Background:Proper estimations of resting energy expenditure (REE) are important for developing weight management strategies, but it is unclear which prediction equations best estimate REE for those with severe obesity. Objectives:This validation study tested 11 previously validated REE prediction equations to determine which equations estimate REE with the least bias and most precision in participants with severe obesity. Methods:REE was measured by indirect calorimetry in 632 females and 148 males with severe obesity from the Utah Obesity Study. A literature search was conducted to identify prediction equations designed from, validated, or commonly used in samples with severe obesity. All equations were tested on each participant. Equations were considered unbiased if mean predicted REE did not differ significantly (P > 0.05) from measured values. Bland-Altman plots characterized bias across measured REE values for prediction equations consistent with measured values. Precision was the percentage of the sample where an equation estimate was within 10% of the measured REE. Equations were further assessed within sex and body mass index subgroups. Results:Only the body weight-based Lazzer equations (Lazzer A) and the Horie-Waitzberg equation generated unbiased predictions across all subgroups, with bias values ranging from -68.1 to 71.6 kcal, yet Bland-Altman plots revealed systematic bias, particularly at extreme values of REE. Equations including body composition did not predict better than body weight-based equations, and no single equation predicted best in every subgroup. Precision measurements never rose above 67.8%. Conclusions:Clinicians may benefit from tailoring their choice of REE prediction equation to the specific characteristics of each patient, favoring equations with lower bias and greater precision within relevant subgroups. However, because of the low precision of REE prediction equations and the systematic bias revealed at REE extremes, it is highly recommended to measure REE whenever possible.

OBJECTIVE:This study addressed the paucity of data exploring long-term effects of metabolic and bariatric surgery (MBS)-related weight loss on fitness. METHODS:Data from MBS patients (SURG; n = 82) and comparable non-surgery participants (NSURG; n = 88) were collected from a subset of a prospective trial, the Utah Obesity Study. Fitness was assessed through maximal and submaximal treadmill tests using a modified Bruce protocol. Submaximal exercise tests were performed preceding surgery at baseline and 11.5 years later. A subset (n = 97) of the 170 participants also performed maximal treadmill tests 2 and 6 years after baseline. Weight and BMI were recorded at each visit. Between-group treadmill time comparisons were adjusted for sex and weight. RESULTS:As expected, SURG had lower BMI and weight than NSURG at all follow-up visits (p < 0.0001). Treadmill time, adjusted for sex, baseline treadmill time, and weight over the 11.5-year period, was elevated in surgery compared to non-surgery groups at all follow-up visits (p < 0.01), but the fitness advantage gradually decreased over time. CONCLUSIONS:An initially dramatic fitness benefit achieved with weight loss in MBS patients gradually declined but remained higher than non-surgery counterparts beyond a decade. An emphasis on physical activity may help sustain improved fitness after bariatric surgery.

Background/Objectives: Metabolic and bariatric surgery (MBS) is known to reduce cancer risk. However, the association between specific bariatric procedures and cancer incidence is not well-studied. This study examined the association between four different MBS procedures and cancer incidence. Methods: Bariatric surgery registry data were linked with statewide cancer registry data from 1979 to 2018. The study included 27,092 adult subjects (aged ≥ 18 years old at surgery) who underwent MBS (BMI ≥ 30 kg/m2 at surgery) from 1979 to 2017. Cancer records were linked to MBS patient records, resulting in 1547 cancer cases. Cox proportional hazards regression was used to examine the association between MBS procedure types and cancer incidence. Results: Of all patients, 75% underwent Roux-en-Y gastric bypass (RYGB), 9% adjustable gastric banding (AGB), 10% sleeve gastrectomy (SG), and 6% duodenal switch (BPD-DS). The overall cancer incidence during the follow-up period was 6.4% for RYGB, 4.6% for AGB, 1.6% for SG, and 5.9% for BPD-DS. The mean follow-up duration from surgery to cancer incidence or censoring was 167 months (standard deviation = 121 months). Compared to RYGB, patients who underwent AGB (Hazard Ratio [HR] = 1.26, p = 0.03) and BPD-DS (HR = 1.91, p < 0.01) had a significantly higher hazard of developing cancer, while SG (HR = 1.17, p = 0.33) showed no significant difference. Conclusions: These findings suggest that AGB and BPD-DS may be associated with higher cancer risks compared to RYGB. Additional large population studies are needed to better understand the long-term cancer risks and mechanisms associated with different MBS types.

