Effects of insulin on left ventricular function during dynamic exercise in overweight and obese subjects.

AIMS: We designed this study in order to determine the effect of insulin on cardiac function in overweight and obese subjects during exercise. METHODS AND RESULTS: The cardiac function of 62 normal glucose tolerant subjects, aged 30-40 and divided into normal weight (group 1, n=22, BMI 20-24.9 kg/m(2)), overweight (group 2, n=20, BMI 25-29.9 kg/m(2)), and obesity (group 3, n=20, BMI 30-35 kg/m(2)) was evaluated at rest and during dynamic exercise through angiocardioscintigraphy, when on hyperinsulinaemic euglycaemic clamp (test A) and when on normal saline infusion (test B). Left ventricular function at rest was statistically greater (P<0.05) in both tests in overweight and obese subjects compared with normal weight controls, with no statistical difference (P=0.057) within groups between insulin and normal saline infusion. During exercise, cardiac function improved in all the subjects in both tests. The increase was lower in overweight and obese patients, even if statistically significant only in obese vs. control subjects in both tests (P<0.05). Insulin sensitivity showed a significant correlation (P< or =0.001) with left ventricular ejection fraction (LVEF) at rest and with change in LVEF during clamp. CONCLUSION: Our findings suggest a metabolic pathogenesis for the impaired LV function in obesity.     

Impact of body mass index on the five-year outcome of patients having percutaneous coronary interventions with drug-eluting stents

The purpose of this study was to assess the impact of body mass index (BMI) on clinical outcome of patients treated by percutaneous coronary intervention (PCI) using drug-eluting stents. Patients were stratified according to BMI as normal (<25 kg/m(2)), overweight (25 to 30 kg/m(2)), or obese (>30 kg/m(2)). At 5-year follow-up all-cause death, myocardial infarction, clinically justified target vessel revascularization (TVR), and definite stent thrombosis were assessed. A complete dataset was available in 7,427 patients, of which 45%, 22%, and 33% were classified according to BMI as overweight, obese, and normal, respectively. Mean age of patients was significantly older in those with a normal BMI (p <0.05). Incidence of diabetes mellitus, hypertension, and dyslipidemia increased as BMI increased (p <0.05). Significantly higher rates of TVR (15.3% vs 12.8%, p = 0.02) and early stent thrombosis (1.5% vs 0.9%, p = 0.04) were observed in the obese compared to the normal BMI group. No significant difference among the 3 BMI groups was observed for the composite of death/myocardial infarction/TVR or for definite stent thrombosis at 5 years, whereas the normal BMI group was at higher risk for all-cause death at 5 years (obese vs normal BMI, hazard ratio 0.74, confidence interval 0.53 to 0.99, p = 0.05; overweight vs normal BMI, hazard ratio 0.73, confidence interval 0.59 to 0.94, p = 0.01) in the multivariate Cox proportional hazard model. Age resulted in a linearly dependent covariate with BMI in the all-cause 5-year mortality multivariate model (p = 0.001). In conclusion, the "obesity paradox" observed in 5-year all-cause mortality could be explained by the higher rate of elderly patients in the normal BMI group and the existence of colinearity between BMI and age. However, obese patients had a higher rate of TVR and early stent thrombosis and a higher rate of other risk factors such as diabetes mellitus, hypertension, and hypercholesterolemia.     

Relation of body mass index to fatal and nonfatal cardiovascular events after cardiac rehabilitation

The aim of the present study was to determine whether body mass index (BMI) influences survival and recurrent cardiovascular events in a cardiac rehabilitation population. We followed 389 consecutive entrants to cardiac rehabilitation for 6.4 +/- 1.8 years. Patients were stratified into 3 groups: normal (BMI 18 to 24.9 kg/m(2)), overweight (BMI 25 to 29.9 kg/m(2)), and obese (BMI > or =30 kg/m(2)). Total and cardiovascular mortality were inversely associated with BMI category in bivariate models. However, only cardiovascular mortality was significant after adjustment for age and gender (p < 0.044), with cardiovascular death rates of 10% in normal, 8% in overweight, and 2% in obese patients. The rates of nonfatal recurrent events were 10% in normal, 24% in overweight, and 25% in obese patients. Our data indicate that BMI is inversely related to cardiovascular mortality but positively related to the risk of nonfatal recurrent events.     

Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study

BACKGROUND: The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD. METHODS: COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2)). RESULTS: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI. CONCLUSIONS: BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.     

Body mass index, prognosis and mode of death in chronic heart failure: results from the Valsartan Heart Failure Trial

AIMS: To assess the relationship between body mass index (BMI), mortality and mode of death in chronic heart failure (CHF) patients; to define the shape of the relationship between BMI and mortality. METHODS AND RESULTS: We performed a post-hoc analysis of 5010 patients from the Valsartan Heart Failure Trial. The end-points of the study were all-cause and cardiovascular mortality. Mortality rate was 27.2% in underweight patients (BMI<22 kg/m2), 21.7% in normal weight patients (BMI 22-24.9 kg/m2), 17.9% in overweight patients (BMI 25-29.9 kg/m2) and 16.5% in obese patients (BMI>30 kg/m2) (p<0.0001). The rates of non-cardiovascular death did not differ among groups. The risk of death due to progressive heart failure was 3.4-fold higher in the underweight than in the obese patients (p<0.0001). Normal weight, overweight and obese patients had lower risk of death as compared with underweight patients (p=0.019, HR 0.76, 95% CI 0.61-0.96; p=0.0005, HR 0.68, 95% CI 0.55-0.84; p=0.003, HR 0.67, 95% CI 0.52-0.88, respectively) independently of symptoms, ventricular function, beta-blocker use, C-reactive protein and brain natriuretic peptide levels. CONCLUSIONS: In CHF patients a higher BMI is associated with a better prognosis independently of other clinical variables. The relationship between mortality and BMI is monotonically decreasing.     

Impact of body mass index on in-hospital outcomes following percutaneous coronary intervention (report from the New York State Angioplasty Registry)

Although obesity traditionally has been considered a risk factor for coronary revascularization, recent data from registry studies have shown a possible protective effect of obesity on outcomes after percutaneous coronary intervention (PCI). Using data from the New York State Angioplasty database over a 4-year period, we analyzed 95,435 consecutive patients who underwent PCI. Classification of body mass index (BMI) was: underweight (<18.5 kg/m(2)), healthy weight (18.5 to 24.9 kg/m(2)), overweight (25 to 29.9 kg/m(2)), moderate obesity (class I) (30 to 34.9 kg/m(2)), severe obesity (class II) (35 to 39.9 kg/m(2)), and very severe obesity (class III) (>40 kg/m(2)). In-hospital postprocedural mortality and complications were compared among these groups. Compared with healthy weight patients, patient with class I or II obesity had lower in-hospital mortality and major adverse cardiac events (MACE) (combined death, myocardial infarction, and emergency surgery), whereas patients at the extremes of BMI (underweight and class III obese patients) had significantly higher mortality and MACE rates. Adjusted hazards ratios for in-hospital mortality according to BMI were: underweight (2.69), healthy weight (1.0), overweight (0.90), class I obese (0.74), class II obese (0.67), and class III obese (1.63). Patients at the extremes of BMI (<18.5 and >40 kg/m(2)) were at increased risk of MACEs, including mortality after PCI, whereas patients who were moderately to severely obese (BMIs 30 to 40 kg/m(2)) were at lower risk than healthy weight patients.     

Medical therapies and invasive treatments for coronary artery disease by body mass: the "obesity paradox" in the Get With The Guidelines database

