Cardiorespiratory Fitness and Incidence of Type 2 Diabetes in United States Veterans on Statin Therapy

Stroke Incidence in Patients With Hypertension According to Cardiorespiratory Fitness

BACKGROUND

Hypertension and physical inactivity are risk factors for stroke. The effect of cardiorespiratory fitness (CRF) on stroke risk in patients with hypertension has not been assessed. We evaluated stroke incidence in patients with hypertension according to CRF and changes in CRF.

METHODS

We included 483 379 patients with hypertension (mean age±SD; 59.4±9.0 years) and no evidence of unstable cardiovascular disease as indicated by a standardized exercise treadmill test. Patients were assigned to 5 age- and sex-specific CRF categories based on peak metabolic equivalents achieved at the initial exercise treadmill test and in 4 categories based on metabolic equivalent changes over time (n=110 576). Multivariable Cox models, adjusted for age, and comorbidities were used to estimate hazard ratios and 95% CIs for stroke risk.

RESULTS

During a median follow-up of 10.6 (interquartile range, 6.6-14.6) years, 15 925 patients developed stroke with an average yearly rate of 3.1 events/1000 person-years. Stroke risk declined progressively with higher CRF and was 55% lower for the High-fit individuals (hazard ratio, 0.45 [95% CI, 0.42-0.48]) compared with the Least-fit. Similar associations were observed across the race, sex, and age spectra. Poor CRF was the strongest predictor of stroke risk of all comorbidities studied (hazard ratio, 2.24 [95% CI, 2.10-2.40]). Changes in CRF reflected inverse and proportional changes in stroke risk.

CONCLUSIONS

Poor CRF carried a greater risk than any of the cardiac risk factors in patients with hypertension, regardless of age, race, or sex. The lower stroke risk associated with improved CRF suggests that increasing physical activity, even later in life, may reduce stroke risk.

Progression to Insulin Therapy in Patients With Type 2 Diabetes According to Cardiorespiratory Fitness, Body Mass Index, and Statin Therapy

OBJECTIVE

To evaluate the association between statin therapy, cardiorespiratory fitness (CRF), body mass index (BMI), and progression to insulin therapy in type 2 diabetes mellitus (T2DM).

METHODS

Participants were patients with T2DM (mean age, 62.7±8.4 years; men, 178,992; women, 8360) not treated with insulin, with no evidence of uncontrolled cardiovascular disease, who completed an exercise treadmill test between October 1, 1999, and September 3, 2020. Of these, 158,578 were treated with statins and 28,774 were not. We established 5 age-specific CRF categories according to peak metabolic equivalents of task achieved during an exercise treadmill test.

RESULTS

During a median follow-up period of 9.0 years, 51,182 patients progressed to insulin therapy with an average annual incidence rate of 28.4 events/1000 person-years. The adjusted progression rate was 27% higher in statin-treated patients (hazard ratio [HR], 1.27; 95% CI, 1.24 to 1.31), related directly to BMI and inversely related to CRF. A progressively higher rate was noted in statin-treated vs non-statin-treated patients within all BMI categories, ranging from 23% for normal weight to 90% for those with BMI of 35 kg/m2 and higher. The statin-CRF interaction revealed 43% higher rate in the least-fit statin-treated patients (HR, 1.43; 95% CI, 1.35 to 1.51) and a progressive decline with increased CRF to 30% lower risk in highly fit statin-treated patients (HR, 0.70; 95% CI, 0.66 to 0.75).

CONCLUSION

In patients with T2DM, the statin-related progression to insulin therapy was associated with relatively low CRF and high BMI levels. The progression rate was mitigated by increased CRF regardless of BMI. Clinicians should foster regular exercise for patients with T2DM to enhance CRF and to lessen the rate of progression to insulin therapy.

Physical Activity and Cardiorespiratory Fitness as Modulators of Health Outcomes: A Compelling Research-Based Case Presented to the Medical Community

The beneficial health effects and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF have higher annual health care costs, higher rates of surgical complications, and are two to three times more likely to die prematurely than their fitter counterparts when matched for risk factor profile or coronary calcium score. Increased levels of habitual PA before hospitalization for acute coronary syndromes are also associated with better short-term cardiovascular outcomes. Accordingly, this review examines these relations and the potential underlying mechanisms of benefit (eg, exercise preconditioning), with specific reference to the incidence of cardiovascular, cancer, and coronavirus diseases, and the prescriptive implications and exercise thresholds for optimizing health outcomes. To assess the evidence supporting or refuting the benefits of PA and CRF, we performed a literature search (PubMed) and critically reviewed the evidence to date. In aggregate, these data are presented in the context of clarifying the impact that regular PA and/or increased CRF have on preventing and treating chronic and infectious diseases, with reference to evidence-based exercise thresholds that the medical community can embrace and promote.

