Body mass index and mortality in heart failure: a meta-analysis

Cachexia and sarcopenia: emerging syndromes of importance in dogs and cats

Cachexia is the loss of lean body mass (LBM) that affects a large proportion of dogs and cats with congestive heart failure (CHF), chronic kidney disease (CKD), cancer, and a variety of other chronic diseases. Sarcopenia, the loss of LBM that occurs with aging, is a related syndrome, although sarcopenia occurs in the absence of disease. As many of the diseases associated with muscle loss are more common in aging, cachexia and sarcopenia often are concurrent problems. Both cachexia and sarcopenia have important clinical implications because they are associated with increased morbidity and mortality. The pathophysiology of these 2 syndromes is complex and multifactorial, but recent studies have provided new information that has helped to clarify mechanisms and identify potential new targets for treatment. Newly identified mechanisms and pathways that mediate cachexia appear to act by increasing energy requirements, decreasing energy intake, impairing nutrient absorption, and causing metabolic alterations. Whereas cachexia and sarcopenia are important areas of research for drug development in people, they are only beginning to be recognized in veterinary medicine. Greater awareness and earlier diagnosis will help provide practical approaches to managing body weight and lean tissue in dogs and cats, as well as more directed targets for treatment.

Inverse relation of body weight and weight change with mortality and morbidity in patients with type 2 diabetes and cardiovascular co-morbidity: an analysis of the PROactive study population

CONTEXT

Although weight reduction is a recommended goal in type 2 diabetes mellitus (T2DM), weight loss is linked to impaired survival in patients with some chronic cardiovascular diseases.

OBJECTIVE

To assess the association of weight and weight change with mortality and non-fatal cardiovascular outcomes (hospitalisation, myocardial infarction and stroke) in T2DM patients with cardiovascular co-morbidity and the effect of pioglitazone-induced weight change on mortality.

SETTING AND PARTICIPANTS

We assessed in a post hoc analysis body weight and weight change in relation to outcome in 5202 patients from the PROactive trial population who had T2DM and evidence of pre-existing cardiovascular disease. Patients were randomized to treatment with pioglitazone or placebo in addition to their concomitant glucose-lowering and cardiovascular medication. Mean follow up was 34.5 months.

MAIN OUTCOME MEASURE

The impact of body weight and body weight change on all-cause mortality, cardiovascular mortality, on non-fatal cardiovascular events and on hospitalisation.

RESULTS

The lowest mortality was seen in patients with BMI 30-35 kg/m(2) at baseline. In comparison to this (reference group), patients in the placebo group with BMI <22 kg/m(2) (Hazard Ratio (95% confidence intervals) 2.96 [1.27 to 6.86]; P=0.012) and BMI 22 to 25 kg/m(2) (HR 1.88 [1.11 to 3.21]; P=0.019) had a higher all-cause mortality. Weight loss was associated with increased total mortality (HR per 1% body weight: 1.13 [1.11 to 1.16]; P<0.0001), with increased cardiovascular mortality, all-cause hospitalisation and the composite of death, myocardial infarction and stroke. Weight loss of ≥7.5% body weight (seen in 18.3% of patients) was the strongest cut-point to predict impaired survival (multivariable adjusted HR 4.42 [3.30 to 5.94]. Weight gain was not associated with increased mortality. Weight gain in patients treated with pioglitazone (mean+4.0±6.1 kg) predicted a better prognosis (HR per 1% weight gain: 0.96 [0.92 to 1.00] P=0.037) compared to patients without weight gain.

CONCLUSION

Among patients with T2DM and cardiovascular co-morbidity, overweight and obese patients had a lower mortality compared to patients with normal weight. Weight loss but not weight gain was associated with increased mortality and morbidity. There may be an "obesity paradox" in patients with type 2 diabetes and cardiovascular risk. The original PROactive trial is registered as an International Standard Randomized Controlled Trial (Number ISRCTN NCT00174993).

Usefulness of body mass index to characterize nutritional status in patients with heart failure

The obesity paradox in heart failure (HF) is criticized because of the limitations of body mass index (BMI) in correctly characterizing overweight and obese patients, necessitating a better evaluation of nutritional status. The aim of this study was to assess nutritional status, BMI, and significance in terms of HF survival. Anthropometry and biochemical nutritional markers were assessed in 55 HF patients. Undernourishment was defined as the presence of ≥2 of the following indexes below the normal range: triceps skinfold, subscapular skinfold, arm muscle circumference, albumin, and total lymphocyte count. Patients were also stratified by BMI and followed for a median of 26.7 months. Across BMI strata, no patient was underweight, 31% were normal weight, 42% were overweight, and 27% were obese. Undernourishment was present in 53% of normal-weight patients, 22% of overweight patients, and none of the obese patients (p = 0.001). Undernourished patients had significantly higher mortality (p = 0.009) compared to well-nourished patients. In multivariate analysis, only undernutrition (hazard ratio 3.149, 95% confidence interval 1.367 to 7.253), New York Heart Association functional class (hazard ratio 3.374, 95% confidence interval 1.486 to 7.659), and age (hazard ratio 1.115, 95% confidence interval 1.045 to 1.189) remained in the model. Among nutritional indicators, subscapular skinfold was the best predictor of mortality; patients with subscapular skinfold in the fifth percentile had higher mortality (p = 0.0001). In conclusion, BMI does not indicate true nutritional status in HF. Classifying patients as well nourished or undernourished may improve risk stratification.