Previous studies of hospitalized patients have suggested an "obesity paradox" with lower short-term mortality as weight increases. We hypothesized that some of this difference might be related to more aggressive management. To evaluate the effect of body mass index (BMI) on treatments and outcomes in patients with coronary artery disease (CAD), the Get With The Guidelines database was investigated. From 409 United States hospitals, 130,139 hospitalizations for CAD were identified with documented height and weight. Patients were stratified by BMI, with 3,305 (2.5%) underweight (BMI <18.5 kg/m(2)), 34,697 (27%) of healthy weight (BMI 18.5 to 24.9 kg/m(2)), 47,883 (37%) overweight (BMI 25 to 29.9 kg/m(2)), 37,686 (29%) obese (BMI 30 to 39.9 kg/m(2)), and 6,568 (5%) extremely obese (BMI > or =40 kg/m(2)). As BMI increased, patients were significantly younger but more likely to be men and have hypertension, diabetes, and hyperlipidemia. Unadjusted in-hospital mortality was highest in the underweight group (10.4%) and significantly lower in the healthy-weight (5.4%), overweight (3.1%), obese (2.4%), and extremely obese (2.9%) patients. Higher BMI was associated with increased use of standard medical therapies such as aspirin, beta blockers, inhibitors of the renin-angiotensin system, and lipid-lowering therapy in the hospital and at discharge. In adjusted analyses, compared with the healthy-weight group, overweight and obese patients were more likely to undergo invasive procedures and had lower mortality (p <0.01 for all odds ratios). In conclusion, increasing BMI appears to be associated with better use of guideline-recommended medical treatment and invasive management of CAD, which may explain the observed lower rates of in-hospital mortality.     

Effect of peripheral arterial disease on functional and clinical outcomes in patients with heart failure (from HF-ACTION)

Patients with peripheral arterial disease (PAD) have lower functional capacity and worse clinical outcomes than age- and gender-matched patients. Few data exist on the relation of PAD to functional and clinical outcomes in patients with heart failure (HF). We sought to compare patients with HF with and without PAD for baseline functional capacity, response to exercise training, and clinical outcomes. HF-ACTION was a randomized controlled trial comparing usual care to structured exercise training plus usual care in patients with HF and an ejection fraction ≤35% and New York Heart Association class II to IV HF symptoms. Cardiopulmonary exercise testing occurred at enrollment, 3 months, and 1 year. Clinical follow-up occurred up to 4 years. Of the 2,331 HF-ACTION patients, 157 (6.8%) had PAD. At baseline, patients with HF and PAD had a shorter exercise duration (8.0 vs 9.8 minutes, p <0.001), lower peak oxygen consumption (12.5 vs 14.6 ml/kg/min, p <0.001), and shorter 6-minute walking distance (306 vs 371 m, p <0.001) compared to patients with HF without PAD. At 3 months patients with HF and PAD had less improvement on cardiopulmonary exercise testing (exercise duration 0.5 vs 1.1 minutes, p = 0.002; mean change in peak oxygen consumption 0.1 vs 0.6 ml/kg/min, p = 0.04) compared to patients with HF without PAD. PAD was an independent predictor of all-cause death or hospitalization (hazard ratio 1.31, 95% confidence interval 1.06 to 1.62, p = 0.011). Patients with PAD and HF had deceased baseline exercise capacity and decreased response to exercise training. In conclusion, PAD is an independent predictor of all-cause death or hospitalization in patients with HF.     

Impact of body mass index on in-hospital outcomes after percutaneous coronary intervention for ST segment elevation acute myocardial infarction.

BACKGROUND: The impact of body mass index (BMI) on outcomes after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) remains unclear. METHODS AND RESULTS: A total of 3,076 patients undergoing PCI for AMI within 48 h after symptom onset were studied. Patients were divided into 4 groups according to baseline BMI: lean (<20 kg/m(2)), normal weight (20.0-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)) and obese (>or=30.0 kg/m(2)). Obese patients were younger and had a higher frequency of diabetes mellitus, hyperlipidemia, hypertension and smoking. Lean patients were older, usually women and had a lower frequency of the aforementioned risk factors. Killip class on admission, renal insufficiency, and final Thrombolysis In Myocardial Infarction (TIMI) flow grade did not differ among the 4 groups. In lean, normal weight, overweight and obese patients, in-hospital mortality was 9.2%, 4.4%, 2.5% and 1.8%, respectively (p<0.01). Multivariate analysis showed that compared with normal weight patients, odds ratios for in-hospital death in lean, overweight and obese patients were 1.92, 0.79 and 0.40, respectively (p=NS). Independent predictors were age, Killip class on admission, renal insufficiency and final TIMI flow grade. CONCLUSION: BMI itself had no impact on in-hospital mortality in patients undergoing primary PCI for AMI. The phenomenon ;obesity paradox' may be explained by the fact that obese patients were younger at presentation.     

