Value of weight reduction in patients with cardiovascular disease

The Relationship between Body Mass Index and the Severity of Coronary Artery Disease in Patients Referred for Coronary Angiography

Background and Aim. Obesity is associated with an increased risk of cardiovascular disease and may be associated with more severe coronary artery disease (CAD); however, the relationship between body mass index [BMI (kg/m²)] and CAD severity is uncertain and debatable. The aim of this study was to examine the relationship between BMI and angiographic severity of CAD. Methods. Duke Jeopardy Score (DJS), a prognostic tool predictive of 1-year mortality in CAD, was assigned to angiographic data of patients ≥18 years of age (N = 8,079). Patients were grouped into 3 BMI categories: normal (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥30 kg/m²); and multivariable adjusted hazard ratios for 1-year all-cause and cardiac-specific mortality were calculated. Results. Cardiac risk factor prevalence (e.g., diabetes, hypertension, and hyperlipidemia) significantly increased with increasing BMI. Unadjusted all-cause and cardiac-specific 1-year mortality tended to rise with incremental increases in DJS, with the exception of DJS 6 (p < 0.001). After adjusting for potential confounders, no significant association of BMI and all-cause (HR 0.70, 95% CI .48–1.02) or cardiac-specific (HR 1.11, 95% CI .64–1.92) mortality was found. Conclusions. This study failed to detect an association of BMI with 1-year all-cause or cardiac-specific mortality after adjustment for potential confounding variables.

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.

Gender, race and cardiac rehabilitation in the United States: is there a difference in care?

Coronary heart disease is the leading cause of death within the United States, involving both genders and among all races and ethnic populations. Cardiac rehabilitation (CR) has been shown to significantly improve morbidity and mortality, and these benefits extend to individuals of both genders and all ages with coronary heart disease. Despite this, referral and participation rates remain surprisingly low. Furthermore, women and minorities have even lower referral rates than do their male and white counterparts. Over the course of this article, we will review CR referral and participation among women, as well as racial and ethnic minorities in the United States. We will also examine barriers to CR participation among these subgroups.

Low weight and overweightness in older adults: risk and clinical management

The prevalence of individuals who are overweight or obese is growing exponentially in the United States and worldwide. This growth is concerning, as both overweightness and obesity lead to impaired physical function, decreased quality of life, and increased risk of chronic diseases. Additionally, overweightness and obesity are related to increased mortality among young and middle-aged adults. This weight-related risk of mortality is more ambiguous among older adults. In fact, obesity may be protective in this population, a relationship described as the "obesity paradox". In this review we discuss the effects of overweightness and obesity among the elderly on cardiovascular disease and all-cause mortality, along with the risks of low weight. We conclude by discussing the goal of weight management among older adults, focusing particularly on benefits of preserving lean body mass and muscular strength while stabilizing body fat. Ideally, overweight or mildly obese elderly individuals should devise a plan with their physicians to maintain their weight, while increasing lean body mass through a plan of healthy diet, behavioral therapy, and physical activity.

New and emerging drug molecules against obesity

Obesity has become a growing pandemic of alarming proportions in the developed and developing countries over the last few decades. The most perturbing fact regarding obesity is the increased predisposition for coronary artery disease, congestive heart failure and sudden cardiac death. The modest efficacy of current anti-obesity agents such as orlistat and the increasing withdrawals of several anti-obesity agents such as sibutramine, rimonabant have led to huge gaps in the pharmacotherapy of obesity. Lorcaserin and Phentermine-topiramate combination (phen-top) are two drugs approved by US FDA in 2012. Lorcaserin, a 5HT2C agonist has moderate efficacy with an acceptable safety profile. Clinical trials with Phen-top have shown a reasonable efficacy but at the cost of risks such as teratogenicity and psychiatric disturbances. Cetilistat, a lipase inhibitor is claimed to have superior safety profile to orlistat and is in phase 3 clinical trials. Other promising anti-obesity molecules acting on the gut which are in clinical trials include exenatide and liraglutide. Drugs which act on the monoaminergic and opioid systems include bupropion-naltrexone and bupropion-zonisamide. Other novel first-in-class drugs which have been explored and have limited success in early clinical development include velneperit, tesofensine, and beloranib. Tesofensine is a triple monoamine re-uptake inhibitor, velneperit acts as a neuropeptide Y5 receptor antagonist and beloranib is a methionine amino peptidase 2 inhibitor. Novel targets such as histamine H3 receptor, VEGF, matrix-metalloproteinase, sirtuin receptors are also being investigated. This review is an attempt to describe the new and emerging molecules that are in clinical development for obesity.

