intervention; 25/29, 86.2% delayed intervention) completed the 6-month assessment. The average intervention group attendance was 55%. There was a significant difference in weight loss (P=.04) between participants in the intervention (–1.5 (SE 0.5) kg) and control (0.11 (SE 0.6) kg) groups. Among participants in the intervention group, the correlation between the number of SMS text messages sent and the percent body fat loss was r=.3 with P=.04. The participants reported high satisfaction with the automated SMS text messages.

Conclusions

Automated SMS text messages were well-received by participants, suggesting that more enhanced mHealth technologies are a viable option for interventions targeting African American adults.

Trial Registration

ClinicalTrials.gov NCT02863887; https://clinicaltrials.gov/ct2/show/NCT02863887 (Archived by WebCite at http://www.webcitation.org/71JiYzizO)

Protocol for regional implementation of collaborative self-management services to promote physical activity

BACKGROUND

Chronic diseases are generating a major health and societal burden worldwide. Healthy lifestyles, including physical activity (PA), have proven efficacy in the prevention and treatment of many chronic conditions. But, so far, national PA surveillance systems, as well as strategies for promotion of PA, have shown low impact. We hypothesize that personalized modular PA services, aligned with healthcare, addressing the needs of a broad spectrum of individual profiles may show cost-effectiveness and sustainability.

METHODS

The current manuscript describes the protocol for regional implementation of collaborative self-management services to promote PA in Catalonia (7.5 M habitants) during the period 2017-2019. The protocols of three implementation studies encompassing a broad spectrum of individual needs are reported. They have a quasi-experimental design. That is, a non-randomized intervention group is compared to a control group (usual care) using propensity score methods wherein age, gender and population-based health risk assessment are main matching variables. The principal innovations of the PA program are: i) Implementation of well-structured modular interventions promoting PA; ii) Information and communication technologies (ICT) to facilitate patient accessibility, support collaborative management of individual care plans and reduce costs; and iii) Assessment strategies based on the Triple Aim approach during and beyond the program deployment.

DISCUSSION

The manuscript reports a precise roadmap for large scale deployment of community-based ICT-supported integrated care services to promote healthy lifestyles with high potential for comparability and transferability to other sites.

TRIAL REGISTRATION

This study protocol has been registered at ClinicalTrials.org ( NCT02976064 ). Registered November 24th, 2016.

The 2016 global and national burden of diabetes mellitus attributable to PM2·5 air pollution

BACKGROUND

PM_2·5 air pollution is associated with increased risk of diabetes; however, a knowledge gap exists to further define and quantify the burden of diabetes attributable to PM_2·5 air pollution. Therefore, we aimed to define the relationship between PM_2·5 and diabetes. We also aimed to characterise an integrated exposure response function and to provide a quantitative estimate of the global and national burden of diabetes attributable to PM_2·5.

METHODS

We did a longitudinal cohort study of the association of PM_2·5 with diabetes. We built a cohort of US veterans with no previous history of diabetes from various databases. Participants were followed up for a median of 8·5 years, we and used survival models to examine the association between PM_2·5 and the risk of diabetes. All models were adjusted for sociodemographic and health characteristics. We tested a positive outcome control (ie, risk of all-cause mortality), negative exposure control (ie, ambient air sodium concentrations), and a negative outcome control (ie, risk of lower limb fracture). Data for the models were reported as hazard ratios (HRs) and 95% CIs. Additionally, we reviewed studies of PM_2·5 and the risk of diabetes, and used the estimates to build a non-linear integrated exposure response function to characterise the relationship across all concentrations of PM_2·5 exposure. We included studies into the building of the integrated exposure response function if they scored at least a four on the Newcastle-Ottawa Quality Assessment Scale and were only included if the outcome was type 2 diabetes or all types of diabetes. Finally, we used the Global Burden of Disease study data and methodologies to estimate the attributable burden of disease (ABD) and disability-adjusted life-years (DALYs) of diabetes attributable to PM_2·5 air pollution globally and in 194 countries and territories.