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

OBJECTIVES: To evaluate the influence of elevated body mass index (BMI) on short- and long-term survival following acute myocardial infarction (AMI). BACKGROUND: Recent studies suggest an obesity survival paradox in individuals undergoing percutaneous coronary intervention with better 30-day and 1-year outcomes in obese relative to normal weight patients. We tested a similar obesity paradox hypothesis following acute myocardial infarction. METHODS: Short- and long-term all-cause mortality, and risk of recurrent AMI were evaluated according to BMI status in 894 consecutive survivors of AMI <80 years of age admitted to the Mayo Clinic Coronary Care Unit between January 1, 1988 and April 16, 2001. Normal weight, overweight and obesity were defined as BMI <25, 25-29.9, and >30 kg/m(2), respectively. RESULTS: Overall mortality following hospital discharge was significantly lower in overweight and obese patients and was mostly attributable to lower 6-month mortality (adjusted HR = 0.47, P = 0.01 for BMI >25 kg/m(2)) relative to normal weight patients, while long-term mortality among 6-month survivors was similar in all 3 groups. The risk of recurrent AMI was higher in patients with BMI >25 kg/m(2) (adjusted HR = 2.30, P = 0.01). Overweight and obese patients were significantly more likely to die from cardiac rather than non-cardiac causes (P < 0.01). CONCLUSIONS: Following AMI, overweight and obese individuals although paradoxically protected from short-term death have a long-term mortality risk that is similar to normal weight individuals. Younger age at the time of initial infarction and fewer non-cardiovascular comorbidities presumably explain the short-lived obesity survival paradox following myocardial infarction.     

B-type natriuretic peptide levels in obese patients with advanced heart failure.

Although recent studies show that obesity, or elevated body mass index (BMI), is associated with lower levels of B-type natriuretic peptide (BNP), it is unknown whether BMI affects the prognostic value of BNP in heart failure (HF). This study confirms the relationship between high BMI and low BNP in patients with advanced systolic HF. Despite relatively lower levels of BNP in overweight and obesity, BNP predicts worse symptoms, impaired hemodynamics, and higher mortality in HF at all levels of BMI.OBJECTIVES: This study aimed to examine the influence of obesity on the predictive value of the B-type natriuretic peptide (BNP) assay in heart failure (HF). BACKGROUND: Recent studies show that obesity, or elevated body mass index (BMI), is associated with lower circulating levels of BNP both in the general population and in patients with HF. METHODS: We analyzed data from 316 systolic HF (left ventricular ejection fraction [LVEF] < or =40%) patients [age, 53 +/- 13 years; mean LVEF, 24 +/- 7%; 48% ischemic] followed up at a university HF center. Patients were divided into categories of BMI: lean (BMI <25 kg/m2), overweight (BMI = 25 to 29.9 kg/m2), and obese (BMI > or =30 kg/m2). RESULTS: The BNP levels were significantly lower in overweight and obese compared with lean patients (p = 0.0001); median BNP (interquartile range) for the lean (n = 131), overweight (n = 99), and obese (n = 86) groups was 747 (272 to 1,300), 380 (143 to 856), and 332 (118 to 617) pg/ml, respectively. In each BMI category, elevated BNP was significantly associated with worse symptoms and higher pulmonary capillary wedge pressure. Higher BNP was also a significant independent predictor of survival independent of BMI. Optimal BNP cutoff for prediction of death or urgent transplant in lean, overweight, and obese HF patients was 590, 471, and 342 pg/ml, respectively. CONCLUSIONS: Although BNP levels are relatively lower in overweight and obese HF patients, BNP predicts worse symptoms, impaired hemodynamics, and higher mortality at all levels of BMI.     