Obesity is associated with increased cancer risk. Because of the substantial and sustained weight loss following bariatric surgery, postsurgical patients are ideal to study the association of weight loss and cancer.

Background Metabolic and bariatric surgery (MBS) is an effective treatment for obesity and may reduce mortality. Several factors are associated with higher mortality following MBS. The purpose of this study was to examine whether pre-operative arthritis was associated with long-term mortality following MBS. Methods Using a retrospective cohort design, subjects who underwent MBS were identified from the Utah Bariatric Surgery Registry. These subjects were linked to the Utah Population Database. State death records from 1998 through 2021 were used to identify deaths following MBS. ICD-9/10 diagnosis codes were used to identify a pre-operative diagnosis of arthritis and to classify the cause of death. All causes of death, internal cause of death (e.g., diabetes, heart disease), and external cause of death (e.g., suicide) were defined as outcomes. Entropy balancing (EB) was applied to create weights to balance the baseline characteristics of the two groups. Weighted Cox proportional hazards regression was used to evaluate the association of pre-operative arthritis with long-term mortality following MBS. Results The final sample included 15,112 patients. Among them, 36% had a pre-operative arthritis diagnosis. Average (SD) age was 48(12) years old at surgery, and 75% were female. Patients with pre-operative arthritis had 25% ( p < 0.01) and 26% ( p < 0.01) higher risk of all cause of death and internal cause of death, respectively, compared to patients without pre-operative arthritis. Conclusion Individuals with arthritis prior to MBS may have higher hazard of long-term mortality than those without pre-operative arthritis.

Metabolic and bariatric surgery (MBS) has been associated with reduced all-cause mortality. While the number of subjects with substance use disorders (SUD) before MBS has been documented, the impact of pre-operative SUD on long-term mortality following MBS is unknown. This study assessed long-term mortality of patients with and without pre-operative SUD who underwent MBS. Two statewide databases were used for this study: Utah Bariatric Surgery Registry (UBSR) and the Utah Population Database. Subjects who underwent MBS between 1997 and 2018 were linked to death records (1997–2021) to identify any death and cause for death following MBS. All deaths (internal, external, and unknown reasons), internal deaths, and external deaths were the primary outcomes of the study. External causes of death included death from injury, poisoning, and suicide. Internal causes of death included deaths that were associated with natural causes such as heart disease, cancer, and infections. A total of 17,215 patients were included in the analysis. Cox regression was used to estimate hazard ratios (HR) of controlled covariates, including the pre-operative SUD. The subjects with pre-operative SUD had a 2.47 times higher risk of death as compared to those without SUD (HR = 2.47, p < 0.01). Those with pre-operative SUD had a higher internal cause of death than those without SUD by 129

ObjectiveThis retrospective study incorporated long-term mortality results after different bariatric surgery procedures and for multiple age at surgery groups. MethodsParticipants with bariatric surgery (surgery) and without (non-surgery) were matched (1:1) for age, sex, BMI, and surgery date with a driver license application/renewal date. Mortality rates were compared by Cox regression, stratified by sex, surgery type, and age at surgery. ResultsParticipants included 21,837 matched surgery and non-surgery pairs. Follow-up was up to 40 years (mean [SD], 13.2 [9.5] years). All-cause mortality was 16% lower in surgery compared with non-surgery groups (hazard ratio, 0.84; 95% CI: 0.79-0.90; p < 0.001). Significantly lower mortality after bariatric surgery was observed for both females and males. Mortality after surgery versus non-surgery decreased significantly by 29%, 43%, and 72% for cardiovascular disease, cancer, and diabetes, respectively. The hazard ratio for suicide was 2.4 times higher in surgery compared with non-surgery participants (95% CI: 1.57-3.68; p < 0.001), primarily in participants with ages at surgery between 18 and 34 years. ConclusionsReduced all-cause mortality was durable for multiple decades, for multiple bariatric surgical procedures, for females and males, and for greater than age 34 years at surgery. Rate of death from suicide was significantly higher in surgery versus non-surgery participants only in the youngest age at surgery participants.

