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.     

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.     

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.     

Impact of obesity on disease-specific health status after percutaneous coronary intervention in coronary disease patients

OBJECTIVE: Several investigators have focused on obesity as a specific risk factor for mortality in patients undergoing bypass surgery, but few have examined it as a risk factor among patients undergoing percutaneous coronary interventions (PCI). In addition, none have evaluated the impact of obesity on post-PCI quality of life or disease-specific health status. This study examined whether obesity is a risk factor for poor quality of life or diminished health status 12-months postprocedure among a large cohort of PCI patients. RESEARCH METHODS AND PROCEDURES: A total of 1631 consecutive PCI patients were enrolled into the study and classified as underweight (BMI <20 kg/m2), normal weight range (BMI >/=20 and <25 kg/m2), overweight (BMI >/=25 and <30 kg/m2), class I obese (BMI >/=30 kg/m2), or class II and III obese (BMI >/=35 kg/m2). The 12-month postprocedure outcomes included need for repeat procedure, survival, quality of life and health status, assessed using the Seattle Angina Questionnaire (SAQ) and the Short Form-12. RESULTS: Obese patients with and without a history of revascularization were significantly younger than overweight, normal weight range, or underweight patients at the time of PCI. However, obese patients demonstrated similar long-term recovery and improved disease-specific health status and quality of life when compared to patients in the normal weight range after PCI. In addition, mortality and risk for repeat procedure was similar to those patients in the normal weight range patients at 12-months postrevascularization. Underweight patients who had no previous history of revascularization reported lower quality of life (F=3.02; P=0.018) and poorer physical functioning (F=2.82; P=0.024) than other BMI groups. CONCLUSION: Obese patients presenting for revascularization were younger when compared to patients in the normal weight range, regardless of previous history of revascularization. However, weight status was not a significant predictor of differences in long-term disease-specific health status, quality of life, repeat procedures, or survival. Underweight patients demonstrated less improvement in quality of life and physical functioning than other BMI groups.     

Relation among body mass index, exercise training, and outcomes in chronic systolic heart failure

Exercise training (ET) in patients with heart failure (HF), as demonstrated in the Heart Failure: A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION), was associated with improved exercise tolerance and health status and a trend toward reduced mortality or hospitalization. The present analysis of the HF-ACTION cohort examined the effect of ET in overweight and obese subjects compared to normal weight subjects with HF. Of 2,331 subjects with systolic HF randomized to aerobic ET versus usual care in the HF-ACTION, 2,314 were analyzed to determine the effect of ET on all-cause mortality, hospitalizations, exercise parameters, quality of life, and body weight changes by subgroups of body mass index (BMI). The strata included normal weight (BMI 18.5 to 24.9 kg/m(2)), overweight (BMI 25.0 to 29.9 kg/m(2)), obese I (BMI 30 to 34.9 kg/m(2)), obese II (BMI 35 to 39.9 kg/m(2)), and obese III (BMI ≥40 kg/m(2)). At enrollment, 19.4% of subjects were normal weight, 31.3% were overweight, and 49.4% were obese. A greater BMI was associated with a nonsignificant increase in all-cause mortality or hospitalization. ET was associated with nonsignificant reductions in all-cause mortality and hospitalization in each weight category (hazard ratio 0.98, 0.95, 0.92, 0.89, and 0.86 in the normal weight, overweight, obese I, obese II, and obese III categories, respectively; all p >0.05). Modeled improvement in exercise capacity (peak oxygen consumption) and quality of life in the ET group was seen in all BMI categories. In conclusion, aerobic ET in subjects with HF was associated with a nonsignificant trend toward decreased mortality and hospitalization and a significant improvement in quality of life across the range of BMI categories.     