Effect of body mass index on early outcomes in patients undergoing coronary artery bypass surgery

OBJECTIVES: This study sought to quantify the effect of body mass index (BMI) on early clinical outcomes following coronary artery bypass grafting (CABG). BACKGROUND: Obesity is considered a risk factor for postoperative morbidity and mortality after cardiac surgery, although existing evidence is contradictory. METHODS: A concurrent cohort study of consecutive patients undergoing CABG from April 1996 to September 2001 was carried out. Main outcomes were early death; perioperative myocardial infarction; infective, respiratory, renal, and neurological complications; transfusion; duration of ventilation, intensive care unit, and hospital stay. Multivariable analyses compared the risk of outcomes between five different BMI groups after adjusting for case-mix. RESULTS: Out of 4,372 patients, 3.0% were underweight (BMI <20 kg/m(2)), 26.7% had a normal weight (BMI >or=20 and <25 kg/m(2)), 49.7% were overweight (BMI >or=25 and <30 kg/m(2)), 17.1% obese (BMI >or=30 and <35 kg/m(2)) and 3.6% severely obese (BMI >or=35 kg/m(2)). Compared with the normal weight group, the overweight and obese groups included more women, diabetics, and hypertensives, but fewer patients with severe ischemic heart disease and poor ventricular function. Underweight patients were more likely than normal weight patients to die in hospital (odds ratio [OR] = 4.0, 95% CI 1.4 to 11.1), have a renal complication (OR = 1.9, 95% confidence interval [CI] 1.0 to 3.7), or stay in hospital longer (>7 days) (OR = 1.7, 95% CI 1.1 to 2.5). Overweight, obese, and severely obese patients were not at higher risk of adverse outcomes than normal weight patients, and were less likely than normal weight patients to require transfusion (ORs from 0.42 to 0.86). CONCLUSIONS: Underweight patients undergoing CABG have a higher risk of death or complications than normal weight patients. Obesity does not affect the risk of perioperative death and other adverse outcomes compared to normal weight, yet obese patients appear less likely to be selected for surgery than normal weight patients.     

Body mass index, metabolic syndrome, and risk of type 2 diabetes or cardiovascular disease

CONTEXT: Metabolic risk conferred by adiposity may be due to associated risk factor clustering. OBJECTIVE: The objective of this study was to assess risk for diabetes or cardiovascular disease (CVD) stratified by body mass index (BMI) and the presence or absence of metabolic syndrome (MetS) or insulin resistance (IR). DESIGN, SETTING, AND PARTICIPANTS: This was a community-based, longitudinal study of 2902 people (55% women, mean age 53 yr) without diabetes or CVD in 1989-1992 followed for up to 11 yr. We categorized subjects by normal weight (BMI < 25 kg/m(2)), overweight (25-29.9 kg/m(2)), or obese (>30 kg/m(2)) and by the National Cholesterol Education Program's Adult Treatment Panel MetS or the top quartile of homeostasis model IR. We used proportional hazard models to estimate risk relative to normal weight and no MetS or IR. MAIN OUTCOME MEASURE: Incident type 2 diabetes (treatment or fasting glucose > or = 7 mmol/liter, 141 events) or CVD (myocardial infarction, stroke, or claudication, 252 events) were measured. RESULTS: Among 1056 normal-weight subjects, 7% had MetS and a risk factor-adjusted relative risk for diabetes of 3.97 (95% confidence interval, 1.35-11.6) and for CVD of 3.01 (1.68-5.41). Among 638 obese subjects, 37% did not have MetS or significantly increased risk. Obese subjects with MetS had an adjusted relative risk for diabetes of 10.3 (5.44-19.5) and for CVD of 2.13 (1.43-3.18). Results were similar in analyses of BMI-IR categories. CONCLUSIONS: People with normal weight and MetS or IR or with obesity but no MetS or IR were not uncommon in our sample. Risk factor clustering or IR appear to confer much of the risk for diabetes or CVD commonly associated with elevated BMI.     

Elevated body mass index and intermediate-term clinical outcomes after acute coronary syndromes

