Remission and Relapse of Dyslipidemia After Vertical Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass in a Racially and Ethnically Diverse Population.

Importance: The comparative effectiveness of the most common operations in the long-term management of dyslipidemia is not clear. Objective: To compare 4-year outcomes associated with vertical sleeve gastrectomy (VSG) vs Roux-en-Y gastric bypass (RYGB) for remission and relapse of dyslipidemia. Design, Setting, and Participants: This retrospective comparative effectiveness study was conducted from January 1, 2009, to December 31, 2016, with follow-up until December 31, 2018. Participants included patients with dyslipidemia at the time of surgery who underwent VSG (4142 patients) or RYGB (2853 patients). Patients were part of a large integrated health care system in Southern California. Analysis was conducted from January 1, 2018, to December 31, 2021. Exposures: RYGB and VSG. Main Outcomes and Measures: Dyslipidemia remission and relapse were assessed in each year of follow-up for as long as 4 years after surgery. Results: A total of 8265 patients were included, with a mean (SD) age of 46 (11) years; 6591 (79.8%) were women, 3545 (42.9%) were Hispanic, 1468 (17.8%) were non-Hispanic Black, 2985 (36.1%) were non-Hispanic White, 267 (3.2%) were of other non-Hispanic race, and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 44 (7) at the time of surgery. Dyslipidemia outcomes at 4 years were ascertained for 2168 patients (75.9%) undergoing RYGB and 3999 (73.9%) undergoing VSG. Remission was significantly higher for those who underwent RYGB (824 [38.0%]) compared with VSG (1120 [28.0%]) (difference in the probability of remission, 0.10; 95% CI, 0.01-0.19), with no differences in relapse (455 [21.0%] vs 960 [24.0%]). Without accounting for relapse, remission of dyslipidemia after 4 years was 58.9% (1279) for those who underwent RYGB and 51.9% (2079) for those who underwent VSG. Four-year differences between operations were most pronounced for patients 65 years or older (0.39; 95% CI, 0.27-0.51), those with cardiovascular disease (0.43; 95% CI, 0.24-0.62), or non-Hispanic Black patients (0.13; 95% CI, 0.01-0.25) and White patients (0.13; 95% CI, 0.03-0.22). Conclusions and Relevance: In this large, racially and ethnically diverse cohort of patients who underwent bariatric and metabolic surgery in clinical practices, RYGB was associated with higher rates of dyslipidemia remission after 4 years compared with VSG. However, almost one-quarter of all patients experienced relapse, suggesting that patients should be monitored closely throughout their postoperative course to maximize the benefits of these operations for treatment of dyslipidemia.

Comparative effectiveness of gastric bypass and sleeve gastrectomy on predicted 10-year risk of cardiovascular disease 5 years after surgery.

BACKGROUND: Comparative evidence is needed when deciding which bariatric operation to undergo for long-term cardiovascular risk reduction. OBJECTIVES: The Effectiveness of Gastric Bypass vs. Gastric Sleeve for Cardiovascular Disease (ENGAGE CVD) study compared the effectiveness of vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) operations for reduction of the American College of Cardiology and the American Heart Association-predicted 10-year atherosclerotic cardiovascular disease (ASCVD) risk 5 years after surgery. SETTING: Data for this study came from a large integrated healthcare system in the Southern California region of the United States. This is one of the most ethnically diverse (64% non-White) bariatric populations in the literature. METHODS: The ENGAGE CVD cohort consisted of 22,095 patients who underwent VSG or RYGB from 2009-2016. The VSG and RYGB were compared using a local instrumental variable approach to address observed and unobserved confounding, as well as to conduct heterogeneity of treatment effects for patients of different age groups, baseline-predicted 10-year CVD risk using the ASCVD risk score, and those who had type 2 diabetes (T2D) at the time of surgery. RESULTS: Patients (2771 RYGB and 6256 VVSG) were primarily women (80.6%), Hispanic or non-Hispanic Black (63.7%), and 46 ± 10 years of age, with a body mass index of 43.40 ± 6.5 kg/m2. The predicted 10-year ASCVD risk at surgery was 4.1% for VSG and 5.1% for RYGB, decreasing to 2.6% for VSG and 2.8% for RYGB 1 year postoperatively. By 5 years after surgery, patients remained with relatively low risk levels (3.0% for VSG and 3.3% for RYGB) and there were no significant differences in predicted 10-year ASCVD risk between VSG and RYGB at any time. CONCLUSION: Predicted 10-year ASCVD risk was low in this population and remained low up to 5 years for those with diabetes, Black and Hispanic patients, and older adults. Literature reporting significant differences between VSG and RYGB in 10-year ASCVD risk may be a result of residual confounding.

