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Is it time to abandon excess weight loss in reporting surgical weight loss?
... Weight loss is probably the most useful measure for informing, since it is easy to understand, commonly used, and in the lexicon of most people. Slightly more complex but generally understood is percentage of weight lost (%WL) [8] . To provide encouragement, the percentage of excess weight lost (%EWL) is a larger number than %WL which may translate to perception of greater success. ...
... Finally, and the focus of this manuscript, is a measure which can be used to compare treatments, or different cohorts undergoing the same treatment. Although standards have been called for [4,8,11] , they have not yet been agreed upon. Issues described above have been used as arguments against proposed standards, and they are legitimate. ...
... The journal Obesity Surgery in 2007 "strongly encouraged" the use of %EWL based on the "old Metropolitan Tables" [7] or %EBMIL. This recommendation is curious since the interpretation of %EWL is affected by the choice of the "ideal" body weight [11,16] and the concept of an ideal body weight, whether it be from the Metropolitan Life Tables or particular value(s) of BMI is inherently flawed [8] . ...
Background:
Although it is recognized that a standardized approach to reporting weight change is essential to meaningful comparisons among cohorts and across studies, consensus is lacking. This study aimed to propose a method of reporting weight change that would allow meaningful comparisons among studies of patients who underwent bariatric surgery and to demonstrate its utility using an example from the Longitudinal Assessment of Bariatric Surgery (LABS).
Methods:
Relationships among several measures of weight change are described. Results from an observational, longitudinal cohort study of adults undergoing bariatric surgery and from simulation studies are used to illustrate the proposed method.
Results:
Baseline weight is a critical parameter when assessing weight change. Men undergoing a bariatric procedure other than gastric bypass or adjustable band tended to have greater weight loss 12 months after surgery than men undergoing gastric bypass when not accounting for baseline weight, but the opposite was found when results were adjusted for baseline weight. Simulation results show that with relatively modest sample sizes, the adjusted weight loss was significantly different between the 2 groups of men.
Conclusion:
A consistent metric for reporting weight loss after bariatric surgery is essential to interpret outcomes across studies and among subgroups. The baseline weight adjusted percent of weight loss (A%WL) uses a standard population (e.g., the LABS cohort) to account for differences between cohorts with respect to baseline weight, and its use can change the interpretation of results compared with an unadjusted measure.
... However, several thresholds have been commonly used to classify BS patients as good or poor responders without an established clinical relevance. Although the use of excess baseline weight loss (EWL) as an outcome measure after BS has been previously questioned [18], 50% EWL is still the most frequently used threshold for defining insufficient weight loss (IWL) [19][20][21]. Another suggested cutoff point is 20% of total body-weight loss (TBWL). ...
... No previous study has reported the prevalence of IWL applying the 20% TBWL criteria. However, in The Dutch Bariatric Chart study, a multicenter observational study, including more than 9000 participants who underwent RYGB or SG, a 1-year TBWL between 15 and 20% corresponded to −2SD of TBWL distribution [18]. Thus, despite the significant association between these measures and long-term MACE occurrence, it could be argued that the proposed thresholds, especially the 20% of TBWL, might be excessively permissive. ...
Whether the extent of weight loss (WL) modulates bariatric surgery (BS) cardiovascular benefits has scarcely been assessed. Several WL thresholds have been commonly used to classify BS patients as good or poor responders without a proven clinical relevance. We examined the relationship between the magnitude of WL after BS and post-surgery major adverse cardiovascular-event (MACE) incidence. We also compared the performance of three different insufficient weight-loss (IWL) criteria for their association with MACE.
All individuals who underwent a primary Roux-en Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in our institution at least six years before data analysis (12/2020) were included in the study. Data on MACE were available in 1638 of 1700 participants (96.4%). Proportional-hazard Cox analyses were performed to ascertain the association between MACE, WL, and the three IWL criteria. IWL was defined as: <50% excess weight loss (<50% EWL), <20% total body-weight loss (<20% TBWL), and −1 standard deviation of alterable weight-loss percentage (<1 SD% AWL).
During a mean follow-up of 10.2 ± 2.8 years, 86 participants experienced a first post-surgery MACE. Higher WL at one year (HR: 0.77 (95% CI: 0.61–0.98)) and 5 years (HR: 0.63 (95% CI: 0.42–0.92)) was related to a lower incidence of MACE. All short-term criteria for defining IWL were similarly associated with MACE, yet <1 SD% AWL identified more at-risk subjects. Five-year TBWL < 20% and 5-year <1 SD-AWL% were significantly associated with a higher risk for CV events. TBWL < 20% identified more subjects at risk.
The extent of WL is closely related to long-term MACE incidence. Patients who lost −1SD% AWL at one year or <20% TBWL at five years may be considered poor responders.
... This measure represents the proportion of lost weight to the total amount of excess weight over the ideal weight; the ideal weight corresponds to the body mass index (BMI) of 25 kg/m 2 since Deitel et al. redefined this metric in 2007 [3]. However, there has been a consistent argument against the use of %EWL since it shows significant variation by the baseline BMI of the patients and is rarely used in non-surgical studies [1,[4][5][6][7][8]. Percentage of total weight loss (%TWL) is the most commonly adopted method of weight loss reported in the field of medical treatment for obesity. ...
... Percentage of total weight loss (%TWL) is the most commonly adopted method of weight loss reported in the field of medical treatment for obesity. Surgeons have recently advocated using %TWL after bariatric surgery because it is less associated with preoperative BMI and more intuitive than %EWL [8,9]. It was recently adopted as a mandatory measure for reporting weight loss outcomes by leading bariatric scientific societies [10]. ...
Background:
Percentage of excess weight loss (%EWL) is the most common metric used after bariatric surgery. However, there has been consistent argument against its use since it varies significantly by initial body mass index (BMI). This study aimed to validate the newly suggested percentage of alterable weight loss (%AWL) metric in Korean patients.
Methods:
A retrospective review of the prospectively established database at Soonchunhyang University Seoul Hospital identified 165 patients who underwent primary laparoscopic Roux-en-Y gastric bypass (RYGB) and had at least 2-year follow-up weight loss results after surgery. Patients were classified into subgroups based on initial BMI, and their weight loss results expressed as BMI, %EWL, %AWL, and percentage of total weight loss (%TWL) were compared in terms of nadir weight and weight loss trajectory.
Results:
The study cohort included 27 male (16.4%) and 138 female (83.6%) patients with a mean baseline BMI of 38.1 ± 5.4. Nadir weight was achieved at mean 24.1 ± 10.6 months postoperatively. Female patients required significantly longer to achieve nadir weight than male patients (16.2 vs. 22.4 months, p = 0.001), and they achieved less weight loss expressed as nadir BMI, %EWL, and %AWL. Of these metrics, only %AWL was not significantly influenced by preoperative BMI and showed the least variation (25.2%) for reporting weight loss.
Conclusion:
The AWL metric can report weight loss regardless of baseline BMI in Korean patients undergoing RYGB; however, it must be validated in a larger population involving multiple centers from the Asia-Pacific area before being used clinically.
... %EWL is based on weight loss divided by ''excess'' weight and multiplied by 100. ''Excess'' weight (actual weight minus ''ideal weight'') is based on the 1983 Metropolitan Life Insurance Company standard height-weight tables for ''medium frame'' men and women [16]. Karmali et al. recommended abandoning %EWL given that it is based on an outdated concept of ''ideal'' weight, difficult to explain, potentially misleading, and a barrier to comparing surgical and nonsurgical weight loss [16]. ...
... ''Excess'' weight (actual weight minus ''ideal weight'') is based on the 1983 Metropolitan Life Insurance Company standard height-weight tables for ''medium frame'' men and women [16]. Karmali et al. recommended abandoning %EWL given that it is based on an outdated concept of ''ideal'' weight, difficult to explain, potentially misleading, and a barrier to comparing surgical and nonsurgical weight loss [16]. Except when there was insufficient data to calculate %TBWL or when %EWL was used as a study's primary endpoint, we used %TBWL as the primary outcome measure. ...
Introduction:
The FDA recently approved three intragastric balloon (IGB) devices, ReShape, ORBERA™, and Obalon for treatment of obesity. Given the high cost, complication risk, and invasiveness of bariatric surgery, IGB treatment may present a safer and lower cost option for weight reduction. IGBs are generally placed in the stomach endoscopically for up to 6 months to reduce gastric capacity, enhance feelings of fullness, and induce weight loss. The mechanism of action likely involves stimulation of gastric mechanoreceptors triggering short-acting vagal signals to brain regions implicated in satiety. Balloon efficacy may be influenced by balloon volume, patient gastric capacity, and treatment duration.
Methods:
This review focused on eight recent (2006-present) randomized controlled trials (RCTs) comparing percentage total body weight loss (%TBWL) between IGB and control groups including three reviewed by the FDA. %TBWL based on the reviewed studies was also compared with bariatric surgery and pharmacotherapy.
Results:
Of the eight IGB studies, five had balloon treatment duration of 6 months. Efficacy at 6 months, based on a pooled weighted-mean %TBWL, was 9.7%, and the control-subtracted %TBWL was 5.6%. When one study without SDs was removed, the weighted mean %TBWL was 9.3 ± 5.7% SD, and control-subtracted %TBWL was 5.5 ± 7.8%, which was statistically greater than controls. IGB showed lower efficacy than bariatric surgery (median weight loss of 27% for Rouen-Y gastric bypass (RYGB). The control-subtracted %TBWL over 6 months of 5.5-5.6% is less than the most efficacious FDA-approved weight loss drug, Qsymia. At the recommended dose, Qsymia has a placebo-subtracted %TBWL at 6 months of approximately 6.6%. The weighted mean reported incidence of serious adverse events (SAEs) in the IGB group across all eight studies was 10.5%. Only six of the eight reviewed studies reported adverse events (AEs) in the IGB group, with a pooled reported incidence of 28.2%. Recently, the FDA reported new AEs including acute pancreatitis with ReShape and ORBERA™.
