ReviewObesity paradox in elderly patients with cardiovascular diseases
Introduction
Recent publications have shown that obesity in different populations such as elderly people and patients with cardiovascular diseases (CVD), like heart failure (HF) or coronary artery disease (CAD), is surprisingly not associated with a higher but with a lower mortality risk. This fact has thus been termed “obesity paradox”. A major overlap between those two population groups, in which the obesity paradox is usually observed, should here be taken into account: many elderly people are affected by CVD and the majority of CVD patients are elderly people [1], [2].
In the general population overweight and obesity are well-known risk factors for the development of cardiovascular diseases [3], [4] like HF [5], ischemic heart diseases [6], abnormal left ventricular geometry, endothelial dysfunction, systolic and diastolic dysfunction and atrial fibrillation [4]. Overweight and obesity increase overall mortality and predict premature death [7], [8], [9], [10]. Furthermore obesity is associated with the development of cardiovascular risk factors like increased insulin resistance and type 2 diabetes mellitus, hypertension and dyslipidemia. The majority of studies evaluating obesity-related cardiovascular risk factors have been conducted in middle-aged, not in older adults, however, the prevalences of most of the obesity-related cardiovascular risk factors, such as hypertension and diabetes mellitus increase with age.
Prevalence of overweight and obesity are increasing in all age groups, including elderly people [11], [12], [13]. On the other hand, until recently, underweight, malnutrition and frailty in elderly people constituted the most important issues. However, the increase in prevalence of overweight and obesity due to an increase in this overall prevalence and due to the ongoing expansion of the elderly proportion in the population in industrial nations has led to a focus of this problem in the elderly, too. Obesity in older subjects is associated with increased morbidity such as infections [14], functional limitations and poor quality of life [15], [16], and obese older persons are admitted more frequently to nursing homes compared to those who are not [17]. Additionally, obesity in the elderly is correlated with decreased autonomy and mobility, with increased handicap in activities of daily living (such as personal hygiene, washing and eating) and instrumental activities of daily living (such as climbing stairs and shopping) [18]. A high BMI is associated with a lower quality of life, as a study in 5362 patients with coronary artery diseases one year after their index cardiac catheterization revealed. This is especially marked in subjects with severe obesity [19].
If the role of overweight and obesity in older patients and in patients with heart diseases is controversial, clinical consequences and the role of weight management in elderly patients, in patients with heart disease and in subjects with a combination of both are even more so. Hence, it was the aim of this review to analyze the role of obesity in the elderly in the development of cardiovascular risk factors and CVD. Furthermore, the so called obesity paradox in elderly and in patients with CVD is analyzed and possible explanations discussed. The association of aging, obesity, CVD and mortality and underlying patho-physiological mechanisms are reviewed and the effect of weight loss in elderly subjects and in patients with CVD examined. The recommendations of medical associations in terms of weight management in patients for whom an obesity paradox has been reported are accumulated, and based on the analyzed literature, possible clinical implications are summarized.
Section snippets
Definition of obesity
Obesity is commonly classified as BMI ≥ 30 kg/m, whereas a BMI < 18.5 is classified as underweight, a BMI of 18.5–24.9 as normal weight and a BMI of 25–29.9 as overweight [20], [21]. This classification does not take into account sex or age. In a systematic meta-analysis BMI cut-offs to diagnose obesity showed a pooled sensitivity of only 0.50 (95% CI 0.43–0.57) and a specificity of 0.90 (95% CI 0.86–0.94) [22]. In older persons, age-related changes in body composition like decrease in fat free
The obesity paradox
An unexpected finding which showed that obese patients with terminal renal insufficiency and hemodialyses seemed to live longer compared to normal weight subjects formed the basis for the “obesity-survival paradox”, first published in 1999 [28]. The fact that obesity and other classical cardiovascular risk factors like hypercholesterolemia and hypertension apparently seemed to decrease and not increase the risk in chronic diseases, like terminal kidney diseases and chronic HF, was acknowledged
Prevalence of cardiovascular risk factors in the elderly
The metabolic syndrome and its components which include excess abdominal fat, insulin-resistance, dyslipidemia, and high blood pressure are highly prevalent in older populations (NCEP, 2002). The prevalence of the metabolic syndrome increases with age and reaches a peak in men aged 50–70 years and women aged 60–80 years [39]. In the adult population with age fasting plasma glucose and postprandial glucose increase by 1–2 mg/dl and 10–20 mg/dl, respectively, for each decade [40]. As a consequence,
Obesity in the elderly, cardiovascular risk factors and risk of cardiovascular diseases
Abdominal obesity is associated with the development of the metabolic syndrome, even in men and women aged 70–79 years [44]. Older adults who are physically active and do not have increased abdominal circumference are much less likely to develop type 2 diabetes mellitus [45]. Obesity and hypertension continue to be correlated, even in old age [46], [47]. Dyslipidemia, low HDL-cholesterol and high triglycerides are also associated with abdominal obesity, even in old adults [48], [49], [50]. In a
