Combined effect of cardiorespiratory fitness and adiposity on mortality in patients with coronary artery disease

The independent and joint associations of cardiorespiratory fitness and adiposity with cardiometabolic risk factors and metabolic syndrome in United States college students

Objective To examine the association of CRF and adiposity with cardiometabolic risk factors and metabolic syndrome among emerging adults. Participants: 5681 (60.1% Men; 21 ± 1years) college students from a large university located in the northeast of the United States. Methods: Participants completed an objective health assessment that involved the assessment cardiometabolic risk factors, CRF, and adiposity. Data of 5681 students' (60.1% Men; 21 ± 1years) who had CRF, adiposity, all risk factors necessary to determine metabolic syndrome evaluated were analyzed using logistic regression analyses. Results: Poor CRF and elevated adiposity were associated with cardiometabolic risk factors and metabolic syndrome regardless of sex, with the association between adiposity and risk factors found to be stronger compared to CRF. Conclusions: Targeted and tailored screening and interventions are urgently needed to reduce adiposity and increase CRF to avoid serious short and long-term negative health outcomes in this population.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

An Examination of the Practice Approaches of Canadian Dietitians Who Counsel Higher-Weight Adults Using a Novel Framework: Emerging Data on Non-Weight-Focused Approaches

Non-weight-focused approaches (NWFAs) may be used by some clinicians when working with higher-weight clients. In contrast to weight-focused approaches (WFAs), NWFAs de-emphasize or negate weight loss and emphasize overall diet quality and physical activity. The extent to which WFAs, NWFAs, or a combination of both WFAs and NWFAs are used by dietitians is unknown in Canada and globally. This study surveyed Canadian Registered Dietitians (RDs) who counsel higher-weight clients to assess which practice approaches are most commonly used, how they view the importance of weight, and how they define "obesity" for the study population. Five practice approaches were initially defined and used to inform the survey: solely weight-focused; moderately weight-focused; those who fluctuate between weight-focused/weight-inclusive approaches (e.g., used both approaches); weight inclusive and; weight liberated. Participants (n = 383; 94.8% women; 82.2% white) were recruited using social media and professional listservs. Overall, 45.4% of participants used NWFAs, 40.5% fluctuated between weight-focused/moderately weight-focused, and 14.1% used weight-focused approaches (solely weight focused and moderately weight focused). Many participants (63%) agreed that weight loss was not important for higher-weight clients. However, 81% of participants received no formal preparation in NWFAs during their education or training. More research is needed to understand NWFAs and to inform dietetic education in support of efforts to eliminate weight stigma and provide inclusive access to care.

Body weight and physical fitness in women with ischaemic heart disease: does physical fitness contribute to our understanding of the obesity paradox in women?

AIMS

Body mass index (BMI) defined obesity is paradoxically associated with lower all-cause mortality in patients with known cardiovascular disease. This study aims to determine the role of physical fitness in the obesity paradox in women with ischaemic heart disease (IHD).

METHODS AND RESULTS

Women undergoing invasive coronary angiography with signs/symptoms of IHD in the Women's Ischemia Syndrome Evaluation (WISE) prospective cohort (enrolled 1997-2001) were analysed. This study investigated the longer-term risk of major adverse cardiovascular events (MACE) and all-cause mortality associated with BMI and physical fitness measured by Duke Activity Status Index (DASI). Overweight was defined as BMl ≥25 to 30 kg/m2, obese as BMI ≥30 kg/m2, unfit as DASI scores <25, equivalent to ≤7 metabolic equivalents. Among 899 women, 18.6% were normal BMI-fit, 11.4% overweight-fit, 10.4% obese-fit, 15.3% normal BMI-unfit, 23.8% overweight-unfit, and 30.4% obese-unfit. In adjusted models compared to normal BMI-fit, normal BMI-unfit women had higher MACE risk [hazard ratio (HR) 1.65, 95% confidence interval (CI) 1.17-2.32; P = 0.004]; whereas obese-fit and overweight-fit women had lower risk of mortality (HR 0.60, 95% CI 0.40-0.89; P = 0.012 and HR 0.62, 95% CI 0.41-0.92; P = 0.018, respectively).

CONCLUSION

To address the paradox of body weight and outcomes in women, we report for the first time that among women with signs/symptoms of IHD overweight-fit and obese-fit were at lower risk of long-term all-cause mortality; whereas normal BMI-unfit were at higher risk of MACE. Physical fitness may contribute to the obesity paradox in women, warranting future studies to better understand associations between body weight, body composition, and physical fitness to improve cardiovascular outcomes in women.

The Obesity Paradox in Chronic Heart Disease and Chronic Obstructive Pulmonary Disease

Obesity in recent years has become an epidemic. A high body mass index (BMI) is one of today's most crucial population health indicators. BMI does not directly quantify body fat but correlates well with easier body fat measurements. Like smoking, obesity impacts multiple organ systems and is a major modifiable risk factor for countless diseases. Despite this, reports have emerged that obesity positively impacts the prognosis of patients with chronic illnesses such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD), a phenomenon known as the Obesity Paradox. This article attempts to explain and summarize this phenomenon.

As it stands, two theories explain this paradox. The muscle mass hypothesis states that obese patients are better adapted to tide through acute exacerbations due to increased reserve because of greater muscle mass. The other theory focuses on brown adipose tissue and its anti-inflammatory effects on the body.

We performed a literature review on research articles published in English from 1983 to the present in the following databases - PubMed, Elsevier, and Google Scholar. The following search strings and Medical Subject Headings (MeSH) terms were used: "Obesity," "Heart Failure," "COPD," and "Cardio-Respiratory Fitness." In this review, we looked at the obesity paradox in Heart Failure and COPD. We summarized the current literature on the Obesity Paradox and reviewed its relationship with Cardio-Respiratory Fitness.

Synergistic Assessment of Mortality Risk According to Body Mass Index and Exercise Ability and Capacity in Patients Referred for Radionuclide Stress Testing

OBJECTIVE

To determine the interrelationship between body mass index (BMI), mode of stress testing (exercise or pharmacological), exercise capacity, and all-cause mortality in patients referred for stress-rest single photon emission computed tomography myocardial perfusion imaging.

PATIENTS AND METHODS

We evaluated all-cause mortality in 21,638 patients undergoing stress-rest single photon emission computed tomography myocardial perfusion imaging between January 2, 1991, and December 31, 2012. Patients were divided into exercise and pharmacologically tested groups and 9 BMI categories. The median follow-up was 12.8 years (range, 5.0-26.8 years).

RESULTS

In exercise patients, mortality was increased with both low and high BMI vs patients with a normal referent BMI of 22.5 to 24.9 kg/m². In pharmacologically tested patients, only low BMI, but not high BMI, was associated with increased mortality vs normal BMI. When exercise and pharmacologically tested groups were compared directly, pharmacologically tested patients manifested a marked increase in mortality risk vs exercise patients within each BMI category, ranging from an approximately 4-fold increase in mortality in those with normal or high BMI to a 12.3-fold increase in those with low BMI values. Similar findings were observed in a cohort of 4804 exercise and 4804 pharmacologically tested patients matched to have similar age and coronary artery disease risk factor profiles. In exercise patients, further risk stratification was achieved when considering both BMI and metabolic equivalent tasks of achieved exercise.

