Su-Hsin Chang

The effectiveness and risks of bariatric surgery: an updated systematic review and meta-analysis, 2003-2012.

IMPORTANCE The prevalence of obesity and outcomes of bariatric surgery are well established. However, analyses of the surgery impact have not been updated and comprehensively investigated since 2003. OBJECTIVE To examine the effectiveness and risks of bariatric surgery using up-to-date, comprehensive data and appropriate meta-analytic techniques. DATA SOURCES Literature searches of Medline, Embase, Scopus, Current Contents, Cochrane Library, and Clinicaltrials.gov between 2003 and 2012 were performed. STUDY SELECTION Exclusion criteria included publication of abstracts only, case reports, letters, comments, or reviews; animal studies; languages other than English; duplicate studies; no surgical intervention; and no population of interest. Inclusion criteria were a report of surgical procedure performed and at least 1 outcome of interest resulting from the studied surgery was reported: comorbidities, mortality, complications, reoperations, or weight loss. Of the 25,060 initially identified articles, 24,023 studies met the exclusion criteria, and 259 met the inclusion criteria. DATA EXTRACTION AND SYNTHESIS A review protocol was followed throughout. Three reviewers independently reviewed studies, abstracted data, and resolved disagreements by consensus. Studies were evaluated for quality. MAIN OUTCOMES AND MEASURES Mortality, complications, reoperations, weight loss, and remission of obesity-related diseases. RESULTS A total of 164 studies were included (37 randomized clinical trials and 127 observational studies). Analyses included 161,756 patients with a mean age of 44.56 years and body mass index of 45.62. We conducted random-effects and fixed-effect meta-analyses and meta-regression. In randomized clinical trials, the mortality rate within 30 days was 0.08% (95% CI, 0.01%-0.24%); the mortality rate after 30 days was 0.31% (95% CI, 0.01%-0.75%). Body mass index loss at 5 years postsurgery was 12 to 17. The complication rate was 17% (95% CI, 11%-23%), and the reoperation rate was 7% (95% CI, 3%-12%). Gastric bypass was more effective in weight loss but associated with more complications. Adjustable gastric banding had lower mortality and complication rates; yet, the reoperation rate was higher and weight loss was less substantial than gastric bypass. Sleeve gastrectomy appeared to be more effective in weight loss than adjustable gastric banding and comparable with gastric bypass. CONCLUSIONS AND RELEVANCE Bariatric surgery provides substantial and sustained effects on weight loss and ameliorates obesity-attributable comorbidities in the majority of bariatric patients, although risks of complication, reoperation, and death exist. Death rates were lower than those reported in previous meta-analyses.

A systematic review of body fat distribution and mortality in older people

We conducted a systematic review investigating body fat distribution in older adults and its association with morbidity and mortality. Our search yielded 2702 citations. Following three levels of screening, 25 studies were selected to evaluate the association between body fat distribution and comorbidity, and 17 studies were used in the mortality analysis. Most of the selected studies in our analyses used anthropometric measures, e.g., body mass index (BMI), waist circumference, and waist-hip ratio; relatively few studies used direct measures, such as body fat/lean mass, and percentage body fat. Studies reported inconsistent findings regarding the strongest predictor(s) of morbidity and mortality. However, the majority of studies suggested that BMI per se was not the most appropriate predictor of morbidity and mortality in the elderly because of its inability to discern or detect age-related body fat redistribution. In addition, studies using BMI found that the optimal BMI range for the lowest mortality in the elderly was overweight (25 kg/m(2)≤BMI<30 kg/m(2)) or mildly obese (30 kg/m(2)≤BMI<35 kg/m(2)). Our findings suggest that the current clinical guidelines, recommending that overweight and obesity are major risk factors for increased morbidity and mortality are not applicable to this population. Therefore, the central message of this review is to advise the government to establish new guidelines specifically for this population, using a combination of body fat distribution measurements, and to certify that these guidelines will not be applied to inappropriate populations.

Cost-Effectiveness of Bariatric Surgery: Should it Be Universally Available?

This paper is the first to conduct cost-effectiveness analyses of bariatric surgery comparing obese patients with obesity-related diseases to obese people without comorbidities across different BMI categories, using the meta-analysis results of surgery outcomes for our effectiveness inputs. We find that surgery treatment is in general cost-effective for people whose BMI is greater than 35 kg/m(2) with or without obesity-related comorbidities, and it is even cost-saving for super obese (BMI ≥ 50 kg/m(2)) with obesity-related comorbidities. Our results also suggest that surgery can be cost-effective for the mildly obese (BMI ≥ 30 kg/m(2)). The bottom line is that bariatric surgery should be universally available to all classes of obese people.

Increased Body Mass Index Is Associated With Improved Survival in United States Veterans With Diffuse Large B-Cell Lymphoma

PURPOSE Obesity increases the risk of death from many malignancies, including non-Hodgkins lymphoma (NHL). In diffuse large B-cell lymphoma (DLBCL), the most common form of NHL, the association between body mass index (BMI) at diagnosis and survival is unclear. PATIENTS AND METHODS We evaluated the association between BMI at diagnosis and overall survival in a retrospective cohort of 2,534 United States veterans diagnosed with DLBCL between October 1, 1998 and December 31, 2008. Cox modeling was used to control for patient- and disease-related prognostic variables. RESULTS Mean age at diagnosis was 68 years (range, 20 to 100 years); 64% of patients were overweight (BMI, 25 to < 30) or obese (BMI, ≥ 30). Obese patients were significantly younger, had significantly fewer B symptoms, and trended toward lower-stage disease, compared with other BMI groups. Cox analysis showed reduced mortality in overweight and obese patients (overweight: hazard ratio [HR], 0.73; 95% CI, 0.65 to 0.83; obese: HR, 0.68; 95% CI, 0.58 to 0.80), compared with normal-weight patients (BMI, 18.5 to < 25). Treatment during the rituximab era reduced the risk of death without affecting the association between BMI and survival. Disease-related weight loss occurred in 29% of patients with weight data 1 year before diagnosis. Cox analysis based on BMI 1 year before diagnosis continued to demonstrate reduced risk of death in overweight and obese patients. CONCLUSION Being overweight or obese at the time of DLBCL diagnosis is associated with improved overall survival. Understanding the mechanisms responsible for this association will require further study.