Conclusion:
Based on the available evidence, it is unlikely that IGB use will supplant other forms of obesity treatment. The estimated cost of endoscopic balloon implantation and retrieval is US $8,150. Collectively, a relatively small control-subtracted %TBWL and the potential for serious complications makes IGB unlikely to become widely adopted. Given the recent FDA warning, IGB longevity on the market is questionable.
... Currently, there is no agreement on the best tool to describe WL after bariatric surgery. Commonly used metrics include percent excess WL (%EWL), percent excess body mass index loss (%EBL), number of BMI units lost, and percent total body WL (%TWL) [12,13]. Recently, %TWL has been suggested as the most accurate method because it is reported to be less influenced by confounding anthropometric factors, and WL results can be compared with behavioral and pharmacological series reported in the non-bariatric medical literature [14,15]. ...
... It reports a percentage of WL relative to an Bideal^BMI or weight, and numerous studies have arbitrarily defined suboptimal WL as %EWL less than 50 % [19]. However, some controversies arise when using %EWL as the sole measure of procedural efficacy [12]. For instance, WL calculations using %EWL are based on an ideal BMI of 25 kg/m 2 or are extracted from the Metropolitan Life Insurance Company tables, and this arbitrary definition is significantly influenced by a patient's height [20,21]. ...
Background
Currently, there is no agreement on the best method to describe weight loss (WL) after bariatric surgery. The aim of this study is to evaluate short-term outcomes using percent of total body weight loss (%TWL).
Methods
A single-institution retrospective study of 2420 patients undergoing Roux-en-Y gastric bypass (RYGB) was performed. Suboptimal WL was defined as %TWL < 20 % at 12 months.
Results
Mean preoperative BMI was 46.8 ± 7.8 kg/m2. One year after surgery, patients lost an average 14.1 kg/m2 units of body mass index (BMI), 30.0 ± 8.5 %TWL, and 68.5 ± 22.9 %EWL. At 6 and 12 months after RYGB, mean BMI and percent excess WL (%EWL) significantly improved for all baseline BMI groups (p < 0.01, BMI; p = 0.01, %EWL), whereas mean %TWL was not significantly different among baseline BMI groups (p = 0.9). The regression analysis between each metric outcome and preoperative BMI demonstrated that preoperative BMI did not significantly correlate with %TWL at 1 year (r = 0.04, p = 0.3). On the contrary, preoperative BMI was strongly but negatively associated with the %EWL (r = −0.52, p < 0.01) and positively associated with the BMI units lost at 1 year (r = 0.56, p < 0.01). In total, 11.3 % of subjects achieved <20 %TWL at 12 months and were considered as suboptimal WL patients.
Conclusion
The results of our study confirm that %TWL should be the metric of choice when reporting WL because it is less influenced by preoperative BMI. Eleven percent of patients failed to achieve successful WL during the in the first year after RYGB based on our definition.
... Currently, there is no consensus on the best method for characterizing WL after RYGB, and the arguments for or against any one of these metrics have been dominated by considerations of biological/ mechanistic plausibility, ease of communication to the research and clinical communities, historical precedent and perceived clinical relevance. [15][16][17][18][19][20][21] Percent EBWL, a metric that is used primarily in describing WL after bariatric surgery, 21 describes the percent of weight loss relative to achieving an "ideal" BMI. Recently, it was proposed that %EBWL be the standard metric for reporting WL after bariatric surgery, and be extended to describing outcomes of other interventions for obesity. ...
... The use of %WL also has several advantages over the use of %EBWL beyond its statistical properties. 17 First, %EBWL is based on a somewhat arbitrary target, or "ideal" weight, whether this is defined according to a BMI standard (e.g., a BMI of 25 kg/m 2 ) or another standard such as the Metropolitan Life Insurance Company life tables. It is not intrinsically clear what the "right" target should be, and the choice of target can substantially skew the results, particularly if the starting BMI is relatively low (e.g., <35 kg/m 2 ) as is more often the case with recent studies examining the efficacy of novel drugs, medical devices or the efficacy of surgery specifically for the treatment of DM. ...
Objective
Although Roux-en-Y gastric bypass (RYGB) is a generally effective treatment for severe obesity, weight loss (WL) after this operation is highly variable. Accurate predictors of outcome would thus be useful in identifying those patients who would most benefit from this invasive therapy. WL has been characterized using several different metrics, including the number of BMI units lost (ΔBMI), percent baseline WL (%WL), and percent excess body WL (%EBWL). To identify clinically relevant predictors most sensitively it is necessary to avoid confounding by other factors, including preoperative BMI (pBMI), the strongest known predictor of RYGB-induced WL.
Design and Methods
To determine the WL measure least associated with pBMI, we analyzed outcomes of 846 patients undergoing RYGB.
Results
Patients in this cohort had an average pBMI of 50.0 kg/m2. At weight nadir, they lost an average 19.4 kg/m2, 38.7% WL, and 81.2% EBWL. pBMI was strongly and positively associated with ΔBMI at both one year (r=0.56, p=4.7×10−51) and nadir (r=0.58, p=2.8×10−77) and strongly but negatively associated with %EBWL at one year (r=−0.52, p=3.8×10−44) and nadir (r=−0.45, p=7.2×10−43). In contrast, pBMI was not significantly associated with %WL at one year (r=0.04, p=0.33), and only weakly associated at nadir (r=0.13, p=0.0002).
Conclusions
Of the metrics examined, %WL is the parameter describing WL after RYGB least influenced by pBMI. It thus improves comparison of WL outcomes across studies of patients undergoing surgery and facilitates the most sensitive identification of novel predictors of surgery-induced WL. We therefore recommend that %WL be adopted more broadly in reporting weight loss after RYGB.
... (10,12) Only one relevant article (8) has examined percent of initial body weight loss (%IBWL [= %TBWL]), which may be less likely to yield a particular conclusion and has been suggested as an alternative to reporting postoperative %EBWL. (13,14) Interestingly, this study found that SSO vs. non-SSO individuals showed a lower %EBWL at both 6 and 12 mo post-surgery but did not differ in %IBWL at either time point. (8) Thus, it remains unclear whether preoperative BMI has an effect on postoperative %IBWL. ...
... This may explain the seemingly perplexing findings of Farkas et al., (8) who demonstrated significant SSO vs. non-SSO differences in %EBWL, but no differences in %IBWL, at 6 and 12 mo post RYGB. Thus, despite the convention of reporting %EBWL in postoperative reports, (13) %IBWL may be a better weight loss outcome measure in analyses of the effect of preoperative weight on postoperative weight loss. ...
Background:
Previous studies suggest that individuals with body mass index (BMI) above versus below 60 kg/m(2) attain lower percentage of excess weight loss (%EWL) after bariatric surgery. The objectives of this study were to (1) test whether conclusions drawn about the effect of preoperative BMI on postoperative weight loss depend on the outcome measure, (2) test for evidence of a threshold effect at BMI = 60 kg/m(2), and (3) test the effect from surgery to 12-month follow-up, relative to 12- to 36-month follow-up.
Methods:
Retrospective analyses of participants grouped according to preoperative BMI: 35-39.9 (n = 232); 40-49.9 (n = 1166); 50-59.9 (n = 429);≥60 (n = 166).
Results:
As anticipated, individuals with higher versus lower preoperative BMI had greater total weight loss but lower %EWL at all postoperative time points (all, P<.0005). However, these individuals also had lower percentage of initial weight loss (%IWL) at all time points beyond 1 month postsurgery (all, P<.0005). From 12- to 36-months, individuals with BMI 35-39.9 had 3.2±14.3 %IWL (P<.0001); 40-49.9 had 1.0±8.9 %IWL (P<.0005); 50-59.9 had-2.4±10.0 %IWL (P<.0005); and≥60 had-3.6±11.5 %IWL (P<.0005). Overall F3,1989 = 20.2, P< .0005.
Conclusions:
Conclusions drawn about the effect of preoperative BMI may depend on the outcome measure. A dosage effect of preoperative BMI was apparent, with heavier individuals showing lower percentages of initial and excess weight loss, regardless of BMI above or below 60 kg/m(2). Finally, this effect was particularly apparent after the initial 12-month rapid weight loss phase, when less obese (BMI<50) individuals continued losing weight, while heavier individuals (BMI≥50) regained significant weight.
... Furthermore, ROC analyses revealed that the AUC of the %TWL was significantly greater than that of the %EWL, which demonstrated that the %TWL was more predictive. In line with our study, previous studies have suggested that the %TWL can yield a more accurate outcome without the need for defining ideal body weight [19]. Because the %EWL is based on a somewhat arbitrary target, or "ideal" weight, whether this is defined according to a BMI standard (e.g., a BMI of 25 kg/m 2 in Caucasian, 24 kg/m 2 in Asian). ...
The need for a unified definition of weight loss (WL) after bariatric surgery has recently been highlighted. We aimed to evaluate the reliability of two clinically common WL indications including percentage of total WL (%TWL) and percentage of excess WL (%EWL) through comparing their performances in predicting metabolic syndrome (MetS) remission 1 year after bariatric surgery.
A total of 430 individuals with obesity who underwent bariatric surgery were enrolled. Participants were evaluated for changes in anthropometric parameters, metabolic indexes, MetS components and medications before and 1 year after surgery. MetS was defined using the criteria of the National Cholesterol Education Program Adult Treatment Panel III criteria for Asian-Americans.
The prevalence of MetS is 92.3% (397) at baseline. One year after bariatric surgery, 337 individuals (84.9%) were in MetS remission. The multivariate adjusted ORs were 1.16 (95% confidence interval [CI] 1.10–1.22) for each 1% increase in %TWL for MetS remission and 1.18 (95% CI 1.11–1.25) for each 5% increase in %EWL. This association with MetS remission remained statistically significant for %TWL after additional adjustment for %EWL (P for trend 0.029), and disappeared for %EWL. Receiver operating curve (ROC) analyses showed that the %TWL was more predictive than the %EWL (AUC%TWL vs. AUC%EWL, 0.749 vs. 0.700, p = 0.023). The Youden index indicated that the optimal %TWL cutoff point to identify MetS remission was 25%.