CONCLUSION

The combined assessment of BMI and exercise ability and capacity provides synergistic and marked risk stratification of future mortality risk in patients referred for radionuclide stress testing, providing considerable insights into the "obesity paradox" that is observed in populations referred for stress testing.

Cardiorespiratory fitness measured with cardiopulmonary exercise testing and mortality in patients with cardiovascular disease: A systematic review and meta-analysis

BACKGROUND

Cardiorespiratory fitness (CRF) is inversely associated with mortality in apparently healthy subjects and in some clinical populations, but evidence for the association between CRF and all-cause and/or cardiovascular disease (CVD) mortality in patients with established CVD is lacking. This study aimed to quantify this association.

METHODS

We searched for prospective cohort studies that measured CRF with cardiopulmonary exercise testing in patients with CVD and that examined all-cause and CVD mortality with at least 6 months of follow-up. Pooled hazard ratios (HRs) were calculated using random-effect inverse-variance analyses.

RESULTS

Data were obtained from 21 studies and included 159,352 patients diagnosed with CVD (38.1% female). Pooled HRs for all-cause and CVD mortality comparing the highest vs. lowest category of CRF were 0.42 (95% confidence interval (95%CI): 0.28-0.61) and 0.27 (95%CI: 0.16-0.48), respectively. Pooled HRs per 1 metabolic equivalent (1-MET) increment were significant for all-cause mortality (HR = 0.81; 95%CI: 0.74-0.88) but not for CVD mortality (HR = 0.75; 95%CI: 0.48-1.18). Coronary artery disease patients with high CRF had a lower risk of all-cause mortality (HR = 0.32; 95%CI: 0.26-0.41) than did their unfit counterparts. Each 1-MET increase was associated with lower all-cause mortality risk among coronary artery disease patients (HR = 0.83; 95%CI: 0.76-0.91) but not lower among those with heart failure (HR = 0.69; 95%CI: 0.36-1.32).

CONCLUSION

A better CRF was associated with lower risk of all-cause mortality and CVD. This study supports the use of CRF as a powerful predictor of mortality in this population.

Obesity paradox and heart failure

BACKGROUND

There is scientific consensus that obesity increases the risk of cardiovascular diseases (CVD), including heart failure (HF). However, in CVD, many studies observed greater survival in overweight or class 1 obesity individuals. This counterintuitive observation was termed "obesity paradox" (OP).

OBJECTIVE AND METHODS

This article is a narrative overview of the relationship between OP and CVD, particularly HF. The sources used were MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from 2001 to 31 May 2020, exception for a 1983 work of historical importance. Studies reporting association and prognostic impact of obesity in HF and the impact of body composition on cardiac structure and myocardial function in obesity were also included in this review. In addition, we examined references from the retrieved articles and explored several related websites. Ultimately, we chose 79 relevant documents. Fifty-three were specifically focused on OP and HF.

RESULTS

In this review, we made a summary of the evidence coming from a series of studies investigating OP. Many of these studies do not take into consideration or underestimate some of the more important morpho-functional variables of patients suffering from HF: among these, body composition and visceral adiposity, sarcopenic obesity, muscle fitness (MF), and cardiorespiratory fitness (CRF). A high body mass index (BMI) represents a risk factor for HF, but it also seems to exert a protective effect under certain circumstances. Fat distribution, lean mass, and cardio fitness could play an essential role in determining the observed differences in the HF population.

CONCLUSION

BMI does not distinguish between the metabolically healthy and metabolically unhealthy obesity. The obesity impact on morbidity and premature mortality can be underestimated and, therefore, may lead to incorrect clinical courses.

LEVEL OF EVIDENCE

Level V, Narrative review.

Fitness, Fatness, and Mortality in Men and Women From the UK Biobank: Prospective Cohort Study

Background Cardiorespiratory fitness may moderate the association between obesity and all-cause mortality (ie, the "fat-but-fit" hypothesis), but unaddressed sources of bias are a concern. Methods and Results Cardiorespiratory fitness was estimated as watts per kilogram from a submaximal bicycle test in 77 169 men and women from the UK Biobank cohort and combined with World Health Organization standard body mass index categories, yielding 9 unique fitness-fatness combinations. We also formed fitness-fatness combinations based on bioimpedance as a direct measure of body composition. All-cause mortality was ascertained from death registries. Multivariable-adjusted Cox regression models were used to estimate hazard ratios and 95% CIs. We examined the association between fitness-fatness combinations and all-cause mortality in models with progressively more conservative approaches for accounting for reverse causation, misclassification of body composition, and confounding. Over a median follow-up of 7.7 years, 1731 participants died. In our base model, unfit men and women had higher risk of premature mortality irrespective of levels of adiposity, compared with the normal weight-fit reference. This pattern was attenuated but maintained with more conservative approaches in men, but not in women. In analysis stratified by sex and excluding individuals with prevalent major chronic disease and short follow-up and using direct measures of body composition, mortality risk was 1.78 (95% CI, 1.17-2.71) times higher in unfit-obese men but not higher in obese-fit men (0.94 [95% CI, 0.60-1.48]). In contrast, there was no increased risk in obese-unfit women (1.09 [95% CI, 0.44-1.05]) as compared with the reference. Conclusions Cardiorespiratory fitness modified the association between obesity and mortality in men, but this pattern appeared susceptible to biases in women.

Association of obesity with cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease: Insights from TECOS

BACKGROUND

Obesity is a risk factor for type 2 diabetes (T2D) and cardiovascular disease (CVD). Whether obesity affects outcomes among those with T2D and atherosclerotic CVD (ASCVD) remains uncertain. Our objective was to investigate the relationship between body mass index (BMI) and ASCVD outcomes among TECOS participants with T2D and ASCVD.

METHODS

BMI categories were defined as underweight/normal weight (BMI <25 kg/m²), overweight (25-29.9 kg/m²), obese class I (30-34.9 kg/m²), obese class II (35-39.9 kg/m²), and obese class III (≥ 40 kg/m²). Asian-specific BMI categories were applied to Asian participants. Kaplan-Meier survival analysis and Cox proportional hazards models were used to examine associations between baseline BMI and a composite CV outcome (CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina).

RESULTS

For 14,534 TECOS patients with available BMI, mean age was 65.5 years; 29.3% were female, 32.0% non-White, and 23.1% insulin-treated, with median 3 years' follow-up. At baseline, 11.6% (n = 1686) were underweight/normal weight, 38.1% (n = 5532) overweight, 32.2% (n = 4683) obese class I, 12.4% (n = 1806) obese class II, and 5.7% (n = 827) obese class III. The composite CV outcome occurred in 11.4% (n = 1663) of participants; the outcome risk was lower, compared with under/normal weight, in overweight (HR 0.83, 95% CI 0.71-0.98) and obese class I (HR 0.79, 95% CI 0.67-0.93) individuals. Obesity was not associated with worse glycemic control.

CONCLUSIONS

The majority of TECOS participants with ASCVD and T2D were overweight or obese, yet overweight or obese class I individuals had lower CV risk than those who were under/normal weight. These results suggest the presence of an obesity paradox, but this paradox may reflect an epidemiological artifact rather than a true negative association between normal weight and clinical outcomes.

A sex-specific evaluation of predicted lean and fat mass composition and cardiovascular disease onset and progression: A combined analysis of the ATTICA and GREECS prospective epidemiological studies

OBJECTIVES

To evaluate the association of predicted lean and fat mass on 10-year first and recurrent CVD incidence separately for men and women.