Minimum Threshold of Bariatric Surgical Weight Loss for Initial Diabetes Remission.

OBJECTIVE: There are few studies testing the amount of weight loss necessary to achieve initial remission of type 2 diabetes mellitus (T2DM) following bariatric surgery and no published studies with use of weight loss to predict initial T2DM remission in sleeve gastrectomy (SG) patients. RESEARCH DESIGN AND METHODS: With Cox proportional hazards models we examined the relationship between initial T2DM remission and percent total weight loss (%TWL) after bariatric surgery. Categories of %TWL were included in the model as time-varying covariates. RESULTS: Of patients (N = 5,928), 73% were female; mean age was 49.8 ± 10.3 years and BMI 43.8 ± 6.92 kg/m2, and 57% had Roux-en-Y gastric bypass (RYGB). Over an average follow-up of 5.9 years, 71% of patients experienced initial remission of T2DM (mean time to remission 1.0 year). With 0-5% TWL used as the reference group in Cox proportional hazards models, patients were more likely to remit with each 5% increase in TWL until 20% TWL (hazard ratio range 1.97-2.92). When categories >25% TWL were examined, all patients had a likelihood of initial remission similar to that of 20-25% TWL. Patients who achieved >20% TWL were more likely to achieve initial T2DM remission than patients with 0-5% TWL, even if they were using insulin at the time of surgery. CONCLUSIONS: Weight loss after bariatric surgery is strongly associated with initial T2DM remission; however, above a threshold of 20% TWL, rates of initial T2DM remission did not increase substantially. Achieving this threshold is also associated with initial remission even in patients who traditionally experience lower rates of remission, such as patients taking insulin.

Comparative Effectiveness of Gastric Bypass and Vertical Sleeve Gastrectomy for Hypertension Remission and Relapse: The ENGAGE CVD Study.

[Figure: see text].

Effectiveness of Gastric Bypass Versus Gastric Sleeve for Cardiovascular Disease: Protocol and Baseline Results for a Comparative Effectiveness Study.

BACKGROUND: When compared with conventional weight loss strategies, bariatric surgery results in substantially greater durable weight loss and rates of disease remission. OBJECTIVE: The ENGAGE CVD (Effectiveness of Gastric Bypass versus Gastric Sleeve for Cardiovascular Disease) cohort study aimed to provide population-based, comprehensive, rigorous evidence for clinical and policy decision making regarding the choice between gastric bypass and gastric sleeve for overall cardiovascular disease (CVD) risk reduction, risk factor remission, and safety. METHODS: The cohort had 22,095 weight loss surgery patients from a large integrated health care system in Southern California assembled from 2009 to 2016 who were followed up through 2018. Bariatric surgery patients were followed up for the length of their membership in the health care system. Of the patients who had at least five years of follow-up (surgery between 2009 and 2013), 85.86% (13,774/16,043) could contribute to the outcome analyses for the ENGAGE CVD cohort. RESULTS: Patients in the ENGAGE CVD cohort were 44.6 (SD 11.4) years old, mostly women (17,718/22,095; 80.19%), with 18.94% (4185/22,095) non-Hispanic black and 41.80% (9235/22,095) Hispanic, and had an average BMI of 44.3 (SD 6.9) kg/m2 at the time of surgery. When compared with patients who did not contribute data to the 5-year outcome analysis for the ENGAGE CVD cohort (2269/16,043; 14.14%), patients who contributed data (13,774/16,043; 85.86%) were older (P=.002), more likely to be women (P=.02), more likely to be non-Hispanic white (P<.001), more likely to have had an emergency department visit in the year before surgery (P=.006), less likely to have a mental illness before surgery (P<.001), and more likely to have had a CVD event at any time before surgery (P<.001). CONCLUSIONS: This study had one of the largest populations of gastric sleeve patients (n=13,459). The 5-year follow-up for those patients who had surgery between 2009 and 2013 was excellent for a retrospective cohort study at 85.86% (13,774/16,043). Unlike almost any study in the literature, the majority of the ENGAGE CVD cohort was racial and ethnic minority, providing a rare opportunity to study the effects of bariatric surgery for different racial and ethnic groups, some of whom have the highest rates of severe obesity in the United States. Finally, it also used state-of-the-art statistical and econometric comparative effectiveness methods to mimic the effect of random assignment and control for sources of confounding inherent in large observational studies. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/14936.