FINDINGS

We examined the relationship of PM_2·5 and the risk of incident diabetes in a longitudinal cohort of 1 729 108 participants followed up for a median of 8·5 years (IQR 8·1-8·8). In adjusted models, a 10 μg/m³ increase in PM_2·5 was associated with increased risk of diabetes (HR 1·15, 95% CI 1·08-1·22). PM_2·5 was associated with increased risk of death as the positive outcome control (HR 1·08, 95% CI 1·03-1·13), but not with lower limb fracture as the negative outcome control (1·00, 0·91-1·09). An IQR increase (0·045 μg/m³) in ambient air sodium concentration as the negative exposure control exhibited no significant association with the risk of diabetes (HR 1·00, 95% CI 0·99-1·00). An integrated exposure response function showed that the risk of diabetes increased substantially above 2·4 μg/m³, and then exhibited a more moderate increase at concentrations above 10 μg/m³. Globally, ambient PM_2·5 contributed to about 3·2 million (95% uncertainty interval [UI] 2·2-3·8) incident cases of diabetes, about 8·2 million (95% UI 5·8-11·0) DALYs caused by diabetes, and 206 105 (95% UI 153 408-259 119) deaths from diabetes attributable to PM_2·5 exposure. The burden varied substantially among geographies and was more heavily skewed towards low-income and lower-to-middle-income countries.

INTERPRETATION

The global toll of diabetes attributable to PM_2·5 air pollution is significant. Reduction in exposure will yield substantial health benefits.

FUNDING

US Department of Veterans Affairs.

Importance of Achieving a "Fit" Cardiorespiratory Fitness Level for Several Years on the Incidence of Type 2 Diabetes Mellitus: A Japanese Cohort Study

Background

The “Physical Activity Reference for Health Promotion 2013” provides “fit” reference values for cardiorespiratory fitness (CRF) for good health. The importance of achieving a fit CRF level for several years on the subsequent prevention of type 2 diabetes mellitus (T2DM) remains to be clarified.

Methods

This cohort study was conducted in 2,235 nondiabetic males aged 21 to 59 years, enrolled in April 1986 through March 1987. We calculated the ratio of the area under the curve (AUC_ratio) for actual measured values and the AUC for the reference values of CRF in each individual during an 8-year measurement period before the baseline. According to whether they met a fit CRF level or not, participants were categorized into groups based on the AUC_ratio (Fit_AUC or Unfit_AUC) and initial CRF (Fit_initial or Unfit_initial), respectively. T2DM was evaluated on health checkups until March 2010.

Results

During the follow-up period, 400 men developed T2DM. After adjustment for confounders, as compared with those in the Fit_AUC group, the hazard ratio (HR) for those in the Unfit_AUC group was 1.33 (95% confidence interval [CI], 1.06–1.65). A combined analysis with the categories of initial value and AUC_ratio showed that, compared with the Fit_initial and Fit_AUC group, the HRs of Fit_initial and Unfit_AUC, Unfit_initial and Fit_AUC, and Unfit_initial and Unfit_AUC groups were 1.41 (95% CI, 0.99–2.00), 1.18 (95% CI, 0.81–1.70), and 1.40 (95% CI, 1.08–1.83), respectively.

Conclusion

Achievement of a fit CRF level established in the Japan physical activity guideline for several years was associated with lower subsequent risk of T2DM.

Factors that influence planning for physical activity among workers in small- and medium-sized enterprises

Physical activity (PA) is necessary for improving the health of workers in small- to medium-sized enterprises (SMEs). However, behavioral changes conducive to PA are often difficult to achieve despite intentions. Because intention to perform PA does not always translate to action, proper planning may be critical for achieving PA. In this study, we aimed to identify factors related to planning for PA among workers in SMEs because this is one population that has been identified as being at higher risk for lifestyle-related diseases in Japan. Participants completed a series of validated questionnaires. Of 353 valid responses, 226 individuals (149 men; aged 47.5 ± 8.7 years) stated their intention to perform PA. Multiple regression analysis indicated that a higher PA planning score was significantly associated with higher self-efficacy for PA (p < 0.001), higher risk perception regarding inactivity (p = 0.012), and greater knowledge of information about PA community services (p = 0.019). Therefore, we recommend that self-efficacy, risk perception, and information regarding PA community services are enhanced in the daily working lives of workers at their workplaces. In this manner, they can promote their planning of health behavioral changes in a supportive environment, drawing upon available services, supports, and other resources.