METHODS

Two prospective studies, ATTICA (2002-2012, n=3042 subjects free-of-CVD, n=1514 men (46±13 years) and n=1528 women (45±14 years)) and GREECS (2004-2014, n=2172 subjects with acute coronary syndrome (ACS), n=1649 men (65±13 years) and n=523 women (62±11 years)) were used. Lean mass index (LMI) and fat mass index (FMI) were created through total body lean and fat mass (indirectly calculated through population formulas based on body weight, height and waist circumference) divided by height squared. Follow-up was performed in n=2020 of ATTICA (n=317 first CVD events) and in n=2172 patients of GREECS (n=811 recurrent CVD events).

RESULTS

In ATTICA study, CVD rate from 1st to 3rd FMI tertile was 9.4%, 16.1% and 19.9% while in GREECS 36.2%, 37.0%, 38.3%. The LMI-related rates were 17.1%, 15.0% and 11.9% vs. 38.8%, 35.8% and 36.7%. Multiadjusted analysis revealed U-shape trend between LMI and CVD recurrence with 2nd LMI tertile having the best prognosis; this observation was more evident in women. In apparently healthy subjects, LMI-cardioprotective association was revealed only in 3rd tertile (HR=0.91 95%CI (0.74, 0.95)); this was more evident in men. The FMI aggravating association (3rd tertile) was retained significant only in healthy women and ACS men.

CONCLUSION

This work expands previous findings regarding body composition and cardiac health, implying that the association of lean and fat mass on long-term CVD incidence varies according to sex and prevention stage.

Subclinical carotid atherosclerosis predicts all-cause mortality and cardiovascular events in obese patients with negative exercise echocardiography

BACKGROUND

Obesity is a major health problem due to its high prevalence. The relationship between obesity and cardiovascular disease is unclear. Some studies agree that certain conditions associated with obesity, such as physical inactivity or cardiovascular risk factors, are responsible for cardiovascular risk excess among obese people. Carotid intima-media thickness and carotid plaques (CP) have been associated with cardiovascular adverse events in healthy populations, and recent data suggest a higher prevalence of subclinical carotid atherosclerosis in obese and metabolically unhealthy patients. However, there are no studies correlating subclinical atherosclerosis and adverse events (AE) in obese subjects.

AIM

To determine the association between carotid disease and AE in obese patients with negative exercise echocardiography (EE).

METHODS

From January 1, 2006 to December 31, 2010, 2000 consecutive patients with a suspicion of coronary artery disease were submitted for EE and carotid ultrasonography. Exclusion criteria included previous vascular disease, left ventricular ejection fraction < 50%, positive EE, significant valvular heart disease and inferior to submaximal EE. An AE was defined as all-cause mortality, myocardial infarction and cerebrovascular accident. Subclinical atherosclerosis was defined as CP presence according to Manheim and the American Society of Echocardiography Consensus.

RESULTS

Of the 652 patients who fulfilled the inclusion criteria, 226 (34.7%) had body mass indexes ≥ 30 kg/m2, and 76 of them (33.6%) had CP. During a mean follow-up time of 8.2 (2.1) years, 27 AE were found (11.9%). Mean event-free survival at 1, 5 and 10 years was 99.1% (0.6), 95.1% (1.4) and 86.5% (2.7), respectively. In univariate analysis, CP predicted AE [hazard ratio (HR) 2.52, 95% confidence interval (CI) 1.17-5.46; P = 0.019]. In multivariable analysis, the presence of CP remained a predictor of AE (HR 2.26, 95%CI 1.04-4.95, P = 0.041). Other predictors identified were glomerular filtration rate (HR 0.98, 95%CI 0.96-0.99; P = 0.023), peak metabolic equivalents (HR 0.83, 95%CI 0.70-0.99, P = 0.034) and moderate mitral regurgitation (HR 5.02, 95%CI 1.42-17.75, P = 0.012).

CONCLUSION

Subclinical atherosclerosis defined by CP predicts AE in obese patients with negative EE. These patients could benefit from aggressive prevention measures.

Exercise training for patients with type 2 diabetes and cardiovascular disease: What to pursue and how to do it. A Position Paper of the European Association of Preventive Cardiology (EAPC)

Patients with type 2 diabetes mellitus suffer from dysregulation of a plethora of cardiovascular and metabolic functions, including dysglycaemia, dyslipidaemia, arterial hypertension, obesity and a reduced cardiorespiratory fitness. Exercise training has the potential to improve many of these functions, such as insulin sensitivity, lipid profile, vascular reactivity and cardiorespiratory fitness, particularly in type 2 diabetes mellitus patients with cardiovascular comorbidities, such as patients that suffered from an acute myocardial infarction, or after a coronary intervention such as percutaneous coronary intervention or coronary artery bypass grafting. The present position paper aims to provide recommendations for prescription of exercise training in patients with both type 2 diabetes mellitus and cardiovascular disease. The first part discusses the relevance and practical applicability of treatment targets that may be pursued, and failure to respond to these targets. The second part provides recommendations on the contents and methods to prescribe exercise training tailored to these treatment targets as well as to an optimal preparation and dealing with barriers and risks specific to type 2 diabetes mellitus and cardiac comorbidity.

Lifetime predictors of stroke in subjects without a diagnosis of hypertension: the aerobics center longitudinal study

BACKGROUND AND PURPOSE

Although several studies have assessed the importance of traditional risk factors in predicting stroke, none have concurrently addressed the stroke-predicting ability of these risk factors across the lifespan of subjects without a hypertension (HTN) diagnosis. Thus, this study aimed to assess the importance of blood-pressure-related risk indicators, cardiorespiratory fitness (CRF), weight status, diabetes mellitus (DM), and lifestyle factors as predictors of stroke in different stages of life among non-hypertensive subjects.

MATERIALS AND METHODS

This study was a long-term follow-up study including 33,254 men and 10,598 women from the Aerobics Center Longitudinal Study (ACLS) who were 18-100 years old and did not have a HTN diagnosis at baseline. Logistic regression models were constructed using forward selection procedures for each age category, with stroke occurrence as the dependent variable, and pulse pressure (PP), mean arterial pressure (MAP), systolic blood pressure (SBP), smoking status, CRF, drinking behavior, DM status, and weight status as potential predictors.

RESULTS

In total, 507 subjects had a stroke during an average follow-up period of 17 years (range=1-34 years). Logistic regression models showed that MAP values (P=0.043) in those aged 19-39 years; SBP (P<0.001), CRF (P=0.001), weight status (P=0.005), and alcohol consumption (P=0.001) in those 40-60 years old; and CRF (P=0.002), weight status (P=0.005), and DM status (P=0.037) in those over 60 years old were predictors of stroke.

CONCLUSION

These findings suggest that, among individuals without a baseline HTN diagnosis, classic modifiable risk factors for stroke change across different stages of life.

Association of body mass index with mortality in cardiovascular disease: New insights into the obesity paradox from multiple perspectives

Over the past 4 decades, prevalence of obesity has increased rapidly at both the national and global level and presents a major public health challenge. Obesity is associated with increased risk of morbidity from cardiovascular diseases. Data suggesting that the presence of obesity may be protective in individuals with clinically manifest cardiovascular disease have led to discussion of an "obesity paradox", stirring controversy and leading to unclear messaging regarding the true health risks of excess weight. This review explores the relationship between obesity and fatal and non-fatal outcomes in patients with prevalent cardiovascular disease and offers novel insights into the obesity paradox.

Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project

OBJECTIVES

To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies.

PATIENTS AND METHODS

This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models.

RESULTS

During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively).

CONCLUSION

Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies.

Is Cardiorespiratory Fitness Related to Cardiometabolic Health and All-Cause Mortality Risk in Patients with Coronary Heart Disease? A CARE CR Study

Background

Higher cardiorespiratory fitness (CRF) is associated with lower morbidity and mortality in patients with coronary heart disease (CHD). The mechanisms for this are not fully understood. A more favourable cardiometabolic risk factor profile may be responsible; however, few studies have comprehensively evaluated cardiometabolic risk factors in relation to CRF amongst patients with CHD. We aimed to explore differences in cardiometabolic risk and 5-year all-cause mortality risk in patients with CHD who have low, moderate, and high levels of CRF.

Methods

Patients with CHD underwent maximal cardiopulmonary exercise testing, echocardiogram, carotid intima-media thickness measurement, spirometry, and dual X-ray absorptiometry assessment. Full blood count, biochemical lipid profiles, high-sensitivity (hs) C-reactive protein, and NT-proBNP were analysed. Patients were defined as having low, moderate, or high CRF based on established prognostic thresholds.

Results

Seventy patients with CHD (age 63.1 ± 10.0 years, 86% male) were recruited. Patients with low CRF had a lower ventilatory anaerobic threshold, peak oxygen pulse, post-exercise heart rate recovery, and poor ventilatory efficiency. The low CRF group also had higher NT pro-BNP, hs-CRP, non-fasting glucose concentrations, and lower haemoglobin and haematocrit. Five-year mortality risk (CALIBER risk score) was also greatest in the lowest CRF group (14.9%).

Conclusions

Practitioners should interpret low CRF as an important clinical risk factor associated with adverse cardiometabolic health and poor prognosis, study registry; www.researchregistry.com.

Thrombosis in central obesity and metabolic syndrome: Mechanisms and epidemiology

Central obesity is a key feature of the metabolic syndrome (metS), a multiplex risk factor for subsequent development of type 2 diabetes and cardiovascular disease. Many metabolic alterations closely related to this condition exert effects on platelets and vascular cells. A procoagulant and hypofibrinolytic state has been identified, mainly underlain by inflammation, oxidative stress, dyslipidaemia, and ectopic fat that accompany central obesity. In support of these data, central obesity independently predisposes not only to atherothrombosis but also to venous thrombosis.

Interaction of Physical Activity and Body Mass Index on Mortality in Coronary Heart Disease: Data from the Nord-Trøndelag Health Study

OBJECTIVE

The role of physical activity in the relationship between body mass index (BMI) and survival in coronary heart disease is unclear. Our aim was to examine the isolated and combined associations among BMI, physical activity, and mortality in subjects with coronary heart disease.

METHODS

A total of 6493 participants (34.4% were women) with coronary heart disease from the Nord-Trøndelag Health Study, with examinations in 1986, 1996, and 2007, were followed to the end of 2014. We calculated hazard ratios (HRs) for all-cause and cardiovascular disease mortality, estimated using Cox proportionate hazard regression adjusted for age, smoking, diabetes, hypertension, self-reported health status, and alcohol.

RESULTS

A total of 3818 patients died (62.1% of cardiovascular disease) during 30 (median 12.5) years of follow-up. Compared with a BMI of 18.5 to 22.4 kg/m², BMI categories of 25.0 to 27.4 kg/m², 27.5 to 29.9 kg/m², and 30.0 to 34.9 kg/m² had reduced all-cause mortality risk: HR, 0.80; 95% confidence interval (CI), 0.72-0.90; HR, 0.80; 95% CI, 0.71-0.90; HR, 0.83; 95% CI, 0.74-0.95, respectively. The BMI categories 25.0 to 27.4 kg/m² and 27.5 to 29.9 kg/m² had reduced cardiovascular disease mortality risk: HR, 0.81; 95% CI, 0.70-0.94; HR, 0.83; 95% CI, 0.71-0.96, respectively. Compared with physically inactive, all levels of physical activity were associated with reduced all-cause and cardiovascular disease mortality risk. In physically inactive, all BMI categories >25.0 kg/m² had reduced all-cause mortality risk (HRs across BMI categories: 0.77, 0.79, 0.79, 0.74), whereas in subjects who were following or exceeding the recommended level of physical activity, BMI was not associated with survival.

CONCLUSIONS

Overweight and obese subjects with coronary heart disease had reduced all-cause and cardiovascular disease mortality, but such an obesity paradox was seen only in participants who did not adhere to current recommendations of physical activity.

Aerobic fitness and metabolic health in children: A clinical validation of directly measured maximal oxygen consumption versus performance measures as markers of health

High aerobic fitness is consistently associated with a favorable metabolic health profile in children. However, measurement of oxygen uptake, regarded as the gold standard for evaluating aerobic fitness, is often not feasible. Thus, the aim of the present study was to perform a clinical validation of three measures of aerobic fitness (peak oxygen consumption [VO_2peak] and time to exhaustion [TTE] determined from a graded treadmill protocol to exhaustion, and the Andersen intermittent running test) with clustered metabolic health in 10-year-old children. We included 93 children (55 boys and 38 girls) from Norway during 2012–2013 in the study. Associations between aerobic fitness and three different composite metabolic health scores (including lipoprotein subgroup particle concentrations, triglyceride, glucose, systolic blood pressure, and waist-to-height ratio) were determined by regression analyses adjusting for sex. The relationships among the measures of aerobic fitness were r = 0.78 for VO_2peak vs. TTE, r = 0.63 for VO_2peak vs. the Andersen test, and r = 0.67 for TTE vs. the Andersen test. The Andersen test showed the strongest associations across all markers of metabolic health (r = − 0.45 to − 0.31, p < 0.002), followed by VO_2peak (r = − 0.35 to − 0.12, p < 0.256), and TTE (r = − 0.28 to − 0.10, p < 0.334). Our findings indicate that indirect measures of aerobic fitness do not stand back as markers of metabolic health status in children, compared to VO_2peak. This is of great importance as good field tests provide opportunities for measuring aerobic fitness in many settings where measuring VO_2peak are impossible.

Predictors of Suboptimal Gain in Exercise Capacity After Cardiac Rehabilitation

Cardiac rehabilitation (CR) improves exercise capacity (EC), but not all CR participants achieve such improvements. Our primary aim was to develop a tool to identify those with suboptimal improvement in EC after CR. We retrospectively analyzed 541 patients enrolled in a phase-II CR program after a cardiac event or intervention from 2003 to 2014. EC was assessed with the 6-minute walk test. We developed a multivariate linear regression model and corresponding nomogram to predict EC after CR. The predictors included in the final model were age, gender, baseline EC, primary referral diagnosis, body mass index, systolic blood pressure at rest, triglycerides, low-density lipoprotein cholesterol, lipid-lowering medication use, and an interaction term of low-density lipoprotein cholesterol with lipid-lowering therapy. The prediction model was internally validated using bootstrap methods, and a nomogram was created for ease of use. In conclusion, this tool helps to identify those patients with suboptimal improvement in EC who could be targeted for individualized interventions to increase their performance.