The relationship of body mass index to outcomes after percutaneous coronary intervention

OBJECTIVES: To evaluate the effect of body mass index (BMI) on in-hospital outcomes in patients undergoing percutaneous coronary intervention (PCI) at a tertiary care hospital center in Ontario, Canada. BACKGROUND: Obesity is present in a large population of patients undergoing revascularization with PCI. METHODS: Retrospective analysis of 4,631 patients aged 62.0 +/- 12 years, stratified by BMI into five groups: nonobese (<25 kg/m2); overweight (25-29.9 kg/m2); class I obese (30-34.9 kg/m2); class II obese (35-39.9 kg/m2); and class III obese (> or =40 kg/m2). RESULTS: A BMI >25 kg/m2 was present in 79% of patients, and 35% were obese (BMI > or =30 kg/m2). Obese patients, particularly the class III obese, were significantly younger and had higher prevalence of diabetes, hypertension, and dyslipidemia (P < 0.0001). After adjustment for several covariates, lower BMI was independently associated with higher risk of major bleeding requiring transfusion (adjusted odds ratio [OR]= 1.40, 95% confidence interval [CI] 1.04-1.88, P = 0.025), and femoral hematoma (adjusted OR = 1.14, 95% CI 1.05-1.25, P = 0.003) in lean (<20 kg/m2) and normal BMI (20-24.9 kg/m2) patients. Obesity was not associated with death, myocardial infarction, repeat PCI, coronary artery bypass grafting, or major adverse cardiac event. CONCLUSIONS: Obesity is not associated with increased risk of adverse postprocedural in-hospital outcomes. These findings, however, do not discount the need for sustained efforts in secondary prevention of obesity and its consequences.     

Impact of obesity as a mortality predictor in high-risk patients with myocardial infarction or chronic heart failure: a pooled analysis of five registries

AIMS: To explore the influence of obesity on prognosis in high-risk patients with myocardial infarction (MI) or heart failure (HF). METHODS AND RESULTS: Individual data of 21 570 consecutively hospitalized patients from five Danish registries were pooled together. After a follow-up of 10.4 years, all-cause mortality using multivariate model and adjusted hazard ratios (HR) with 95% confidence intervals were calculated. Compared with normal weight [body mass index (BMI) 18.5-24.9 kg/m2], obesity class II (BMI >or= 35 kg/m2) was associated with increased risk of death in patients with MI but not HF [HR = 1.23 (1.06-1.44), P = 0.006 and HR = 1.13 (0.95-1.36), P = 0.95] (P-value for interaction = 0.004). Obesity class I (BMI 30-34.9 kg/m2) was not associated with increased risk of death in MI or HF [HR = 0.99 (0.92-1.08) and 1.00 (0.90-1.11), P > 0.1]. Pre-obesity (BMI 25-29.9 kg/m2) was associated with decreased death risk in MI but not HF [HR = 0.91 (0.87-0.96), P = 0.0006 and 1.04 (0.97-1.12), P = 0.34] (P-value for interaction = 0.007). Underweight (BMI < 18.5 kg/m2) patients were in increased death risk regardless of MI or HF [HR = 1.54 (1.35-1.75) and 1.37 (1.18-1.59), P < 0.001]. CONCLUSION: In patients with MI but not HF, the relationship between BMI and mortality is U-shaped with highest mortality in underweight and obese class II, but lowest in the other BMI classes.     

The association between body mass index and in-hospital outcome among patients with acute myocardial infarction—Insights from China Acute Myocardial Infarction (CAMI) registry

BackgroundThe relationship between body mass index (BMI) and in-hospital mortality risk among patients with acute myocardial infarction (AMI) remains controversial.Methods and ResultsWe included 35,964 patients diagnosed with AMI in China Acute Myocardial Infarction registry between January 2013 and December 2016. Patients were categorized into 4 groups according to BMI level: BMI <18.5, 18.5–24.9, 25–30, and ≥30 kg/m² for underweight, normal, overweight, and obese groups, respectively. Clinical data were extracted for each patient, and multivariable logistic regression analysis was used to examine the association between BMI level and in-hospital mortality. Compared with normal-weight patients, obese patients were younger, more often current smokers, and more likely to have hypertension, hyperlipidemia, and diabetes. Multivariable regression analysis results demonstrated that compared with normal group, underweight group had significantly higher in-hospital mortality (odds ratio [OR]: 1.34; 95% confidence interval [CI]: 1.06–1.69; p = 0.016), while overweight group (OR: 0.86; 95% CI: 0.77–0.97; p = 0.011) and obese group (OR: 0.65; 95% CI: 0.46–0.91; p = 0.013) had lower mortality. All subgroups showed a trend toward lower in-hospital mortality risk as BMI increased.ConclusionsOur study provided robust evidence supporting “obesity paradox” in a contemporary large-scale cohort of patients with AMI and demonstrated that increased BMI was independently associated with lower in-hospital mortality.     