The obesity paradox and weight loss

BACKGROUND

An "obesity paradox," in which overweight and obese individuals with established cardiovascular disease have a better prognosis than normal weight subjects, has been reported in a number of clinical cohorts, but little is known about the effects of weight loss on the obesity paradox and its association with health outcomes.

METHODS

Weight was determined in 3834 men at the time of a clinically referred exercise test and again during a clinical evaluation a mean of 7 years later. The associations among weight changes, baseline fitness, and other risk markers with cardiovascular and all-cause mortality were determined by Cox proportional hazards analysis.

RESULTS

During the follow-up period, 314 subjects died (72 of cardiovascular causes). In a multivariate analysis (including baseline weight, weight change, exercise capacity, and cardiovascular disease), weight gain was associated with lower mortality and weight loss was associated with higher mortality (4% higher per pound lost per year, P<.001) compared with stable weight. For all-cause mortality, the relative risks for the no change, weight gain, and weight loss groups were 1.0 (referent), 0.64 (95% confidence interval, 0.50-0.83), and 1.49 (95% confidence interval, 1.17-1.89), respectively (P<.001). Those who died and exhibited weight loss had a significantly higher prevalence of deaths due to cancer and cardiovascular causes.

CONCLUSION

Weight loss was related to higher mortality and weight gain was related to lower mortality when compared with stable weight. The obesity paradox in our sample is explained in part by a combination of non-volitional weight loss related to occult disease and a protective effect of weight gain.

Body weight after stroke: lessons from the obesity paradox

BACKGROUND AND PURPOSE

Outcome after acute stroke is determined to a large extent by poststroke complications. Nutritional status and metabolic balance may substantially contribute to outcome after stroke. Key mechanisms of stroke pathophysiology can induce systemic catabolic imbalance with impaired metabolic efficiency and degradation of body tissues.

SUMMARY

Tissue wasting, sarcopenia, and cachexia may impair and delay poststroke rehabilitation and worsen the prognosis. Although current guidelines for secondary prevention after stroke recommend weight reduction, increasing evidence suggests that patients who are overweight and mildly obese may actually have a better outcome. An "obesity paradox" has been identified to describe the contrasting impact of being overweight in patients with chronic illness compared with healthy populations. We present an overview on the metabolic regulation in patients with stroke and evaluate current data on the impact of body weight and weight change after stroke. The emerging picture suggests that being overweight and obese may impact patients with stroke differently than it does healthy subjects.

CONCLUSIONS

We propose that current knowledge on obesity and its management in primary prevention cannot be transferred to patients with established stroke. Systematic studies on changes in body composition after stroke and on treatment options are warranted to establish the pathophysiology and evidence-driven management of nutritional status in these patients.

Association between body condition and survival in dogs with acquired chronic kidney disease

BACKGROUND

Obesity in people with chronic kidney disease (CKD) is associated with longer survival. The purpose of this study was to determine if a relationship exists between body condition score (BCS) and survival in dogs with CKD.

HYPOTHESIS/OBJECTIVES

Higher BCS is a predictor of prolonged survival in dogs with CKD.

ANIMALS

One hundred dogs were diagnosed with CKD (International Renal Interest Society stages II, III or IV) between 2008 and 2009.

METHODS

Retrospective case review. Data regarding initial body weight and BCS, clinicopathologic values and treatments were collected from medical records and compared with survival times.

RESULTS

For dogs with BCS recorded (n = 72), 13 were underweight (BCS = 1-3; 18%), 49 were moderate (BCS = 4-6; 68%), and 10 were overweight (BCS = 7-9; 14%). For dogs with at least 2 body weights recorded (n = 77), 21 gained weight, 47 lost weight, and 9 had no change in weight. Dogs classified as underweight at the time of diagnosis (median survival = 25 days) had a significantly shorter survival time compared to that in both moderate (median survival = 190 days; P < .001) and overweight dogs (median survival = 365 days; P < .001). There was no significant difference in survival between moderate and overweight dogs (P = .95).

CONCLUSIONS AND CLINICAL IMPORTANCE

Higher BCS at the time of diagnosis was significantly associated with improved survival. Further research on the effects of body composition could enhance the management of dogs with CKD.

B-type natriuretic peptide and anthropometric measures in a Brazilian elderly population with a high prevalence of Trypanosoma cruzi infection

B-type natriuretic peptide (BNP) is a diagnostic and prognostic tool in heart failure and also in Chagas disease, which is caused by the protozoan Trypanosoma cruzi and has cardiomyopathy as a main feature. BNP lipolytic actions and T. cruzi infection in the adipose tissue have been recently described. We aim to investigate the relationship between BNP and anthropometric measures and whether it is influenced by T. cruzi infection. We measured BNP, body mass index (BMI), waist circumference (WC), triceps skin-fold thickness (TSF) and performed serological, biochemical and electrocardiographic exams in 1398 subjects (37.5% infected with T. cruzi) in a community-dwelling elderly population in Bambui city, Brazil. Linear multivariate regression analysis was performed to investigate determinants of BNP levels. BNP levels were significantly (p<0.05) higher in T. cruzi-infected subjects than in the non-infected group (median=121 and 64pg/mL, respectively). BMI, WC and TSF in infected subjects were significantly lower than those in non-infected subjects (24.3 vs. 25.5kg/m2; 89.2 vs. 92.4cm; and 14.5 vs. 16.0mm, respectively). There was an inverse relationship between BNP levels and BMI (b=-0.018), WC (b=-0.005) and TSF (b=-0.193) levels. Infected and non-infected groups showed similar inverse relationships between BNP and BMI (b=-0.021 and b=-0.015, respectively). In conclusion, there was an inverse relationship between BNP levels and the anthropometric measures. Despite the actions in the adipose tissue, T. cruzi infection did not modify the associations between BNP and BMI, suggesting that body mass does not modify the accuracy of BNP in Chagas disease.

