Bariatric surgery: a primer.

OBJECTIVE: To review the management of bariatric surgical patients. QUALITY OF EVIDENCE: MEDLINE, EMBASE, and Cochrane Library databases were searched, as well as PubMed US National Library, from January 1950 to December 2009. Evidence was levels I, II, and III. MAIN MESSAGE: Bariatric surgery should be considered for obese patients at high risk of morbidity and mortality who have not achieved adequate weight loss with lifestyle and medical management and who are suffering from the complications of obesity. Bariatric surgery can result in substantial weight loss, resolution of comorbid conditions, and improved quality of life. The patient's weight-loss history; his or her personal accountability, responsibility, and comprehension; and the acceptable level of risk must be taken into account. Complications include technical failure, bleeding, abdominal pain, nausea or vomiting, excess loose skin, bowel obstruction, ulcers, and anastomotic stricture. Lifelong monitoring by a multidisciplinary team is essential. CONCLUSION: Limited long-term success of behavioural and pharmacologic therapies in severe obesity has led to renewed interest in bariatric surgery. Success with bariatric surgery is more likely when multidisciplinary care providers, in conjunction with primary care providers, assess, treat, monitor, and evaluate patients before and after surgery. Family physicians will play a critical role in counseling patients about bariatric surgery and will need to develop skills in managing these patients in the long-term.

Accuracy and reliability of a portable indirect calorimeter compared to whole-body indirect calorimetry for measuring resting energy expenditure.

BACKGROUND/OBJECTIVES: Resting energy expenditure (REE) is the largest component of total energy expenditure. As such, inaccurate estimation or measurement of REE may impact the development of individualized energy intake recommendations. The objective of this observational study was to assess the accuracy and reliability of REE measured with a portable indirect calorimeter with ventilated hood - Fitmate GS - compared to REE from whole-body indirect calorimetry (WBC). METHODS: REE was assessed using the Fitmate GS and compared to REE from WBC in male and female adults. Fitmate GS tests were repeated on a separate visit. Body fat percent, fat mass, and fat-free mass were assessed using dual X-ray absorptiometry in a subset of individuals with body mass index (BMI) ≥35 kg/m2. Paired t-tests and Bland-Altman analyses were used to describe REE accuracy; intra-class correlation coefficient (ICC) examined test-retest reliability of repeated Fitmate GS assessments. RESULTS: Fitmate GS and WBC REE was assessed in 77 adults (age 32 ± 8 years; 63.6% females; 53.2% with BMI ≥ 30 kg/m2). The Fitmate GS underestimated REE (1680 ± 420 vs. 1916 ± 461 kcal/day, p < 0.001) and wide limits of agreement were observed (95% confidence intervals [CI]: -727, 246 kcal/day). Bias was similar across sex and BMI categories and did not correlate to any body composition parameter. Fitmate GS ICC was 0.80 (95% CI: 0.70-0.87), indicating 'good' reliability with repeated testing after median follow-up of 4 days (interquartile range 2-7 days). CONCLUSION: The Fitmate GS did not accurately quantify REE but produced reliable REE measurements.

Accuracy of the MedGem® portable indirect calorimeter for measuring resting energy expenditure in adults with class II or III obesity.

BACKGROUND AND AIMS: The accuracy of some portable indirect calorimeters in estimating resting energy expenditure (REE) - and hence energy recommendations - among pre-bariatric patients is unknown. Our objective was to assess the accuracy of the MedGem® among individuals with class II or III obesity awaiting bariatric surgery. METHODS: Male and female adults who were awaiting bariatric surgery were recruited to this cross-sectional study. MedGem-derived oxygen consumption (O2) and REE were compared to O2 and REE from a metabolic cart. REE was also calculated using several common equations to assess the clinical utility of this portable tool. Body composition was assessed by dual energy X-Ray absorptiometry. Paired t-test and Bland-Altman analysis (expressed as bias [average difference] and limits of agreement [bias ± 2 standard deviations]) evaluated O2 and REE accuracy. RESULTS: Twenty-six individuals were included (34 ± 9 years old; n = 20, 76.9% female), with the majority (n = 15, 57.7%) having class II obesity. Neither O2 (MedGem: 283 ± 63 vs. metabolic cart: 293 ± 64 ml/min, p = 0.114) nor REE (MedGem: 1963 ± 437 vs. metabolic cart: 2047 ± 440 kcal/day, p = 0.057) were different between devices. Body composition did not relate to bias. The MedGem had wide limits of agreement for REE (-504 to 336 kcal/day), which was similar to predictive equations. CONCLUSIONS: Although REE from the MedGem was not different than REE from the metabolic cart, individual-level accuracy was poor and similar to predictive equations in patients with class II or III obesity. Nonetheless, efficacy of repeated assessments during weight loss warrant future investigation.

Poor Physical Function as a Marker of Sarcopenia in Adults with Class II/III Obesity.