PURPOSE: Obesity is a coronary disease risk factor, but its independent effect on clinical outcomes following acute coronary syndromes has not been quantified. We evaluated the relationship between elevated body mass index (BMI) and 30-day, 90-day, and 1-year clinical outcomes postacute coronary syndromes. SUBJECTS AND METHODS: Using 15 071 patients (normal weight [BMI = 18.5-24.9 kg/m(2)], overweight [BMI = 25-29.9 kg/m(2)], obese [BMI = 30-34.9 kg/m(2)] or very obese [BMI > or =35 kg/m(2)]) randomized from 1997-1999 in the SYMPHONY (Sibrafiban vs aspirin to Yield Maximum Protection from ischemic Heart events postacute cOroNary sYndromes) and 2nd SYMPHONY trials, we evaluated the relationships between BMI and 30-day, 90-day, and 1-year mortality and 30-day and 90-day death or myocardial infarction. RESULTS: Increasing BMI was associated with younger age, multiple comorbidities, and greater cardiac medication and procedure use; however, systolic function and coronary disease extent were similar for all BMI categories. Unadjusted Kaplan-Meier mortality estimates were higher for normal-weight patients than for all other BMI groups. After multivariable adjustment, the 30-day mortality hazard ratios (95% confidence interval [CI]) were: overweight, 0.66 (95% CI: 0.47 to 0.94); obese, 0.61 (95% CI: 0.39 to 0.97); very obese, 0.89 (95% CI: 0.48 to 1.64). Adjusted hazard ratios were similar for 90-day and 1-year mortality. There were no statistically significant differences among BMI groups in 30-day and 90-day death or myocardial infarction (unadjusted or adjusted). CONCLUSION: Overweight and obese BMI classifications were associated with better intermediate-term survival after acute coronary syndromes than normal weight and very obese, but death or myocardial infarction rates were similar. Further study is required to understand the apparent association of overweight and moderate obesity with better intermediate-term outcomes.     

The impact of body mass index on short- and long-term outcomes inpatients undergoing coronary revascularization. Insights from the bypass angioplasty revascularization investigation (BARI)

OBJECTIVES: We sought to investigate the impact of body mass index (BMI) on short- and long-term outcomes after initial revascularization with percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass graft surgery (CABG). BACKGROUND: Equivocal results exist on the impact of BMI on the risk of in-hospital complications after PTCA or CABG, and no long-term mortality data exist from a large series of revascularized patients. METHODS: From the randomized series and observational registry of the Bypass Angioplasty Revascularization Investigation (BARI), 2,108 patients who had PTCA and 1,526 patients who had CABG were evaluated by taking their BMI at study entry. They were classified as follows: low (< 20 kg/m(2)), normal (20 to 24.9 kg/m(2)), overweight (25 to 29.9 kg/m(2)), class I obese (30 to 34.9 kg/m(2)) and class II/III obese (greater-than-or-equal 35 kg/m(2)). In-hospital complications and short- and long-term mortalities were compared between levels of BMI within each mode of initial revascularization. RESULTS: Among patients who had PTCA, each unit increase in BMI was associated with a 5.5% lower adjusted risk of a major in-hospital event (death, myocardial infarction, stroke, coma); among patients who had CABG, no difference in the in-hospital outcome was observed according to BMI. In contrast, BMI was not associated with five-year mortality in the PTCA group; among the CABG group, adjusted relative risks of five-year cardiac mortality according to levels of BMI were 0.0 (low), 1.0 (normal), 2.02 (overweight), 3.16 (class I obese) and 4.85 (class II/III obese) (linear p < 0.001).CONCLUSIONS: Body mass index appears to have a differential impact on short- and long-term outcomes after coronary revascularization. These results underscore the need for further research to identify factors responsible for the apparent short-term protective effect of a higher BMI in patients undergoing PTCA and to study the impact of weight reduction on the long-term survival of obese patients undergoing CABG.     