Weight and mortality following heart failure hospitalization among diabetic patients

BACKGROUND

Type 2 diabetes is an important risk factor for heart failure and is common among patients with heart failure. The impact of weight on prognosis after hospitalization for acute heart failure among patients with diabetes is unknown. The objective of this study was to examine all-cause mortality in relation to weight status among patients with type 2 diabetes hospitalized for decompensated heart failure.

METHODS

The Worcester Heart Failure Study included adults admitted with acute heart failure to all metropolitan Worcester medical centers in 1995 and 2000. The weight status of 1644 patients with diabetes (history of type 2 diabetes in medical record or admission serum glucose ≥200 mg/dL) was categorized using body mass index calculated from height and weight at admission. Survival status was ascertained at 1 and 5 years after hospital admission.

RESULTS

Sixty-five percent of patients were overweight or obese and 3% were underweight. Underweight patients had 50% higher odds of all-cause mortality within 5 years of hospitalization for acute heart failure than normal weight patients. Class I and II obesity were associated with 20% and 40% lower odds of dying. Overweight and Class III obesity were not associated with mortality. Results were similar for mortality within 1 year of hospitalization for acute heart failure.

CONCLUSIONS

The mechanisms underlying the association between weight status and mortality are not fully understood. Additional research is needed to explore the effects of body composition, recent weight changes, and prognosis after hospitalization for heart failure among patients with diabetes.

Glucose metabolism and cardiac hypertrophy

The most notable change in the metabolic profile of hypertrophied hearts is an increased reliance on glucose with an overall reduced oxidative metabolism, i.e. a reappearance of the foetal metabolic pattern. In animal models, this change is attributed to the down-regulation of the transcriptional cascades promoting gene expression for fatty acid oxidation and mitochondrial oxidative phosphorylation in adult hearts. Impaired myocardial energetics in cardiac hypertrophy also triggers AMP-activated protein kinase (AMPK), leading to increased glucose uptake and glycolysis. Aside from increased reliance on glucose as an energy source, changes in other glucose metabolism pathways, e.g. the pentose phosphate pathway, the glucosamine biosynthesis pathway, and anaplerosis, are also noted in the hypertrophied hearts. Studies using transgenic mouse models and pharmacological compounds to mimic or counter the switch of substrate preference in cardiac hypertrophy have demonstrated that increased glucose metabolism in adult heart is not harmful and can be beneficial when it provides sufficient fuel for oxidative metabolism. However, improvement in the oxidative capacity and efficiency rather than the selection of the substrate is likely the ultimate goal for metabolic therapies.

Body mass index in a large cohort of patients assigned to age decades between <20 and ≥80 years: relationship with cardiovascular morbidity and medication

OBJECTIVE

There is an ongoing debate about the relationship between obesity and morbidity in the elderly, the clinical relevance of overweight and obesity in older patients and the need or harms of treatment. The main purpose of our study was to investigate whether a higher BMI is associated with a worse cardiovascular risk in all age groups, especially in the older ones.

SUBJECTS AND DESIGN

We performed a retrospective evaluation of clinical data from 3926 patients who visited a medical outdoor center for diagnostic and/or therapeutic interventions in the period from January 1995 to July 2010. Patients were assigned to eight age groups of one decade from <20 years to ≥80 years.

RESULTS

The Body Mass Index (BMI) of our patients showed a continuous increase with increasing age with peak values in the age decade 61-70 years (26.29 ±4.42 kg/m2). This was paralleled by an increase in cardiovascular events and need for continuous medication, demonstrating peak values in the age decade 61-70 years (22.3% in the female and 24.7% in the male group). In all age decades up to 80 years the BMI values were higher in patients with events compared to those without it. multivariable linear regression analysis - including confounding variables (blood pressure, fasting glucose, HDL-cholesterol, triglycerides, physical activity, smoking) - revealed for all age groups a strong positive relation of BMI and a negative relation of fat free mass (FFM) to the probability for a cardiovascular event and need for medication.

CONCLUSION

In all age groups, the percentage of cardiovascular events was directly correlated with the BMI. Having in mind the transition to an aging society, therapeutic and preventive strategies should, therefore, include weight management strategies also for the elderly.

Life expectancy and life expectancy with disability of normal weight, overweight, and obese smokers and nonsmokers in Europe

The goal of this study was to estimate life expectancy (LE) and LE with disability (LwD) among normal weight, overweight, and obese smokers and nonsmokers in Western Europe. Data from four waves (1998-2001) of the European Community Household Panel (ECHP) were used; a standardized multipurpose annual longitudinal survey. Self-reported health and socioeconomic information was collected repeatedly using uniform questionnaires for 66,331 individuals in nine countries. Health status was measured in terms of disability in daily activities. Multistate Markov (MSM) models were applied to obtain hazard ratios (HRs) and age-specific transition rates according to BMI and smoking status. Multistate life tables were computed using the predicted transition probabilities to estimate LE and LwD. Significant associations were observed between disability incidence and BMI (HR = 1.15 for overweight, HR = 1.64 for obese, compared to normal weight). The risk of mortality was negatively associated with overweight status among disabled (HR = 0.77). Overweight people had higher LE than people with normal-weight and obesity. Among women, overweight and obese nonsmokers expect 3.6 and 6.1 more years of LwD than normal weight persons, respectively. In contrast, daily smokers expect lower LE but a similar LwD. The same patterns were observed among people with high education and those with low education. To conclude, daily smoking is associated with mortality more than with disability, whereas obesity is associated with disability more than with mortality. The findings suggest that further tobacco control would contribute to increasing LE, while tackling the obesity epidemic is necessary to prevent an expansion of disability.