Purpose Obesity is a well-known risk factor for depression and mental illnesses. Metabolic and bariatric surgery (MBS) is a common treatment for individuals with severe obesity. Studies suggest that MBS is associated with increased risk of depression. However, little is known if pregnant women following MBS have greater incidence of depression/anxiety than non-surgical pregnant women with severe obesity. Materials and Methods Utah Bariatric Surgery Registry (UBSR) was used to identify subjects who underwent bariatric surgery between 1996 and 2016 and were matched (1:2 matching) to subjects with severe obesity from the Utah Population Database (UPDB). Depression and anxiety diagnoses during pregnancy were identified from birth records and electronic medical records (EMRs) during 10 months before birth. A multivariate logistic regression with clustering due to same subjects with multiple births was used. Results Patients included 1427 MBS women (associated 2492 births) and 2854 non-surgical women (associated 4984 births). In the surgical group, 24.4% of the pregnancies had diagnosed depression/anxiety, while 14.3% of the pregnancies in the control group had depression/anxiety ( p < 0.01). The surgery group had 1.51 times higher odds of depression and/or anxiety during pregnancy than the control group after controlling for covariates (OR = 1.51, p < 0.01). Conclusion The present study provides evidence that women who previously underwent MBS have higher odds of depression/anxiety during pregnancy than women with obesity who did not undergo MBS.

Dementia, including Alzheimer’s disease, interfere with daily function and are one of the major causes of disability, institutionalization, and death. Obesity is associated with an increased risk of dementia. However, the effect of significant and sustained weight loss following bariatric surgery on dementia is not known. The purpose of this study was to assess the long-term risk of dementia following bariatric surgery. A surgical cohort was identified from the Utah Bariatric Surgery Registry and was linked to the Utah Population Database that includes electronic medical records, death records, and State Facility data. Adult subjects (≥ 18 years old) at time of surgery (1996–2016) were matched with non-surgical subjects. The final sample included 51,078 subjects (1:2 matching); surgery group n = 17,026; non-surgery subjects n = 34,052). Dementia were identified by ICD-9/10 diagnosis codes following surgery year or matched baseline year. Cox proportional hazard model was used to calculate the hazard ratio in the outcome between the groups. Average (SD) age of the subjects was 42 (12) years old at surgery or matched baseline year, 78

BackgroundObesity is a prevalent health threat and risk factor for type 2 diabetes. In this study, we evaluate the relationship between ceramides, which inhibit insulin secretion and sensitivity, and markers of glucose homeostasis and diabetes remission or recursion in patients who have undergone a Roux-en-Y gastric bypass (RYGB).MethodsThe Utah Obesity Study is a prospective cohort study, with targeted ceramide and dihydroceramide measurements performed on banked serum samples. The Utah Obesity Study consists of 1,156 participants in three groups: a RYGB surgery group, a non-surgery group denied insurance coverage, and severely obese population controls. Clinical examinations and ceramide assessments were performed at baseline and 2 and 12 years after RYGB surgery.FindingsSurgery patients (84% female, 42.2 ± 10.6 years of age at baseline) displayed lower levels of several serum dihydroceramides and ceramides at 2 and 12 years after RYGB. By contrast, neither the control group (77% female, 48.7± 6.4 years of age at baseline) nor the non-surgery group (95% female, 43.0± 11.4 years of age at baseline) experienced significant decreases in any species. Using a linear mixed effect model, we found that multiple dihydroceramides and ceramides positively associated with the glycemic control measures HOMA-IR and HbA1c. In surgery group participants with prevalent diabetes, ceramides inversely predict diabetes remission, independent of changes in weight.ConclusionsCeramide decreases may explain the insulin sensitization and diabetes resolution observed in most RYGB surgery patients.FundingFunded by the National Institutes of health (NIH), The Juvenile Diabetes Research Foundation, and the American Heart Association.