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Physical activity (PA) action is essential for the health of middle-aged workers.

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Planning for PA is the key skill that lies between intention and action for PA.

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Self-efficacy, risk perception, and services information promote planning for PA.

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It is recommended that workplaces enhance the planning of health behavioral modifications.

Cardiorespiratory fitness, fatness and incident diabetes

AIMS

Increases in prevalence have led to a diabetes pandemic. Obesity and low cardiorespiratory fitness (CRF) are considered to be central mechanisms. We investigated if the effect of CRF on diabetes risk was equivalent across levels of fatness among healthy men.

METHODS

In total 4988 middle-aged Caucasian employed men free of cardiovascular disease, diabetes and cancer were included from the Copenhagen Male Study starting in 1970-71. CRF was assessed using a sub-maximal bicycle ergometer test and body mass index (BMI) was measured by height and weight. Their interaction and stratified associations with diabetes incidence were estimated in multivariable Cox-models including conventional risk factors and social class. Diabetes incidence was assessed through a national register.

RESULTS

During 44 years of follow-up, 518 (10.4%) incident cases of diabetes occurred. In the multi-adjusted model, the obese had a significantly higher risk of diabetes compared to normal weight men (Hazard Ratio (HR):4.89; 95% CI: 3.62-6.61) and CRF was significantly inversely associated with diabetes (HR:0.86; 95% CI: 0.75-0.98 per 10-unit increase in ml/kg/min¹ CRF). A significant multi-adjusted interaction between CRF, BMI and diabetes was found (p=0.009). The stratified multi-adjusted analyses on BMI showed a significantly stronger reduced risk of diabetes per 10-unit increase in ml/kg/min¹ of CRF among the obese (HR:0.58; CI: 0.38-0.89), but a weaker association among overweight (HR:0.86; CI: 0.71-1.03) and normal weight (HR:0.97; CI: 0.76-1.23).

CONCLUSION

High CRF has a stronger protective effect on diabetes among obese than among normal weight men, supporting the recommendation of fitness-enhancing physical activity for preventing diabetes among the obese.

Relation of Exercise Capacity to Risk of Development of Diabetes in Patients on Statin Therapy (the Henry Ford Exercise Testing Project)

High exercise capacity (EC) has been associated with a lower risk of incident diabetes, whereas statin therapy has been associated with a higher risk. We sought to investigate whether the association between EC and diabetes risk is modified by statin therapy. This retrospective cohort study included 47,337 patients without diabetes or coronary artery disease at baseline (age 53 ± 13 years, 48% women, 66% white) who underwent clinical treadmill stress testing within the Henry Ford Health System from January 1, 1991, to May 31, 2009. The patients were stratified by baseline statin use and estimated peak METs achieved during exercise testing. Hazard ratios for incident diabetes were calculated using Cox proportional hazards models adjusted for demographic characteristics, co-morbidities, pertinent medications, and stress test indication. We observed 6,921 new diabetes cases (14.6%) over a median follow-up period of 5.1 years (interquartile interval of 2.6 to 8.2 years). Compared with the statin group, the no-statin group achieved higher mean METs (8.9 ± 2.7 vs 9.6 ± 3.0, respectively; p <0.001). After adjustment for covariates, a higher EC was associated with a lower risk of incident diabetes, irrespective of statin use (p-interaction = 0.15). Each 1-MET increment was associated with an 8%, 8%, and 6% relative risk reduction in the total cohort, the no-statin, and the statin groups, respectively (95% confidence interval, 0.91 to 0.93, 0.91 to 0.93, and 0.91 to 0.96, respectively; p <0.001 for all). We conclude that a higher EC is associated with a lower risk of incident diabetes regardless of statin use.