[Paradox of obesity in heart failure: results from the Spanish RICA Registry]

BACKGROUND AND OBJECTIVES

Obesity is a risk factor for heart failure (HF). Paradoxically, it has been described that body mass index (BMI) is inversely associated with mortality. The aim of this study was to analyse the relationship between BMI and mortality in a cohort of patients with HF.

PATIENTS AND METHODS

All patients included in the RICA Registry between March 2008 and September 2009 were analysed. RICA is a multicenter, prospective cohort study that includes patients admitted for decompensated HF in Spanish Internal Medicine Services. Patients were divided according to the WHO body weight categories.

RESULTS

712 patients were included; 54% were women and mean age was 77.3 years. Hypertensive cardiopathy was the most common etiology of HF with some differences according to BMI categories, being valvular disease more frequent among obese and overweight patients and ischemic HF among normal weight patients. Mean left ventricle ejection fraction was 50.2% and it was higher among higher BMI categories. Natriuretic peptide levels were significantly lower among higher BMI categories (P<.05). Overall mortality after one-year of follow-up was 13.9% and it was significantly lower among higher BMI categories: normal BMI 20.4%, overweight 14.7% and obesity 8.5% (P<.01). In the multivariate analysis, overweight was significantly and independently associated with an increased mortality risk in comparison with obesity: RR 3.05 (IC95% 1.24-7.54).

CONCLUSIONS

An increase in BMI was associated with lower levels of natriuretic peptides and lower mortality.

Metabolic syndrome and heart failure--the risk, paradox, and treatment

The constellation of obesity, hypertension, dyslipidemia, and insulin resistance-together referred to as metabolic syndrome (MetS)-is increasing in prevalence in the American population and also worldwide. The individual components of MetS and MetS as a whole increase the risk of heart failure, cardiovascular mortality, and all-cause mortality. Despite this adverse association, numerous studies have documented an obesity paradox, in which overweight and obese people with established cardiovascular disease, including hypertension, coronary heart disease, heart failure, and peripheral arterial disease, have a better prognosis than patients who are not overweight or obese. Current treatment strategies for these patients include weight loss, control of blood pressure and cholesterol levels, and treatment of hyperglycemia. Because of increasing evidence for the obesity paradox, some physicians question whether obesity should be treated when it is associated with heart failure. Several studies have shown improvement in left ventricular function and decreased mortality and morbidity from heart failure with weight loss and treatment of elevated blood pressure, cholesterol, and hyperglycemia. The most reasonable approach at this time appears to be weight loss and exercise, lowering blood pressure to less than 130/80 mm Hg, low-density lipoprotein (LDL) cholesterol to less than 100 mg/dL, and glycosylated hemoglobin levels to less than 7%.

The obesity paradox and cardiovascular disease

Obesity is increasingly recognized as a global pandemic that threatens the health of millions of people. Obesity is considered to be an important cardiovascular risk factor, but there is increasing evidence that patients with elevated body mass index may be better off than others if they develop cardiovascular or renal disease. This phenomenon has been described as the "obesity paradox" or "reverse epidemiology." This article reviews some recent publications that have studied this phenomenon as it relates to heart failure, coronary artery disease, peripheral arterial disease, kidney disease, and a cohort of patients undergoing nonbariatric surgery.

The role of dietary fatty acids in predicting myocardial structure in fat-fed rats

Background

Obesity increases the risk for development of cardiomyopathy in the absence of hypertension, diabetes or myocardial ischemia. Not all obese individuals, however, progress to heart failure. Indeed, obesity may provide protection from cardiovascular mortality in some populations. The fatty acid milieu, modulated by diet, may modify obesity-induced myocardial structure and function, lending partial explanation for the array of cardiomyopathic phenotypy in obese individuals.

Methods

Adult male Sprague-Dawley rats were fed 1 of the following 4 diets for 32 weeks: control (CON); 50% saturated fat (SAT); 40% saturated fat + 10% linoleic acid (SAT+LA); 40% saturated fat + 10% α-linolenic acid (SAT+ALA). Serum leptin, insulin, glucose, free fatty acids and triglycerides were quantitated. In vivo cardiovascular outcomes included blood pressure, heart rate and echocardiographic measurements of structure and function. The rats were sacrificed and myocardium was processed for fatty acid analysis (TLC-GC), and evaluation of potential modifiers of myocardial structure including collagen (Masson's trichrome, hydroxyproline quantitation), lipid (Oil Red O, triglyceride quantitation) and myocyte cross sectional area.

Results

Rats fed SAT+LA and SAT+ALA diets had greater cranial LV wall thickness compared to rats fed CON and SAT diets, in the absence of hypertension or apparent insulin resistance. Treatment was not associated with changes in myocardial function. Myocardial collagen and triglycerides were similar among treatment groups; however, rats fed the high-fat diets, regardless of composition, demonstrated increased myocyte cross sectional area.