Association of Estimated Cardiorespiratory Fitness in Midlife With Cardiometabolic Outcomes and Mortality

IMPORTANCE

The associations of estimated cardiorespiratory fitness (eCRF) during midlife with subclinical atherosclerosis, arterial stiffness, incident cardiometabolic disease, and mortality are not well understood.

OBJECTIVE

To examine associations of midlife eCRF with subclinical atherosclerosis, arterial stiffness, incident cardiometabolic disease, and mortality.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 2962 participants in the Framingham Study Second Generation (conducted between 1979 and 2001). Data were analyzed from January 2020 to June 2020.

EXPOSURES

eCRF was calculated using sex-specific algorithms (including age, body mass index, waist circumference, physical activity, resting heart rate, and smoking) and was categorized as: (1) tertiles of standardized eCRF at examination cycle 7 (1998 to 2001); (2) tertiles of standardized average eCRF between examination cycles 2 and 7 (1979 to 2001); and (3) eCRF trajectories between examination cycles 2 and 7, with the lowest tertile or trajectory (ie, low eCRF) as referent group.

MAIN OUTCOMES AND MEASURES

Subclinical atherosclerosis (carotid intima-media thickness [CIMT], coronary artery calcium [CAC] score); arterial stiffness (carotid-femoral pulse wave velocity [-1000/CFPWV]); incident hypertension, diabetes, chronic kidney disease (CKD), cardiovascular disease (CVD), and mortality after examination cycle 7.

RESULTS

A total of 2962 participants were included in this cohort study (mean [SD] age, 61.5 [9.2] years; 1562 [52.7%] women). The number of events or participants at risk after examination cycle 7 (at a mean follow-up of 15 years) was 728 of 1506 for hypertension, 214 of 2268 for diabetes, 439 of 2343 for CKD, 500 of 2608 for CVD, and 770 of 2962 for mortality. Compared with the low eCRF reference value, high single examination eCRF was associated with lower CFPWV (β [SE], -11.13 [1.33] ms/m) and CIMT (β [SE], -0.12 [0.05] mm), and lower risk of hypertension (hazard ratio [HR], 0.63; 95% CI, 0.46-0.85), diabetes (HR, 0.38; 95% CI, 0.23-0.62), and CVD (HR, 0.71; 95% CI, 0.53-0.95), although it was not associated with CKD or mortality. Similarly, compared with the low eCRF reference, high eCRF trajectories and mean eCRF were associated with lower CFPWV (β [SE], -11.85 [1.89] ms/m and -10.36 [1.54] ms/m), CIMT (β [SE], -0.19 [0.06] mm and -0.15 [0.05] mm), CAC scores (β [SE], -0.67 [0.25] AU and -0.63 [0.20] AU), and lower risk of hypertension (HR, 0.54; 95% CI, 0.34-0.87 and HR, 0.48; 95% CI, 0.34-0.68), diabetes (HR, 0.27; 95% CI, 0.15-0.48 and HR, 0.31; 95% CI, 0.18-0.54), CKD (HR, 0.63; 95% CI, 0.40-0.97 and HR, 0.64; 95% CI, 0.44-0.94), and CVD (HR, 0.46; 95% CI, 0.31-0.68 and HR, 0.43; 95% CI, 0.30-0.60). Compared with the reference value, a high eCRF trajectory was associated with lower risk of mortality (HR, 0.69; 95% CI, 0.50-0.95).

CONCLUSIONS AND RELEVANCE

In this cohort study, higher midlife eCRF was associated with lower burdens of subclinical atherosclerosis and vascular stiffness, and with a lower risk of hypertension, diabetes, chronic kidney disease, cardiovascular disease, and mortality. These findings suggest that midlife eCRF may serve as a prognostic marker for subclinical atherosclerosis, arterial stiffness, cardiometabolic health, and mortality in later life.

Sports activity patterns and cardio-metabolic health over time among adults in Germany: Results of a nationwide 12-year follow-up study

BACKGROUND

Physical activity is favorable for health, and vigorous sports activity is particularly beneficial. This study investigates the association between changes in sports participation patterns over time and cardio-metabolic and self-perceived health outcomes.

METHODS

Data from 3752 adults (18-79 years of age) who participated in 2 national health interview and examination surveys in 1997-1999 and 2008-2011 were included, with a mean follow-up time of about 12 years. A change in self-reported sports activity was analyzed with respect to the incidence of type 2 diabetes, coronary heart disease (CHD), hypertension, obesity, dyslipidemia, metabolic syndrome, and poor self-perceived health. Participants with pre-existing disease or risk factor of interest at baseline were excluded from the analysis. Being sufficiently active in sports was specified as doing sports for at least 1-2 h per week, and 4 activity categories were defined: 1) inactive at both time points (inactive-inactive), 2) inactive at baseline and active at follow-up (inactive-active), 3) active at baseline and inactive at follow-up (active-inactive), and 4) active at both time points (active-active). Associations between sports activity engagement and health outcomes were estimated by logistic regression models with different stages of adjustments.