Laparoscopic Roux-en-Y gastric bypass and sleeve gastrectomy achieve comparable weight loss at 1 year.

Laparoscopic sleeve gastrectomy has gained popularity as a weight loss surgical option for morbidly obese patients. Although initial studies have shown weight loss and comorbidity resolution comparable to those after laparoscopic Roux-en-Y gastric bypass (RYGB), many of these studies are limited by the small patient size. Thus, the purpose of this study was to compare the outcomes of laparoscopic sleeve gastrectomy and laparoscopic RYGB. A retrospective chart review of all morbidly obese patients who underwent laparoscopic RYGB or sleeve gastrectomy between 2007 and 2009 at an HMO hospital was conducted. Data points collected included age, gender, completion of a preoperative weight loss program, initial body mass index (BMI), pre- and postoperative weights, and presence of diabetes mellitus (DM), hypertension (HTN), osteoarthritis, obstructive sleep apnea, and gastroesophageal reflux disease (GERD). Outcomes measures included excess weight loss, resolution of comorbidities, postoperative complications, and mortality. A total of 345 laparoscopic RYGBs and 192 sleeve gastrectomies were performed. On average, the patients who received RYGB were younger (46 vs 48 years, P = 0.05) and had higher BMI (47 vs 43 kg/m(2), P < 0.0001). There was a higher incidence of DM in the RYGB group (32 vs 22%, P = 0.01), whereas the incidences of HTN and GERD were similar in both surgical groups. Ninety-three per cent of the patients who underwent RYGB and 90 per cent of the patients who underwent sleeve gastrectomy completed a preoperative weight loss program. The median length of hospital stay for both groups was 3 days. The complication rate in both groups was 9 per cent. The incidence of gastric leak was 1 per cent in both groups. There was only one mortality, which occurred in the RYGB group. The postoperative resolution of DM was comparable in both groups. The RYGB group had greater resolution of HTN (48 vs 34%, P = 0.03) and GERD (73 vs 34%, P < 0.0001). At 12 months, sleeve gastrectomy achieved superior excess weight loss compared with RYGB (72 vs 61%, P = 0.0015). After adjusting for age and BMI, the excess weight loss for RYGB and sleeve gastrectomy was similar at 12 months (t parameter estimate -0.06, P = 0.08). Laparoscopic RYGB and sleeve gastrectomy had comparable postoperative morbidity and mortality rates. At 1 year, sleeve gastrectomy achieved only slightly greater weight loss. The two operations are both legitimate standalone bariatric procedures and their applications need to be based on individual patient characteristics and needs.

Increased SRF transcriptional activity in human and mouse skeletal muscle is a signature of insulin resistance.

Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human muscle biopsies from patients with T2D; normoglycemic but insulin-resistant subjects with a parental family history (FH(+)) of T2D; and family history-negative control individuals (FH(­)). Actin cytoskeleton genes regulated by serum response factor (SRF) and its coactivator megakaryoblastic leukemia 1 (MKL1) had increased expression in T2D and FH(+) groups. Furthermore, striated muscle activator of Rho signaling (STARS), an activator of SRF, was upregulated in T2D and FH(+) and was inversely correlated with insulin sensitivity. Skeletal muscle from insulin-resistant mice recapitulated this gene expression pattern and showed reduced G-actin and increased nuclear localization of MKL1, each of which regulates SRF activity. Overexpression of MKL1 or reduction in G-actin decreased insulin-stimulated Akt phosphorylation, whereas reduction of STARS expression increased insulin signaling and glucose uptake. Pharmacological SRF inhibition by CCG-1423 reduced nuclear MKL1 and improved glucose uptake and tolerance in insulin-resistant mice in vivo. Thus, SRF pathway alterations are linked to insulin resistance, may contribute to T2D pathogenesis, and could represent therapeutic targets.