Conclusions

Under conditions of high-fat feeding, replacement of 10% saturated fat with either LA or ALA is associated with thickening of the cranial LV wall, but without concomitant functional changes. Increased myocyte size appears to be a more likely contributor to early LV thickening in response to high-fat feeding. These findings suggest that myocyte hypertrophy may be an early change leading to gross LV hypertrophy in the hearts of "healthy" obese rats, in the absence of hypertension, diabetes and myocardial ischemia.

Systolic blood pressure and incident heart failure in the elderly. The Cardiovascular Health Study and the Health, Ageing and Body Composition Study

BACKGROUND

The exact form of the association between systolic blood pressure (SBP) and heart failure (HF) risk in the elderly remains incompletely defined, especially in individuals not receiving antihypertensive drugs.

OBJECTIVE

To examine the association between SBP and HF risk in the elderly.

DESIGN

Competing-risks proportional hazards modelling of incident HF risk, using 10-year follow-up data from two NIH-sponsored cohort studies: the Cardiovascular Health Study (inception: 1989-90 and 1992-3) and the Health ABC Study (inception: 1997-8).

SETTING

Community-based cohorts.

PARTICIPANTS

4408 participants (age, 72.8 (4.9) years; 53.1% women, 81.7% white; 18.3% black) without prevalent HF and not receiving antihypertensive drugs at baseline.

MAIN OUTCOME MEASURES

Incident HF, defined as first adjudicated hospitalisation for HF.

RESULTS

Over 10 years, 493 (11.2%) participants developed HF. Prehypertension (120-139 mm Hg), stage 1 (140-159 mm Hg), and stage 2 (≥160 mm Hg) hypertension were associated with escalating HF risk; HRs versus optimal SBP (<120 mm Hg) in competing-risks models controlling for clinical characteristics were 1.63 (95% CI 1.23 to 2.16; p=0.001), 2.21 (95% CI 1.65 to 2.96; p<0.001) and 2.60 (95% CI 1.85 to 3.64; p<0.001), respectively. Overall 255/493 (51.7%) HF events occurred in participants with SBP <140 mm Hg at baseline. Increasing SBP was associated with higher HF risk in women than in men; no race-SBP interaction was seen. In analyses with continuous SBP, HF risk had a continuous positive association with SBP to levels as low as 113 mm Hg in men and 112 mm Hg in women.

CONCLUSIONS

There is a continuous positive association between SBP and HF risk in the elderly for levels of SBP as low as <115 mm Hg; over half of incident HF events occur in individuals with SBP <140 mm Hg.

Diets and enteral supplements for improving outcomes in chronic kidney disease

Protein-energy wasting (PEW), which is manifested by low serum levels of albumin or prealbumin, sarcopenia and weight loss, is one of the strongest predictors of mortality in patients with chronic kidney disease (CKD). Although PEW might be engendered by non-nutritional conditions, such as inflammation or other comorbidities, the question of causality does not refute the effectiveness of dietary interventions and nutritional support in improving outcomes in patients with CKD. The literature indicates that PEW can be mitigated or corrected with an appropriate diet and enteral nutritional support that targets dietary protein intake. In-center meals or oral supplements provided during dialysis therapy are feasible and inexpensive interventions that might improve survival and quality of life in patients with CKD. Dietary requirements and enteral nutritional support must also be considered in patients with CKD and diabetes mellitus, in patients undergoing peritoneal dialysis, renal transplant recipients, and in children with CKD. Adjunctive pharmacological therapies, such as appetite stimulants, anabolic hormones, and antioxidative or anti-inflammatory agents, might augment dietary interventions. Intraperitoneal or intradialytic parenteral nutrition should be considered for patients with PEW whenever enteral interventions are not possible or are ineffective. Controlled trials are needed to better assess the effectiveness of in-center meals and oral supplements.

Body mass index and long-term mortality in an elderly Mediterranean population

OBJECTIVES

To describe the relationship of body mass index and mortality in older adults, examining the influence of sex and cardiovascular morbidity.

METHODS

Sixteen-year cohort of a population sample of 1,008 people aged 65 and over. BMI mortality hazard ratios are estimated controlling for age, sex, education, physical activity, smoking, chronic conditions, and ADL (activities of daily living) disability.

RESULTS

At baseline the median BMI is 26.8 (Interquartile range: 24.2-29.7 Kg/m(2)). Findings show that during 16 years there were 672 deaths. The U-shaped curve of the mortality hazard by BMI is wide. The minimum mortality occur at BMI = 30.5 Kg/m(2). Findings show that men had lower mortality risk with increasing BMI and that cardiovascular disease was associated with high mortality in the low-BMI category.

DISCUSSION

Underweight is a risk factor for mortality among elderly people, whereas overweight and mild obesity are associated with the lowest mortality particularly among men and those with cardiovascular morbidity.

Body mass index and adverse cardiovascular outcomes in heart failure patients with preserved ejection fraction: results from the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial

BACKGROUND

Obesity is a major risk factor for incident heart failure (HF). Paradoxically, in HF with reduced left ventricular ejection fraction (HFREF), a high body mass index (BMI) appears to be beneficial. Approximately 50% of HF patients have a preserved left ventricular ejection fraction (HFPEF). However, there are few data regarding the relationship between BMI and outcomes in HFPEF.