Lifestyle Modification in Secondary Prevention: Beyond Pharmacotherapy

Despite significant advances in medical technology and pharmacology, cardiovascular disease (CVD) remains a major contributor to health care expenses and the leading cause of death in the United States. Patients with established CVD and their health care providers are challenged with achieving cardiovascular risk reduction to decrease the likelihood of recurrent cardiovascular events. This "secondary prevention" can be achieved, in part, through adherence to prescribed pharmacotherapies that favorably modify major coronary risk factors (ie, hypertension, hypercholesterolemia, diabetes, and obesity). However, lifestyle modification can also be helpful in this regard, providing independent and additive benefits to the associated reductions in cardiovascular morbidity and mortality. Accordingly, physicians and other health care providers should routinely counsel their coronary patients to engage in structured exercise and increased lifestyle physical activity, consume a heart-healthy diet, quit smoking and avoid secondhand smoke, and purposefully address psychosocial stressors that may elevate cardiovascular risk. These lifestyle interventions, either as an adjunct to medication therapy or independently in those patients where medications may be poorly tolerated, cost prohibitive, or ineffective, can significantly decrease cardiovascular mortality and the risk of recurrent cardiac events.

Reference values for and cross-validation of time to exhaustion on a modified Balke protocol in Norwegian men and women

The aims of the present study were to provide reference values for time to exhaustion (TTE) on a modified Balke treadmill protocol, and to perform a cross-validation of TTE as a measure of maximal oxygen consumption (VO_2max ), in Norwegian men and women 20-85 years of age. Reference values for TTE were derived from a national sample of 765 subjects. An additional sample of 119 subjects was included in the cross-validation (total n = 884), where prediction equations for VO_2max was established. A decline in TTE was seen with increased age. Prediction of VO_2max in an independent dataset (n = 319) resulted in a R²  = 0.78 and standard error of the estimate = 4.55 mL/kg/min. The observed-predicted bias was small (mean difference <1.24 mL/kg/min), whereas random error was considerable (95% limits of agreement ± 7.11-9.70 mL/kg/min) across age in both men and women. Despite limitations concerning the prediction of VO_2max on an individual level, TTE from the Balke protocol is a good measure of aerobic fitness in adults across a range of settings, and could be evaluated according to the suggested reference values.

Obesity or obesities? Controversies on the association between body mass index and premature mortality

Obesity is still defined on the basis of body mass index (BMI) and BMI in itself is generally accepted as a strong predictor of overall early mortality. However, an inverse association between BMI and mortality has been reported in patients with many disease states and in several clinical settings: hemodialysis, cardiovascular diseases, hypertension, stroke, diabetes, chronic obstructive pulmonary disease, surgery, etc. This unexpected phenomenon is usually called obesity-survival paradox (OP). The contiguous concepts of metabolically healthy obesity (MHO, a phenotype having BMI ≥ 30 but not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance, HOMA, <2.5) and metabolically obese normal weight (MONW, normal-weight individuals displaying obesity-related phenotypic characteristics) have received a great deal of attention in recent years. The interactions that link MHO, MONW and OP with body composition, fat distribution, aging and cardiorespiratory fitness are other crucial areas of research. The article is an introductory narrative overview of the origin and current use of the concepts of MHO, MONW and OP. These phenomena are very controversial and appear as a consequence of the frail current diagnostic definition of obesity based only on BMI. A new commonly established characterization and classification of obesities based on a number of variables is needed urgently.

Effects of aerobic training, resistance training, or both on cardiorespiratory and musculoskeletal fitness in adolescents with obesity: the HEARTY trial

The purpose of this study was to examine the effects of aerobic, resistance, and combined exercise training on cardiorespiratory and musculoskeletal fitness in postpubertal adolescents with obesity. After a 4-week supervised moderate-intensity exercise run-in, 304 adolescents aged 14-18 years with body mass index ≥85th percentile were randomized to 4 groups for 22 weeks of aerobic training, resistance training, combined training, or a nonexercising control. All participants received dietary counselling with a maximum daily energy deficit of 250 kcal. Cardiorespiratory fitness (peak oxygen consumption) was measured by indirect calorimetry using a graded treadmill exercise test. Musculoskeletal fitness was measured using the 2003 Canadian Physical Activity Fitness and Lifestyle Appraisal tests (hand grip, push-ups, partial curl-ups, sit and reach, and vertical jump). Muscular strength was assessed using an 8-repetition maximum test on the bench press, seated row, and leg press machines. A greater increase in peak oxygen consumption in the aerobic exercise group (30.6 ± 0.6 to 33.4 ± 0.7 mLO2/kg/min) was measured relative to the control group (30.6 ± 0.5 to 30.9 ± 0.7 mLO2/kg/min) (p = 0.002). Similarly, the number of partial curl-ups increased in the aerobic group (19 ± 1 to 23 ± 1) while no differences were measured in the control group (19 ± 1 to 20 ± 1) (p = 0.015). Increases in muscular strength and number of push-ups were greatest in the resistance group versus the control and combined groups versus the aerobic group (p < 0.05). In conclusion, aerobic training had the strongest effect on cardiorespiratory fitness, while resistance and combined training improved both muscular strength and endurance more than control and aerobic training alone, respectively, in adolescents with obesity.

Cardiorespiratory fitness attenuates risk for major adverse cardiac events in hyperlipidemic men and women independent of statin therapy: The Henry Ford ExercIse Testing Project

AIMS

We sought to evaluate the effect of cardiorespiratory fitness (CRF) in predicting mortality, myocardial infarction (MI), and revascularization in patients with hyperlipidemia after stratification by gender and statin therapy.

METHODS AND RESULTS

This retrospective cohort study included 33,204 patients with hyperlipidemia (57 ± 12 years old, 56% men, 25% black) who underwent physician-referred treadmill stress testing at the Henry Ford Health System from 1991 to 2009. Patients were stratified by gender, baseline statin therapy, and estimated metabolic equivalents from stress testing. We computed hazard ratios using Cox regression models after adjusting for demographics, cardiac risk factors, comorbidities, pertinent medications, interaction terms, and indication for stress testing.

RESULTS

There were 4,851 deaths, 1,962 MIs, and 2,686 revascularizations over a median follow-up of 10.3 years. In men and women not on statin therapy and men and women on statin therapy, each 1-metabolic equivalent increment in CRF was associated with hazard ratios of 0.86 (95% CI 0.85-0.88), 0.83 (95% CI 0.81-0.85), 0.85 (95% CI 0.83-0.87), and 0.84 (95% CI 0.81-0.87) for mortality; 0.93 (95% CI 0.90-0.96), 0.87 (95% CI 0.83-0.91), 0.89 (95% CI 0.86-0.92), and 0.90 (95% CI 0.86-0.95) for MI; and 0.91 (95% CI 0.88-0.93), 0.87 (95% CI 0.83-0.91), 0.89 (95% CI 0.87-0.92), and 0.90 (95% CI 0.86-0.94) for revascularization, respectively. No significant interactions were observed between CRF and statin therapy (P > .23).

CONCLUSION

Higher CRF attenuated risk for mortality, MI, and revascularization independent of gender and statin therapy in patients with hyperlipidemia. These results reinforce the prognostic value of CRF and support greater promotion of CRF in this patient population.

Prognostic value of exercise capacity in patients with coronary artery disease: the FIT (Henry Ford ExercIse Testing) project

OBJECTIVE

To examine the prognostic value of exercise capacity in patients with nonrevascularized and revascularized coronary artery disease (CAD) seen in routine clinical practice.