Thyroid hormone-related regulation of gene expression in human fatty liver.

CONTEXT: Fatty liver is an important complication of obesity; however, regulatory mechanisms mediating altered gene expression patterns have not been identified. OBJECTIVE: The aim of the study was to identify novel transcriptional changes in human liver that could contribute to hepatic lipid accumulation and associated insulin resistance, type 2 diabetes, and nonalcoholic steatohepatitis. DESIGN: We evaluated gene expression in surgical liver biopsies from 13 obese (nine with type 2 diabetes) and five control subjects using Affymetrix U133A microarrays. PCR validation was performed in liver biopsies using an additional 16 subjects. We also tested thyroid hormone responses in mice fed chow or high-fat diet. SETTING: Recruitment was performed in an academic medical center. PARTICIPANTS: Individuals undergoing elective surgery for obesity or gallstones participated in the study. RESULTS: The top-ranking gene set, down-regulated in obese subjects, was comprised of genes previously demonstrated to be positively regulated by T(3) in human skeletal muscle (n = 399; P < 0.001; false discovery rate = 0.07). This gene set included genes related to RNA metabolism (SNRPE, HNRPH3, TIA1, and SFRS2), protein catabolism (PSMA1, PSMD12, USP9X, IBE2B, USP16, and PCMT1), and energy metabolism (ATP5C1, COX7C, UQCRB). We verified thyroid hormone regulation of these genes in the liver after injection of C57BL/6J mice with T(3) (100 microg/100 g body weight); furthermore, T(3)-induced increases in expression of these genes were abolished by high-fat diet. In agreement, expression of these genes inversely correlated with liver fat content in humans. CONCLUSIONS: These data suggest that impaired thyroid hormone action may contribute to altered patterns of gene expression in fatty liver.

Serum bile acids are higher in humans with prior gastric bypass: potential contribution to improved glucose and lipid metabolism.

The multifactorial mechanisms promoting weight loss and improved metabolism following Roux-en-Y gastric bypass (GB) surgery remain incompletely understood. Recent rodent studies suggest that bile acids can mediate energy homeostasis by activating the G-protein coupled receptor TGR5 and the type 2 thyroid hormone deiodinase. Altered gastrointestinal anatomy following GB could affect enterohepatic recirculation of bile acids. We assessed whether circulating bile acid concentrations differ in patients who previously underwent GB, which might then contribute to improved metabolic homeostasis. We performed cross-sectional analysis of fasting serum bile acid composition and both fasting and post-meal metabolic variables, in three subject groups: (i) post-GB surgery (n = 9), (ii) without GB matched to preoperative BMI of the index cohort (n = 5), and (iii) without GB matched to current BMI of the index cohort (n = 10). Total serum bile acid concentrations were higher in GB (8.90 +/- 4.84 micromol/l) than in both overweight (3.59 +/- 1.95, P = 0.005, Ov) and severely obese (3.86 +/- 1.51, P = 0.045, MOb). Bile acid subfractions taurochenodeoxycholic, taurodeoxycholic, glycocholic, glycochenodeoxycholic, and glycodeoxycholic acids were all significantly higher in GB compared to Ov (P < 0.05). Total bile acids were inversely correlated with 2-h post-meal glucose (r = -0.59, P < 0.003) and fasting triglycerides (r = -0.40, P = 0.05), and positively correlated with adiponectin (r = -0.48, P < 0.02) and peak glucagon-like peptide-1 (GLP-1) (r = 0.58, P < 0.003). Total bile acids strongly correlated inversely with thyrotropic hormone (TSH) (r = -0.57, P = 0.004). Together, our data suggest that altered bile acid levels and composition may contribute to improved glucose and lipid metabolism in patients who have had GB.

Best practices in policy and access (coding and reimbursement) for weight loss surgery.