RESULTS

Not engaging in any regular sports activity at both time points (inactive-inactive) was associated with higher rates of type 2 diabetes (odds ratio (OR) = 1.82, 95% confidence interval (95%CI): 1.08-3.08), CHD (OR = 1.82, 95%CI: 1.16-2.84), hypertension (OR = 1.36, 95%CI: 1.03-1.81), metabolic syndrome (OR = 1.58, 95%CI: 1.08-2.32), and poor self-perceived health (OR = 2.54, 95%CI: 1.83-3.53) compared to doing regular sports for a minimum of 1-2 h per week over time (active-active). In case of change from inactivity to any regular sports activity (inactive-active), the rate of risk factor occurrence was not statistically different from the active-active reference group except for poor self-perceived health, but it was higher for type 2 diabetes (OR = 2.15, 95%CI: 1.12-4.14) and CHD (OR = 1.77, 95%CI: 1.03-3.03). Being active at baseline but inactive at follow-up (active-inactive) was not associated with higher disease incidence of type 2 diabetes (OR = 0.70, 95%CI: 0.25-1.97) or CHD (OR = 1.20, 95%CI: 0.49-2.99), but was associated with higher rates of hypertension (OR = 1.61, 95%CI: 1.11-2.34), obesity (OR = 2.34, 95%CI: 1.53-3.57), metabolic syndrome (OR = 1.70, 95%CI: 1.11-2.63), and poor self-perceived health (OR = 2.16, 95%CI: 1.53-3.07) at follow-up.

CONCLUSION

Even a low weekly quantity (1-2 h) of regular sports activity is partly associated with health benefits. Being formerly but not currently active was not associated with an increased disease incidence, but was associated with a higher risk-factor development compared to the reference group (active-active). Becoming active was preventive for risk-factor development but was not preventive for disease incidence, which probably means that the health benefits from sports activity are not sustainable and disease incidence is only shifted to a later period in life. For this reason, the promotion of and commitment to regular sports activity should be addressed as early as possible over the lifespan to achieve the best health benefits.

Rationale for the use of metformin and exercise to counteract statin-associated side effects

INTRODUCTION

Statins are the most widely prescribed drugs for lowering low-density lipoprotein cholesterol (LDL-C) and reducing cardiovascular morbidity and mortality. They are usually well-tolerated, but have two main safety concerns: statin-associated muscle symptoms (SAMS) and new-onset type 2 diabetes (NOD).

METHODS

A PubMed search was carried out using the following key words were used: statins, statin-associated muscle symptoms, statin myalgia, statin-associated diabetes, metformin and statins, exercise and statins.

RESULTS

Mitochondrial damage and muscle atrophy are likely the central mechanisms producing SAMS, whereas decreased glucose transport, fatty acid oxidation and insulin secretion are likely involved in the development of NOD. Metformin and exercise training share many pathways that could potentially contrast SAMS and NOD. Clinical evidence also supports the combination of statins with metformin and exercise.

CONCLUSION

This combination appears attractive both from a clinical and an economical viewpoint, since all three therapies are highly cost-effective and their combination could result in diabetes and cardiovascular disease prevention.

The impact of moving more, physical activity, and cardiorespiratory fitness: Why we should strive to measure and improve fitness

A large and growing body of epidemiologic research spanning roughly 7 decades has demonstrated that individuals who are more physically active have a lower incidence of cardiovascular disease (CVD) and all-cause mortality compared to those who are comparatively sedentary. Despite these well-established benefits of physical activity (PA), most adults and children do not get an adequate amount of PA. This is true not just in the United States but has been increasingly recognized throughout advanced countries. The theme of this Progress in Cardiovascular Diseases Symposium is "moving more", recognizing that any amount of increased physical movement, including occupational, recreational, household tasks, etc., has significant health benefits. Being physically active is associated with better health outcomes independent of cardiorespiratory fitness (CRF), a concept that would have been considered heretical a few decades ago. We now recognize that simply moving from a sedentary to a moderately active group or modest increases in CRF (e.g. moving from the least fit quintile of CRF to the next least fit quintile) has the most noticeable health benefits. In this review, the concept of "moving more" and its implications for CRF are discussed as they relate to the prevention and treatment of CVD.