METHODS AND RESULTS

Baseline characteristics and cardiovascular outcomes were assessed in the 4109 patients (mean age, 72 years; mean follow-up, 49.5 months) in the Irbesartan in HF with Preserved Ejection Fraction (I-PRESERVE) trial. Based on the BMI distribution, 5 BMI categories were defined: <23.5, 23.5 to 26.4, 26.5 to 30.9, 31 to 34.9, and ≥35 kg/m(2). Most patients (71%) had a BMI ≥26.5, 21% had a BMI between 23.5 and 26.4, and 8% had a BMI <23.5 kg/m(2). Patients with higher BMI were younger, more often women, and more likely to have hypertension and diabetes and higher left ventricular ejection fraction. Patients with BMI of 26.5 to 30.9 kg/m(2) had the lowest rate for the primary composite outcome (death or cardiovascular hospitalization) and were used as reference group. After adjustment for 21 risk variables including age, sex, and N-terminal pro-brain natriuretic peptide, the hazard ratio for the primary outcome was increased in patients with BMI <23.5 (hazard ratio, 1.27; 95% confidence interval, 1.04 to 1.56; P=0.019) and in those with BMI ≥35 kg/m(2) (hazard ratio, 1.27; 95% confidence interval, 1.06 to 1.52; P=0.011) compared with the referent group. A similar relationship was found for all-cause mortality and for HF hospitalization.

CONCLUSIONS

Obesity is common in HFPEF patients and is accompanied by multiple differences in clinical characteristics. Independent of other key prognostic variables, there was a U-shaped relationship, with the greatest rate of adverse outcomes in the lowest and highest BMI categories.

CLINICAL TRIAL REGISTRATION- URL

http://www.clinicaltrials.gov. Unique identifier: NCT000095238.

Obesity and chronic kidney disease in patients with chronic heart failure: an insight from the China Heart Survey

BACKGROUND

Obesity and decreased kidney function have been shown to be prevalent in Western patients with heart failure; however, whether this phenomenon exists in Chinese patients with chronic heart failure (CHF) is not known.

METHODS AND RESULTS

One thousand and nine patients with CHF from the China Heart Survey were assessed. The prevalence of chronic kidney disease (CKD) was 34.2%, and there was a stepwise increase in the prevalence of CKD with New York Heart Association (NYHA) classes (P < 0.001). Moreover, patients with CKD had a significantly elevated risk for developing severe extent of CHF (OR = 1.69, 95% CI: 1.27-2.24, P < 0.001). The prevalence of obesity and central obesity was 35.7% and 62.5%, respectively. Notably, there was a downward trend in the prevalence of obesity with advanced NYHA classes (trend test, P = 0.003). Multivariate analysis further supported the finding that obesity, but not central obesity, was inversely associated with the extent of CHF (OR = 0.72, 95% CI: 0.55-0.94, P = 0.017).

CONCLUSIONS

Renal dysfunction is common in Chinese patients with CHF and is independently associated with advanced NYHA classes. Obesity was inversely associated with the extent of CHF, which further supports the notion that obesity confers improved prognosis in patients with heart failure.

Survival of the fattest: unexpected findings about hyperglycaemia and obesity in a population based study of 75-year-olds

OBJECTIVE

To study the relationship between body mass index (BMI) and mortality among 75-year-olds with and without diabetes mellitus type 2 (DM) or impaired fasting glucose (IFG).

DESIGN

Prospective population-based cohort study with a 10-year follow-up.

PARTICIPANTS

A random sample of 618 of the 1100 inhabitants born in 1922 and living in the city of Västerås in 1997 were invited to participate in a cardiovascular health survey; 70% of those invited agreed to participate (432 individuals: 210 men, 222 women).

OUTCOME MEASURES

All-cause and cardiovascular mortality.

RESULTS

163 of 432 (38%) participants died during the 10-year follow-up period. The prevalence of DM or IFG was 41% (35% among survivors, 48% among non-survivors). The prevalence of obesity/overweight/normal weight/underweight according to WHO definitions was 12/45/42/1% (14/43/42/1% among survivors, 9/47/42/2% among non-survivors). The hazard rate for death decreased by 10% for every kg/m(2) increase in BMI in individuals with DM/IFG (HR 0.91, 95% CI 0.86 to 0.97; p=0.003). After adjustment for sex, current smoking, diagnosed hypertension, diagnosed angina pectoris, previous myocardial infarction and previous stroke/transient ischaemic attack, the corresponding decrease in mortality was 9% (HR 0.92, 95% CI 0.86 to 0.99; p=0.017). These findings remained after exclusion of individuals with BMI<20 or those who died within 2-year follow-up. In individuals without DM/IFG, BMI had no effect on mortality (HR 1.01, 95% CI 0.95 to 1.07; p=0.811). The HR for BMI differed significantly between individuals with and without DM/IFG (p interaction=0.025). The increased all-cause mortality in individuals with DM/IFG in combination with lower BMI was driven by cardiovascular death.

CONCLUSION

High all-cause and cardiovascular mortality was associated with lower BMI in 75-year-olds with DM/IFG but not in those without DM/IFG. Further studies on the combined effect of obesity/overweight and DM/IFG are needed in order to assess the appropriateness of current guideline recommendations for weight reduction in older people with DM/IFG.

Contribution of anorexia to tissue wasting in cachexia

PURPOSE OF REVIEW

Anorexia is a severe debilitating symptom characterizing the clinical course of several chronic diseases. It negatively impacts on patient outcome by contributing to weight loss, lean body mass catabolism and adipose tissue wasting. Although disease-associated anorexia may stand alone as a clinically relevant symptom, it is now considered as a component of the cachexia syndrome. The present review discusses experimental and clinical data indicating that the pathogenic mechanisms of anorexia may also suggest a neural control of tissue wasting in cachexia.