Physical activity in patients with COPD: the impact of comorbidities

INTRODUCTION

Comorbidities are common in patients with chronic obstructive pulmonary disease (COPD) and it plays an important role on physical activity (PA) in this population. Since low PA levels have been described as a key factor to predict morbi-mortality in COPD, it seems crucial to review the current literature available on this topic. Areas covered: This review covers the most common comorbidities found in COPD, their prevalence and prognostic implications. We explore the differences in PA between COPD patients with and without comorbidities, as well as the impact of the number or type of comorbidities on activity levels of this population. The effect of different comorbidities on activities of daily living in patients with COPD is also reviewed. Finally, we discuss options for the treatment of inactivity in COPD patients considering their comorbidities and limitations. Expert commentary: Comorbidities are highly prevalent in patients with COPD and further deteriorate PA levels in this population. Despite the wide range of interventions available in COPD, the evidence in the field seems to point at PA coaching with feedback on individual goals and longer lasting PR programmes with more than 12 weeks of duration when attempting to raise the activity levels of this population.

Association of daily physical activity level with health-related factors by gender and age-specific differences among Korean adults based on the sixth (2014-2015) Korea national health and nutrition examination survey

[Purpose]

This study examined the effects of daily physical activity level on health-related factors according to gender and identified age-specific differences among Korean adults.

[Methods]

Using data from the Korea National Health and Nutrition Examination Survey VI (2014-2015), we selected adults aged 19-64 years who participated in both a health examination and health interview survey. The study included 6,457 participants 19-64 years of age (2,611 men, 3,846 women).

[Results]

Assessment of the differences in health-related factors according to age and physical activity in men and women by repeated two-way analysis of variance (ANOVA) revealed significant interaction effects on total cholesterol (TC) and triglyceride (TG) levels and diastolic blood pressure (DBP) in male participants, but there were no significant interaction effects for any health-related factors in female participants. The group of female participants aged 40-64 years with daily physical activity levels over 200 kcal showed a significantly increased prevalence of 46% for dyslipidemia compared to that in female participants with daily physical activity levels below 200 kcal. Physical activity was positively correlated with weight and high-density lipoprotein cholesterol (HDL-C) levels in men 19-39 years of age, compared to weight, waist circumference (WC), body mass index (BMI), and DBP in men 40-64 years of age, and weight, WC, BMI, glycated hemoglobin (HbA1c) and triglyceride (TG) levels in women 19-39 years of age. In women 40- 64 years of age, physical activity was especially significantly positively correlated with weight, BMI, HDL-C and negatively correlated with fasting glucose and TG levels.

[Conclusion]

In male and female participants, the 40-64-year age group showed negative results for health-related factors compared to those in the 19-39-year age group. The higher the weight, WC, BMI, the higher is the physical activity level. Physical activity levels were significantly positively correlated with health-related variables.

Addition of estimated cardiorespiratory fitness to the clinical assessment of 10-year coronary heart disease risk in asymptomatic men

The Framingham Risk Score (FRS) was developed to quantify a patient's coronary heart disease (CHD) risk. Non-exercise estimated CRF (e-CRF) may provide a clinically practical method for describing cardiorespiratory fitness. We computed e-CRF and tested its association with the FRS and CHD.

Male participants (n = 29,854) in the Aerobics Center Longitudinal Study (ACLS) who completed a baseline examination between 1979–2002 were followed for 12 years to determine incident CHD defined by self-report of myocardial infarction, revascularization, or CHD mortality. e-CRF was defined from a 7-item scale and categorized using age-specific tertiles. Multivariable survival analysis determined associations between FRS, e-CRF, and CHD. Interaction between e-CRF and FRS was tested by stratified analysis by ‘low’ and ‘moderate or high’ 10-year CHD risk.

Men with high e-CRF were significantly (p-value < 0.0001) younger, and less likely to be smokers, compared to men with low e-CRF. Multivariable survival analysis reported men with high e-CRF were 29% (HR = 0.71; 95% 0.56, 0.88) less likely to experience a CHD event compared to men with low e-CRF. Stratified analyses showed men with ‘low’ 10-year FRS predicted CHD risk and high e-CRF had a 28% (HR = 0.72; 95% CI 0.57, 0.91) lower CHD-mortality risk compared to men with low e-CRF, no association was found in this group and men with moderate e-CRF. Men who were more fit had a decreased risk for CHD compared to men in the lowest third of fitness. Estimated CRF may add clinical value to the FRS and help clinicians better predict long-term CHD risk.

