Bariatric Surgery Prior to Index Screening Colonoscopy Is Associated With a Decreased Rate of Colorectal Adenomas in Obese Individuals

Clinical significance of colonoscopy before laparoscopic bariatric/metabolic surgery in Japanese patients

PURPOSE

Obesity is known to be associated with colorectal adenoma (CRA) and colorectal cancer (CRC); yet colonoscopy is not considered an essential preoperative evaluation before bariatric/metabolic surgery. The aim of this study was to clarify the clinical significance of preoperative colonoscopy for obese Japanese patients.

METHODS

The subjects of this retrospective study were 114 patients who underwent screening colonoscopy before bariatric/metabolic surgery. Multivariate analyses were performed to evaluate the independent predictors of CRA/CRC among the characteristics identified as significant or nearly significant by univariate analyses.

RESULTS

Colonoscopy revealed abnormal findings indicating the need for biopsy or polypectomy in 20 of the 114 patients (17.5%), and CRA was diagnosed in 13 patients (11.4%). Three patients (2.6%), who were all ≥ 56 years old, had a CRA ≥ 10 mm in diameter. The multivariate analysis showed that older age and male sex were significant predictors of CRA/CRC, which was identified in 46.2% of the male patients aged ≥ 46 years.

CONCLUSION

Our findings suggest that older age and male sex may be risk factors for CRA/CRC in obese Japanese candidates for bariatric/metabolic surgery; thus, preoperative colonoscopy should be considered for these high-risk patients.

The Risk of Colorectal Polyps after Weight Loss Therapy Versus Obesity: A Propensity-Matched Nationwide Cohort Study

BACKGROUND

A fundamental understanding of the impact of bariatric surgery (BRS) on mechanisms of colorectal carcinogenesis is limited. For instance, studies report a reduced risk of colorectal cancer in females but not in males after BRS. We examined whether this sex-specific difference existed at the earlier polyp development stage.

METHODS

This retrospective cohort study included 281,417 adults from the 2012-2020 MarketScan database. We compared polyps rates on colonoscopy in four groups: post- vs. pre-BRS (treatment) to post- vs. pre-severe obesity (SO) diagnosis (control). We focused our main analysis on a propensity-matched sample that yielded a balanced distribution of covariates in our four groups (n = 9680 adults, 21.9% males). We also adjusted for important covariates.

RESULTS

Metabolic syndrome parameters improved after bariatric surgery and worsened after severe obesity diagnosis (p < 0.05). The rate of polyps was 46.7% at a median of 0.5 years pre-BRS and 47.9% at a median of 0.6 years pre-SO diagnosis. The polyps rate was 45.4% at a median (range) of 3.2 (1.0-8.5) years post-BRS. Conversely, 53.8% of adults had polyps at 3.0 (1.0-8.6) years post-SO. There was no change in the risk of colorectal polyps in males or females post- vs. pre-BRS. However, the risk of polyps was higher in males (OR = 1.32, 95% CI: 1.02-1.70) and females (OR = 1.29, 95% CI: 1.13-1.47) post- vs. pre-SO. When compared to the control group (SO), the odds ratios for colorectal polyps were lower for males and females after bariatric surgery (OR = 0.63, 95% CI: 0.44-0.90, and OR = 0.79, 95% CI: 0.66-0.96, respectively).

CONCLUSIONS

Obesity is associated with an increased risk of colorectal polyps, an effect that is ameliorated after bariatric surgery. These data are relevant for studies investigating colorectal carcinogenesis mechanisms.

The impact of surgical weight loss procedures on the risk of metachronous colorectal neoplasia: the differential effect of surgery type, sex, and anatomic location

Patients with prior colorectal polyps are at high risk for metachronous colorectal neoplasia, especially in the presence of obesity. We assessed the impact of 2 common bariatric surgeries, vertical sleeve gastrectomy and roux-n-Y gastric bypass, on the risk of colorectal neoplasia recurrence. This nationally representative analysis included 1183 postbariatric adults and 3193 propensity score-matched controls, who all had prior colonoscopy with polyps and polypectomy. Colorectal polyps reoccurred in 63.8% of bariatric surgery patients and 71.7% of controls at a mean follow-up of 53.1 months from prior colonoscopy. There was a reduced odds of colorectal polyp recurrence after bariatric surgery compared with controls (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.58 to 0.83). This effect was most pronounced in men (OR = 0.58, 95% CI = 0.42 to 0.79), and post roux-n-Y gastric bypass (OR = 0.57, 95% CI = 0.41 to 0.79). However, the risk of rectal polyps or colorectal cancer remained consistent between groups. This study is the first to our knowledge to show a reduction in risk of polyp recurrence following bariatric surgery.