BACKGROUND: Adults with class II/III obesity [body mass index (in kg/m2) ≥35] may present with a phenotype characterized by low lean mass and excess fat mass, a condition known as sarcopenic obesity (SO). Little is known about the prevalence and relevance of SO in these individuals, primarily due to a lack of relevant diagnostic criteria. OBJECTIVE: Here, we explored the definition of SO based on physical function as an outcome of interest in adults with class II/III obesity and applied this definition to compare clinical characteristics between SO and non-SO patients. METHODS: In this cross-sectional analysis, patients' demographic, anthropometric, and biochemical characteristics, as well as comorbidities and physical activity levels, were collected at an obesity specialty clinic prior to any treatment. Body composition was assessed by dual-energy X-ray absorptiometry. Physical function was assessed by self-reported difficulties with activities of daily living (ADLs) from an 11-item questionnaire. Five SO definitions were tested against reported difficulty with ADLs with the use of receiver operating characteristic (ROC) analysis. RESULTS: A total of 120 subjects (86% women) aged 46 ± 11 y were included. Based on ROC analysis, SO was best defined by an appendicular skeletal mass (ASM)/weight x 100 (%) <19.35% for women and <24.33% for men, resulting in a prevalence of 25% (n = 30, women 22.3%, men 41.2%). SO was significantly associated with older age, higher waist circumference, higher triglycerides, greater use of antihypertensive medications, and lower physical activity. CONCLUSIONS: In this sample of adults with class II/III obesity, difficulties with ADLs were best associated with measures of ASM in relation to total body weight. Patients identified with SO using this criterion presented with poorer clinical outcomes such as factors of elevated cardiometabolic risk.

Prevalence of Sarcopenic Obesity in Adults with Class II/III Obesity Using Different Diagnostic Criteria.

Background/Objective. Sarcopenic obesity (SO) is a hidden condition of reduced lean soft tissue (LST) in context of excess adiposity. SO is most commonly reported in older adults and both its risk and prevalence increase with age. A variety of body composition indices and cut points have been used to define this condition, leading to conflicting prevalence and risk prediction. Here, we investigate variability in the prevalence of SO in an adult sample of individuals with class II/III obesity (BMI ≥ 35 kg/m2) using different diagnostic criteria. Methods. SO definitions were identified from a literature review of studies using dual-energy X-ray absorptiometry (DXA) to assess LST. Demographics, anthropometrics, and body composition (by DXA) were measured in n = 120, 86% female (46.9 ± 11.1 years). Results. LST was extremely variable in individuals, even with similar body sizes, and observed across the age spectrum. The prevalence of SO ranged from 0 to 84.5% in females and 0 to 100% in males, depending upon the definition applied, with higher prevalence among definitions accounting for measures of body size or fat mass. Conclusion. SO is present, yet variable, in adults with class II/III obesity. Accounting for body mass or fat mass may identify a higher number of individuals with SO, although risk prediction remains to be studied.

Practical Considerations for Body Composition Assessment of Adults with Class II/III Obesity Using Bioelectrical Impedance Analysis or Dual-Energy X-Ray Absorptiometry.

PURPOSE OF REVIEW: The purpose of this review is to explore the practical considerations for body composition assessment of adults with class II/III obesity. Studies assessing adults (18-64 years) with a body mass index (BMI) ≥35 kg/m2 with bioelectrical impedance analysis (BIA) and/or dual-energy X-ray absorptiometry (DXA) were included. RECENT FINDINGS: Twelve studies met inclusion criteria. Five considerations were identified: variances in equipment and technology, equipment weight capacity, subject positioning, tissue penetration, and total body hydration. In subjects with BMI ≥35 kg/m2, BIA overestimated fat-free mass with scaling errors as BMI increased. DXA provided accurate and reliable body composition measures, but equipment-related barriers prevented assessment of some taller, wider, and heavier subjects. BIA is an unreliable method to assess body composition in class II/III obesity. Advancements in DXA technology (e.g., iDXA), methodology (e.g., subject positioning, longer scan times), and more inclusive testing criteria (e.g., use equipment limits not just BMI) may improve access and understanding of body composition in this cohort.

Nutrition care for patients with weight regain after bariatric surgery.

Achieving optimal weight outcomes for patients with obesity is important to the management of their chronic disease. All interventions present risks for weight regain. Bariatric surgery is the most efficacious treatment, producing greater weight losses that are sustained over more time compared to lifestyle interventions. However, approximately 20-30% of patients do not achieve successful weight outcomes, and patients may experience a regain of 20-25% of their lost weight. This paper reviews several factors that influence weight regain after bariatric surgery, including type of surgery, food tolerance, energy requirements, drivers to eat, errors in estimating intake, adherence, food and beverage choices, and patient knowledge. A comprehensive multidisciplinary approach can provide the best care for patients with weight regain. Nutrition care by a registered dietitian is recommended for all bariatric surgery patients. Nutrition diagnoses and interventions are discussed. Regular monitoring of weight status and early intervention may help prevent significant weight regain.

Income status and approval for bariatric surgery in a publicly funded regional obesity program.

BACKGROUND: Bariatric surgery has emerged as an effective and safe treatment for severe obesity and utilization rates have increased dramatically. In private health care settings, low socioeconomic status is associated with a reduced likelihood of undergoing a bariatric procedure. Whether this relationship is also present in a universally accessible, publicly funded health care system is not currently known. METHODS: A retrospective analysis of the Edmonton Weight Wise obesity program clinical registry was conducted. Patients who were unemployed, on long-term disability or receiving social assistance were classified as "low income" status. The remaining patients were categorized as "regular income" status. Multivariable logistic regression analysis was used to examine the association between low income status and approval for surgery within 1 year of program entry. RESULTS: Thirty-three (7%) of 419 patients were ineligible for surgery or excluded because of missing income status data. Of the remaining 386 patients, 72 (19%) were of low income status and 89 (23%) were approved for surgery. Low income patients were older, heavier, and had greater comorbidity. Compared to patients of regular income status, those with low income status were less likely to be approved for surgery (15.3% versus 24.8%; adjusted OR 0.45; 95% CI 0.22 to 0.94). CONCLUSIONS: Within a publicly funded and universally accessible regional obesity program, lower income status patients were less likely to be approved for bariatric surgery. Further study is necessary to clarify this apparent disparity and to determine if program modifications are necessary to ensure equity across all socioeconomic strata.