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.     

The associations of body mass index, C-peptide and metabolic status in Chinese Type 2 diabetic patients.

BACKGROUND: Chinese Type 2 diabetic subjects are generally less obese than their Caucasian counterparts. We hypothesized that lean and obese Chinese Type 2 diabetic subjects have different metabolic and insulin secretory profiles. We compared the clinical features, C peptide and metabolic status between lean/normal weight and obese diabetic subjects. STUDY DESIGN: We conducted a cross-sectional study on 521 consecutive diabetic subjects newly referred to a Diabetes Clinic in 1996. The subjects were categorized into underweight (< 18.5 kg/m(2)), normal weight (18.5-23 kg/m(2)) and overweight (>/= 23 kg/m(2)) according to the re-defined WHO criterion for obesity in Asia Pacific Region. Metabolic and anthropometric parameters were compared between groups with different levels of obesity. RESULTS: In this cohort, 5.8, 30.6 and 63.7% of subjects were underweight, normal weight and overweight, respectively, using the 'Asian' criteria. Of these 521 subjects, 20% had fasting C-peptide less than 0.2 nmol/l, suggesting insulin deficiency. Fasting C-peptide showed linear increasing trend (P < 0.001) while HbA(1c) showed decreasing trend (P = 0.001) with BMI after adjustment for duration of disease. There were more subjects in the underweight group who were treated with insulin (41.3% vs. 13.9 and 8.2%, P < 0.001). Although homeostasis model assessment was similar amongst the three groups, systolic (P = 0.006) and diastolic blood pressure (P < 0.001) and triglyceride (P < 0.001) showed increasing, while HDL-C (P < 0.001) showed decreasing, trends across different BMI groups. The underweight patients had the lowest C-peptide and highest HbA(1c) while overweight patients had the highest C-peptide, blood pressure, triglyceride but lowest HbA(1c) levels. CONCLUSION: In Chinese Type 2 diabetic patients, lean subjects had predominant insulin deficiency and obese subjects had features of metabolic syndrome. Clinicians should have low threshold to initiate insulin therapy in lean Type 2 diabetic patients with suboptimal glycaemic control. In obese diabetic patients, aggressive control of multiple cardiovascular risks is of particular importance.     

不同BMI患者内脏脂肪差异性分析

目的探讨不同体质量指数（BMI）患者其内脏脂肪（VAT）含量的差异。 方法应用计算机断层扫描（CT）测量符合纳排标准的1094例于2017年1月1日至12月31日在广州医科大学附属第一医院门诊或住院患者的VAT含量、皮下脂肪（SAT）含量和腰围（WC）。根据上述患者的BMI水平将所有患者分为四组：体重过低组（BMI<18.5 kg/m²,n=56）,体重正常组（18.5 kg/m²≤BMI<24 kg/m²,n=444）,超重组（24 kg/m²≤BMI<28 kg/m²,n=253）和肥胖组（BMI≥28.0 kg/m²,n=81）。采用秩和检验方法探讨四组患者VAT、SAT和WC的差异。采用Spearman相关分析方法了解BMI分别和VAT、SAT、WC等指标间的相关关系。 结果1094例患者中数据齐全的共834例,其中患有心血管系统疾病有71例,呼吸系统疾病114例,消化系统疾病349例,泌尿系统疾病210例,生殖系统疾病19例,内分泌系统疾病29例。不同疾病种类患者在各BMI水平的VAT含量差异无统计学意义（P>0.05）。四组间的VAT、SAT和WC均存在显著的差异（P<0.01）。组间比较结果显示：SAT含量在肥胖组>超重组>体重正常组>体重过轻组（P<0.01）。VAT含量及WC两个指标的组间比较则显示,超重及肥胖组>体重正常组>体重过轻组（P<0.01）,在肥胖与超重两个组别间的比较则未发现差异的显著性（P>0.05）。Spearman相关分析结果显示,在正常体重组和超重组,BMI与VAT呈正相关关系（r分别为0.402、0.195,P<0.05）;在体重过轻组和肥胖组未发现两者的相关性（P>0.05）。BMI与SAT在正常体重组呈正相关关系（r=0.296,P<0.05）,而在其余三组则未发现（P>0.05）。BMI与WC的正相关关系体现在正常体重组和超重组（r分别为0.199、0.144,P<0.05）,而在体重过轻组和肥胖组未发现两者的相关关系（P>0.05）。 结论BMI作为肥胖程度判断的临床常用指标,与影像学肥胖的判断指标存在有限的相关关系。一定范围内的BMI水平有助于推测内脏脂肪含量,当体重过轻或肥胖达到某种程度时,BMI水平可能难以用于推测内脏脂肪的严重程度及其分布特征。     