We recommend that good responders to bariatric surgery should be defined as those exhibiting %TWL ≥ 25%.
... An often-used outcome parameter is percentage EWL. However, several studies showed that EWL is not suitable for comparing weight loss outcomes of non-randomized groups, due to variation caused by individual initial BMI [12,13]. Furthermore, expressing weight loss as EWL is prone to misinterpretation by both health care professionals as well as patients, since it is based on the difference between the patients BMI and a 'normal' or 'ideal' BMI of 25 kg/m 2 . ...
PurposePrimary nonresponse (1NR) – inability to achieve adequate weight loss after surgery - and secondary nonresponse (2NR) – excessive weight regain after initial adequate weight loss after surgery – can occur in up to 25–35% of patients after bariatric surgery. The aim of this study was to explore the variations in both definition as well as management of 1NR and 2NR amongst bariatric surgeons.Materials and Methods
An online survey was distributed to all members of the national bariatric societies in the Netherlands and Belgium regarding questions about definition, work-up and treatment of 1NR and 2NR after bariatric surgery.ResultsA total of 45 responses from bariatric surgeons were obtained, representing 32 medical centers that perform bariatric procedures. When assessing 1NR, excess weight loss(EWL) was reported to be used by most respondents(30/45), total body weight loss(TBWL) by 18/45 and body mass index(BMI) by 25/45. A great variation in cut off values was observed. When assessing 2NR, percentage weight gain from the lowest (nadir) weight was preferred most by 22/45 respondents with cut off values varying from 5 to 20%. Most respondents deemed 18 months after initial surgery the most appropriate timeframe to determine 1NR or 2NR.Conclusions
The current practice regarding primary and secondary nonresponse after bariatric surgery has a wide variety in definitions, work-up and treatment options. Consensus on the definition of 1NR and 2NR is needed to optimize the treatment of bariatric patients.
... puede considerar un éxito, aunque esto en general varía según el tipo, la agresividad y la complejidad de la cirugía. Sin embargo, Karmali et al. recomiendan el uso del porcentaje de pérdida de peso frente a los otros métodos, con el principal argumento de que el límite de peso normal de 25 kg/m 2 es arbitrario y los beneficios sobre las enfermedades concomitantes se logran antes de obtener el "peso ideal" (37) . Además, lograr un IMC de 25 kg/m 2 o menor es imposible o insostenible para la gran mayoría de los pacientes (38) . ...
La cirugía bariátrica se asocia a alteraciones metabólicas, desnutrición proteico-calórica y deficiencias nutricionales cuando no se hace un manejo y un seguimiento médico nutricional adecuado del paciente por parte de equipos interdisciplinarios. Hasta el año 2012 Colombia no contaba con una guía de manejo propia y se desconocía la práctica actual de los grupos de cirugía bariátrica. Por lo tanto, este estudio tuvo como objetivo conocer el seguimiento y manejo nutricional que realizan los médicos y nutricionistas involucrados en la cirugía bariátrica en el país.
... Preoperative BMI was positively related to weight regain when definitions were based on changes in BMI, %EWL, and kilograms. Recent studies have also shown that weight loss measures based on %EWL or BMI are influenced by preoperative BMI, and this study confirms that these measures are less suitable for comparing patients [32][33][34][35]. ...
Introduction
The prevalence and clinical significance of weight regain after bariatric surgery remains largely unclear due to the lack of a standardized definition of significant weight regain. The development of a clinically relevant definition of weight regain requires a better understanding of its clinical significance.
Objectives
To assess rates of weight regain 5 years after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), applying six definitions and investigating their association with clinical outcomes.
Methods
Patients were followed up until 5 years after surgery and weight regain was calculated. Regression techniques were used to assess the association of weight regain with health-related quality of life (HRQoL) and the presence of comorbidities.
Results
A total of 868 patients participated in the study, with a mean age of 46.6 (± 10.4) years, of which 79% were female. The average preoperative BMI was 44.8 (± 5.9) kg/m² and the total maximum weight loss was 32% (± 8%). Eighty-seven percent experienced any regain. Significant weight regain rates ranged from 16 to 37% depending on the definition. Three weight regain definitions were associated with deterioration in physical HRQoL (p < 0.05), while associations between definitions of weight regain and the presence of comorbidities 5 years after surgery were not significant.
Conclusion
These results indicate that identifying one single categorical definition of clinically significant weight regain is difficult. Additional research into the clinical significance of weight regain is needed to inform the development of a standardized definition that includes all dimensions of surgery success: weight, HRQoL, and comorbidity remission.
... Body mass index (BMI, kg/m 2 ) was calculated as the weight (kg) / height (m 2 ). Percentage of excess weight loss (%EWL) was calculated as [(preweightpostweight) / excess weight] × 100, where the excess weight = preweight -ideal weight [28] , and percentage of excess BMI loss (%EBMIL) was calculated as (initial BMI − post-BMI) / (initial BMI − 25) × 100 [29] . FPG and serum insulin measurements were used in the updated homeostasis model assessment (HOMA2) index to evaluate iHOMA2-β%, insulin resistance iHOMA-IR, and insulin sensitivity [24] . ...
Background:
Angiopoietin-like 8 (ANGPTL8) a hepatic protein, is implicated by several studies with a role in promoting pancreatic β-cell proliferation and improving glucose tolerance. Although a matter of controversy, a growing number of reports support ANGPTL8's potential, yet unclear, role in type 2 diabetes (T2D).
Objectives:
To examine changes in fasting ANGPTL8 level in people with morbid obesity, with or without diabetes after laparoscopic sleeve gastrectomy (LSG) in a 1-year prospective study.
Setting:
Dasman Diabetes Institute, government, and private hospitals, Kuwait.
Methods:
Fasting serum ANGPTL8 was measured by enzyme-linked immunosorbent assay at baseline in participants with morbid obesity, 17 with diabetes and 23 without diabetes, and in healthy weight participants, 19 with and 15 without diabetes, during 1 year post-LSG in participants with morbid obesity.
Results:
At baseline, people with T2D had higher ANGPTL8 level, (morbid obese, mean ± standard error of the mean; 1415 ± 196.4 pg/mL, and healthy weight, 2231 ± 328.1 pg/mL), compared with individuals without T2D (morbid obese, 876 ± 155.0 pg/mL, and healthy weight controls 868.9 ± 218.7 pg/mL). In participants with diabetes and morbid obesity, T2D remission occurred 15 days post-LSG, defined by a sustained reduced fasting blood glucose levels <6.9 mmol/L. In this group, the 1-year post-LSG measurement of ANGPTL8 showed unique biphasic changes, first a prominent elevation (day 60, 3336 ± 916.5 pg/mL, P < .01), followed by a gradual decrease to reach almost the baseline level (day 360, 1184 ± 119.3 pg/mL).
Conclusion:
Elevated baseline ANGPTL8 in participants with diabetes at baseline reflected a link to T2D. Interestingly, the unique biphasic pattern of change in fasting ANGPTL8 post-LSG, occurred only in people with diabetes, suggesting ANGPTL8's potential role in T2D remission.
... Indeed, defining a BMI of 25 kg/m 2 as a weight target is arbitrary and irrelevant in severely obese patients who will remain with a BMI > 30 kg/m 2 after surgery. 116,117 An average weight loss of 50% of excess weight at 5 years The SOS study is the largest and longest prospective, nonrandomized, interventional trial to examine the effects of bariatric surgery in 4047 obese patients matched with conventionally treated control subjects. 62 Results demonstrated that in the surgical group, there was a 23.4% decrease in weight at 2 years and a 16.1% decrease at 10 years. ...
Severe obesity is associated with increased morbidity and mortality and represents a major health care problem with increasing incidence worldwide. Bariatric surgery, through its efficacy and improved safety, is emerging as an important available treatment for patients with severe obesity. Classically, bariatric surgery has been described as either a restrictive or a hybrid surgery, which is a combination of restriction and malabsorption. For most severely obese patients, bariatric surgery results in the remission of major obesity-related comorbidities including type 2 diabetes mellitus, sleep apnea, hypertension, and dyslipidemia. Thus, bariatric surgery reduces cardiovascular risk burden, and overall mortality risk. Early complications (< 30 days) after bariatric surgery were reported to be < 10% and tend to be lower in restrictive surgeries compared with hybrid surgeries. Most common early complications reported are gastric and anastomosis leak (1.6%-5.1%), bleeding (0.5%-3.5%), and pulmonary embolism (0.2%-1%). Long-term complications (> 30 days) might differ depending on the type of bariatric surgery. According to the type of surgery and the type of study, the 30-day operative mortality rates differ from 0.1% to 1.2%. Studies on postoperative outcomes, investigations on weight loss physiology, and mechanism of action after bariatric surgery provide a better understanding of the bariatric surgery metabolic benefits. In this article, we present an overview of bariatric procedures with their effects, including risks and benefits, on the severely obese patients' health. It provides evidence to support surgical treatment of severe obesity to achieve cardiovascular disease risk reduction in severely obese patients.
Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Purpose
To identify weight loss prediction models by validating previous models using weight loss success criteria.
Materials and Methods
Patients with morbid obesity from 4 hospitals were retrospectively analyzed between Jan 2019 and 2022. Preoperative demographics, postoperative data, and 1-year follow-up weight loss outcomes were compared between 2 groups who underwent laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB). Additionally, the predictive factors for the success of excess weight loss (EWL) (>50%) and total weight loss (TWL) (>25%) were analyzed.
Results
Of the 162 patients, 137 were enrolled during the study period, 75 underwent LSG, and 62 underwent LRYGB. The >50% EWL and >25% TWL 1 year after surgery were 61.3% and 43.1%, respectively. Diabetes mellitus medication use was reduced in 94.8% of patients with type 2 diabetes mellitus. Male sex and body mass index (BMI) were independent risk factors for successful weight loss (SWL) or >50% EWL (odds ratio [OR] for BMI 0.830, 95% confidence interval [CI] 0.764–0.902), whereas achieving >25% TWL was not affected by sex or BMI (OR for BMI 1.010, 95% CI 0.957–1.065). External validation of the prediction models showed an acceptable range of accuracy (adjusted R² 66.5–71.3%).