Obstructive sleep apnoea and type 2 diabetes mellitus: a bidirectional association

Obstructive sleep apnoea and type 2 diabetes are common medical disorders that have important clinical, epidemiological, and public health implications. Research done in the past two decades indicates that obstructive sleep apnoea, through the effects of intermittent hypoxaemia and sleep fragmentation, could contribute independently to the development of insulin resistance, glucose intolerance, and type 2 diabetes. Conversely, type 2 diabetes might increase predisposition to, or accelerate progression of, obstructive and central sleep apnoea, possibly through the development of peripheral neuropathy and abnormalities of ventilatory and upper airway neural control. Although more research is needed to clarify the mechanisms underlying the bidirectional association between the two disorders, their frequent coexistence should prompt all health-care professionals to embrace clinical practices that include screening of a patient presenting with one disorder for the other. Early identification of obstructive sleep apnoea in patients with metabolic dysfunction, including type 2 diabetes, and assessment for metabolic abnormalities in those with obstructive sleep apnoea could reduce cardiovascular disease risk and improve the quality of life of patients with these chronic diseases.

Relation of body fat categories by Gallagher classification and by continuous variables to mortality in patients with coronary heart disease

Although obesity is a coronary heart disease risk factor, in cohorts of patients with coronary heart disease, an "obesity paradox" exists whereby patients with obesity have a better prognosis than do leaner patients. Obesity is generally defined by body mass index, with relatively little described regarding body fat (BF). In this study, 581 consecutive patients with coronary heart disease divided into the Gallagher BF categories of underweight (n = 12), normal (n = 189), overweight (n = 214), and obese (n = 166) were evaluated, and 3-year mortality was assessed using the National Death Index. Mortality was U shaped, being highest in the underweight group (25%, p <0.0001 vs all groups) and lowest in the overweight group (2.3%), with intermediate mortality in the normal-BF (6.4%, p = 0.02 vs overweight) and obese (3.6%) groups. In multiple regression analysis, high BF (odds ratio 0.89, 95% confidence interval 0.82 to 0.95) and higher Gallagher class (odds ratio 0.46, 95% confidence interval 0.25 to 0.84) were independent predictors of lower mortality. In conclusion, on the basis of Gallagher BF, an obesity paradox exists, with the highest mortality in the underweight and normal-BF groups and the lowest mortality in the overweight group. Lower BF as a continuous variable and by Gallagher classification as a categorical value were independent predictors of higher mortality.

Physical activity, cardiorespiratory fitness, and exercise training in primary and secondary coronary prevention

Substantial data have established that higher levels of physical activity (PA), participating in exercise training (ET), and higher overall cardiorespiratory fitness (CRF) provide considerable protection in the primary and secondary prevention of coronary heart disease (CHD). This review surveys data from epidemiological and prospective ET studies supporting the favorable impact of PA, ET, and CRF in primary CHD prevention. Clearly, cardiac rehabilitation and ET (CRET) programs have been underutilized for patients with CHD, particularly considering the effect of CRET on CHD risk factors, including CRF, obesity indices, fat distribution, plasma lipids, inflammation, and psychological distress, as well as overall morbidity and mortality. These data strongly support the routine referral of patients with CHD to CRET programs and that patients should be vigorously encouraged to attend CRET following major CHD events.

Cardiac rehabilitation and exercise therapy in the elderly: Should we invest in the aged?

Coronary heart disease (CHD) is the leading cause of death worldwide and becomes increasingly prevalent among patients aged 65 years and older. Elderly patients are at a higher risk for complications and accelerated physical deconditioning after a cardiovascular event, especially compared to their younger counterparts. The last few decades were privy to multiple studies that demonstrated the beneficial effects of cardiac rehabilitation (CR) and exercise therapy on mortality, exercise capacity, psychological risk factors, inflammation, and obesity among patients with CHD. Unfortunately, a significant portion of the available data in this field pertains to younger patients. A viable explanation is that older patients are grossly underrepresented in these programs for multiple reasons starting with the patient and extending to the physician. In this article, we will review the benefits of CR programs among the elderly, as well as some of the barriers that hinder their participation.