Impact of body mass index on outcomes following critical care

STUDY OBJECTIVES: To determine the impact of body mass index (BMI) on outcomes in critically ill patients. DESIGN: Retrospective analysis of a large multi-institutional ICU database. MEASUREMENTS: The influence of BMI classification (underweight, < 20 kg/m(2); normal [control subjects], 20 to 25 kg/m(2); overweight, 25 to 30 kg/m(2); obese, 30 to 40 kg/m(2); severe obesity, > 40 kg/m(2)) on hospital survival, functional status at hospital discharge, and ICU/hospital length of stay (LOS) was analyzed via multivariate analysis, adjusting for age, gender, type of hospital admission, and severity score (ie, simplified acute physiologic score [SAPS] II and mortality prediction model [MPM] at time zero). Univariate analysis also was performed according to the quartile of the severity score. All comparisons were to the normal BMI group. RESULTS: Of 63,646 patient datasets, 41,011 were complete for height, weight, and at least one of the two severity scores. We found increased mortality in underweight patients (odds ratio [OR] of death: SAPS group, 1.19; MPM group, 1.26) but not in overweight, obese, or severely obese patients. ICU and hospital LOS were increased in both the severely obese (OR of discharge: ICU, 0.81 and 0.84, respectively; hospital, 0.83 and 0.87, respectively) and underweight groups (OR of discharge: ICU, 0.96 and 0.94, respectively; hospital, 0.91 and 0.90, respectively). Only in the SAPS group did the obese group have increased ICU LOS (OR, 0.96) and hospital LOS (OR, 0.96). Functional status at discharge was impaired in underweight patients (OR of disability: ICU, 1.11; hospital, 1.19). Overweight patients had decreased discharge disability (OR of disability: SAPS, 0.93; MPM, 0.94), while the results in the obese group were discordant between the two severity score groups (SAPS, not significant; MPM, 0.91; p < 0.05 for all ORs). CONCLUSIONS: Low BMI, but not high BMI, is associated with increased mortality and worsened hospital discharge functional status. LOS is increased in severely obese patients and, to a lesser extent, in underweight patients. Patients in the overweight and obese BMI groups may have improved mortality and discharge functional status.     

Body mass index and mortality in patients with severe coronary artery diseases: A cohort study from China

Background and aimsIt is still controversial whether obesity and overweight increase the risk of mortality for patients with coronary artery disease. The current study aimed to investigate the relationship between body mass index (BMI) and mortality in patients with triple-vessel disease (TVD).Methods and resultsFrom April 2004 to February 2011, 8943 patients with angiographically confirmed TVD were consecutively enrolled. Patients were divided into five groups according to BMI: underweight (<18.5 kg/m²), normal weight (18.5–23.9 kg/m²), overweight: (24–27.9 kg/m²), mild obesity (28–31.9 kg/m²), and severe obesity (≥32 kg/m²). The primary end point was all-cause death. Subgroup analysis was performed for treatment strategies: revascularization and medical treatment alone. During a median follow-up of 7.5 years, lower risks of mortality were observed in patients with overweight (adjusted HR 0.85, 95% CI 0.75–0.97) and mild obesity (adjusted HR 0.83, 95% CI 0.69–1.00) compared to those with normal weight. Polynomial Cox regression suggested a U-shape association between BMI and adjusted mortality risk. In the revascularization subgroup, there was a significantly higher mortality risk in patients with severe obesity (adjusted HR 1.57, 95% CI 1.03–2.40) than in those with normal weight. While in the medical treatment subgroup, mortality risk decreased as BMI increased, with the lowest risk being observed in patients with severe obesity.ConclusionThere is a U-shape relationship between BMI and all-cause death in patients with TVD, with increased risks among both underweight and severely obese patients. This relationship may be influenced by treatment strategies.     