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Men with low e-CRF had a higher proportion of CHD events compared to high-fit men.

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E-CRF was a protective factor of CHD in crude and adjusted analysis.

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E-CRF could be used to capture patient CRF during clinic visits.

Energy Expenditure in People with Diabetes Mellitus: A Review

Physical activity (PA) is an important non-therapeutic tool in primary prevention and treatment of diabetes mellitus (DM). To improve activity-based health management, patients need to quantify activity-related energy expenditure and the other components of total daily energy expenditure. This review explores differences between the components of total energy expenditure in patients with DM and healthy people and presents various tools for assessing the energy expenditure in subjects with DM. From this review, it appears that patients with uncontrolled DM have a higher basal energy expenditure (BEE) than healthy people which must be considered in the establishment of new BEE estimate equations. Moreover, studies showed a lower activity energy expenditure in patients with DM than in healthy ones. This difference may be partially explained by patient with DMs poor compliance with exercise recommendations and their greater participation in lower intensity activities. These specificities of PA need to be taken into account in the development of adapted tools to assess activity energy expenditure and daily energy expenditure in people with DM. Few estimation tools are tested in subjects with DM and this results in a lack of accuracy especially for their particular patterns of activity. Thus, future studies should examine sensors coupling different technologies or method that is specifically designed to accurately assess energy expenditure in patients with diabetes in daily life.

Physical activity and type 2 diabetes mellitus risk: population studies review

Physical activity is one of the most important components of a healthy lifestyle. Regular physical activity helps to maintain normal blood glucose levels and reduce the risk of type 2 diabetes mellitus. This review presents population studies investigating physical activity as a factor for type 2 diabetes mellitus risk. A search using the keywords ‘physical activity’, ‘type 2 diabetes mellitus’ and ‘risk’ identified more than 40 relevant original studies and meta-analyses, which are presented in this review. Different types of physical activity have positive protective effects on type 2 diabetes mellitus risk and reduce the risk of death in patients with type 2 diabetes mellitus.

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

Lifestyle Approaches and Glucose Intolerance

Glucose intolerance is a global health concern that encompasses glucose metabolism abnormalities such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes (T2D). There is an urgent need to focus on the prediabetes (ie, IGT and IFG) stage before the disease actually occurs. The progression from IGT to T2D can be prevented or delayed by modifying the lifestyles in high-risk individuals, and these health benefits are well documented in various ethnicities with prediabetes across the world. Specifically, consuming a healthy diet (high in polyunsaturated fatty acids, monounsaturated fatty acids, fiber, and whole grains), losing weight, quitting smoking, consuming alcohol in moderation, and increasing physical activity can improve glucose tolerance and reduce the risk of T2D. Also, pharmacological agents and botanicals can be used to manage glucose intolerance if the implementation of lifestyle changes is challenging. Pharmacological treatments have been successful in managing glucose intolerance; however, they have adverse effects. Also, more research on botanicals is warranted before a definitive recommendation can be made for their use in managing glucose intolerance. To make progress on this worldwide problem, efforts are needed to improve the awareness of prediabetes, increase promotion of healthy behaviors, and improve the availability of evidence-based lifestyle intervention programs to the community.

Skeletal muscle ultrastructure and function in statin-tolerant individuals

INTRODUCTION

Statins have well-known benefits on cardiovascular mortality, though up to 15% of patients experience side effects. With guidelines from the American Heart Association, American College of Cardiology, and American Diabetes Association expected to double the number of statin users, the overall incidence of myalgia and myopathy will increase.

METHODS

We evaluated skeletal muscle structure and contractile function at the molecular, cellular, and whole tissue levels in 12 statin tolerant and 12 control subjects.

RESULTS

Myosin isoform expression, fiber type distributions, single fiber maximal Ca(2+) -activated tension, and whole muscle contractile force were similar between groups. No differences were observed in myosin-actin cross-bridge kinetics in myosin heavy chain I or IIA fibers.