To update evidence-based best practice guidelines for coding and reimbursement and establish policy and access standards for weight loss surgery (WLS). Systematic search of English-language literature on WLS and health-care policy, access, insurance reimbursement, coding, private payers, public policy, and mandated benefits published between April 2004 and May 2007 in MEDLINE, EMBASE, and the Cochrane Library. Use of key words to narrow the search for a selective review of abstracts, retrieval of full articles, and grading of evidence according to systems used in established evidence-based models. We identified 51 publications in our literature search; the 20 most relevant were examined in detail. These included reviews, cost-benefit analyses, and trend and cost studies from administrative databases. Literature on policy issues surrounding WLS are very sparse and largely focused on economic analyses. Reports on policy initiatives in the public and private arenas are primarily limited to narrative reviews of nonsurgical efforts to fight obesity. A substantial body of work shows that WLS improves or reverses most obesity-related comorbidities. Mounting evidence also indicates that WLS confers a significant survival advantage for those who undergo it. WLS is a viable and cost-effective treatment for an increasingly common disease, and policy decisions are more frequently being linked to incentives for national health-care goals. However, access to WLS often varies by payer and region. Currently, there are no uniform criteria for determining patient appropriateness for surgery.

Human insulin analog--induced lipoatrophy.

OBJECTIVE: To characterize the pathophysiology of recombinant human insulin-induced lipoatrophy. RESEARCH DESIGN AND METHODS: We performed immunologic laboratory evaluation and skin testing for different insulin analogs and diluents in patients with type 1 diabetes and severe insulin-induced local lipoatrophy. Subcutaneous adipose tissue biopsies of areas of acute (7 days) and chronic insulin administration were examined. Topical sodium cromolyn was applied twice a day to atrophic areas and prophylactically to new sites of insulin administration. RESULTS: Subcutaneous adipose biopsies showed an elevated population of tryptase-positive, chymase-positive degranulated mast cells. Of five patients treated with topical sodium cromolyn, none had new lipoatrophic sites and four showed improvements in old lesions. CONCLUSIONS: Tryptase-positive/chymase-postitive mast cells, known to be sensitive to sodium cromolyn, may contribute to the destructive immune process mediated in response to exogenous insulin. Mast cell stabilizing therapy with topical cromolyn may reverse early and prevent new lipoatrophic lesions.

Peptide YY levels are elevated after gastric bypass surgery.

OBJECTIVE: Mechanisms that promote effective and sustained weight loss in persons who have undergone Roux-en-Y gastric bypass surgery are incompletely understood but may be mediated, in part, by changes in appetite. Peptide YY (PYY) is a gut-derived hormone with anorectic properties. We sought to determine whether gastric bypass surgery alters PYY levels or response to glucose. RESEARCH METHODS AND PROCEDURES: PYY and ghrelin levels after a 75-gram oral glucose tolerance test were measured in 6 morbidly obese patients 1.5 +/- 0.7 (SE) years after gastric bypass compared with 5 lean and 12 obese controls. RESULTS: After substantial body weight loss (36.8 +/- 3.6%) induced by gastric bypass, the PYY response to an oral glucose tolerance test was significantly higher than in controls (p = 0.01). PYY increased approximately 10-fold after a 75-gram glucose load to a peak of 303.0 +/- 37.0 pg/mL at 30 minutes (p = 0.03) and remained significantly higher than fasting levels for all subsequent time-points. In contrast, PYY levels in obese and lean controls increased to a peak of approximately 2-fold, which was only borderline significant. Ghrelin levels decreased in a symmetric but opposite fashion to that of PYY. DISCUSSION: Gastric bypass results in a more robust PYY response to caloric intake, which, in conjunction with decreased ghrelin levels, may contribute to the sustained efficacy of this procedure. The findings provide further evidence for a role of gut-derived hormones in mediating appetite changes after gastric bypass and support further efforts to determine whether PYY(3-36) replacement could represent an effective therapy for obesity.

Therapy insight: weight-loss surgery and major cardiovascular risk factors.

Weight-loss surgery is an effective treatment for severe, medically complicated and refractory obesity. It reverses, eliminates or significantly ameliorates major cardiovascular risk factors related to obesity. In a large proportion of patients, the therapy produces significant weight loss, reduces the risk of disability and premature death, and improves quality of life. Surgical treatment by gastric-restrictive and malabsorptive procedures started several decades ago in the US. Since the 1970s, accrued clinical experience and advances in technology, particularly in minimally invasive surgical approaches, have changed this therapy. Some procedures have evolved, whereas others have become obsolete. Today's weight-loss operations are safe, effective and potentially life-saving options for severely obese cardiology patients. This review describes weight-loss surgery procedures and their effects on cardiovascular risk factors.