PATIENTS AND METHODS

We analyzed 9852 adults with known CAD (mean ± SD age, 61±12 years; 69% men [n=6836], 31% black race [n=3005]) from The Henry Ford ExercIse Testing (FIT) Project, a retrospective cohort study of patients who underwent physician-referred stress testing at a single health care system between January 1, 1991, and May 31, 2009. Patients were categorized by revascularization status (nonrevascularized, percutaneous coronary intervention [PCI], or coronary artery bypass graft [CABG] surgery) and by metabolic equivalents (METs) achieved on stress testing. Using Cox regression models, hazard ratios for mortality, myocardial infarction (MI), and downstream revascularizations were calculated after adjusting for potential confounders, including cardiac risk factors, pertinent medications, and stress testing indication.

RESULTS

There were 3824 all-cause deaths during median follow-up of 11.5 years. In addition, 1880 MIs, and 1930 revascularizations were ascertained. Each 1-MET increment in exercise capacity was associated with a hazard ratio (95% CI) of 0.87 (0.85-0.89), 0.87 (0.85-0.90), and 0.86 (0.84-0.89) for mortality; 0.98 (0.96-1.01), 0.88 (0.84-0.92), and 0.93 (0.90-0.97) for MI; and 0.94 (0.92-0.96), 0.91 (0.88-0.95), and 0.96 (0.92-0.99) for downstream revascularizations in the nonrevascularized, PCI, and CABG groups, respectively. In each MET category, the nonrevascularized group had similar mortality risk as and higher MI and downstream revascularization risk than the PCI and CABG surgery groups (P<.05).

CONCLUSION

Exercise capacity was a strong predictor of mortality, MI, and downstream revascularizations in this cohort. Furthermore, patients with similar exercise capacities had an equivalent mortality risk, irrespective of baseline revascularization status.

Dietary restriction and exercise for diabetic patients with chronic kidney disease: a systematic review

BACKGROUND

Obesity and sedentary lifestyle are major health problems and key features to develop cardiovascular disease. Data on the effects of lifestyle interventions in diabetics with chronic kidney disease (CKD) have been conflicting.

STUDY DESIGN

Systematic review.

POPULATION

Diabetes patients with CKD stage 3 to 5. SEARCH STRATEGY AND SOURCES: Medline, Embase and Central were searched to identify papers.

INTERVENTION

Effect of a negative energy balance on hard outcomes in diabetics with CKD.

OUTCOMES

Death, cardiovascular events, glycaemic control, kidney function, metabolic parameters and body composition.

RESULTS

We retained 11 studies. There are insufficient data to evaluate the effect on mortality to promote negative energy balance. None of the studies reported a difference in incidence of Major Adverse Cardiovascular Events. Reduction of energy intake does not alter creatinine clearance but significantly reduces proteinuria (mean difference from -0.66 to -1.77 g/24 h). Interventions with combined exercise and diet resulted in a slower decline of eGFR (-9.2 vs. -20.7 mL/min over two year observation; p<0.001). Aerobic and resistance exercise reduced HbA1c (-0.51 (-0.87 to -0.14); p = 0.007 and -0.38 (-0.72 to -0.22); p = 0.038, respectively). Exercise interventions improve the overall functional status and quality of life in this subgroup. Aerobic exercise reduces BMI (-0.74% (-1.29 to -0.18); p = 0.009) and body weight (-2.2 kg (-3.9 to -0.6); p = 0.008). Resistance exercise reduces trunk fat mass (-0,7±0,1 vs. +0,8 kg ±0,1 kg; p = 0,001-0,005). In none of the studies did the intervention cause an increase in adverse events.

LIMITATIONS

All studies used a different intervention type and mixed patient groups.

CONCLUSIONS

There is insufficient evidence to evaluate the effect of negative energy balance interventions on mortality in diabetic patients with advanced CKD. Overall, these interventions have beneficial effects on glycaemic control, BMI and body composition, functional status and quality of life, and no harmful effects were observed.

Long-term outcomes from Healthy Eating and Exercise Lifestyle Program for overweight people with heart disease and diabetes

BACKGROUND

The benefits of exercise and weight reduction for overweight or obese people with coronary heart disease and/or diabetes mellitus are well recognised. The Healthy Eating and Exercise Lifestyle Program demonstrated these outcomes at 4 months, but longer-term outcomes are not yet reported.

AIM

To determine whether positive weight, body mass index, waist and exercise duration outcomes were sustained in the long term (12 months) and to identify the independent predictors of these outcomes at 4 and 12 months.

METHODS

Longitudinal design, combining data of all Healthy Eating and Exercise Lifestyle Program participants (intervention and wait-list control, n = 134). Participants had a body mass index between 27 and 39 kg/m(2) and had completed cardiac rehabilitation and/or diabetes education programmes. Healthy Eating and Exercise Lifestyle Program intervention included an active phase of two 1-hour group-based supervised structured exercise sessions every week for 4 months and four 90-minute group information and support sessions. The maintenance phase included one 90-minute group-based booster information session and three 15-minute goal-focused telephone follow-up calls over 8 months.

RESULTS

Participants had statistically significant reductions from baseline in weight, body mass index and waist circumference and improvements in exercise duration and capacity at 4 and 12 months. Time, self-efficacy, depressive symptoms and male gender were independent predictors for body mass index, waist and/or exercise duration (p < 0.05).

CONCLUSION

The Healthy Eating and Exercise Lifestyle Program was an effective programme to achieve and sustain weight loss and increase exercise participation over 1 year.

The relationship between obesity and coronary artery disease

Obesity continues to be a growing issue in the United States, with an estimated prevalence of 72 million people. There are major health implications associated with obesity, including its relationship with hypertension, diabetes mellitus type 2, metabolic syndrome, and dyslipidemia, all independent risk factors for coronary artery disease (CAD). Despite the increased risk of developing CAD, in recent years an "obesity paradox" has been described in which moderately obese individuals with established cardiovascular disease, including CAD, appear to have mortality similar to their normal-weight counterparts. This review examines the relationship between obesity and CAD, including the increased risk of hypertension, diabetes mellitus, metabolic syndrome, and dyslipidemia, along with a discussion of the obesity paradox and the benefits of weight reduction.

Body composition and mortality in a large cohort with preserved ejection fraction: untangling the obesity paradox

OBJECTIVE

To evaluate the effects of body composition as a function of lean mass index (LMI) and body fat (BF) on the correlation between increasing body mass index (BMI; calculated as the weight in kilograms divided by the height in meters squared) and decreasing mortality, which is known as the obesity paradox.

PATIENTS AND METHODS

We retrospectively assessed 47,866 patients with preserved left ventricular ejection fraction (≥50%). We calculated BF by using the Jackson-Pollock equation and LMI using (1 - BF) × BMI. The population was divided according to the sex-adjusted BMI classification, sex-adjusted LMI classification, and sex-adjusted BF tertiles. The population was analyzed by using multivariate analysis for total mortality over a mean follow-up duration of 3.1 years by using the National Death Index, adjusting for left ventricular ejection fraction, left ventricular mass index, age, sex, and relative wall thickness.