Conclusion
LSG and LRYGB are feasible and effective bariatric procedures for SWL in Korean patients with morbid obesity. The TWL model was a more appropriate criterion than EWL, and weight loss prediction models may help assess the 1-year outcomes of bariatric surgery.
This is the first systematic review to synthesize the evidence concerning early post-operative variables predictive of later weight and psychosocial outcomes in bariatric surgery. Eight electronic databases for empirical studies were searched (1954 to 2016). Most of the 39 included studies reported solely on weight outcomes; eating and psychosocial outcomes were less common. A better early weight loss trajectory was the most consistent predictor of more successful medium-term weight outcome (≤24 months); however, its relationship to longer term weight loss maintenance is less certain. Early eating adaptation may be associated with later weight loss, but further research is needed. Evidence is lacking for associations between early adherence or early psychosocial variables and later outcome. In particular, the relationship between early post-operative depression and later weight remains unclear. Little research has considered early prediction of later eating or psychosocial outcomes. Consideration of mediating or moderating relationships is lacking. The body of evidence is limited, and synthesis is hampered by heterogeneity in the type and time at which predictors and outcomes are measured and quality of statistical reporting. Further research on prospective prediction of bariatric surgery outcome is needed to guide early post-operative intervention for those at greatest risk of poor outcomes.
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Background:
Percentage excess weight loss (%EWL) outcome of bariatric surgery is distorted by deviations in baseline body mass index (BMI). It has been reported that this can lead to false conclusions, most likely because bariatric weight loss in fact is baseline-BMI independent.
Objectives:
If the metabolic effect of bariatric surgery is baseline-BMI independent as well, could %EWL also lead to false conclusions on metabolic surgery?
Setting:
Bariatric Center of Excellence, general hospital, Netherlands.
Methods:
Retrospective analysis of 1-year outcome of all consecutive primary gastric bypass patients with type 2 diabetes (T2DM). Metabolic outcome (glycated hemoglobin [HbA1c], T2DM medication) was compared with bariatric outcome (weight loss) using 3 different metrics: %EWL, the most popular weight loss metric among bariatric surgeons; percentage (total) weight loss (%WL), most commonly used by nonsurgical professionals; and percentage alterable weight loss (%AWL), the only metric rendering weight loss outcome independent of baseline BMI. Metabolic success (HbA1c≤6.0%, T2DM remission) was compared with different definitions of bariatric success (≥50 %EWL, BMI<35 kg/m(2), %AWL percentiles; Mann-Whitney test; P< .05).
Results:
Until May 2014, 2001 patients underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB), of whom 449 had T2DM with baseline BMI 43.3 kg/m(2), mean 1.6 number of T2DM medication and HbA1c 7.5%. At 1 year 95% follow-up, with BMI 30.5 kg/m(2), 52.1% T2DM remission, 86.9% HbA1c<7.0%, and 63.6% without T2DM medication. No significant differences in T2DM outcome and weight loss were found with different baseline BMI, except for %EWL (P<.001). Weight loss was significantly better with better T2DM outcome, but for %EWL contradictory relationships were found in baseline-BMI subgroups. T2DM outcome was not less successful for patients with<50 %EWL.
Conclusion:
In T2DM patients, weight loss after gastric bypass does not depend on BMI, HbA1c, or T2DM medication at baseline. The popular %EWL metric and the 50 %EWL success criterion are problematic in comparing bariatric and metabolic outcome of gastric bypass surgery. They should be abandoned. The %WL metric is the best and most commonly used alternative, whereas %AWL is ideal for selected logistics in bariatric research. Weight loss percentiles are best suited for defining bariatric success in metabolic surgery.
Obesity is a chronic and complex medical condition associated with a large number of complications affecting most organs and systems through multiple pathways. Strategies for weight management include behavioral, pharmacological, and surgical interventions, all of which can result in a reduction in obesity-related comorbidities and improvements in quality of life. However, subsequent weight regain often reduces the durability of these improvements. The objective of this article is to review evidence supporting the long-term effects of intentional weight loss on morbidity, mortality, quality of life, and health-care cost. Overall, considerable evidence suggests that intentional weight loss is associated with clinically relevant benefits for the majority of obesity-related comorbidities. However, the degree of weight loss that must be achieved and sustained to reap these benefits varies widely between comorbidities. Expected final online publication date for the Annual Review of Nutrition Volume 35 is July 17, 2015. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Background:
Weight loss after bariatric surgery is commonly reported as either a percentage of initial body weight (%IBW) or 100% minus %IBW which is a percentage of total weight loss (%TWL). These are basically equivalent expressions. Weight loss is also reported as %EWL or as a percentage of excess body mass index loss (%EBMIL). These last two expressions incorporate the concepts of ideal body weight and BMI = 25 as reference points. More straightforward but less commonly used is absolute weight loss. This study compares these various measures using the Bariatric Outcomes Longitudinal Database (BOLD).
Methods:
BOLD data, 2008-2011, was accessed for outcomes on 239,659 gastric bypass (GB) and sleeve gastrectomy (SG) patients with approval of the Surgical Review Corporation. The outcome data was converted into %TWL, %EWL, and %EBMIL. %EBMIL was varied by changing the reference BMI from 1 to 25 kg/m(2). The post operation data was analyzed for both procedures. Variation coefficients (VC) were compared using different measurements on the same data pool. We assumed that the lesser the variation, the more reliable the measure is, and therefore, we made use of the VC to compare the different reporting methods.
Results:
There were 164,247 patients who remained after removal of errors and missing data. Demographics are as follows: 78.1% female, 73.1% white, 12.5% black, 8.71% Hispanic, 81.6% GB, 18.4% SG, mean age of 44.8 years, height of 167.0 cm, weight of 132.0 kg, and BMI of 47.1 kg/m(2). GB patients had 26.8%TWL at 6 months (VC = 21.5) and 34.2%TWL at 12 months (VC = 27.0). %EWL was 54.7 at 6 months (VC = 27.3) and 69.4 at 12 months (VC = 30.9). Varying the reference BMI for %EBMIL showed the lowest VC to be 0-2 kg/m(2) for GB up to 12 months post operation. SG patients had 24.0%TWL at 6 months (VC = 25.4) and 29.5 at 12 months (VC = 30.5). %EWL was 50.0% at 6 months (VC = 31.4) and 60.2% at 12 months (VC = 34.5). Varying the reference BMI for %EBMIL showed that the lowest VC occurred when the reference weight was chosen as 0 kg/m(2) for both GB and SG. %TWL or, equivalently, %IBW had the lowest variation coefficient and therefore is the more accurate measure of weight loss following bariatric surgery.
Conclusions:
For ease and accuracy of comparison, the percentage of initial body weight or percentage of total weight loss should be used for the expression of weight loss after surgery.
Percentage alterable weight loss (AWL) is the only known weight loss metric independent of the initial body mass index (BMI), a unique feature ideal for use in weight loss research. AWL was not yet validated. The aim of the study is to validate the AWL metric and to confirm advantages over the excess weight loss (EWL) metric.
AWL is tested with 2-year weight loss results of all primary laparoscopic Roux-en-Y gastric bypass patients operated in our hospital. Nadir results of patients with higher and lower initial BMI are compared (Mann-Whitney; p < 0.05) using outcome metrics BMI, percentage weight loss (WL), EWL, and AWL, for the whole group, for each gender, and for <40 and ≥40 years separately.
Five-hundred patients (401 female) out of 508 (98.4 %) had 2-year follow-up. Of all four metrics, only AWL rendered results not significantly influenced by initial BMI. The AWL outcome is initial BMI independent for both genders and age-groups. Results also confirm that women and younger patients had significantly higher AWL outcome.
The recently developed AWL metric, defined as 100% × (initialBMI - BMI) / (initialBMI - 13), is now validated. In contrast to the well-known outcome metrics BMI, EWL, and WL, the AWL metric is independent of the initial BMI. It should replace the misleading EWL metric for comparing weight loss results in bariatric research and for expressing the effectiveness of bariatric procedures. This effectiveness does not act on the total body mass, or on the excess part, but on the alterable part, defined as BMI minus 13 kg/m(2) for all adult patients, female, male, young, and old.
Background:
Recent evidence suggests that National Health Service (NHS) rationing of bariatric surgery is biased toward super-obese patients without scientific basis. The aim of this study was to compare health, quality of life, and employment outcomes in morbidly obese (MO) versus super-obese (SO) patients after laparoscopic Roux-en-Y gastric bypass (LRYGB) to provide a basis for rationing.
Methods:
Consecutive patients undergoing LRYGB from January 2008-September 2009, with baseline body mass index (BMI)<45 kg/m(2) (MO) and BMI>60 kg/m(2) (SO) were identified from a prospective database. Seventy-six eligible patients were invited to complete a questionnaire comprising BAROS (bariatric analysis and reporting outcome system), EQ-5D (EuroQol-5D), EQVAS (Euro-QoL visual analog score), and employment status preoperatively and postoperatively. Anthropometric, demographic, and clinical data were recorded.
Results:
Fifty-one patients responded: 23 MO and 28 SO. Groups were matched for demographic characteristics and co-morbidities. The MO group had significantly higher percentage excess weight loss (%EWL) (82% versus 53%; t test: P<.001) and mean BAROS score (5.47 versus 4.21; t test: P = .025) than the SO group. EQ-5D improved significantly for both groups in 3 domains (self care, anxiety/depression, and pain/discomfort); there was no significant difference in improvement between groups. EQVAS was significantly higher for the MO group (90 versus 70; Mann-Whitney U: P = .001). Employment status changed for 8 patients postoperatively, but there was no significant difference between groups.
Conclusion:
These results suggest that MO patients appear to benefit more than SO patients from LRYGB and yet seem to be disadvantaged in some NHS Trusts in the United Kingdom for access to bariatric surgery. This study provides a baseline framework for further research to generate evidence for more scientific rationing of bariatric surgery.