CONCLUSIONS

We found no evidence for statin-induced changes in muscle morphology at the molecular, cellular, or whole tissue levels. Collectively, our data show that chronic statin therapy in healthy asymptomatic individuals does not promote deleterious myofilament structural or functional adaptations.

Type 2 diabetes in migrant south Asians: mechanisms, mitigation, and management

South Asians, particularly when living in high-income countries, are at a substantially elevated risk of type 2 diabetes compared with white Europeans, and typically develop the disease 5-10 years earlier and at a lower BMI. Migrant south Asians seem to be more insulin resistant than white Europeans across the life course and potentially experience β-cell exhaustion at a younger age. Differences in adiposity (high percentage of body fat and high proportion of deep subcutaneous and visceral fat) and skeletal muscle (low percentage of lean mass and low cardiorespiratory fitness) are likely to contribute these factors. No clear evidence is available suggesting genetic factors make a major contribution to the increased risk of diabetes in south Asians, but epigenetic factors might have a role. Irrespective of future mechanistic discoveries, south Asians need to be encouraged and helped-by various culturally appropriate methods--to maintain a high physical activity level and low bodyweight across the life course to prevent diabetes. In clinical terms, cardiovascular risks have attenuated over time in migrant south Asians with diabetes but retinopathy and renal complication risks remain high because of the high levels of glycaemia and rapid glycaemic deterioration noted in this population. We review these aspects and suggest areas for future research.

Physical activity level and incident type 2 diabetes among Chinese adults

PURPOSE

The objective is to examine the association between physical activity level (PAL) and incident type 2 diabetes among middle-age and older Chinese men and women in urban China.

METHODS

This prospective study included 6348 participants (age 35 to 74 yr) who were free of diabetes and cardiovascular disease at baseline. PAL was estimated on the basis of self-reported overall physical activity on a typical day. According to PAL, participants were classified into four groups: sedentary (PAL, 1.00-1.39), low active (PAL, 1.40-1.59), active (PAL, 1.60-1.89), and very active (PAL, >1.89). The association of PAL with incident diabetes was examined by Cox proportional hazards model.

RESULTS

During 7.9 yr of follow-up (50,293 person-years), 478 incident cases of type 2 diabetes were identified. After adjustment for age, sex, geographic region, educational level, smoking, alcohol use, and family history of diabetes, the HR (95% CI) values for type 2 diabetes across increasing categories of PAL were 1.00 (reference), 0.82 (0.62-1.09), 0.63 (0.47-0.83), and 0.47 (0.36-0.61), respectively (P for trend <0.0001). Additional adjustment for baseline body mass index or waist circumference attenuated the magnitude of risk reduction, but it remained significant. The inverse association between PAL and risk of incident diabetes was persistent in subgroup analyses according to age, sex, hypertension, smoking, body mass index, waist circumference, and fasting plasma glucose level.

CONCLUSIONS

Higher PAL is associated with substantial reduction in risk of type 2 diabetes. Our findings suggest the importance of a physically active lifestyle in the prevention of diabetes.

Association between Changes in Muscle Quality with Exercise Training and Changes in Cardiorespiratory Fitness Measures in Individuals with Type 2 Diabetes Mellitus: Results from the HART-D Study

Introduction

Type 2 diabetes mellitus (T2DM) is associated with a reduction in muscle quality. However, there is inadequate empirical evidence to determine whether changes in muscle quality following exercise are associated with improvement in cardiorespiratory fitness (CRF) in individuals with T2DM. The objective of this study was to investigate the association between change in muscle quality following a 9-month intervention of aerobic training (AT), resistance training (RT) or a combination of both (ATRT) and cardiorespiratory fitness (CRF) in individuals with T2DM.

Material and Methods

A total of 196 participants were randomly assigned to a control, AT, RT, or combined ATRT for a 9-months intervention. The exposure variable was change in muscle quality [(Post: leg muscle strength/leg muscle mass)-[(Pre: leg muscle strength/leg muscle mass)]. Dependent variables were change in CRF measures including absolute and relative VO_2peak, and treadmill time to exhaustion (TTE) and estimated metabolic equivalent task (METs).