RESULTS

In the entire population, higher BMI was narrowly associated (hazard ratio [HR], 0.99; P<.001) with lower mortality. The higher LMI group was clearly protective (HR, 0.71; P<.001), whereas BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.87; P<.001 without LMI; HR, 0.97; P=.23 with LMI). In the lean patients, low BMI was clearly associated with higher mortality (HR, 0.92; P<.001) and lower BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.80; P<.001 without LMI; HR, 1.01; P=.83 with LMI). The underweight patients stratified by BF seemed to have an increased mortality (HR, 1.91; 95% CI, 1.56-2.34) that was independent of LMI. However, in obese patients, both BMI (HR, 1.03; P<.001) and BF (HR, 1.18; P=.003) were associated with higher mortality, even after adjusting for LMI, which remained protective (HR, 0.57; P<.001) independently of BF.

CONCLUSION

Body composition could explain the inverse J shape of the mortality curve noted with increasing BMI. Body fat seems to be protective in this cohort only if no adjustment was made for LMI, although being underweight stratified by BF seems to be an independent risk factor. Lean mass index seems to remain protective in obese patients even when BMI is not.

Relationship of body mass index with total mortality, cardiovascular mortality, and myocardial infarction after coronary revascularization: evidence from a meta-analysis

OBJECTIVE

To investigate the relationship of body mass index (BMI) with total mortality, cardiovascular (CV) mortality, and myocardial infarction (MI) after coronary revascularization procedures (coronary artery bypass grafting [CABG] and percutaneous coronary intervention [PCI]).

PATIENTS AND METHODS

Systematic search of studies was conducted using PubMed, CINAHL, Cochran CENTRAL, Scopus, and the Web of Science databases. We identified studies reporting the rate of MI, CV mortality, and total mortality among coronary artery disease patients' postcoronary revascularization procedures in various BMI categories: less than 20 (underweight), 20-24.9 (normal reference), 25-29.9 (overweight), 30-34.9 (obese), and 35 or more (severely obese). Event rates were compared using a random effects model assuming interstudy heterogeneity.

RESULTS

A total of 36 studies (12 CABG; 26 PCI) were selected for final analyses. The risk of total mortality (relative risk [RR], 2.59; 95% CI, 2.09-3.21), CV mortality (RR, 2.67; 95% CI, 1.63-4.39), and MI (RR, 1.79; 95% CI, 1.28-2.50) was highest among patients with low BMI at the end of a mean follow-up period of 1.7 years. The risk of CV mortality was lowest among overweight patients (RR, 0.81; 95% CI, 0.68-0.95). Increasing degree of adiposity as assessed by BMI had a neutral effect on the risk of MI for overweight (RR, 0.92; 95% CI, 0.84-1.01), obese (RR, 0.99; 95% CI, 0.85-1.15), and severely obese (RR, 0.93; 95% CI, 0.78-1.11) patients.

CONCLUSION

After coronary artery disease revascularization procedures (PCI and CABG), the risk of total mortality, CV mortality, and MI was highest among underweight patients as defined by low BMI and CV mortality was lowest among overweight patients.

Cardiorespiratory fitness and the paradoxical BMI-mortality risk association in male veterans

OBJECTIVE

To assess the effect of fitness status on the paradoxical body mass index (BMI)-mortality risk association.

PATIENTS AND METHODS

From February 1, 1986, through December 30, 2011, we assessed fitness and BMI in 18,033 male veterans (mean age, 58.4 ± 11.4 years) in 2 Veterans Affairs Medical centers. We established 3 fitness categories on the basis of peak metabolic equivalents achieved during an exercise test as well as 5 BMI categories. The primary outcome was all-cause mortality.

RESULTS

During the follow-up period (median, 10.8 years, comprising a total of 207,168 person-years), 5070 participants (28%) died. After adjusting for age, risk factors, muscle-wasting diseases, medications, and year of entry, mortality risk was higher for individuals with a BMI of 20.1 to 23.9 kg/m(2) (hazard ratio [HR], 1.21; 95% CI, 1.12-1.30) and 18.5 to 20.0 kg/m(2) (HR, 1.56; 95% CI, 1.37-1.77) than for those with a BMI of 24.0 to 27.9 kg/m(2); mortality risk was not increased for those with a BMI of 28.0 kg/m(2) or greater. When stratified by fitness, the trend was similar for low-fit and moderate-fit individuals. However, mortality risk was not increased for high-fit individuals across BMI categories. When fitness status was considered within each BMI category, mortality risk increased progressively with decreased fitness and was more pronounced for moderate-fit (HR, 2.52; 95% CI, 2.06-3.08) and low-fit (HR, 2.48; 95% CI, 2.0-3.06) individuals with a BMI of 18.5-20.0 kg/m(2). Mortality risk was not significantly increased for high-fit individuals (HR, 1.17; 95% CI, 0.78-1.78; P=.45).

CONCLUSION

A high mortality risk associated with low BMI levels was observed only in moderate-fit and low-fit individuals, and not in high-fit individuals. Thus, fitness greatly affects the paradoxical BMI-mortality risk association. Furthermore, our findings indicate that lower BMI levels do not increase the risk for premature death as long as they are associated with high fitness. Thus, the paradoxically higher mortality risk observed with lower body weight as represented by lower BMI is likely the result of unhealthy reduction in body weight and, perhaps most importantly, considerable loss of lean body mass.

Atherosclerosis burden in patients with acute chest pain: obesity paradox

Obesity paradox has been described in various populations of coronary artery disease, mainly asymptomatic subjects. However, relationship between obesity and coronary artery calcification detected by cardiac CT in symptomatic patients has rarely been demonstrated. This study seeks to investigate whether the paradoxical relationship between obesity and coronary artery calcification exists in patients with acute chest pain. A final cohort of 1030 chest pain patients presenting at our emergency department who underwent coronary evaluation by multidetector cardiac CT were examined. With absent-to-mild coronary calcification (CAC score < 100) as a referent, multivariable analysis showed that presence of obesity (OR 0.564; 95% CI 0.395, 0.806; P 0.002), body mass index (OR 0.945; 95% CI 0.920, 0.971; P < 0.001), body weight (OR 0.987; 95% CI 0.979, 0.995; P 0.001), and body surface area (OR 0.582; 95% CI 0.369, 0.920; P 0.020) were inversely associated with moderate-to-severe coronary calcification (CAC score ≥ 100). This study extends the concept of obesity paradox to symptomatic patients undergoing coronary artery calcium score assessment. However, biological explanation(s) of this paradox remains unanswered.

Obesity and cardiovascular diseases: implications regarding fitness, fatness, and severity in the obesity paradox

Obesity has been increasing in epidemic proportions, with a disproportionately higher increase in morbid or class III obesity, and obesity adversely affects cardiovascular (CV) hemodynamics, structure, and function, as well as increases the prevalence of most CV diseases. Progressive declines in physical activity over 5 decades have occurred and have primarily caused the obesity epidemic. Despite the potential adverse impact of overweight and obesity, recent epidemiological data have demonstrated an association of mild obesity and, particularly, overweight on improved survival. We review in detail the obesity paradox in CV diseases where overweight and at least mildly obese patients with most CV diseases seem to have a better prognosis than do their leaner counterparts. The implications of cardiorespiratory fitness with prognosis are discussed, along with the joint impact of fitness and adiposity on the obesity paradox. Finally, in light of the obesity paradox, the potential value of purposeful weight loss and increased physical activity to affect levels of fitness is reviewed.