The rate of obesity is rising logarithmically, especially in those with severe obesity (body mass index [BMI] >40 kg/m2). Cardiologists, endocrinologists, internists, family practitioners, and most healthcare professionals are increasingly confronted with the severely obese patient and with postoperative bariatric patients because obesity is associated with significant morbidity and increased mortality. In addition, more adolescents these days are severely obese. Substantial long-term successes of lifestyle modifications and drug therapy have been disappointing in this population. The National Institutes of Health has suggested that surgical therapy be proposed to those patients with BMI >40 kg/m2 or >35 kg/m2 with serious obesity-related comorbidities such as systemic hypertension, type 2 diabetes mellitus, and obstructive sleep apnea. When indicated, surgical intervention leads to significant improvements in decreasing excess weight and comorbidities that can be maintained over time. These include diabetes mellitus, dyslipidemia, liver disease, systemic hypertension, obstructive sleep apnea, and cardiovascular dysfunction. Recent prospective, nonrandomized, observational, or case-control population studies have also shown bariatric surgery to prolong survival in the severely obese. Different types of bariatric procedures are being performed. Historically, operative mortality was between 0.1% and 2.0% with more recent data not exceeding 1%. Early complications include pulmonary embolus (0.5%), anastomotic leaks (1.0% to 2.5%), and bleeding (1.0%). Late complications include anastomotic stricture, anastomotic ulcers, hernias, band slippage, and behavioral maladaptation. The number of bariatric operations being performed is increasing tremendously as a result of increasing medical need and the evolution of safer surgical techniques and guidelines. Currently, bariatric surgery should be reserved for patients who have severe obesity in whom efforts at medical therapy have failed and an acceptable operative risk is present.
The terms overweight, obese, and severe obesity refer to a clinical continuum. Excess adiposity should be considered a chronic disease that has serious health consequences. An …
Bariatric results expressed in the relative measure excess weight loss (%EWL) vary significantly by initial body mass index (BMI): the heavier the patient, the lower the %EWL. We examine if this variation is caused by using a wrong outcome measure and argue that no relative weight loss measure can express bariatric or metabolic goals unequivocally.
Nadir weight loss results after laparoscopic gastric bypass in 168 women with initial BMI ≥35 to <60 kg/m2 are calculated for %EWL and 61 different relative measures using the formula 100% × (initial BMI - nadir BMI) / (initial BMI-a), with a ranging from -30 to +30. Standard deviations are compared mutually and with those reported in the literature. For each relative measure, the significance of any variation by initial BMI is determined with the Mann-Whitney U test.
Mean initial BMI was 44.9 ± 6.7 (35.0-59.7) kg/m2. Mean nadir BMI was 28.8 ± 5.8 (18.5-44.4) kg/m2. Mean nadir excess BMI loss (%EBL; a = 25) was 87.0 ± 28.0 (19.4-155.1)%. Mean nadir (total) weight loss (%TWL; a = 0) was 35.9 ± 8.5 (9.5-57.1)%. Mean nadir %EWL was 77.3 ± 22.8 (17.7-135.2)%. The smallest variation coefficient was 23.7% at a ranging from -1 to +3, including %TWL (a = 0). This is lower than variation coefficients of %EWL results in our series and in the literature. Variation by initial BMI is significant using relative measures with a ≥3, including %EBL and %EWL (both p < 0.0001) and not significant with a <3, including %TWL (p = 0.13).
In contrast to their widespread use, %EBL and %EWL are not suited for comparing different patients or nonrandomized groups. They cause variation by initial BMI, which disappears using %TWL. In general, absolute terms should be preferred for bariatric outcome and goals. The power of bariatric procedures is best represented by their mean %TWL value.
To provide a historical perspective on the origin and similarity of the "ideal" body weight (IBW) equations, and clarify the terms ideal and lean body weight (LBW).
Primary and review literature were identified using MEDLINE (1966-November 1999) and International Pharmaceutical Abstracts (1970-November 1999) pertaining to ideal and lean weight, height-weight tables, and obesity. In addition, textbooks and relevant reference lists were reviewed.
All articles identified through the data sources were evaluated. Information deemed to be relevant to the objectives of the review were included.
Height-weight tables were generated to provide a means of comparing a population with respect to their relative weight. The weight data were found to correlate with mortality and resulted in the use of the terms desirable or ideal to describe these weights. Over the years, IBW was interpreted to represent a "fat-free" weight and thus was used as a surrogate for LBW. In addition, the pharmacokinetics of certain drugs were found to correlate with IBW and resulted in the use of IBW equations published by Devine. These equations were consistent with an old rule that was developed from height-weight tables to estimate IBW. Efforts to improve the IBW equations through regression analyses of height-weight data resulted in equations similar to those published by Devine.
The similarity between the IBW equations was a result of the general agreement among the various height-weight tables from which they were derived. Therefore, any one of these equations may be used to estimate IBW.
To compare the association of obesity and abdominal obesity with cardiometabolic risk factor burden and global estimated coronary heart disease (CHD) risk among multiethnic US adults.
Cross-sectional, survey study.
A total of 4456 participants (representing 194.9 million adults) aged 20-79 years in the 2003-2004 National Health and Nutrition Examination Survey (NHANES).
Body mass index (BMI) and waist circumference (WC) measures, CHD risk factors and a 10-year estimated CHD risk based on Framingham algorithms. Obesity was defined as a BMI >or=30 kg/m(2) and abdominal obesity as a WC >88 cm in women and >102 cm in men. High CHD risk status included diabetes, cardiovascular disease (CVD) or a 10-year Framingham risk score of >20%.
Overall, abdominal obesity was present in 42.3% of men and 62.5% of women and in 53.6% of whites, 56.9% of blacks and 50.5% of Hispanics (P<0.001 between gender and ethnicity). However, using International Diabetes Federation (IDF)-recommended WC cut points for Hispanics, the prevalence of abdominal obesity was 78.3%. Mean levels of low-density lipoprotein cholesterol (LDL-C), systolic and diastolic blood pressure, fasting glucose and C-reactive protein increased, and high-density lipoprotein cholesterol (HDL-C) decreased (P<0.001) according to BMI and WC categories, although these associations were attenuated in blacks for blood pressure, LDL-C, HDL-C and triglycerides. Of those with high WC, 25-35% had >or=3 cardiometabolic risk factors. High CHD risk among those with high WC was most common in men (27.9%) and non-Hispanic whites (23.9%). Persons with a high vs normal WC, adjusted for age, gender, ethnicity and BMI were more likely to have >or=3 cardiometabolic risk factors (odds ratio (OR)=5.1, 95% confidence interval (CI)=3.9-6.6) and were classified as high CHD risk (OR=1.5, 95% CI=1.1-2.0).
The association of abdominal obesity with risk factors varies by ethnicity and is independently associated with high CHD risk status, further validating its clinical significance.
Public health officials and organizations have disseminated health messages regarding the dangers of obesity, but these have not produced the desired effect.
To estimate the expected number of years of life lost (YLL) due to overweight and obesity across the life span of an adult.
Data from the (1) US Life Tables (1999); (2) Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994); and (3) First National Health and Nutrition Epidemiologic Follow-up Study (NHANES I and II; 1971-1992) and NHANES II Mortality Study (1976-1992) were used to derive YLL estimates for adults aged 18 to 85 years. Body mass index (BMI) integer-defined categories were used (ie, <17; 17 to <18; 18 to <19; 20 to <21; 21 to 45; or > or =45). A BMI of 24 was used as the reference category.
The difference between the number of years of life expected if an individual were obese vs not obese, which was designated YLL.
Marked race and sex differences were observed in estimated YLL. Among whites, a J- or U-shaped association was found between overweight or obesity and YLL. The optimal BMI (associated with the least YLL or greatest longevity) is approximately 23 to 25 for whites and 23 to 30 for blacks. For any given degree of overweight, younger adults generally had greater YLL than did older adults. The maximum YLL for white men aged 20 to 30 years with a severe level of obesity (BMI >45) is 13 and is 8 for white women. For men, this could represent a 22% reduction in expected remaining life span. Among black men and black women older than 60 years, overweight and moderate obesity were generally not associated with an increased YLL and only severe obesity resulted in YLL. However, blacks at younger ages with severe levels of obesity had a maximum YLL of 20 for men and 5 for women.
Obesity appears to lessen life expectancy markedly, especially among younger adults.
© FD-Communications Inc. Obesity Surgery, 13, 2003 159
Obesity Surgery, 13, 159-160
This Journal does not accept reports with the
absolute weight loss (or the percent of weight lost)
as the sole descriptive index – ie. operative weight
minus the weight at a point in time, is not acceptable
as the sole measure of weight loss. The initial
weight in studies differs. Furthermore, after a
bariatric operation in the super-obese, the number of
kilograms lost tends to be greater, but the percent of
excess weight loss tends to be less, than in the morbidly
obese. For comparative bases, weight loss is
preferred as percent of excess weight lost (%EWL)
or change in body mass index (BMI). Metric units
(ie. kg, meters, etc.) are necessary in this scientific
journal.
Ideal Body Weight
Ideal Weight is derived from the 1983 Metropolitan
insurance height and weight tables,1-7 and is the
weight for each height at which mortality was lowest
and longevity was highest. The Ideal Weight is
less than the average weight for a specific height in
the population. The Metropolitan Tables are based
on the 1979 Build Study,8 which was the result of an
18-year mortality study derived from pooled data of
4.2 million individuals from 25 life-insurance companies
in the USA and Canada. The Tables provide
the weight that was found to be associated with
maximum life expectancy. These weights are given
in a range for body frame (small, medium and
large), based on elbow width, measured with a
calipers.1,2,9 The middle 50% of the elbow breadths
(25th-75th percentiles) was designated as the medium
frame, with 25% each falling within the small
and large frames. Generally, the mid-point of the
range of weights for medium frame is chosen as the
“ideal” weight.