The obesity paradox: body mass index and outcomes in patients with heart failure

BACKGROUND: In the general population, obesity is associated with increased risk of adverse outcomes. However, studies of patients with chronic disease suggest that overweight and obese patients may paradoxically have better outcomes than lean patients. We sought to examine the association of body mass index (BMI) and outcomes in stable outpatients with heart failure (HF). METHODS: We analyzed data from 7767 patients with stable HF enrolled in the Digitalis Investigation Group trial. Patients were categorized using baseline BMI (calculated as weight in kilograms divided by the square of height in meters) as underweight (BMI <18.5), healthy weight (BMI, 18.5-24.9, overweight (BMI, 25.0-29.9), and obese (BMI > or =30.0). Risks associated with BMI groups were evaluated using multivariable Cox proportional hazards models over a mean follow-up of 37 months. RESULTS: Crude all-cause mortality rates decreased in a near linear fashion across successively higher BMI groups, from 45.0% in the underweight group to 28.4% in the obese group (P for trend <.001). After multivariable adjustment, overweight and obese patients were at lower risk for death (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.80-0.96, and HR, 0.81; 95% CI, 0.72-0.92, respectively), compared with patients at a healthy weight (referent). In contrast, underweight patients with stable HF were at increased risk for death (HR 1.21; 95% CI, 0.95-1.53). CONCLUSIONS: In a cohort of outpatients with established HF, higher BMIs were associated with lower mortality risks; overweight and obese patients had lower risk of death compared with those at a healthy weight. Understanding the mechanisms and impact of the "obesity paradox" in patients with HF is necessary before recommendations are made concerning weight and weight control in this population.     

Obesity and its effect on survival in patients undergoing orthotopic liver transplantation in the United States.

Studies assessing morbidity and mortality in obese patients undergoing orthotopic liver transplantation (OLT) have produced conflicting results, mainly because of the small sample size. The objective of our study was to determine graft and patient survival in obese adults receiving OLT in the U.S. between 1988 through 1996 using the United Network for Organ Sharing (UNOS) database. Among the 23,675 transplantations performed during the 9-year study period, 18,172 (75%) patients fulfilled the inclusion criteria. Of these, 8,382 (46%) were nonobese (body mass index [BMI] < 25 kg/m(2)), 5,913 (33%) were overweight (BMI, 25.1-30 kg/m(2)), 2,611 (14%) were obese (BMI, 30.1-35 kg/m(2)), 911 (5%) were severely obese (BMI, 35.1-40 kg/m(2)), and 355 (2%) were morbidly obese (BMI, 40.1-50 kg/m(2)). The outcome measures assessed were immediate (30-day), 1-, 2-, and 5-year patient survival. Obese groups had a higher proportion of women, a greater prevalence of cryptogenic cirrhosis (P <.05) and diabetes (P <.05), and a higher serum creatinine. Primary graft nonfunction, and immediate, 1-year, and 2-year mortality were significantly higher in the morbidly obese group (P <.05). Five-year mortality was significantly higher both in the severely and morbidly obese subjects (P <.05), mostly as a result of adverse cardiovascular events. Kaplan-Meier survival was significantly lower in morbidly obese patients, and morbid obesity was an independent predictor of mortality. Obesity is associated with a significant increase in long-term mortality, mostly as a result of cardiovascular events. Weight loss should be recommended for all patients awaiting a liver transplantation, especially if their BMI is more than 35 kg/m(2).     

Clinical Implications of Chronic Heart Failure Phenotypes Defined by Cluster Analysis

Background

Classification of chronic heart failure (HF) is on the basis of criteria that may not adequately capture disease heterogeneity. Improved phenotyping may help inform research and therapeutic strategies.

Objectives

This study used cluster analysis to explore clinical phenotypes in chronic HF patients.

Methods

A cluster analysis was performed on 45 baseline clinical variables from 1,619 participants in the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) study, which evaluated exercise training versus usual care in chronic systolic HF. An association between identified clusters and clinical outcomes was assessed using Cox proportional hazards modeling. Differential associations between clinical outcomes and exercise testing were examined using interaction testing.

Results

Four clusters were identified (ranging from 248 to 773 patients in each), in which patients varied considerably among measures of age, sex, race, symptoms, comorbidities, HF etiology, socioeconomic status, quality of life, cardiopulmonary exercise testing parameters, and biomarker levels. Differential associations were observed for hospitalization and mortality risks between and within clusters. Compared with cluster 1, risk of all-cause mortality and/or all-cause hospitalization ranged from 0.65 (95% confidence interval [95% CI]: 0.54 to 0.78) for cluster 4 to 1.02 (95% CI: 0.87 to 1.19) for cluster 3. However, for all-cause mortality, cluster 3 had a disproportionately lower risk of 0.61 (95% CI: 0.44 to 0.86). Evidence suggested differential effects of exercise treatment on changes in peak oxygen consumption and clinical outcomes between clusters (p for interaction <0.04).