Obesity and mortality in older people
In the general population, all-cause mortality as well as mortality due to cardiovascular diseases depending on the BMI show a J-shaped curve. Both a low and a very high BMI are associated with increased overall as well as cause-specific mortality [3], [57], [58]. In the general population the nadir of this J-shaped curve was found at a BMI of 23.5 to 24.9 in men and 22.0 to 23.4 in women [57]. For older people, a U- or J-shaped mortality curve depending on the BMI has also been described, with
Obesity and mortality in patients with heart failure
In a meta-analysis examining the mortality in HF patients by BMI, nine observational studies were analyzed, including a total sample of 28,209 subjects [63]. The mean age in these studies ranged from 51 to 72 years, the proportion of females ranged from 13 to 39%. In all of these studies overweight and obesity were associated with a lower all-cause mortality risk compared to normal weight, although this association was not statistically significant in either of the studies. The pooled odds ratio
Obesity and mortality in patients with ischemic heart disease
In a meta-analysis, including 22 cohort studies with a total sample size of 196,084 subjects after coronary revascularization the mortality was analyzed by BMI categories [72]. Out of these there were ten studies on mortality post-percutaneous coronary intervention (PCI). The subjects had a mean age between 60 and 67 years and the proportion of females was between 18 and 33%. In the meta-analysis, in the subgroup of post-PCI subjects the odds ratios for 30-day in-hospital mortality for
Possible explanations for the obesity paradox
The so called obesity paradox in elderly subjects and in patients with cardiovascular diseases has been critically analyzed by a number of review articles [83], [84], [85], [86]. The studies that show a significant statistic association between a high BMI and reduced overall mortality are all observational studies and not randomized clinical trials. Based on this design, no clear conclusions can be drawn with regards to causality. A number of potential methodological influences and other
Association between aging, obesity, cardiovascular diseases and mortality and possible involved patho-physiological mechanisms
The association between aging, obesity, cardiovascular diseases and mortality and the role of frailty and inflammation in this cascade are depicted in Fig. 1. In this figure also potential explanations which are discussed to be involved in the obesity paradox are outlined. Aging is not only an independent risk factor for cardiovascular diseases and mortality, aging is also associated with fat redistribution. With age, body composition changes with an increase in fat mass and a decrease in
Effects of weight loss in the elderly
There are several observational studies in which the effect of weight loss on mortality in older age groups has been evaluated. Most studies show that recent weight loss is associated with increased mortality [120], [121], [122]. In a review of 17 studies of weight loss and all-cause mortality the conclusion was that those who remained weight-stable had the lowest mortality rate [123].
In a prospective study of 5722 Swedish overweight and obese, but otherwise healthy men who lost weight were
Recommendation for weight loss in the elderly with CVD
The American Heart Association recommends weight reduction in patients with HF and with a BMI of > 40 kg/m². Weight loss should not be encouraged in patients with HF if the BMI is < 30 kg/m2, but patients should rather be encouraged to monitor for loss of appetite, unexpected weight loss, and muscle wasting [144]. There is no specific recommendation for elderly people with HF, but in the recommendation it is stated that the vast majority of persons with HF seen in clinics and hospitals are older
Conclusion
The clinical implications of the observed interrelation between a high BMI and a lower mortality in the elderly and in patients with cardiovascular diseases remain inconclusive. Since there is a big overlap between elderly patients and patients with CVD, it remains unclear which medical condition causes the so called obesity paradox. Intentional weight reduction as a result of personal choice even in elderly patients with obesity, especially with severe obesity, seems to be beneficial with
Acknowledgement
The authors would like to thank Katharina Viktoria Stein for proof-reading the manuscript. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [147].
References (147)
- et al.
Patterns of coronary heart disease morbidity and mortality in the sexes: a 26-year follow-up of the Framingham population
Am Heart J
(1986) - et al.
Obesity and cardiovascular disease: risk factor, paradox, and impact of weight loss
J Am Coll Cardiol
(2009) Mortality of severely obese subjects
Am J Clin Nutr
(1992)Obesity and functional decline: epidemiology and geriatric consequences
Clin Geriatr Med
(2005)- et al.
Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society
Am J Clin Nutr
(2005) - et al.
Effects of age on body fat distribution and cardiovascular risk factors in women
Am J Clin Nutr
(1997) - et al.
Influence of excess weight on mortality and hospital stay in 1346 hemodialysis patients
Kidney Int
(1999) - et al.
Reverse epidemiology of cardiovascular risk factors in maintenance dialysis patients
Kidney Int
(2003) - et al.
Nutrition and survival in patients with liver cirrhosis
Nutrition
(2001) - et al.