Fitness, fatness, and survival in adults with prediabetes

OBJECTIVE

The purpose of this study was to examine independent and joint associations of cardiorespiratory fitness (CRF) and different adiposity measures with mortality risk in individuals with prediabetes (or impaired fasting glucose).

RESEARCH DESIGN AND METHODS

We examined associations of CRF and fatness with cardiovascular disease (CVD) and all-cause mortality in a cohort of 17,044 participants (89% men) with prediabetes (defined as 100 mg/dL ≤ fasting plasma glucose < 126 mg/dL), who did not have a history of diabetes, CVD, or cancer.

RESULTS

We identified 832 deaths (246 from CVD) during 13.9 ± 7.0 years (mean ± SD) follow-up. Normal-weight individuals who were unfit (lowest one-third) had a higher risk of all-cause (hazard ratio 1.70 [95% CI 1.32-2.18]) and CVD (1.88 [1.13-3.10]) mortality compared with the normal-weight and fit (upper two-thirds) reference group in a model adjusted for age, sex, examination year, and multiple risk factors. The mortality risk for fit individuals who were overweight or obese did not differ significantly from the reference group. Similar patterns were observed for sex-specific thirds of waist circumference and % body fat.

CONCLUSIONS

CRF markedly modifies the relationship between adiposity and mortality in persons with prediabetes. Unfit individuals have a higher and fit individuals have a lower mortality risk irrespective of adiposity level in this high-risk group.

Combined impact of cardiorespiratory fitness and visceral adiposity on metabolic syndrome in overweight and obese adults in Korea

Background

Obesity, especially visceral obesity, is known to be an important correlate for cardiovascular disease and increased mortality. On the other hand, high cardiorespiratory fitness is suggested to be an effective contributor for reducing this risk. This study was conducted to determine the combined impact of cardiorespiratory fitness and visceral adiposity, otherwise known as fitness and fatness, on metabolic syndrome in overweight and obese adults.

Methods

A total of 232 overweight and obese individuals were grouped into four subtypes according to their fitness level. This was measured by recovery heart rate from a step test in addition to visceral adiposity defined as the visceral adipose tissue area to subcutaneous adipose tissue area ratio (VAT/SAT ratio). Associations of fitness and visceral fatness were analyzed in comparison with the prevalence of metabolic syndrome.

Results

The high visceral fat and low fitness group had the highest prevalence of metabolic syndrome [Odds Ratio (OR) 5.02; 95% Confidence Interval (CI) 1.85–13.61] compared with the reference group, which was the low visceral adiposity and high fitness group, after adjustments for confounding factors. Viscerally lean but unfit subjects were associated with a higher prevalence of metabolic syndrome than more viscerally obese but fit subjects (OR 3.42; 95% CI 1.27–9.19, and OR 2.70; 95% CI 1.01–7.25, respectively).

Conclusions

Our study shows that visceral obesity and fitness levels are cumulatively associated with a higher prevalence of metabolic syndrome in healthy overweight and obese adults. This suggests that cardiorespiratory fitness is a significant modifier in the relation of visceral adiposity to adverse metabolic outcomes in overweight and obese individuals.

Obesity paradox in different populations: evidence and controversies

ABSTRACT: An inverse association between BMI and mortality has been reported in patients with coronary heart disease and heart failure. This ‘obesity paradox‘ has recently been reported in other disease states, including stroke, hypertension, incident diabetes, atrial fibrillation, hemodialysis and transcatheter aortic valve replacement. Cardiorespiratory fitness influences the obesity paradox and this inverse association may be present only in individuals with low fitness levels. Intentional weight loss, exercise training and improving lean mass are important and should be advised to all patients. Recent studies have also explored the association between measures of central obesity and direct measures of body fat with mortality. This review will summarize the evidence, controversies and mechanisms associated with the puzzling obesity paradox.

Does the effect of supervised cardiac rehabilitation programs on body fat distribution remained long time?

INTRODUCTION

An increased accumulation of fat in the intra-abdominal cavity is highly correlated with adverse coronary risk profiles. Cardiac rehabilitation (CR) produces a host of health benefits related to modifiable cardiovascular risk factors. Further research is needed to define better program for weight loss and risk improvement in coronary patients. The aim of this study was to determine the effect of supervised and unsupervised cardiac rehabilitation program on body composition and body fat distribution in a population with coronary artery disease.

METHODS

The study investigated 167 patients with coronary artery disease (73% males; mean age = 52.67±9.11 years) before and after a supervised protocol cardiac rehabilitation program, and 12-months later. Target variables included body fat distribution indices (waist and hip circumference and waist to hip ratio), weight and body mass index.

RESULTS

Weight, waist circumference, waist to hip ratio and body mass index significantly decreased with 2 month supervised program (P<0.001), but hip circumference was not significantly changed. Males improved to a greater extent than the female patients. All of measurements relatively returned to baseline at the end of program (after 12 months).

CONCLUSION

Supervised cardiac rehabilitation program results in improvements in body composition and body fat distribution. The effects of non-supervised program were minimal and the program needed to be reviewed.

Cardiac rehabilitation is associated with reduced long-term mortality in patients undergoing combined heart valve and CABG surgery

BACKGROUND

No reports have been published to date on the impact of cardiac rehabilitation (CR) on mortality in patients undergoing combined heart valve and coronary artery bypass graft (CABG) surgery (V + CABG), a procedure that has increased significantly in frequency in recent years.

METHODS

We identified consecutive patients who underwent V + CABG surgery in the Olmsted County from 1996 to 2007. Propensity scores were developed using more than 40 clinical, operative, and post-operative characteristics. The impact of CR on long-term mortality was assessed via landmark analysis and using propensity score regression adjustment and stratification techniques.

RESULTS

A total of 201 patients were included in our study, in whom 86 deaths occurred over a mean follow up of 6.8 years. Forty-seven per cent of patients participated in CR, with a significant trend towards increased participation in recent years (p = 0.04). Conditional on 6-month survival and controlling for propensity factors as well as mortality risk factors, CR participation was associated with a significant reduction in mortality (propensity score adjustment: HR 0.48, p = 0.009; propensity score stratification: HR 0.48, p = 0.016). The absolute risk reduction over 10 years was 14.5% (number needed to treat = 7). Results did not differ significantly based on age, gender, emergent status, or history of heart failure or arrhythmias, but CR participation was more beneficial for patients who underwent a mitral valve procedure (HR 0.24, 95% CI 0.08-0.77).

CONCLUSIONS

This is the first study reporting a significant survival benefit with CR participation in patients who have undergone combined V + CABG surgery. These findings provide evidence in support of recommendations for CR participation after V + CABG surgery.

Contribution of cardiorespiratory fitness to the obesity paradox

Until recently, cardiorespiratory fitness (CRF) has been overlooked as a potential modifier of the inverse association between obesity and mortality (the so-called obesity paradox), observed in patients with known or suspected cardiovascular (CV) disease. Evidence from five observational cohort studies of 30,104 patients (87% male) with CV disease indicates that CRF significantly alters the obesity paradox. There is general agreement across studies that the obesity paradox persists among patients with low CRF, regardless of whether adiposity is assessed by body mass index, waist circumference, or percentage body fat. However, among patients with high CRF, risk of all-cause mortality is lowest for the overweight category in some, but not all, studies, suggesting that higher levels of fitness may modify the relationship between body fatness and survival in patients manifesting an obesity paradox. Further study is needed to better characterize the joint contribution of CRF and obesity on mortality in diverse populations.