The Protective Effect of Bariatric Surgery on the Development of Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity is a known risk factor for developing colorectal cancer (CRC) and is associated with the formation of precancerous colonic adenomas. Bariatric surgery (BRS) is considered to reduce the cancer risk in morbidly obese patients. However, the currently available literature yields contradicting results regarding the impact of bariatric surgery on the incidence of CRC.

METHODS

A systematic literature search of the Medline, Embase, CENTRAL, CINAHL, Web of Science, and clinicaltrials.gov databases was undertaken following the PRISMA guidelines. A random effects model was selected.

RESULTS

Twelve retrospective cohort studies, incorporating a total of 6,279,722 patients, were eligible for inclusion in the final quantitative analysis. Eight studies originated from North America, while four reported on European patients. Patients in the Bariatric Surgery group exhibited a significantly reduced risk for developing colorectal cancer (RR 0.56, 95% CI 0.4-0.8, p < 0.001), while sleeve gastrectomy was found to be significantly associated with a smaller incidence of CRC (RR 0.55, 95% CI 0.36-0.83, p < 0.001), and gastric bypass and banding did not.

CONCLUSIONS

A significant protective effect of BRS against the development of CRC is implied. In the present analysis, the incidence rate of colorectal cancer was approximately halved amongst the obese individuals that were operated on.

Metabolism and Colorectal Cancer

Reprogrammed metabolism is a hallmark of colorectal cancer (CRC). CRC cells are geared toward rapid proliferation, requiring nutrients and the removal of cellular waste in nutrient-poor environments. Intestinal stem cells (ISCs), the primary cell of origin for CRCs, must adapt their metabolism along the adenoma-carcinoma sequence to the unique features of their complex microenvironment that include interactions with intestinal epithelial cells, immune cells, stromal cells, commensal microbes, and dietary components. Emerging evidence implicates modifiable risk factors related to the environment, such as diet, as important in CRC pathogenesis. Here, we focus on describing the metabolism of ISCs, diets that influence CRC initiation, CRC genetics and metabolism, and the tumor microenvironment. The mechanistic links between environmental factors, metabolic adaptations, and the tumor microenvironment in enhancing or supporting CRC tumorigenesis are becoming better understood. Thus, greater knowledge of CRC metabolism holds promise for improved prevention and treatment.

Sex-Dependent Differences in Colorectal Cancer: With a Focus on Obesity

Colorectal cancer (CRC) is the third most common cancer and has the second highest cancer-related mortality in the world. The incident rates of CRC vary country-wise; however, population studies and data from different countries show a general increase in the CRC rate in young adults, males, and females ≥65 years. CRC incidence is affected by age, sex, environmental, dietary, hormonal, and lifestyle factors. Obesity is a known disease that is spreading rapidly throughout the world. A large body of literature indicates that, among many conditions, obesity is the increasing cause of CRC. Even though obesity is one of the known factors for CRC development, limited studies are available that explain the mechanistic link between obesity, sex hormones, and CRC development. Thus, this review summarizes the literature and aims to understand sex-dependent differences in CRC, especially in the context of obesity.

OUP accepted manuscript

Background

Although obesity is a known risk factor, the impact of weight change on colorectal adenoma risk is less clear and could have important implications in disease prevention. We prospectively evaluated weight change in adulthood and incident colorectal adenoma.

Methods

We assessed weight change during early-late (age 20 years to baseline, ie, ages 55-74 years), early-middle (20-50 years), and middle-late (50 years-baseline) adulthood using self-reported weight data in relation to incident distal adenoma in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (cases = 1053; controls = 16 576). For each period, we defined stable weight as greater than −0.5 kg to less than or equal to 1 kg/5 years, weight loss as less than or equal to −0.5 kg/5 years, and weight gain as greater than 1-2, greater than 2-3, or greater than 3 kg/5 years. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression; all tests were 2-sided.