Impact of weight on long-term survival among patients without known coronary artery disease and a normal stress SPECT MPI
J Nucl Cardiol
(2010)
Contribution of visceral fat mass to the insulin resistance of aging
Metabolism
Dyslipidaemia and obesity
Baillières Clin Endocrinol Metab
Associations of body mass index and anthropometric indicators of fat mass and fat free mass with all-cause mortality among women in the first and second National Health and Nutrition Examination Surveys follow-up studies
Ann Epidemiol
Body mass index and mortality in heart failure: a meta-analysis
Am Heart J
Obesity and survival in patients with heart failure and preserved systolic function: a U-shaped relationship
Am Heart J
Influence of etiology of heart failure on the obesity paradox
Am J Cardiol
An obesity paradox in acute heart failure: analysis of body mass index and inhospital mortality for 108,927 patients in the Acute Decompensated Heart Failure National Registry
Am Heart J
Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies
Lancet
Obesity paradox in patients with hypertension and coronary artery disease
Am J Med
Excess weight at time of presentation of myocardial infarction is associated with lower initial mortality risks but higher long-term risks including recurrent re-infarction and cardiac death
Int J Cardiol
The obesity paradox in non-ST-segment elevation acute coronary syndromes: results from the Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the American College of Cardiology/American Heart Association Guidelines Quality Improvement Initiative
Am Heart J
Relationship between body mass index and left main disease: the obesity paradox
Arch Med Res
Medical therapies and invasive treatments for coronary artery disease by body mass: the “obesity paradox” in the Get With The Guidelines database
Am J Cardiol
The obesity paradox: fact or fiction?
Am J Cardiol
B-type natriuretic peptide levels in obese patients with advanced heart failure
J Am Coll Cardiol
Obesity and suppressed B-type natriuretic peptide levels in heart failure
J Am Coll Cardiol
Reverse epidemiology of conventional cardiovascular risk factors in patients with chronic heart failure
J Am Coll Cardiol
The role of tumor necrosis factor in the pathophysiology of heart failure
J Am Coll Cardiol
The endotoxin–lipoprotein hypothesis
Lancet
Prognostic importance of weight loss in chronic heart failure and the effect of treatment with angiotensin-converting-enzyme inhibitors: an observational study
Lancet
Contrasting clinical properties and exercise responses in obese and lean hypertensive patients
J Am Coll Cardiol
Relation between obesity and severity of coronary artery disease in patients undergoing coronary angiography
Am J Cardiol
Changes in nutritional status and patterns of morbidity among free-living elderly persons: a 10-year longitudinal study
Nutrition
Prediction of lifetime risk for cardiovascular disease by risk factor burden at 50 years of age
Circulation
Cause-specific excess deaths associated with underweight, overweight, and obesity
JAMA
Obesity and the risk of heart failure
N Engl J Med
Body weight and weight gain during adult life in men in relation to coronary heart disease and mortality. A prospective population study
Eur Heart J
Obesity in adulthood and its consequences for life expectancy: a life-table analysis
Ann Intern Med
Years of life lost due to obesity
JAMA
Body-mass index and mortality in Korean men and women
N Engl J Med
Prevalence of overweight and obesity in Austrian male and female farmers
Soz Praventivmed
Obesity in 70-year-old Swedes: secular changes over 30 years
Int J Obes Lond
Obesity in nursing homes: an escalating problem
J Am Geriatr Soc
Body mass index and the risk of infections in institutionalised geriatric patients
Br J Nutr
Percentage of body fat and body mass index are associated with mobility limitations in people aged 70 and older from NHANES III
J Am Geriatr Soc
Obesity affects nursing-care facility admission among whites but not blacks
Obes Res
Association between obesity and health-related quality of life in patients with coronary artery disease
Int J Obes Lond
Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults—the evidence report. National Institutes of Health
Obes Res
Obesity: preventing and managing the global epidemic. Report of a WHO consultation
World Health Organ Tech Rep Ser
Diagnostic performance of body mass index to identify obesity as defined by body adiposity: a systematic review and meta-analysis
Int J Obes Lond
Cited by (101)
Obesity paradox in older sarcopenic adults ― a delay in aging: A systematic review and meta-analysis
2024, Ageing Research ReviewsMonitoring body composition change for intervention studies with advancing 3D optical imaging technology in comparison to dual-energy X-ray absorptiometry
2023, American Journal of Clinical NutritionDevelopment of an approach for identifying overnutrition among older adults in community health care settings: - an opinion paper
2023, Clinical Nutrition Open ScienceSex-different changes of body composition in aging: a systemic review
2022, Archives of Gerontology and GeriatricsCitation Excerpt :In contrast, lower extremity fat was associated with a more favorable cardiometabolic profile in women than in men. Likewise, the obesity paradox shows that obesity in the elderly population is favorably associated with cognitive function (Skinner et al., 2017), dementia (Spauwen et al., 2017), and cardiovascular disease (Dorner and Rieder, 2012). Therefore, this systematic review aimed to gather evidence and assess the relationship between sex differences in the association between the amount and distribution of skeletal muscle and body fat and various health conditions in older adults.
Joint Association of Metabolic Health and Obesity with Ten-Year Risk of Cardiovascular Disease among Chinese Adults
2022, Biomedical and Environmental Sciences