Obesity and Prevalence of Cardiovascular Diseases and Prognosis—The Obesity Paradox Updated
Section snippets
Causes of weight gain, obesity, and energy balance
During recent years, the etiology of the obesity epidemic has been hotly debated.3., 10., 11. Regardless, it is widely accepted that changes in body weight and overall adiposity, at the most fundamental level, are the result of chronic positive energy balance, meaning energy expenditure is less than energy intake (or calories burned < calories consumed).3 There certainly have been several studies suggesting that energy or food intake is largely, if not completely, responsible for the obesity
Impact of obesity on hemodynamics and CV structure and function
Overweight and obesity have many adverse effects on risk factors, hemodynamics, and CV structure and function (Fig 1, Table 1)7 which has been reviewed in detail elsewhere.3., 4., 5., 6., 7. Obesity particularly increases blood volume, stroke volume, and cardiac output, which leads to an increase in cardiac work. These changes also lead to left ventricular (LV) dilatation and LV hypertrophy (LVH), both of the eccentric but also the concentric type, the latter particularly occurring when
Obesity and impact on CVD and prognosis—the obesity paradox
Due to the adverse effects that obesity has on CV risk factors and CV structure and function, not surprisingly, the prevalence of almost all CVD is increased in the setting of obesity, however, many studies have demonstrated surprisingly good prognosis among overweight and at least mildly obese patients with CVD, the so-called obesity paradox.3., 7., 8.
Mechanisms of the obesity paradox
The mechanisms of this obesity paradox in various CVD are difficult to reconcile, although several potential mechanisms are listed in Table 2.3 Certainly, it has been argued that some of the obesity paradox may be due to the inaccuracies of BMI to assess true body fatness,36., 37., 38., 54. but we and others have also demonstrated this paradox with % BF25., 26., 27., 28., 55. and even WC.,29., 56. Certainly, many have suggested that this paradox may be due to unmeasured confounders, including
Impact of severity of obesity
The prevalence of class III or “morbid” obesity (BMI ≥ 40 kg/m2) has been dramatically increasing and is now present in over 3% of the US population.1., 2. Although an obesity paradox exists, sometimes even in short-term follow-up even with extreme obesity, generally more severe obesity in long-term follow-up is associated with an ominous prognosis.3., 8., 31., 59., 60. Therefore, the obesity paradox is probably more of an “overweight paradox” or at least more confined to those in the mildly obese
Impact of cardiorespiratory fitness
Body fatness and CRF are strong predictors of CVD risk factors, as well as CV morbidity and mortality.3., 61., 62., 63., 64. In most CVD, patients with high levels of CRF have lower mortality than do patients without this disorder but with low levels of CRF.2 In a major meta-analysis of 33 studies of over 100,000 participants where CRF was assessed by treadmill stress testing, Kodama and colleagues65 demonstrated that for every 1 metabolic equivalent (MET) increase in CRF, all-cause and CHD/CVD
Impact of CRF on the obesity paradox
Several studies have indicated that CRF markedly alters the relationship between fatness and prognosis in both CHD29 and HF,69 as well as in veterans referred for stress testing.58., 70., 71. In a study of nearly 10,000 patients with CHD followed for almost 14 years, only those in the bottom tertile of age- and gender-related levels of CRF demonstrated an obesity paradox, which was present by BMI, % BF, and even by WC or central obesity in the unfit (Fig 3).29 On the other hand, CHD patients
Potential benefits of purposeful weight reduction
Despite the obesity paradox, there are still potential beneficial effects of purposeful weight reduction.3., 4., 5., 6., 78., 79. Whereas weight loss has been questioned, with weight loss being associated with increased mortality in some studies,80 purposeful weight loss during increased PA and exercise training is associated with considerable benefits in patients with CVD,3., 4., 5., 6., 78., 79. although a recent large study in DM did not demonstrate survival benefits from small amounts of
Conclusion
Obesity, generally assessed by BMI, adversely impacts CV risk factors and CV structure and function and is associated with increased risk of most CVD.90., 91. In 2016, however, one cannot discount that an obesity paradox clearly exists, even more so in the elderly population,92 meaning that overweight and, at least, mildly obese patients with most CVD have a better short- and medium-term prognosis than do leaner patients, particularly underweight and those in the lower end of the “normal” BMI
Financial disclosure/conflict of interest
Dr. Lavie served as a Speaker and Consultant for the Coca-Cola Company (but on physical activity, exercise, and fitness and not on their products) and is author of the book The Obesity Paradox.
References (92)
- et al.
Overview of epidemiology and contribution of obesity to cardiovascular disease
Prog Cardiovasc Dis
(2014) - et al.
Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013
Lancet
(2014) - et al.
Obesity and cardiovascular diseases: implications regarding fitness, fatness, and severity in the obesity paradox
J Am Coll Cardiol
(2014) - et al.
Impact of obesity and weight loss on cardiac perrformance and morphology in adults
Prog Cardiovasc Dis
(2014) - et al.
Impact of obesity and the obesity paradox on prevalence and prognosis in heart failure
JACC Heart Fail
(2013) - et al.
The obesity paradox in heart failure: is it all about fitness, fat, or sex?