Ideal weight may be calculated from the formula
(Table 1) which gives values corresponding to the
mid-point of the range for the medium frame on the
Metropolitan Tables, with a margin of error <1%.10
There were a number of criticisms of the
Metropolitan Tables:2 1) minorities were under-represented
in the insurance-purchasing population; 2)
10% of the weights were self-reported; 3) the
insured population was a higher economic group
than the general population; 4) weights were performed
wearing indoor clothing (allowing 5 lb for
males and 3 lb for females, with 1” heels for both
sexes); 5) applicants with major disease (eg. heart
disease, cancer or diabetes at the time of insurance
policy issuance) were excluded, to provide an indication
of the sole effect of weight on mortality; 6)
applicants were ages 25-59 years, although the ideal
weight for survival increased up to age 50.
However, there is no other study on weight survival
based on so vast a sample.
Excess Weight = Actual Weight - Ideal Weight
Percent Excess Weight Loss = [(Operative Weight
– Follow-up Weight) / Operative Excess Weight] X
100. The latter is the preferred means of reporting.
Body Mass Index
BMI is regarded as the most accurate method for
comparing obesity and gives a number which indicates
the degree of weight for all heights. It is calculated
from the formula W/H2 for men and W/H1.5
for women, where the body weight is in kg and the
height is in meters.11 However, the formula for
women is somewhat difficult to use, so that the formula
for men W/H2 is used for all patients. BMI has
a very high correlation with body density and skinfold
thickness measurements, and is the best indica-
Editorial
Recommendations for Reporting Weight Loss
Table 1. Formula for calculation of Ideal Weight*
Adult Female: 5 ft. tall = 119 lb. For each additional
inch, add 3 lb.
Adult Male: 5 ft. 3 inches tall = 135 lb. For each
additional inch, add 3 lb.
1 foot=30.4 cm; 1 inch=2.54.cm.
Divide lb. by 2.2 to change to kg.
*Formula corresponds to mid-point of medium frame of the
Metropolitan Tables, with accuracy within 1%. To convert to
ideal weight for small or large frame, decrease or increase the
result by 10%. Patients without shoes.
tor for “fatness”.12,13
However, disease or mortality studies associated
with BMI have generally been based on population
studies of less than 30,000 individuals. Thus, BMI
may actually have less accuracy in providing an
ideal measure for survival than the 4.2 million people
used in the Metropolitan study, from which the
least mortality BMI was originally derived.
BMI 20-25 kg/m2 is associated with least mortality,
and mortality rises as the BMI rises or falls
beyond the range of these numbers.14 BMI 20-25
indicates normal weight, >25-29.9 indicates overweight,
³30 indicates obesity, ³40 indicates morbid
obesity, and ³50 has been designated as super-obesity.
BMI <17.5 is among the criteria for anorexia
nervosa, and is frequently seen in such malnutritions
as cancer cachexia.
Percent BMI Loss = [(Operative BMI - Follow-up
BMI) / Operative BMI] X 100.
Percent Excess BMI Loss (%EBMIL)
Since the NIH/NIDDK defined excess weight as
starting at a BMI>25,15 BMI units >25 have been
defined as %EBMIL16 by the formula:
%EBMIL = 100 - [(Follow-up BMI - 25 /
Beginning BMI - 25) X 100]
eg. If an individual has an initial BMI of 45, then the
20 BMI units above the upper limit of the normal of
25 BMI units, represents a %EBMIL of 100; a loss
of 10 BMI units (to a BMI of 35) would be a
%EBMIL of 50. It is possible that %EBMIL may
become the standard to present weight loss data in
clinical studies of the overweight and obese.
Patient Follow-up
Changes in %EWL, BMI, or %EBMIL are frequently
shown in graphic form as a curve, with bars
on one side of each time-point indicating the standard
deviation (SD); the number of patients followed
and the number eligible for follow-up at each
time-point should be shown. However, a curve generally
denotes longitudinal analysis which requires
100% follow-up at each time-point.17
Cross-sectional analysis is appropriate for studies
of incomplete follow-up, using a table or bar-graph.
The bar y-axis indicates the weight loss parameter
chosen, with the time-points reported on the x-axis.
Again, the number of patients followed and the
number eligible for follow-up at each time-point
should be indicated. SD may be indicated on top of
each bar.
Mervyn Deitel, MD; Robert J. Greenstein, MD
We thank Kathleen Renquist, BS, IBSR Manager, Nicola
Scopinaro and Horacio Oria, for review and suggestions.
References
1. 1983 Metropolitan Height and Weight Tables. Metropolitan
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(www.surgery.uiowa.edu/ ibsr)
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in transition: background and recommendations for the
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(IGS™) as a therapy for human morbid obesity: report from the
2001 IFSO Symposium in Crete. Obes Surg 2002; 12 (Suppl):
S3-S5.
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160 Obesity Surgery, 13, 2003
To investigate the influence of weight loss expectations (expected 1-year BMI loss, dream and maximum acceptable BMI) on attrition in obese patients seeking treatment.
Obese subjects (1,785; 1,393 women; median age, 46 years; median BMI, 36.7 kg/m(2)) seeking treatment in 23 medical Italian centers were evaluated. Baseline diet and weight history, weight loss expectations, and primary motivation for seeking treatment (health or improving appearance) were systematically recorded. Psychiatric distress, binge eating, and body image dissatisfaction were tested at baseline by self-administered questionnaires (Symptom Check List-90, Binge Eating Scale, and Body Uneasiness Test). Attrition and BMI change at 12 months were prospectively recorded.
At 12 months, 923 of 1,785 patients (51.7%) had discontinued treatment. Compared with continuers, drop-outs had a significantly lower age, a lower age at first dieting, lower dream BMI, a higher expected 1-year BMI loss, and a higher weight phobia. At logistic regression analysis, the strongest predictors of attrition at 12 months were lower age and higher expected 1-year BMI loss. The risk of drop-out increased systematically for unit increase in expected BMI loss at 12 months (hazard ratio, 1.12; 95% confidence interval, 1.04 to 1.20; p = 0.0018). The risk was particularly elevated in the first 6 months.
Baseline weight loss expectations are independent cognitive predictors of attrition in obese patients entering a weight-losing program; the higher the expectations, the higher attrition at 12 months. Unrealistic weight goals should be tackled at the very beginning of treatment.
Morbid obesity results in multiple comorbidities and an increased mortality rate. The National Institutes of Health has stated that surgery is the most effective long-term therapy; therefore, we evaluated a laparoscopically implantable adjustable gastric band.
We reviewed 2 multicenter prospective, open-label, single-arm surgical trials--trial A (3 years) and trial B (1 year)--with ongoing safety follow-up. These trials were conducted in United States community and university hospitals (trial A = 8 sites and trial B = 12 sites). Trial A comprised 292 subjects (mean +/- SD preoperative weight: 133 kg +/- 24.4), and trial B comprised 193 subjects (129 kg +/- 20.8). Intervention included placement of a constrictive, adjustable band around the upper stomach to limit food intake and induce weight loss. Main outcome measures were the primary efficacy end point of weight loss. Secondary end-points were change in quality-of-life, safety parameters, and complications, including band slippage, reoperation, and device explantation.
In the 2 trials, 485 devices were implanted (92% laparoscopically), and no deaths occurred. Of the patients in trial A, 206 (70.5%) completed the 3-year follow-up, and 142 (73.6%) of patients in trial B completed the 1-year follow-up. Weight-loss results, using the last value carried forward, for all 292 patients in trial A and all 193 patients in trial B demonstrated a change in mean body mass index (kg/m2) +/- SD from 47.4 +/- 7.0 to 39.0 +/- 7.3 in trial A and from 46.7 +/- 7.8 to 38.4 +/- 7.6 in trial B subjects at 1 year (P < .001 for both trials A and B), with minimal further change at 3 years (39.0 +/- 8.5) in trial A subjects. The percentage of initial body weight lost at 1 year was 17.7% +/- 9.4% for trial A subjects and 18.2% +/- 8.9% for trial B subjects, whereas the 3-year total for trial A subjects was 18.3% +/- 13.1%. At 1 year, 76% of patients in trial A and 66% of patients in trial B had complications, mostly related to upper gastrointestinal symptoms. By 9 years after surgery, 33% (96 of 292) of trial A subjects had their devices explanted because of complications or inadequate weight loss.
These first-generation implantable adjustable gastric band results suggest that this is a viable bariatric surgery therapeutic option for the treatment of obesity.
Obesity is associated with increased mortality. Weight loss improves cardiovascular risk factors, but no prospective interventional studies have reported whether weight loss decreases overall mortality. In fact, many observational studies suggest that weight reduction is associated with increased mortality.
The prospective, controlled Swedish Obese Subjects study involved 4047 obese subjects. Of these subjects, 2010 underwent bariatric surgery (surgery group) and 2037 received conventional treatment (matched control group). We report on overall mortality during an average of 10.9 years of follow-up. At the time of the analysis (November 1, 2005), vital status was known for all but three subjects (follow-up rate, 99.9%).
The average weight change in control subjects was less than +/-2% during the period of up to 15 years during which weights were recorded. Maximum weight losses in the surgical subgroups were observed after 1 to 2 years: gastric bypass, 32%; vertical-banded gastroplasty, 25%; and banding, 20%. After 10 years, the weight losses from baseline were stabilized at 25%, 16%, and 14%, respectively. There were 129 deaths in the control group and 101 deaths in the surgery group. The unadjusted overall hazard ratio was 0.76 in the surgery group (P=0.04), as compared with the control group, and the hazard ratio adjusted for sex, age, and risk factors was 0.71 (P=0.01). The most common causes of death were myocardial infarction (control group, 25 subjects; surgery group, 13 subjects) and cancer (control group, 47; surgery group, 29).
Bariatric surgery for severe obesity is associated with long-term weight loss and decreased overall mortality.
Context:
The association of body mass index (BMI) with cause-specific mortality has not been reported for the US population.
Objective:
To estimate cause-specific excess deaths associated with underweight (BMI <18.5), overweight (BMI 25-<30), and obesity (BMI > or =30).
Design, setting, and participants:
Cause-specific relative risks of mortality from the National Health and Nutrition Examination Survey (NHANES) I, 1971-1975; II, 1976-1980; and III, 1988-1994, with mortality follow-up through 2000 (571,042 person-years of follow-up) were combined with data on BMI and other covariates from NHANES 1999-2002 with underlying cause of death information for 2.3 million adults 25 years and older from 2004 vital statistics data for the United States.