Conclusions

Cluster analysis of clinical variables identified 4 distinct phenotypes of chronic HF. Our findings underscore the high degree of disease heterogeneity that exists within chronic HF patients and the need for improved phenotyping of the syndrome. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437)     

The Obesity Paradox, Weight Loss, and Coronary Disease

Purpose

Because obesity is a cardiovascular risk factor but is associated with a more favorable prognosis among cohorts of cardiac patients, we assessed this “obesity paradox” in overweight and obese patients with coronary heart disease enrolled in a cardiac rehabilitation and exercise training (CRET) program, making this assessment in patients classified as overweight/obese using both traditional body mass index (BMI) and percent body fat assessments. Additionally, we assessed the efficacy and safety of purposeful weight loss in overweight and obese coronary patients.

Patients and Methods

We retrospectively studied 529 consecutive CRET patients following major coronary events before and after CRET, and compared baseline and post program data in 393 overweight and obese patients (body mass index [BMI] ≥25 kg/m²) divided by median weight change (median = −1.5%; mean +2% vs −5%, respectively). In addition, we assessed 3-year total mortality in various baseline BMI categories as well as compared mortality in those with high baseline percent fat (>25% in men and >35% in women) versus those with low baseline fat.

Results

Following CRET, the overweight and obese with greater weight loss had improvements in BMI (−5%; P <.0001), percent fat (−8%; P <.0001), peak oxygen consumption (+16%; P <.0001), low-density lipoprotein cholesterol (−5%; P <.02), high-density lipoprotein cholesterol (+10%; P <.0001), triglycerides (−17%; P <.0001), C-reactive protein (−40%; P <.0001), and fasting glucose (−4%; P = .02), as well as marked improvements in behavioral factors and quality-of-life scores. Those with lower weight loss had no significant improvements in percent fat, low-density lipoprotein cholesterol, triglycerides, C-reactive protein, and fasting glucose. During 3-year follow-up, overall mortality trended only slightly lower in those with baseline overweightness/obesity who had more weight loss (3.1% vs 5.1%; P = .30). However, total mortality was considerably lower in the baseline overweight/obese (BMI ≥25 kg/m²) than in 136 CRET patients with baseline BMI <25 kg/m² (4.1% vs 13.2%; P <.001), as well as in those with high baseline fat compared with those with low fat (3.8% vs 10.6%; P <.01).

Conclusions

Purposeful weight loss with CRET in overweight/obese coronary patients is associated with only a nonsignificant trend for lower mortality but is characterized by marked improvements in obesity indices, exercise capacity, plasma lipids, and inflammation, as well as behavioral factors and quality of life. Although an “obesity paradox” exists using either baseline BMI or baseline percent fat criteria, these results support the safety and potential long-term benefits of purposeful weight loss in overweight and obese patients with coronary heart disease.     

Influence of obesity on morbidity and mortality after acute myocardial infarction

The influence of being overweight or obese on hospital and late (1 year) mortality and reinfarction was studied in 1760 patients with acute myocardial infarction. Body mass index (BMI) was used to categorize patients as normal weight (BMI less than 25), overweight (BMI 25 to 30), and obese (BMI greater than 30). Clinical features and prognosis were compared in 658 normal weight patients, 884 overweight patients, and 218 obese patients. Complications during hospitalization and 1-year reinfarction rates following discharge were similar among the weight subsets. Hospital mortality was 13% in obese patients, similar to the 14% hospital mortality in normal weight patients, but significantly more than that in overweight patients (9%, p less than 0.05). When stratified according to age, 30% of obese patients greater than or equal to 65 years died in the hospital, compared to 13% of overweight patients (p less than 0.001), and 17% of normal weight patients (p less than 0.01). In patients less than 65 years, the obese group had a 6% mortality compared to a hospital mortality of 5% in overweight and 8% in normal weight groups (NS). In a multivariate analysis, obesity was an independent predictor of hospital death in the older, but not in the younger patient subset. One-year mortality for patients discharged from the hospital was significantly less in obese than in normal weight patients (7% vs 13%, p less than 0.05), but not different from the 11% mortality rate in overweight patients. Differences in mortality disappeared when patients were age stratified.(ABSTRACT TRUNCATED AT 250 WORDS)