Results

Continuous change in muscle quality was independently associated with change in absolute (β = 0.015; p = 0.019) and relative (β = 0.200; p = 0.005) VO_2peak, and TTE (β = 0.170; p = 0.043), but not with estimated METs (p > 0.05). A significant trend was observed across tertiles of change in muscle quality for changes in absolute (β = 0.050; p = 0.005) and relative (β = 0.624; p = 0.002) VO_2peak following 9 months of exercise training. No such association was observed for change in TTE and estimated METs (p > 0.05).

Discussion

The results from this ancillary study suggest that change in muscle quality following exercise training is associated with a greater improvement in CRF in individuals with T2DM. Given the effect RT has on increasing muscle quality, especially as part of a recommended training program (ATRT), individuals with T2DM should incorporate RT into their AT regimens to optimize CRF improvement.

Trial Registration

Clinicaltrials.gov NCT00458133

Physical activity and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis

We investigated the association between specific types of physical activity and the risk of type 2 diabetes in a systematic review and meta-analysis of published studies. PubMed, Embase and Ovid databases were searched for prospective studies and randomized trials up to 2nd of March 2015. Summary relative risks (RRs) were calculated using a random effects model. Eighty-one studies were included. The summary RRs for high versus low activity were 0.65 (95 % CI 0.59-0.71, I(2) = 18 %, n = 14) for total physical activity, 0.74 (95 % CI 0.70-0.79, I(2) = 84 %, n = 55) for leisure-time activity, 0.61 (95 % CI 0.51-0.74, I(2) = 73 %, n = 8) for vigorous activity, 0.68 (95 % CI 0.52-0.90, I(2) = 93 %, n = 5) for moderate activity, 0.66 (95 % CI 0.47-0.94, I(2) = 47 %, n = 4) for low intensity activity, and 0.85 (95 % CI 0.79-0.91, I(2) = 0 %, n = 7) for walking. Inverse associations were also observed for increasing activity over time, resistance exercise, occupational activity and for cardiorespiratory fitness. Nonlinear relations were observed for leisure-time activity, vigorous activity, walking and resistance exercise (p nonlinearity < 0.0001 for all), with steeper reductions in type 2 diabetes risk at low activity levels than high activity levels. This meta-analysis provides strong evidence for an inverse association between physical activity and risk of type 2 diabetes, which may partly be mediated by reduced adiposity. All subtypes of physical activity appear to be beneficial. Reductions in risk are observed up to 5-7 h of leisure-time, vigorous or low intensity physical activity per week, but further reductions cannot be excluded beyond this range.

Cardiorespiratory fitness and incident diabetes: the FIT (Henry Ford ExercIse Testing) project

OBJECTIVE

Prior evidence has linked higher cardiorespiratory fitness with a lower risk of diabetes in ambulatory populations. Using a demographically diverse study sample, we examined the association of fitness with incident diabetes in 46,979 patients from The Henry Ford ExercIse Testing (FIT) Project without diabetes at baseline.

RESEARCH DESIGN AND METHODS

Fitness was measured during a clinician-referred treadmill stress test performed between 1991 and 2009. Incident diabetes was defined as a new diagnosis of diabetes on three separate consecutive encounters derived from electronic medical records or administrative claims files. Analyses were performed with Cox proportional hazards models and were adjusted for diabetes risk factors.

RESULTS

The mean age was 53 years with 48% women and 27% black patients. Mean metabolic equivalents (METs) achieved was 9.5 (SD 3.0). During a median follow-up period of 5.2 years (interquartile range 2.6-8.3 years), there were 6,851 new diabetes cases (14.6%). After adjustment, patients achieving ≥12 METs had a 54% lower risk of incident diabetes compared with patients achieving <6 METs (hazard ratio 0.46 [95% CI 0.41, 0.51]; P-trend < 0.001). This relationship was preserved across strata of age, sex, race, obesity, hypertension, and hyperlipidemia.

CONCLUSIONS

These data demonstrate that higher fitness is associated with a lower risk of incident diabetes regardless of demographic characteristics and baseline risk factors. Future studies should examine the association between change in fitness over time and incident diabetes.