Main outcome measures:
Cause-specific excess deaths in 2004 by BMI levels for categories of cardiovascular disease (CVD), cancer, and all other causes (noncancer, non-CVD causes).
Results:
Based on total follow-up, underweight was associated with significantly increased mortality from noncancer, non-CVD causes (23,455 excess deaths; 95% confidence interval [CI], 11,848 to 35,061) but not associated with cancer or CVD mortality. Overweight was associated with significantly decreased mortality from noncancer, non-CVD causes (-69 299 excess deaths; 95% CI, -100 702 to -37 897) but not associated with cancer or CVD mortality. Obesity was associated with significantly increased CVD mortality (112,159 excess deaths; 95% CI, 87,842 to 136,476) but not associated with cancer mortality or with noncancer, non-CVD mortality. In further analyses, overweight and obesity combined were associated with increased mortality from diabetes and kidney disease (61 248 excess deaths; 95% CI, 49 685 to 72,811) and decreased mortality from other noncancer, non-CVD causes (-105,572 excess deaths; 95% CI, -161 816 to -49,328). Obesity was associated with increased mortality from cancers considered obesity-related (13,839 excess deaths; 95% CI, 1920 to 25,758) but not associated with mortality from other cancers. Comparisons across surveys suggested a decrease in the association of obesity with CVD mortality over time.
Conclusions:
The BMI-mortality association varies by cause of death. These results help to clarify the associations of BMI with all-cause mortality.
Current classifications of obesity based on body mass index, waist circumference and other anthropometric measures, although useful for population studies, have important limitations when applied to individuals in clinical practice. Thus, these measures do not provide information on presence or extent of comorbidities or functional limitations that would guide decision making in individuals. In this paper we review historical and current classification systems for obesity and propose a new simple clinical and functional staging system that allows clinicians to describe the morbidity and functional limitations associated with excess weight. It is anticipated that this system, when used together with the present anthropometric classification, will provide a simple framework to aid decision making in clinical practice.
Twelve patients with refractory rheumatoid arthritis were treated with weekly pulse methotrexate in a double-blind, placebo-controlled, crossover study. After 13 weeks of therapy, patients receiving methotrexate showed greater improvement, judged by degree of joint swelling and tenderness, duration of morning stiffness, and subjective assessments of clinical condition, compared to those receiving placebo (p less than or equal to 0.002). This improvement was associated with a decrease in sedimentation rate and decreases in levels of IgG, IgM, and IgA; no changes were seen in serum rheumatoid factor titer or complement protein levels. Proportions of mononuclear cell subsets that were abnormal before treatment (decreased percentage of total T cells, increased percentage of monocytes) improved toward normal after therapy with methotrexate. However, no changes were seen in elevated pretreatment Leu-3/Leu-2 ratios, in in-vitro proliferative responses of lymphocytes to mitogens, or in immunoglobulin secretory responses to pokeweed mitogen. Weekly pulse methotrexate is effective in the short-term treatment of refractory rheumatoid arthritis. Little evidence for cellular immune suppression was associated with this clinical benefit.
The concept of "desirable" weight derives from analyses of data in which relative body weight is correlated with mortality experience. "Ideal" or lowest-risk weights vary for different populations, and vary for the same population at different times and in relation to different causes of mortality. An ideal weight cannot be identified at a point in time for a person or persons differing from the groups on which desirable-weight tables were based. This fact, plus the limitations of existing tables and databases, has prompted some observers to suggest abandoning the concept of ideal weight. The recent publication of updated data for the U.S. population and updated height-weight tables based on actuarial data have focused attention on this issue. In addition, several studies have attempted to relate body weight to mortality in defined populations. At the same time, some studies have found significant relationships between overweight and mortality whereas others have not.
Sibutramine is a tertiary amine that has been shown to induce dose-dependent weight loss and to enhance the effects of a low-calorie diet for up to a year. We did a randomised, double-blind trial to assess the usefulness of sibutramine in maintaining substantial weight loss over 2 years.
Eight European centres recruited 605 obese patients (body-mass index 30-45 kg/m2) for a 6-month period of weight loss with sibutramine (10 mg/day) and an individualised 600 kcal/day deficit programme based on measured resting metabolic rates. 467 (77%) patients with more than 5% weight loss were then randomly assigned 10 mg/day sibutramine (n=352) or placebo (n=115) for a further 18 months. Sibutramine was increased up to 20 mg/day if weight regain occurred. The primary outcome measure was the number of patients at year 2 maintaining at least 80% of the weight lost between baseline and month 6. Secondary outcomes included changes in uric acid concentrations and glycaemic and lipid variables. Analysis was by intention to treat.
148 (42%) individuals in the sibutramine group and 58 (50%) in the placebo group dropped out. Of the 204 sibutramine-treated individuals who completed the trial, 89 (43%) maintained 80% or more of their original weight loss, compared with nine (16%) of the 57 individuals in the placebo group (odds ratio 4.64, p<0.001). Patients had substantial decreases over the first 6 months with respect to triglycerides, VLDL cholesterol, insulin, C peptide, and uric acid; these changes were sustained in the sibutramine group but not the placebo group. HDL cholesterol concentrations rose substantially in the second year: overall increases were 20.7% (sibutramine) and 11.7% (placebo, p<0.001). 20 (3%) patients were withdrawn because of increases in blood pressure; in the sibutramine group, systolic blood pressure rose from baseline to 2 years by 0.1 mm Hg (SD 12.9), diastolic blood pressure by 2.3 mm Hg (9.4), and pulse rate by 4.1 beats/min (11.9).
This individualised management programme achieved weight loss in 77% of obese patients and sustained weight loss in most patients continuing therapy for 2 years. Changes in concentrations of HDL cholesterol, VLDL cholesterol, and triglyceride, but not LDL cholesterol, exceed those expected either from weight loss alone or when induced by other selective therapies for low concentrations of HDL cholesterol relating to coronary heart disease.
Does dietary fat play a central role in weight gain and development of obesity? Do low-fat diets have adverse effects on blood lipids?
To answer these questions we have reviewed the evidence linking the dietary fat content to energy balance and obesity, and examined the efficacy and safety of ad libitum low fat, high carbohydrate/protein diets in the prevention and management of obesity.
Physiological studies have provided insight into the mechanisms by which the macronutrients differ in their effect on energy balance: (1) energy from fat is less satiating than energy from carbohydrate, and a high fat/carbohydrate ratio in the diet promotes passive overconsumption, a positive energy balance and weight gain in susceptible individuals; (2) fat is more readily absorbed from the intestine and fecal energy loss is much lower with a high dietary fat/carbohydrate ratio; (3) carbohydrate is more thermogenic than fat and energy expenditure is lower during positive energy balance produced by a diet with a high fat/carbohydrate ratio than during positive energy balance produced by a diet with a low fat/carbohydrate ratio. Randomized intervention studies comparing low fat diets to normal fat diets show that low fat diets prevent weight gain in normal weight subjects and produce weight loss in overweight individuals. In our meta-analysis of ad libitum low fat interventions we included 16 trials involving 1728 individuals. The difference in weight loss between intervention and control groups was 2.5 kg (95% CI, 1.5-3.5; P<0.0001). Weight loss was positively related to pre-treatment body weight (r=0.52, P<0.05) and to reduction in percentage energy as fat (0.37 kg/%, P<0.005). Extrapolated to a body mass index (BMI) approximately 30 kg/m(2), and assuming a 10% reduction in dietary fat, the predicted weight loss would be 4.4 kg (95% CI, 2.0-6.8 kg), which has been confirmed in subsequent studies. Newer studies have shown that replacing some carbohydrate with protein may enhance weight loss.
The American Paradox, the observation that obesity prevalence is increasing despite a slight decrease in population dietary fat consumption, is easily explained by the concomitantly decreasing physical activity, which reduces fat requirements and counteracts the beneficial effect of a slight reduction in dietary fat. Low fat diets with a high content of complex carbohydrates and protein do not produce any adverse effect on cardiovascular risk factors when weight loss is allowed to occur, and they have been shown to decrease mortality among high risk subjects.
About 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery.
To determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea).
Electronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations.
A total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22,094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8).
A random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (< or =30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients.
Effective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.
There is variety in the reporting of weight loss outcomes within the bariatric literature. Our aim is to compare methods of reporting weight loss in surgical and medical studies, and in addition look for a minimal reporting requirement that allows meaningful comparison.
A review of methods of reporting weight loss in studies published during 2004 was conducted. Bariatric surgical studies included all reports from MEDLINE-listed journals, and medical studies included reports of non-surgical weight loss from 9 leading journals.
65 surgical and 36 non-surgical reports were retrieved. There were 3 common (>20% of reports) methods of reporting in the surgical literature; mean weight, percentage of excess weight loss (%EWL) and body mass index (BMI), and 4 in the medical literature; mean weight loss, weight, percentage weight loss and BMI. %EWL was reported in 2/3 of surgical reports and in none of the non-surgical. The origin of ideal weight for %EWL calculations was reported in 10 (23%) of these studies and included 5 differing definitions. All methods of reporting other than those using "ideal weight" can be calculated from mean weight and BMI at all time-points.
There is complexity and confusion in the reporting of bariatric surgery weight outcomes when calculations are based on ideal weight. Providing weight (kg) and BMI (kg/m2) at all time-points allows the reader to interpret and compare the results in the context of the population of interest. These two measures should be provided as a minimum by all journals reporting on intentional weight loss.
Rimonabant, a selective cannabinoid-1 receptor (CB1) blocker, has been shown to reduce body weight and improve cardiovascular risk factors in obese patients. The Rimonabant in Obesity-Lipids (RIO-Lipids) study examined the effects of rimonabant on metabolic risk factors, including adiponectin levels, in high-risk patients who are overweight or obese and have dyslipidemia.