Physical training prevents body weight gain but does not modify adipose tissue gene expression

The relationship of body weight (BW) with white adipose tissue (WAT) mass and WAT gene expression pattern was investigated in mice submitted to physical training (PT). Adult male C57BL/6 mice were submitted to two 1.5-h daily swimming sessions (T, N = 18), 5 days/week for 4 weeks or maintained sedentary (S, N = 15). Citrate synthase activity increased significantly in the T group (P < 0.05). S mice had a substantial weight gain compared to T mice (4.06 ± 0.43 vs 0.38 ± 0.28 g, P < 0.01). WAT mass, adipocyte size, and the weights of gastrocnemius and soleus muscles, lung, kidney, and adrenal gland were not different. Liver and heart were larger and the spleen was smaller in T compared to S mice (P < 0.05). Food intake was higher in T than S mice (4.7 ± 0.2 vs 4.0 ± 0.3 g/animal, P < 0.05) but oxygen consumption at rest did not differ between groups. T animals showed higher serum leptin concentration compared to S animals (6.37 ± 0.5 vs 3.11 ± 0.12 ng/mL). WAT gene expression pattern obtained by transcription factor adipocyte determination and differentiation-dependent factor 1, fatty acid synthase, malic enzyme, hormone-sensitive lipase, adipocyte lipid binding protein, leptin, and adiponectin did not differ significantly between groups. Collectively, our results showed that PT prevents BW gain and maintains WAT mass due to an increase in food intake and unchanged resting metabolic rate. These responses are closely related to unchanged WAT gene expression patterns.

The effect of weight loss and exercise training on flow-mediated dilatation in coronary heart disease: a randomized trial

BACKGROUND

More than 80% of patients entering cardiac rehabilitation are overweight, with a high prevalence of associated insulin resistance, diabetes, hypertension, hyperlipidemia, and a prothrombotic state. Because each of these characteristics is associated with abnormalities of endothelial-dependent flow-mediated dilatation (FMD), a predictor of long-term prognosis in patients with coronary heart disease (CHD), we assessed the effect of exercise training and weight reduction on FMD in overweight patients with CHD.

METHODS

All patients (N = 38) participated in behavioral weight loss while taking their usual preventive medications. Subjects were randomized to one of two exercise protocols, which differed by caloric expenditure. The primary outcome was extent (%) of brachial artery FMD measured by ultrasonography before and after the 4-month exercise and weight-loss program.

RESULTS

Both study groups experienced an increase in brachial artery FMD after weight loss and exercise. Patients randomized to the higher-caloric exercise condition (longer-distance walking) lost more weight (8.6 ± 4.1 kg vs 2.3 ± 3.3 kg [P < .001]) and experienced a greater percentage increase in brachial artery FMD (3.6% ± 4.1% vs 1.3% ± 2.1%, P < .05) than did subjects in the lower-caloric-expenditure exercise group who lost less weight. Both groups increased peak aerobic capacity similarly. Increased FMD correlated with changes in body weight more than with measures of abdominal fat, glucose disposal, lipid measure, BP, or measures of physical activity or cardiorespiratory fitness.

CONCLUSIONS

Exercise and weight loss increased FMD in overweight and obese patients with CHD. Greater weight reduction was associated with a greater improvement in FMD; thus, there was a dose effect.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00628277; URL: www.clinicaltrials.gov.

Cardiac rehabilitation and exercise training in secondary coronary heart disease prevention

Substantial evidence indicates that increased levels of physical activity, exercise training, and overall cardiorespiratory fitness provide protection in primary and secondary coronary heart disease (CHD) prevention. Clearly, cardiac rehabilitation and exercise training (CRET) programs have been greatly underused in patients with CHD. We review the benefits of formal CRET programs on CHD risk factors including exercise capacity, obesity indices, plasma lipids, inflammation, and psychosocial stress as well as overall morbidity and mortality. These data support the fact that patients with CHD, especially after major CHD events, need routine referral to CRET programs; and patients should be vigorously encouraged to attend these valuable programs.