RECENT FINDINGS

Consistent data show that selective melanocortin receptor antagonism modulates food intake and reduces wasting in experimental models of chronic disease. Consequently, ghrelin administration, whose prophagic effects are related to melanocortin antagonism, has been tested both in animal studies and human trials, with promising effects, although restoration of lean body mass has been not achieved. More interest is driven by the use of small molecules selectively antagonising hypothalamic melanocortin receptors.

SUMMARY

The 'brain-muscle axis' coordinated by the hypothalamus seems to mediate the onset of not only anorexia but also tissue wasting in cachexia, by centrally influencing energy homeostasis and the balance between anabolism and catabolism.

Measuring distributional inequality: relative body mass index distributions by gender, race/ethnicity, and education, United States (1999-2006)

Few studies consider obesity inequalities as a distributional property. This study uses relative distribution methods to explore inequalities in body mass index (BMI; kg/m(2)). Data from 1999-2006 from the National Health and Nutrition Examination Survey were used to compare BMI distributions by gender, Black/White race, and education subgroups in the United States. For men, comparisons between Whites and Blacks show a polarized relative distribution, with more Black men at increased risk of over or underweight. Comparisons by education (overall and within race/ethnic groups) effects also show a polarized relative distribution, with more cases of the least educated men at the upper and lower tails of the BMI distribution. For women, Blacks have a greater probability of high BMI values largely due to a right-shifted BMI distribution relative to White women. Women with less education also have a BMI distribution shifted to the right compared to the most educated women.

Obesity paradox in elderly patients with cardiovascular diseases

Many elderly people are affected by cardiovascular diseases (CVD) and the majority of CVD patients are elderly people. For both patient populations, studies have shown that a high body mass index (BMI) is associated with lower mortality when compared to normal weight subjects, a fact commonly known as the "obesity paradox". Whether the correlation between obesity and better survival is based on methodological influences and other non-causal factors alone, or whether there is a causal link between obesity and a better survival in these subjects remains widely unexplored. The interrelation between aging, obesity, CVD, frailty and inflammation is a current issue of intensive research. For the elderly, parameters which include measures of body composition, fat and fat-free mass are of greater importance than BMI. Weight management in elderly people with cardiovascular diseases should aim at improvement and maintenance of physical function and quality of life rather than prevention of medical problems associated with obesity in younger and middle aged patients. Although many studies have shown that weight loss in elderly patients is associated with a poor prognosis, recent data demonstrate that intentional weight reduction in obese elderly people ameliorates the cardiovascular risk profile, reduces chronic inflammation and is correlated with an improved quality of life. An individual approach to weight management that includes the participation of the patient, co-morbidity, functional status, and social support should be aspired.

Do anthropometric indices accurately reflect directly measured body composition in men and women with chronic heart failure?

How well anthropometric indices such as body mass index (BMI), waist circumference, waist-stature ratio, and waist index correlate with direct measures of body composition (lean body mass, body fat) in men and women with chronic heart failure (CHF) has not been reported. Body composition was assessed by dual-energy x-ray absorptiometry in 140 patients with CHF. Age-adjusted Pearson correlations between each index and measures of body composition for men and women were calculated. Diagnostic accuracy of detecting obesity or high central fat was also examined. In men, all of the anthropometric indices except waist index were just as strongly correlated with lean body mass (correlation coefficients varied between 0.56 for waist-stature ratio to 0.74 for BMI) as with percentage of body fat (correlation coefficients varied between 0.72 for BMI to 0.79 for waist circumference). In women, all 4 anthropometric measures were unable to significantly differentiate between body fat and lean body mass. The positive likelihood ratios for the detection of obesity varied between 2.26 for waist circumference and 3.42 for BMI, waist-stature ratio, and waist index. Anthropometric indices do not accurately reflect body composition in patients with CHF, especially in women. When accurate assessment of body composition is required, direct measurements should be obtained.

Excess ventilation during exercise and prognosis in chronic heart failure

Excess ventilation during exercise with accompanying dyspnea is characteristic of chronic heart failure (CHF), and these patients often exhibit increased Ve relative to the Vco(2) compared with normal subjects. This can be measured in several ways, including using such variables as the slope of Ve versus Vco(2), the lowest ratio of Ve/Vco(2), and the ratio of Ve/Vco(2) at the lactic acidosis threshold or peak exercise. There is now considerable evidence that the degree of excess ventilation during exercise in patients with CHF is a robust predictor of outcome and identifies higher-risk patients requiring aggressive treatment, including heart transplantation. The mechanism of excess ventilation in patients with CHF during exercise is not completely understood. It may be related to enhanced output of chemoreceptors or peripheral muscle ergoreceptors, increased dead space/Vt ratio due to increased contribution of high ventilation-perfusion lung regions or rapid shallow breathing caused by earlier onset of lactic acidosis, or likely resulting from a combination of these causes.

Obesity paradox and risk of sudden death in heart failure results from the MUerte Subita en Insuficiencia cardiaca (MUSIC) study

BACKGROUND

among patients with heart failure (HF), body mass index (BMI) has been inversely associated with mortality, giving rise to the so-called obesity paradox. The aim of this study was to examine the relationship between BMI and two modes of cardiac death: pump failure death and sudden death.