JACC Heart Fail
(2015) - et al.
Lifestyle choices fuel epidemics of diabetes and cardiovascular disease among Asian Indians
Prog Cardiovasc Dis
(2016) - et al.
The evidence for saturated fat and for sugar related to coronary heart disease
Prog Cardiovasc Dis
(2016) - et al.
Added fructose: a principal drive of type 2 diabetes mellitus and its consequences
Mayo Clin Proc
(2015) - et al.
Increased food energy supply is more than sufficient to explain the US epidemic of obesity
Am J Clin Nutr
(2009)
Maternal inactivity: 45-year trends in mothers' use of time
Mayo Clin Proc
Impact of echocardiographic left ventricular geometry on clinical prognosis
Prog Cardiovasc Dis
Prediction of all-cause mortality by the left atrial volume index in patients with normal left ventricular filling pressure and preserved ejection fraction
Mayo Clin Proc
Left atrial volume index predictive of mortality independent of left ventricular geometry in a large clinical cohort with preserved ejection fraction
Mayo Clin Proc
Obesity paradox in patients with hypertension and coronary artery disease
Am J Med
The impact of obesity on risk factors and prevalence and prognosis of coronary heart disease: the obesity paradox
Prog Cardiovasc Dis
Body composition and coronary heart disease mortality: an obesity or a lean paradox?
Mayo Clin Proc
The obesity paradox, weight loss, and coronary disease
Am J Med
Body composition and survival in stable coronary heart disease: impact of lean mass index and body fat in the “obesity paradox”
J Am Coll Cardiol
The obesity paradox, cardiorespiratory fitness, and coronary heart disease
Mayo Clin Proc
Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies
Lancet
Central obesity and survival in subjects with coronary artery disease: a systematic review of the literature and collaborative analysis with individual subject data
J Am Coll Cardiol
Combining body mass index with measures of central obesity in the assessment of mortality in subjects with coronary disease: role of “normal weight central obesity”
J Am Coll Cardiol
Relation of body fat categories by Gallagher classification and by continuous variables to mortality in patients with coronary heart disease
Am J Cardiol
Obesity and obesity paradox in heart failure
Prog Cardiovasc Dis
Update on obesity and obesity paradox in heart failure
Prog Cardiovasc Dis
Meta-analysis of the relation of body mass index to all-cause and cardiovascular mortality and hospitalization in patients with chronic heart failure
Am J Cardiol
Body mass index and mortality in acutely decompensated heart failure across the world: a global obesity paradox
J Am Coll Cardiol
The heart failure overweight/obesity survival paradox: the missing sex link
JACC Heart Fail
Lifestyle modification in the prevention and treatment of atrial fibrillation
Prog Cardiovasc Dis
Trends in hospitalization in atrial fibrillation: epidemiology, cost, and implications for the future
Prog Cardiovasc Dis
Advances in the prevention and treatment of atrial fibrillation
Prog Cardiovasc Dis
Atrial fibrillation and obesity: results of a meta-analysis
Am Heart J
Obesity and cardiovascular disease: risk factor, paradox, and impact of weight loss
J Am Coll Cardiol
Influence of obesity on outcomes in atrial fibrillation: yet another obesity paradox
Am J Med
Body composition and prognosis in chronic systolic heart failure: the obesity paradox
Am J Cardiol
The obesity paradox in men versus women with systolic heart failure
Am J Cardiol
Obesity and prognosis: just one of many cardiovascular paradoxes
Prog Cardiovasc Dis
Fitness vs. fatness on all-cause mortality: a meta-analysis
Prog Cardiovasc Dis
Physical activity and cardiorespiratory fitness as major markers of cardiovascular risk: their independent and interwoven importance to health status
Prog Cardiovasc Dis
Physical activity versus cardiorespiratory fitness: two (partly) distinct components of cardiovascular health?
Prog Cardiovasc Dis
Role of fitness in the metabolically healthy but obese phenotype: a review and update
Prog Cardiovasc Dis
Impact of cardiorespiratory fitness on the obesity paradox in patients with heart failure
Mayo Clin Proc
Obesity paradox and cardiorespiratory fitness in 12,417 male veterans aged 40 to 70 years
Mayo Clin Proc
Cardiorespiratory fitness and the paradoxical BMI—mortality risk association in male veterans
Mayo Clin Proc
Impact of cardiorespiratory fitness on the obesity paradox in patients with systolic heart failure
Am J Cardiol
Cited by (361)
Effect of caffeine-chitosan nanoparticles and α-lipoic acid on the cardiovascular changes induced in rat model of obesity
2024, International ImmunopharmacologyRelationship between metabolically healthy obesity and coronary artery calcification
2024, Obesity Research and Clinical PracticeThe Prognostic Value and Treatment Strategies of Nutritional Status in Heart Failure Patients
2023, Current Problems in CardiologyTrends and predictions of metabolic risk factors for acute myocardial infarction: findings from a multiethnic nationwide cohort
2023, The Lancet Regional Health - Western PacificUpdates on obesity and the obesity paradox in cardiovascular diseases
2023, Progress in Cardiovascular Diseases
Statement of Conflict of Interest: see page XX.