Coding and reimbursement for weight loss surgery: best practice recommendations.

OBJECTIVE: To review the use and usefulness of billing codes for services related to weight loss surgery (WLS) and to examine third party reimbursement policies for these services. RESEARCH METHODS AND PROCEDURES: The Task Group carried out a systematic search of MEDLINE, the Internet, and the trade press for publications on WLS, coding, reimbursement, and coding and reimbursement policy. Twenty-eight articles were each reviewed and graded using a system based on established evidence-based models. The Massachusetts Dietetics Association provided reimbursement data for nutrition services. Three suppliers of laparoscopic WLS equipment provided summaries of coding and reimbursement information. WLS program directors were surveyed for information on use of procedure codes related to WLS. RESULTS: Recommendations focused on correcting or improving on the current lack of congruity among coding practices, reimbursement policies, and accepted clinical practice; lack of uniform coding and reimbursement data across institutions; inconsistent and/or inaccurate diagnostic and billing codes; inconsistent insurance reimbursement criteria; and inability to leverage reimbursement and coding data to track outcomes, identify best practices, and perform accurate risk-benefit analyses. DISCUSSION: Rapid changes in the prevalence of obesity, our understanding of its clinical impact, and the technologies for surgical treatment have yet to be adequately reflected in coding, coverage, and reimbursement policies. Issues identified as key to effective change include improved characterization of the risks, benefits, and costs of WLS; anticipation and monitoring of technological advances; encouragement of consistent patterns of insurance coverage; and promotion of billing codes for WLS procedures that facilitate accurate tracking of clinical use and outcomes.

Role of protein kinase C in intestinal ischemic preconditioning.

INTRODUCTION: Tissue protection by ischemic preconditioning (IPC) has been previously characterized in organs such as the heart and involves at least in part PKC activation. It is not yet clear whether such preconditioning against ischemia/reperfusion (I/R) injury operates in the intestine, and, if so, whether IPC involves protein kinase C (PKC). MATERIALS AND METHODS: IPC of the small intestine in male Sprague Dawley rats was induced by 10-min superior mesenteric artery (SMA) clamp followed by 120-min reperfusion. Sham-operated control or IPC rats were then rechallenged with 20-min SMA clamp. Histological injury to jejunal mucosa was assessed by microscopic examination and Parks' injury score (Grade 0-4; 0 = no damage). PKC activity was determined by immunoprecipitation of specific isoforms followed by in vitro kinase assay using mucosal scrapings of the harvested jejunum. Data were expressed as mean +/- SEM and analyzed by one-way ANOVA with multiple comparison tests. RESULTS: Ten-minute SMA clamp led to epithelial damage that was fully reversed by 120-min reperfusion. Activity of several PKC isoforms (PKCalpha, -delta, -epsilon) increased after 10-min ischemia. Epithelial injury associated with 20-min SMA clamp was attenuated by prior IPC. The protective effect of IPC on intestinal mucosa was prevented when animals were pretreated with the conventional (c) and novel (n) PKC inhibitor Go6850, but not with Go6976 (selective cPKC inhibitor), rottlerin (selective PKCdelta inhibitor), or saline control. CONCLUSIONS: Brief mesenteric ischemia induces a reversible epithelial injury in rats associated with activation of several PKC isoforms. Injury induced by mesenteric ischemia is reduced by brief ischemic preconditioning, an effect that is abolished by nonselective PKC inhibition but not by a selective inhibitor of cPKC or PKCdelta. The results suggest that activation of nPKC isoform(s), especially PKCepsilon during and following ischemic insults (IPC), may play an important role in protection against I/R injury in the intestine.

Effects of weight loss surgeries on liver disease.