METHODS

nine hundred seventy-nine patients with mild to moderate chronic symptomatic HF from the MUSIC (MUerte Subita en Insuficiencia Cardiaca) Study, a prospective, multicenter, and longitudinal study designed to assess risk predictors of cardiac mortality, were followed up during a median of 44 months. Independent predictors of death were identified by a multivariable Cox proportional hazards model.

RESULTS

higher BMI emerged as an independent predictor of all-cause mortality (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.91-0.97, P = .0003) and pump failure death (HR = 0.93, 95% CI = 0.88-0.98, P = .004). Sudden death accounted for 45% of deaths in obese patients, 53% in overweight patients, and 37% in lean patients. No significant relationship between BMI and sudden death was observed (HR = 0.97, 95% CI = 0.92-1.02, P = .28). The only independent predictors of sudden death were prior history of myocardial infarction (HR = 1.89, 95% CI = 1.23-2.90, P = .004), hypertension (HR = 1.66, 95% CI = 1.05-2.63, P = .03), left ventricular ejection fraction (HR = 0.88, 95% CI = 0.79-0.96, P = .006), and N-terminal pro-B-type natriuretic peptide (HR = 1.01, 95% CI = 1.00-1.02, P = .048).

CONCLUSIONS

the obesity paradox in HF affects all-cause mortality and pump failure death but not sudden death. The risk of dying suddenly was similar across BMI categories in this cohort of ambulatory patients with HF.

Uric acid level and allopurinol use as risk markers of mortality and morbidity in systolic heart failure

BACKGROUND

Previous studies have not extensively examined the association of hyperuricemia and adverse outcomes in systolic heart failure (HF) in relation to xanthine oxidase inhibitor therapy.

METHODS

The Prospective Randomized Amlodipine Survival Evaluation study included New York Heart Association class IIIB or IV patients with left ventricular ejection fraction <30%. For analysis, the population was divided into uric acid quartiles among nonallopurinol users (2.2-7.1, >7.1-8.6, >8.6-10.4, >10.4 mg/dL) and those using allopurinol. Multivariate Cox regression modeling was performed to identify predictors of mortality. Uric acid quartile and allopurinol groups were referenced to the lowest uric acid quartile.

RESULTS

A total of 1,152 patients were included. In general, patients in the allopurinol group and in the highest uric acid quartile had indicators of more severe HF, including worse renal function and greater proportion of New York Heart Association class IV patients, and greater diuretic use. The allopurinol group and highest uric acid quartile had the highest total mortality (41.7 and 42.4 per 100 person-years, respectively) and combined morbidity/mortality (45.6 and 51.0 per 100 person-years, respectively). Allopurinol use and highest uric acid quartile were independently associated with mortality (hazard ratio [HR] 1.65, 95% CI 1.22-2.23, P = .001 and HR 1.35, 95% CI 1.07-1.72, P = .01, respectively) and combined morbidity/mortality (uric acid quartile 4 vs 1: HR 1.32, 95% CI 1.06-1.66, P = .02; allopurinol use: HR 1.48, 95% CI 1.11-1.99, P = .008).

CONCLUSION

Elevated uric acid level was independently associated with mortality in patients with severe systolic HF, even when accounting for allopurinol use.

The obesity epidemic: scope of the problem and management strategies

As the obesity epidemic increases, primary care clinicians are encountering obesity and health problems associated with obesity more frequently than ever before. In 2007, 41% of women were classified as obese, with a body mass index (BMI) of 30 or higher. Non-Hispanic blacks and Hispanics are more likely to be obese than white, non-Hispanics. A wide spectrum of health problems has been associated with obesity, including cardiovascular disease, diabetes, metabolic syndrome, osteoarthritis, and polycystic ovary syndrome. Obesity has been shown to be a low-grade inflammatory state, which may be responsible for many of the comorbidities. The general consensus recommends screening for obesity and counseling to promote weight loss. In some cases, pharmacotherapy and or bariatric surgery may be recommended.

The obesity paradox and mortality associated with surrogates of body size and muscle mass in patients receiving hemodialysis

OBJECTIVE

To determine whether dry weight gain accompanied by an increase in muscle mass is associated with a survival benefit in patients receiving maintenance hemodialysis (HD).

PATIENTS AND METHODS

In a nationally representative 5-year cohort of 121,762 patients receiving HD 3 times weekly from July 1, 2001, through June 30, 2006, we examined whether body mass index (BMI) (calculated using 3-month averaged post-HD dry weight) and 3-month averaged serum creatinine levels (a likely surrogate of muscle mass) and their changes over time were predictive of mortality risk.

RESULTS

In the cohort, higher BMI (up to 45) and higher serum creatinine concentration were incrementally and independently associated with greater survival, even after extensive multivariate adjustment for available surrogates of nutritional status and inflammation. Dry weight loss or gain over time exhibited a graded association with higher rates of mortality or survival, respectively, as did changes in serum creatinine level over time. Among the 50,831 patients who survived the first 6 months and who had available data for changes in weight and creatinine level, those who lost weight but had an increased serum creatinine level had a greater survival rate than those who gained weight but had a decreased creatinine level. These associations appeared consistent across different demographic groups of patients receiving HD.

CONCLUSION

In patients receiving long-term HD, larger body size with more muscle mass appears associated with a higher survival rate. A discordant muscle gain with weight loss over time may confer more survival benefit than weight gain while losing muscle. Controlled trials of muscle-gaining interventions in patients receiving HD are warranted.