We randomly assigned 1036 overweight or obese patients (body-mass index [the weight in kilograms divided by the square of the height in meters], 27 to 40) with untreated dyslipidemia (triglyceride levels >1.69 to 7.90 mmol per liter, or a ratio of cholesterol to high-density lipoprotein [HDL] cholesterol of >4.5 among women and >5 among men) to double-blinded therapy with either placebo or rimonabant at a dose of 5 mg or 20 mg daily for 12 months in addition to a hypocaloric diet.
The rates of completion of the study were 62.6 percent, 60.3 percent, and 63.9 percent in the placebo group, the group receiving 5 mg of rimonabant, and the group receiving 20 mg of rimonabant, respectively. The most frequent adverse events resulting in discontinuation of the drug were depression, anxiety, and nausea. As compared with placebo, rimonabant at a dose of 20 mg was associated with a significant (P<0.001) mean weight loss (repeated-measures method, -6.7+/-0.5 kg, and last-observation-carried-forward analyses, -5.4+/-0.4 kg), reduction in waist circumference (repeated-measures method, -5.8+/-0.5 cm, and last-observation-carried-forward analyses, -4.7+/-0.5 cm), increase in HDL cholesterol (repeated-measures method, +10.0+/-1.6 percent, and last-observation-carried-forward analyses, +8.1+/-1.5 percent), and reduction in triglycerides (repeated-measures method, -13.0+/-3.5 percent, and last-observation-carried-forward analyses, -12.4+/-3.2 percent). Rimonabant at a dose of 20 mg also resulted in an increase in plasma adiponectin levels (repeated-measures method, 57.7 percent, and last-observation-carried-forward analyses, 46.2 percent; P<0.001), for a change that was partly independent of weight loss alone.
Selective CB1-receptor blockade with rimonabant significantly reduces body weight and waist circumference and improves the profile of several metabolic risk factors in high-risk patients who are overweight or obese and have an atherogenic dyslipidemia.
This study examined the relationship between internalization of negative weight-based stereotypes and indices of eating behaviors and emotional well-being in a sample of overweight and obese women. Research Method and Procedures: The sample was comprised of 1013 women who belonged to a national, non-profit weight loss organization. Participants completed an on-line battery of self-report questionnaires measuring frequency of weight stigmatization and coping responses to deal with bias and symptoms of depression and self-esteem, attitudes about weight and obesity, and binge eating behaviors. In addition, participants were asked to list the most common weight-based stereotypes and whether they believed them to be true or false.
Participants who believed that weight-based stereotypes were true reported more frequent binge eating and refusal to diet in response to stigma experiences compared with those who reported stereotypes to be false. The degree to which participants believed stereotypes to be true or false was not related to types or amount of stigma experiences reported, self-esteem, depression, or attitudes toward obese persons. In addition, engaging in weight loss strategies as a response to bias was not predicted by stereotype beliefs or by actual stigma experiences, regardless of the amount or types of stigma reported.
These findings suggest that obese individuals who internalize negative weight-based stereotypes may be particularly vulnerable to the negative impact of stigma on eating behaviors and also challenge the notion that stigma may motivate obese individuals to engage in efforts to lose weight. This study highlights a new area of research that warrants attention to better understand weight stigma and its potential consequences for health.
Emerging data indicate that conventional cardiovascular risk factors (e.g. hypercholesterolemia and obesity) are paradoxically associated with better survival in distinct populations with wasting. We identify these populations and review survival paradoxes and common pathophysiologic mechanisms.
A 'reverse epidemiology' of cardiovascular risk is observed in chronic kidney disease, chronic heart failure, chronic obstructive lung disease, cancer, AIDS and rheumatoid arthritis, and in the elderly. These populations apparently have slowly progressive to full-blown wasting and significantly greater short-term mortality than the general population. The survival paradoxes may result from the time differential between the two competing risk factors [i.e. over-nutrition (long-term killer but short-term protective) versus undernutrition (short-term killer)]. Hemodynamic stability of obesity, protective adipokine profile, endotoxin-lipoprotein interaction, toxin sequestration of fat, antioxidation of muscle, reverse causation, and survival selection may also contribute.
The seemingly counterintuitive risk factor paradox is the hallmark of chronic disease states or conditions associated with wasting disease at the population level. Studying similarities among these populations may help reveal common pathophysiologic mechanisms of wasting disease, leading to a major shift in clinical medicine and public health beyond the conventional Framingham paradigm and to novel therapeutic approaches related to wasting and short-term mortality.
Perception of health risk can affect medical decisions and health behavior change. Yet the concept of risk is a difficult one for the public to grasp. Whether perceptions of risk affect decisions and behaviors often relies on how messages of risk magnitudes (i.e., likelihood) are conveyed. Based on expert opinion, this article offers, when possible, best practices for conveying magnitude of health risks using numeric, verbal, and visual formats. This expert opinion is based on existing empirical evidence, review of papers and books, and consultations with experts in risk communication. This article also discusses formats to use pertaining to unique risk communication challenges (e.g., conveying small-probability events, interactions). Several recommendations are suggested for enhancing precision in perception of risk by presenting risk magnitudes numerically and visually. Overall, there are little data to suggest best practices for verbal communication of risk magnitudes. Across the 3 formats, few overall recommendations could be suggested because of 1) lack of consistency in testing formats using the same outcomes in the domain of interest, 2) lack of critical tests using randomized controlled studies pitting formats against one another, and 3) lack of theoretical progress detailing and testing mechanisms why one format should be more efficacious in a specific context to affect risk magnitudes than others. Areas of future research are provided that it is hoped will help illuminate future best practices.
In a prior systematic review and meta-analysis of the large body of literature describing the laparoscopic adjustable gastric band (LAGB), outcomes for the Swedish Adjustable Gastric Band (SAGB) and Lap-Band (LB), in particular, were reviewed. This article summarizes those results and discusses them in relation to the 3 other published bariatric surgery meta-analyses (JAMA 2004;292:1724-37; Ann Intern Med 2005;142:547-59; and Surgery 2007;142:621-32).
In the gastric banding meta-analysis, systematic review included screening of 4,594 studies published in any language (Jan 1, 1998-April 30, 2006). Studies with at least 10 SAGB or LB patients reporting > or =30-day efficacy or safety outcomes were eligible for review; data were extracted from accepted studies. Weighted means analysis and random-effects meta-analysis of efficacy outcomes of interest were conducted.
In the gastric banding meta-analysis, 129 studies (patients n = 28,980) were accepted (33 SAGB/104 LB studies). In 4,273 patients (36 treatment groups) in 33 SAGB studies, and in 24,707 patients (111 groups) in 104 LB studies, mean baseline age (39.1-40.2 yrs), body mass index ([BMI] 43.8-45.3 kg/m2), and sex (females 79.2%-82.5%) were similar. Three-year mean SAGB/LB excess weight loss (56.36%/50.20%) was significant, as was resolution of type 2 diabetes (61.45%/60.29%) and hypertension (62.95%/43.58%) (P < .05). Adverse event (AE) rates appeared comparable, and early mortality was equivalent (< or =.1%).
In the SAGB and LB meta-analysis at 1, 2, and 3 years, weight loss, resolution of diabetes and hypertension, and adverse events appeared equivalent. All meta-analyses that assessed weight loss found that bariatric surgery produced clinically significant reductions in excess weight across procedures in the short term. One meta-analysis found that bariatric surgery produced significantly more weight loss than medical treatment in patients with BMI >40 kg/m2 in the short term, with malabsorptive procedures producing the greatest weight loss. All studies reporting on comorbidities showed significant resolution or improvement of type 2 diabetes mellitus ([T2DM] > or =60%), hypertension (> or =43%), and dyslipidemia (> or =70%). In one meta-analysis, surgery was found to be superior to medical therapy in resolving T2DM, hypertension, and dyslipidemia. Sleep apnea was significantly resolved/improved in > or =85% across procedures in the one meta-analysis that addressed this comorbidity. One meta-analysis found no differences in AEs between procedures; however, the laparoscopic approach was associated with significantly reduced AEs. In the 4 meta-analyses, mortality was low (.1%-1.11%) for all procedures. Bariatric surgery was observed to be a safe and highly effective therapy for morbid obesity. Heterogeneity in nomenclature, study methods, statistical detail, definitions of weight-loss success and comorbid disease resolution, and completeness of data sets did not allow for comparison of some variables. Initiatives including the Iowa Bariatric Surgery Registry (IBSR), the Longitudinal Assessment of Bariatric Surgery (LABS) consortium, the Surgical Review Corporation (SRC) Center of Excellence initiative, and the Bariatric Outcomes Longitudinal Database [BOLD] are working to improve data standardization, which, in turn, will facilitate summary and comparison of bariatric surgery outcomes.
Whether physical activity reduces the impact of obesity on the risk of acute coronary events is much debated. However, little is known about the role of other potentially modifiable lifestyle factors in combination with obesity.
We followed up 54,783 women and men from the prospective Danish Diet, Cancer and Health study who were 50 to 64 years at baseline (1993 to 1997) and free of coronary artery disease and cancer. During a median of 7.7 years, 1127 incident cases of acute coronary syndrome (ACS) occurred. After multivariable adjustments, each unit of body mass index was associated with a 5% and 7% higher risk of ACS among women and men, respectively (both P<0.0001 for trend). Overweight (body mass index, 25 to 29.9 kg/m(2)) and obesity (body mass index >or=30 kg/m(2)) were associated with a higher risk of ACS among the physically active and inactive, in nonsmokers and smokers, and among those who adhered more or less to a heart-healthy dietary pattern. Obese individuals who were active 1 to 3.5 h/wk had a lower risk than sedentary, obese individuals. In addition, obese nonsmokers had a lower risk than obese smokers. Adherence to a healthy diet was associated with a lower risk of ACS; however, the relative risk was not different among obese individuals with the most healthy diet versus obese individuals with a less healthy diet.
Obesity confers an elevated risk of ACS in both healthy and less healthy subgroups of lifestyle behaviors. Adherence to healthy lifestyle behaviors was associated with a lower risk even among obese individuals.
Effect of sibutramine on weight maintenance after weight loss: a randomized trial
- James