Life Years Lost Associated with Obesity-Related Diseases for U.S. Non-Smoking Adults

The objectives of this paper are to predict life years lost associated with obesity-related diseases (ORDs) for U.S. non-smoking adults, and to examine the relationship between those ORDs and mortality. Data from the National Health Interview Survey, 1997–2000, were used. We employed mixed proportional hazard models to estimate the association between those ORDs and mortality and used simulations to project life years lost associated with the ORDs. We found that obesity-attributable comorbidities are associated with large decreases in life years and increases in mortality rates. The life years lost associated with ORDs is more marked for younger adults than older adults, for blacks than whites, for males than females, and for the more obese than the less obese. Using U.S. non-smoking adults aged 40 to 49 years as an example to illustrate percentage of the life years lost associated with ORDs, we found that the mean life years lost associated with ORDs for U.S. non-smoking black males aged 40 to 49 years with a body mass index above 40 kg/m2 was 5.43 years, which translates to a 7.5% reduction in total life years. White males of the same age range and same degree of obesity lost 5.23 life years on average – a 6.8% reduction in total life years, followed by black females (5.04 years, a 6.5% reduction in life years), and white females (4.7 years, a 5.8% reduction in life years). Overall, ORDs increased chances of dying and lessened life years by 0.2 to 11.7 years depending on gender, race, BMI classification, and age.

Associations of urinary phthalates with body mass index, waist circumference and serum lipids among females: National Health and Nutrition Examination Survey 1999–2004

Background/objectives:Exposure to environmental chemicals could be one of the contributors to the increasing obesity epidemic. Very little is known about the association of phthalates, ubiquitous chemicals widely used in consumer products, with obesity and lipid metabolism. This study investigated the association of urinary phthalate metabolites and, for the first time, the ratios of the major metabolites of the most common phthalate, di-2-ethylhexyl phthalate, with body mass index (BMI), waist circumference and serum lipid levels in the US female population.Methods:This cross-sectional study used the data from the National Health and Nutrition Examination Survey, 1999–2004 and was restricted to women aged ⩾18 years, who were not pregnant and had no history of diabetes. Using multivariate ordered logistic regression, we examined associations of seven urinary phthalate metabolites and their metabolic ratios with the BMI, waist circumferences, total cholesterol, triglycerides and high- and low-density lipoprotein cholesterol.Results:BMI was positively associated with monobutyl phthalate (MBP) and mono-2-ethylhexyl phthalate (MEHP) (odds ratio (OR)=1.13; 95% confidence interval (CI), 1.03–1.23 and OR=1.12; 95% CI, 1.03–1.23, respectively). Waist circumference was positively associated with MBP (OR=1.13; 95% CI, 1.03–1.24). A higher ratio of MEHP to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was positively associated with both BMI (OR=1.21; 95% CI, 1.09–1.34) and waist circumference (OR=1.20; 95% CI, 1.10–1.31). There were no other significant associations.Conclusions:A higher metabolic ratio of MEHP to MEHHP, reflective of slower oxidative conversion of MEHP, is associated with greater BMI and waist circumference.

Life Years Lost and Lifetime Health Care Expenditures Associated With Diabetes in the U.S., National Health Interview Survey, 1997–2000

OBJECTIVE This study analyzed the lifetime health care expenditures and life years lost associated with diabetes in the U.S. RESEARCH DESIGN AND METHODS Data from the National Health Interview Survey (NHIS), the Medical Expenditure Panel Survey from 1997 to 2000, and the NHIS Linked Mortality Public-use Files with a mortality follow-up to 2006 were used to estimate age-, race-, sex-, and BMI-specific risk of diabetes, mortality, and annual health care expenditures for both patients with diabetes and those without diabetes. A Markov model populated by the risk and cost estimates was used to compute life years and total lifetime health care expenditures by age, race, sex, and BMI classifications for patients with diabetes and without diabetes. RESULTS Predicted life expectancy for patients with diabetes and without diabetes demonstrated an inverted U shape across most BMI classifications, with highest life expectancy being for the overweight. Lifetime health care expenditures were higher for whites than blacks and for females than males. Using U.S. adults aged 50 years as an example, we found that diabetic white females with a BMI >40 kg/m2 had 17.9 remaining life years and lifetime health expenditures of

Influence of Body Mass Index on Survival in Veterans With Multiple Myeloma

185,609, whereas diabetic white females with normal weight had 22.2 remaining life years and lifetime health expenditures of

Obesity, Mortality, and Life Years Lost Associated With Breast Cancer in Nonsmoking US Women, National Health Interview Survey, 1997–2000

183,704. CONCLUSIONS Our results show that diabetes is associated with large decreases in life expectancy and large increases in lifetime health care expenditures. In addition to decreasing life expectancy by 3.3 to 18.7 years, diabetes increased lifetime health care expenditures by

Association between metformin use and progression of monoclonal gammopathy of undetermined significance to multiple myeloma in US veterans with diabetes mellitus: a population-based retrospective cohort study

8,946 to