Obesity is the single most significant risk factor for the development of nonalcoholic fatty liver disease (NAFLD) in children and adults. NALFD is estimated to occur in 30 to 100% of obese adults, and in approximately 53% of obese children. The majority of obese patients have ultrasonographic evidence of fatty liver; 30% have histologically documented nonalcoholic steatohepatitis (NASH). Up to 25% of patients with NASH may progress to cirrhosis. In the United States, an estimated 65% of adults are overweight and 31% are obese. Between 2001 and 2002, the number of people with severe obesity, who are more than 100 pounds overweight, rose to nearly 11 million. Since 1970, levels of childhood and teen overweight have climbed to approximately 16% in those aged 6 to 19 years. Recent findings indicate that key features of NAFLD and NASH improve or resolve dramatically with weight loss. This article discusses weight loss surgeries and their effects on liver disease.

Patient-specific dosimetry for 131I thyroid cancer therapy using 124I PET and 3-dimensional-internal dosimetry (3D-ID) software.

UNLABELLED: Compared with conventional, whole-organ, S-factor-based dosimetry, 3-dimensional (3D), patient-specific dosimetry better accounts for radionuclide distribution and anatomic patient variability. Its accuracy, however, is limited by the quality of the cumulated activity information that is provided as input. This input has typically been obtained from SPECT and planar imaging studies. The objective was to implement and evaluate PET-based, patient-specific, 3D dosimetry for thyroid cancer patients. METHODS: Three to 4 PET imaging studies were obtained over a 7-d period in 15 patients with metastatic thyroid carcinoma after administration of (124)I-NaI. Subsequently, patients were treated with (131)I on the basis of established clinical parameters. Retrospective dosimetry was performed using registered (124)I PET images that were corrected for the half-life difference between (124)I and (131)I. A voxel-by-voxel integration, over time, of the resulting (131)I-equivalent PET-derived images was performed to provide a single 3D dataset representing the spatial distribution of cumulated activity values for each patient. Image manipulation and registration were performed using Multiple Image Analysis Utility (MIAU), a software package developed previously. The software package, 3D-Internal Dosimetry (3D-ID), was used to obtain absorbed dose maps from the cumulated activity image sets. RESULTS: Spatial distributions of absorbed dose, isodose contours, dose-volume histograms (DVHs), and mean absorbed dose estimates were obtained for a total of 56 tumors. Mean absorbed dose values for individual tumors ranged from 1.2 to 540 Gy. The absorbed dose distribution within individual tumors was widely distributed ranging from a minimum of 0.3 to a maximum of 4,000 Gy. CONCLUSION: (124)I PET-based, patient-specific 3D dosimetry is feasible, and sequential PET can be used to obtain cumulated activity images for 3D dosimetry.

Serum ghrelin levels in response to glucose load in obese subjects post-gastric bypass surgery.

OBJECTIVE: We sought to elucidate further the mechanisms leading to weight loss after gastric bypass (GBP) surgery in morbidly obese individuals. Ghrelin is a gastroenteric appetite-stimulating peptide hormone, fasting levels of which decrease with increasing adiposity and increase with diet-induced weight loss. In addition, ghrelin levels rapidly decline postprandially. RESEARCH METHODS AND PROCEDURES: We measured serum ghrelin responses to a 75-g oral glucose tolerance test (OGTT) in 6 subjects who had undergone GBP surgery 1.5 +/- 0.7 years before testing and compared these responses with 6 obese subjects about to undergo GBP surgery, 6 obese nonsurgical subjects (matched for BMI to the post-GBP surgical group), and 5 lean subjects. RESULTS: Despite weight loss induced by the GBP surgery, fasting serum ghrelin levels were significantly lower in the post-GBP surgery group than in the lean subject (by 57%) or pre-GBP surgery (by 45%) group. Serum ghrelin levels during the OGTT were significantly lower in postoperative than in lean, obese pre-GBP surgical, or obese nonsurgical subjects. The magnitude of the decline in serum ghrelin levels between 0 and 120 minutes post-OGTT was significantly smaller in postoperative (by 62%), obese pre-GBP surgical (by 80%), or obese nonsurgical (by 69%) subjects in comparison with lean subjects. DISCUSSION: Serum ghrelin levels in response to OGTT are lower in subjects post-GBP surgery than in either lean or obese subjects. Tonically low serum ghrelin levels may be involved in the mechanisms inducing sustained weight loss after GBP surgery.