The relationship between serum 25-hydroxyvitamin D concentration, cardiorespiratory fitness, and insulin resistance in Japanese men

Here, we aim to investigate the independent and combined associations of serum 25-hydroxyvitamin D (25(OH)D) and cardiorespiratory fitness (CRF) with glucose metabolism. Fasting blood samples of 107 men aged 40–79 years were analyzed for 25(OH)D, glucose, insulin, glycated hemoglobin, and lipid profile. Homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated from the fasting concentrations of glucose and insulin. Visceral fat area (VFA) was determined by magnetic resonance imaging and CRF by measuring maximal oxygen uptake. Median 25(OH)D concentration was 36.3 nmol/L, while the prevalence of 25(OH)D deficiency was 74.8%. Participants with high CRF had significantly lower HOMA-IR, glycated hemoglobin, and insulin values than participants with low CRF (p < 0.05). Higher 25(OH)D concentration was strongly correlated with lower HOMA-IR and insulin values independent of VFA (p < 0.01) but significantly affected by CRF. In the high CRF group, participants with higher 25(OH)D concentration had lower HOMA-IR values than participants with low 25(OH)D concentration (p < 0.05). Higher 25(OH)D and CRF are crucial for reducing insulin resistance regardless of abdominal fat. In addition, higher 25(OH)D concentration may strengthen the effect of CRF on reducing insulin resistance in middle-aged and elderly Japanese men with high CRF.

Effect of fitness on incident diabetes from statin use in primary prevention

OBJECTIVE

To assess the effect of cardiorespiratory fitness on the association between the initiation of statin therapy and incident diabetes.

PATIENTS AND METHODS

In a prospective observational study, we studied 6519 generally healthy men and 2334 women with two preventive health examinations from December 15, 1998 through December 18, 2013 which included measurement of fitness levels, statin therapy, risk factors for diabetes, and incident diabetes.

RESULTS

93 cases of incident diabetes occurred during an average follow-up of 3.0 years. After multivariable adjustment, an increased odds of incident diabetes with statin use was observed in those patients with impaired fasting glucose at baseline (odds ratio [OR]: 2.15, [95% CI:1.26 to 3.67]), but not among individuals with normal glucose levels (OR:1.85, [95% CI: 0.76 to 4.52]). Cardiorespiratory fitness attenuated but did not eliminate the increased risk of incident diabetes with statin use.

CONCLUSION

In a population of relatively healthy patients, statin use was not associated with incident diabetes in patients with normal fasting glucose at baseline. However, it was associated with incident diabetes in those patients with impaired fasting glucose at baseline, though this risk was substantially reduced by increasing fitness. In addition, increasing cardiorespiratory fitness was inversely associated with incident diabetes whether or not a patient was treated with a statin.

Effects of an outdoor bicycle-based intervention in healthy rural Indian men with normal and low birth weight

Physical inactivity and low birth weight (LBW) may lead to an increased risk for developing type 2 diabetes. The extent to which LBW individuals may benefit from physical exercise training when compared with those with normal birth weight (NBW) controls is uncertain. We assessed the impact of an outdoor exercise intervention on body composition, insulin secretion and action in young men born with LBW and NBW in rural India. A total of 61 LBW and 56 NBW healthy young men were recruited into the study. The individuals were instructed to perform outdoor bicycle exercise training for 45 min every day. Fasting blood samples, intravenous glucose tolerance tests and bioimpedance body composition assessment were carried out. Physical activity was measured using combined accelerometry and heart rate monitoring during the first and the last week of the intervention. Following the exercise intervention, the LBW group displayed an increase in physical fitness [55.0 ml (O2)/kg min (52.0-58.0)-57.5 ml (O2)/kg min (54.4-60.5)] level and total fat-free mass [10.9% (8.0-13.4)-11.4% (8.0-14.6)], as well as a corresponding decline in the ratio of total fat mass/fat-free mass. In contrast, an increase in total fat percentage as well as total fat mass was observed in the NBW group. After intervention, fasting plasma insulin levels, homoeostasis model assessments (HOMA) of insulin resistance (HOMA-IR) and insulin secretion (HOMA-IS), improved to the same extent in both the groups. In summary, young men born with LBW in rural India benefit metabolically from exercise training to an extent comparable with NBW controls.