Impact of cardiorespiratory fitness on survival in men with low socioeconomic status

AIMS

Although both low socioeconomic status (SES) and poor cardiorespiratory fitness (CRF) are associated with increased chronic disease and heightened mortality, it remains unclear whether moderate-to-high levels of CRF are associated with survival benefits in low SES populations. This study evaluated the hypothesis that SES and CRF predict all-cause mortality and cardiovascular disease mortality and that moderate-to-high levels of CRF may attenuate the association between low SES and increased mortality.

METHODS

This study included 2368 men, who were followed in the Kuopio Ischaemic Heart Disease Study cohort. CRF was directly measured by peak oxygen uptake during progressive exercise testing. SES was characterized using self-reported questionnaires.

RESULTS

During a 25-year median follow-up, 1116 all-cause mortality and 512 cardiovascular disease mortality events occurred. After adjusting for potential confounders, men with low SES were at increased risks for all-cause mortality (hazard ratio 1.49, 95% confidence interval: 1.30-1.71) and cardiovascular disease mortality (hazard ratio1.38, 1.13-1.69). Higher levels of CRF were associated with lower risks of all-cause mortality (hazard ratio 0.54, 0.45-0.64) and cardiovascular disease mortality (hazard ratio 0.53, 0.40-0.69). In joint associations of SES and CRF with mortality, low SES-unfit had significantly higher risks of all-cause mortality (hazard ratio 2.15, 1.78-2.59) and cardiovascular disease mortality (hazard ratio 1.95, 1.48-2.57), but low SES-fit was not associated with a heightened risk of cardiovascular disease mortality (hazard ratio 1.09, 0.80-1.48) as compared with their high SES-fit counterparts.

CONCLUSION

Both SES and CRF were independently associated with subsequent mortality; however, moderate-to-high levels of CRF were not associated with an excess risk of cardiovascular disease mortality in men with low SES.

Obesity, risk of diabetes and role of physical activity, exercise training and cardiorespiratory fitness

The epidemic of obesity contributes to the burden of type 2 diabetes mellitus (T2DM) in the United States and worldwide. Importantly, obesity is not only preventable but can be treated, particularly with lifestyle modifications to forestall T2DM in those with excess adiposity. The mechanisms linking obesity to T2DM are numerous and involve adipose tissue remodeling as a result of unhealthy behaviors, including unhealthy diet, reduced physical activity (PA) and exercise training (ET), and increased sedentary behaviors. Taken together, these factors markedly reduce cardiorespiratory fitness (CRF), one of the strongest predictors for cardiovascular outcomes and all-cause mortality in the general population, but also in those with T2DM. In this review we describe the mechanisms leading to adipose tissue remodeling resulting in obesity, as well as the mechanisms linking excess adiposity to insulin resistance and, in turn, T2DM. We then present the therapeutic strategies that can be implemented in obesity to prevent T2DM, with a brief discussion on weight loss, and greater emphasis on PA and ET. We finally present the evidence to support the beneficial effects of such strategies in patients with established T2DM and discuss the importance of achieving improvements in CRF in this population to potentially improve clinical outcomes.

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).

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.

Association between physical activity and abnormal glucose metabolism-A population-based cross-sectional study in China

BACKGROUND

Association between physical activity and abnormal glucose metabolism (AGM) remains unclear.

METHODS

Data were collected from a random sample of the Chinese population aged 26-77 years. Participants were classified into an AGM group or a normal glucose tolerance (NGT) group. Total physical activity energy expenditure (PAEE), sedentary time, and ratios of PAEE in different domains to the total PAEE were calculated according to the International Physical Activity Questionnaire. Logistic regression was used to analyze the associations between total PAEE, ratios of PAEE under different domains to total PAEE, sedentary time, and AGM.

RESULTS

Data from 3510 participants aged 50 ± 12 years were analyzed; 1390 (39.6%) were diagnosed with AGM. In the multivariate logistic regression analysis, total PAEE (1000 MET-min/week) was significantly associated with AGM [OR (95% CI) 0.96 (0.94, 0.99)]. After stratification by sex and BMI, total PAEE was negatively associated with AGM in men and overweight people. The ratios of PAEE in different domains to total PAEE or sedentary time were not associated with AGM.

CONCLUSIONS

Total PAEE was negatively associated with AGM. Ratios of PAEE in different domains to total PAEE and sedentary time were not associated with AGM in this Chinese population.

Cardiorespiratory Fitness and Health Outcomes: A Call to Standardize Fitness Categories

An inverse association between physical activity or fitness status and health outcomes has been reported by several cohort studies. When fitness categories are established in quartiles or quintiles based on the peak exercise capacity achieved, the association is graded. Although significant health benefits of increased cardiorespiratory fitness (CRF) have been uniformly reported, the degree of protection has varied substantially between studies. This variability is likely due to varying methods used to define CRF categories, and not considering age, despite its strong effect on CRF. To ameliorate these methodological discrepancies, we propose standardized guidelines by which age-specific CRF categories should be defined.