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.     

Effect of body mass index on mortality and clinical status in rheumatoid arthritis

Objective

To study the relative risk (RR) of all‐cause and cause‐specific mortality in rheumatoid arthritis (RA) associated with body mass index (BMI), and to quantify the clinical and outcome consequences of abnormal BMI.

Methods

We studied mortality in 24,535 patients over 12.3 years, dividing patients into 3 age groups, <50, 50–70, and >70 years and fit Cox regression models separately within each age stratum. We used BMI categories of <18.5 kg/m² (underweight), 18.5 to <25 kg/m² (normal weight, reference category), 25 to <30 kg/m² (overweight), and ≥30 kg/m² (obesity).

Results

BMI ≥30 kg/m² was seen in 63–68% and underweight in ～2%. Reduction in the RR (95% confidence interval [95% CI]) for all‐cause (AC) and cardiovascular mortality was seen for overweight (AC 0.8 [95% CI 0.8, 0.9]) and obese groups (AC 0.8 [95% CI 0.7, 0.8]), with and without comorbidity adjustment. Underweight was associated with increased mortality risk (AC 1.9 [95% CI 1.7, 2.3]). By contrast, obesity produced profound changes in clinical variables. Compared with normal weight, the odds ratio in the obese group was 4.8 for diabetes mellitus, 3.4 for hypertension, 1.3 for myocardial infarction, 1.4 for joint replacement, and 1.9 for work disability. Total semiannual direct medical costs were $1,683 greater, annual household income $6,481 less, pain scores 1.1 units higher, Health Assessment Questionnaire 0.28 higher, and EuroQol utility 0.7 units lower in the obese.

Conclusion

Overweight and obesity reduce the RR of all‐cause and cardiovascular mortality across different age groups and durations of RA. By contrast, overweight and obesity are associated with substantial increased risks of comorbidity, total joint replacement, greater pain, medical costs, and decreased quality of life.     

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.     

Effect of body mass index on perioperative complications in thoracic surgery

Obesity is perceived as a risk factor in general thoracic surgery. We conducted a single-center retrospective evaluation of perioperative complications in 822 patients who underwent thoracic surgery between 2000 and 2005. According to body mass index, 82 were underweight (< 18.5 kg m(-2)), 568 were normal (18.5-24.9 kg m(-2)), 155 were overweight (25.0-29.9 kg m(-2)), and 17 were obese (>or=30 kg m(-2)). A significant increase in preoperative comorbidity (hypertension and ischemic heart disease) was observed with increasing body mass index. There was no significant difference in operation time or length of stay in the operating room, but extubation time was significantly different among the 4 groups. Of the intraoperative complications, alveolar-arterial oxygen difference increased significantly with increasing obesity, and hypoxia was least common in the normal group. Postoperatively, there was more pulmonary leakage in the underweight group and less pneumonia in the normal group. Both the underweight and the obese are at increased risk of perioperative complications and need to be carefully observed and managed intraoperatively and postoperatively.     