Background: Bariatric surgery leads to long-term remission and reduced incidence of diabetes, hypertension, and dyslipidemia. Short-term studies suggest reduction in specific fat depots may be more predictive of health improvement than reduced body mass index (BMI). Visceral, subcutaneous, epicardial, and liver fat, measured 11 years after bariatric surgery, were associated with long-term remission and incidence of diabetes, dyslipidemia, and hypertension. Methods: Fat depots an average of 11 (maximum 14) years after surgery were quantified by noncontrast computed tomography in subjects who did (N = 261; 86% gastric bypass) or did not (N = 243) have bariatric surgery. Multiple regression related fat depots to disease endpoints with and without adjustment for change in BMI and surgical status. Results: Visceral fat was 42% lower, subcutaneous fat 20% lower, epicardial fat 30% lower, and liver-to-spleen density ratio 9% higher at follow-up in the bariatric surgery group compared with the nonsurgery group (all P < 0.01). Higher visceral fat at follow-up exam was significantly associated with reduced remission and increased incidence of diabetes, hypertension, and dyslipidemia. Subcutaneous fat was not associated with disease. The liver-to-spleen ratio was associated with the remission and incidence of hypertriglyceridemia and not with other fat depots. Epicardial fat was related to incidence of elevated low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol. Conclusions: Whether or not a patient shows greater long-term diabetes, dyslipidemia, or hypertension remission or incidence after bariatric surgery appears dependent on the amount of fat within specific fat depots measured at follow-up. Furthermore, associations of the three disease endpoints with different fat depots suggest varied fat depot pathology.

OBJECTIVE:Gastric bypass surgery results in long-term weight loss. Small studies have examined protein changes during rapid weight loss (up to 1 or 2 years post surgery). This study tested whether short-term changes were maintained after 12 years. METHODS:A 12-year follow-up, protein-wide association study of 1,297 SomaLogic aptamer-based plasma proteins compared short- (2-year) and long-term (12-year) protein changes in 234 individuals who had gastric bypass surgery with 144 nonintervened individuals with severe obesity. RESULTS:There were 51 replicated 12-year protein changes that differed between the surgery and nonsurgery groups. Adjusting for change in BMI, only 12 proteins remained significant, suggesting that BMI change was the primary reason for most protein changes and not non-BMI-related surgical effects. Protein changes were related to BMI changes during both weight-loss and weight-regain periods. The significant proteins were associated primarily with lipid, uric acid, or resting energy expenditure clinical variables and metabolic pathways. Eight protein changes were associated with 12-year diabetes remission, including apolipoprotein M, sex hormone binding globulin, and adiponectin (p < 3.5 × 10-5 ). CONCLUSIONS:This study showed that most short-term postsurgical changes in proteins were maintained at 12 years. Systemic protection pathways, including inflammation, complement, lipid, and adipocyte pathways, were related to the long-term benefits of gastric bypass surgery.

Background/Objectives While an increased risk for substance use disorders (SUD) and also for several adverse pregnancy and birth outcomes in patients who have undergone bariatric surgery have been well documented when considered separately, an association between these important risk factors has not been investigated. This study explored the potential dependence of these two bariatric surgery-related risks. Subjects/Methods This study was a retrospective cohort study with adult women (18–45) who underwent bariatric surgery between 1996 and 2016 and who gave birth after surgery between 1996 and 2018. The study population consisted of 1849 post-bariatric surgery women with 3010 reported post-surgical births. Subjects with post-surgical, prenatal SUD were identified based on diagnosis codes extracted within the 10 months prior to delivery. Using random-effects logistic regression with retrospective cohort data, preterm birth, low birth weight, macrosomia, Caesarian delivery, congenital anomalies, and neonatal intensive care unit admission were considered as outcomes. Results About 10% ( n = 289) of women had an SUD diagnosis within 10 months prior to child delivery. Women with SUD during pregnancy had significantly more pregnancy and birth complications compared to women without SUD: preterm birth (OR = 2.08, p = 0.03, 95% CI: 1.07–4.03), low birth weight (OR = 3.41, p < 0.01, 95% CI: 1.99–5.84), Caesarian delivery (OR = 9.71, p < 0.01, 95% CI: 2.69–35.05), and neonatal intensive care unit admission (OR = 3.87, p < 0.01, 95% CI: 2.04–7.34). Women with SUD had lower risk for macrosomia than women without SUD (OR = 0.07, p = 0.02, 95% CI: 0.01–0.70). Conclusion Results from this study demonstrated that post-bariatric surgery women who had SUD during pregnancy had significantly more pregnancy- and birth-related complications than post-surgery pregnant women without SUD, despite the reduction in macrosomia. Where possible, greater prenatal surveillance of post-surgery women with SUD should be considered.