Role of body mass index in colon cancer patients in Taiwan

AIM: To determine the effect of body mass index (BMI) on the characteristics and overall outcome of colon cancer in Taiwan.METHODS: From January 1995 to July 2003, 2138 patients with colon cancer were enrolled in this study. BMI categories (in kg/m²) were established according to the classification of the Department of Health of Taiwan. Postoperative morbidities and mortality, and survival analysis including overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) were compared across the BMI categories.RESULTS: There were 164 (7.7%) underweight (BMI < 18.5 kg/m²), 1109 (51.9%) normal-weight (BMI = 18.5-23.9 kg/m²), 550 (25.7%) overweight (BMI = 24.0-26.9 kg/m²), and 315 (14.7%) obese (BMI ≥ 27 kg/m²) patients. Being female, apparently anemic, hypoalbuminemic, and having body weight loss was more likely among underweight patients than among the other patients (P < 0.001). Underweight patients had higher mortality rate (P = 0.007) and lower OS (P < 0.001) and DFS (P = 0.002) than the other patients. OS and DFS did not differ significantly between normal-weight, overweight, and obese patients, while CSS did not differ significantly with the BMI category.CONCLUSION: In Taiwan, BMI does not significantly affect colon-CSS. Underweight patients had a higher rate of surgical mortality and a worse OS and DFS than the other patients. Obesity does not predict a worse survival.     

Clinical profile and outcomes of obese patients in cardiac rehabilitation stratified according to National Heart, Lung, and Blood Institute criteria

PURPOSE: Obesity is a major health problem and must be evaluated and treated in cardiac rehabilitation patients. The purpose of this study was to identify the scope of this problem in an urban-based cardiac rehabilitation program by evaluating the prevalence of obesity, and comparing the clinical and risk factor profiles and outcomes of patients stratified according to National Heart, Lung, and Blood Institute (NHLBI) weight classifications. METHODS: Four hundred forty-nine consecutive cardiac rehabilitation patients, aged 57 +/- 11 years, were stratified according to the NHLBI criteria as: normal (body mass index [BMI] 18-24.9 kg/m2), overweight (BMI 25-29.9 kg/m2), class I/II obese (BMI 30-39.9 kg/m2), and class III morbidly obese (BMI > or = 40 kg/m2). Baseline cardiac risk factors and dietary habits were identified, and both pre- and postexercise training measurements of exercise tolerance, weight, and lipid profile were obtained. RESULTS: Overweight and obesity (BMI > or = 25 kg/m2) were present in 88% of patients. Compared to normal weight patients, obese patients were younger and had a greater adverse risk profile (higher prevalence of diabetes and hypertension, larger waist circumference, lower exercise capacity, lower high-density lipoprotein cholesterol level) at entry. After 10 weeks, all groups had a significant increase in exercise capacity, and on average obese patients in each category lost weight (Class I/II--4 lbs and Class III--12 lbs). Dropout rates were similar among the groups. CONCLUSION: Overweight and obesity are highly prevalent in cardiac rehabilitation. Overweight and obese patients had a greater adverse cardiovascular risk profile, including a lower exercise capacity in the latter. Thus, targeted interventions toward weight management in contemporary cardiac rehabilitation programs are important. Although short-term outcomes appear promising, greater efforts to improve these outcomes and to support long-term management are needed.     

Evaluation of nutritional status in patients undergoing hematopoietic SCT

The aims of this study were to establish the nutritional status of patients during hematopoietic SCT (HSCT) and to determine if body mass index (BMI) is a valid indicator of nutritional status in this population when compared with nitrogen balance (NB). In total, 50 patients were enrolled (mean age: 25.7+/-9.0 years). Patients (14%) were underweight (BMI<18.5 kg/m(2)), 58% in a normal BMI (between 18.5 and 24.9 kg/m(2)) and 28% were overweight or obese (BMI >or= 25 kg/m(2)). NB dropped after transplantation and increased from days +5 to +20 after transplantation (P=0.006). There was a significant negative relationship between patients' BMI and time to engraftment (r=-0.45, P=0.001). Engraftment of underweight patients was 3.0 days (P=0.002) and 4.0 days (P<0.001) later than in normal and overweight or obese patients, respectively. There was no significant correlation between NB before transplantation and time to engraftment (r=-0.22, P=0.16). The results of this study demonstrate that patients undergoing HSCT may have suboptimal nutritional status and that pre-HSCT-BMI rather than NB may have a greater correlation in HSCT patients with the time of engraftment. Therefore, it may be useful to consider patient's BMI before transplantation for earlier engraftment time.