Results

Compared with stable weight, weight loss during early-late adulthood was associated with reduced adenoma risk (OR = 0.54, 95% CI = 0.34 to 0.86), particularly among those who were overweight or obese at age 20 years (OR = 0.39, 95% CI = 0.18 to 0.84). Results were similar for early-middle adulthood but less pronounced for middle-late adulthood. Weight gain greater than 3 kg/5 years during early-late adulthood was associated with increased risk (OR = 1.30, 95% CI = 1.07 to 1.58, P_trend < .001). Findings appeared stronger among men (OR for >3 kg/5 years = 1.41, 95% CI = 1.11 to 1.80) than women (OR = 1.09, 95% CI = 0.79 to 1.50, P_interaction = .21).

Conclusions

Weight loss in adulthood was associated with reduced adenoma risk, particularly for those who were overweight or obese, whereas weight gain greater than 3 kg/5 years increased risk. Findings underscore the importance of healthy weight maintenance throughout adulthood in preventing colorectal adenoma.

Impact of smoking on weight loss outcomes after bariatric surgery: a literature review

BACKGROUND

The association between smoking and surgical complications after bariatric surgery has been well-established. However, given that this patient population is inherently weight-concerned, understanding the effects of tobacco use on postoperative weight loss is essential to guiding clinicians in counseling patients. We aimed to summarize the current literature examining the effects of preoperative and postoperative smoking, as well as changes in smoking status, on bariatric surgery weight loss outcomes.

METHODS

Ovid MEDLINE, PubMed, and SCOPUS databases were queried to identify relevant published studies.

RESULTS

Overall, 20 studies were included. Preoperative and postoperative smoking rates varied widely across studies, as did requirements for smoking cessation prior to bariatric surgery. Reported preoperative smoking prevalence ranged from 1 to 62%, and postoperative smoking prevalence ranged from 6 to 43%. The majority of studies which examined preoperative and/or postoperative smoking habits found no association between smoking habits and postoperative weight loss outcomes. A minority of studies found relatively small differences in postoperative weight loss between smokers and nonsmokers; these often became nonsignificant with longer follow-up. No studies found significant associations between changes in smoking status and weight loss outcomes.

CONCLUSION

While smoking has been associated with weight loss in the general population, most current evidence demonstrates that smoking habits are not associated with weight loss outcomes after bariatric surgery. However, due to the heterogeneity in study design and analysis, no definitive conclusions can be made, and more robust studies are needed to investigate any relationship between smoking and long-term weight loss outcomes. Given the established increased risk of surgical complications and mortality in smokers, smoking cessation should be encouraged.

Incidence of Colorectal Adenomas After Bariatric Surgery: Pre-operative Super Morbid Obesity Is Independently Associated with Increased Risk

PURPOSE

The impact of pre-bariatric surgery BMI on the incidence of colorectal adenomas in the post-operative period is unknown. Here we aim to evaluate the incidence of colorectal adenomas after bariatric surgery and to assess super morbid obesity (SMO) as a risk factor for post-operative colorectal adenomas.

MATERIALS AND METHODS

An inception cohort of 1639 patients that underwent bariatric surgery between 2011 and 2019 in a referral center was retrospectively analyzed. SMO was defined as BMI > 50.0 kg/m². Cox regression analysis was performed to assess the influence of pre-operative BMI on the primary outcome.

RESULTS

A total 381 patients (23.2% of the cohort) underwent colonoscopy and included in the analysis. Mean age was 51.1 years (± 10.6) with mean BMI of 42.2 kg/m² (± 6.2), and 49 patients (12.9%) had SMO. Median time to colonoscopy was 3.5 years. One hundred nine patients (28.6%) had colorectal polyps, and 38/109 (34.8%) had advanced adenoma. Two patients had colorectal cancer (CRC). Pre-procedural SMO was associated with diagnosis of colorectal polyp (HR 2.4, 95% CI 1.5-3.9, p < 0.001) and advanced adenomas (HR 4.2, 95% CI 2.0-8.9, p < 0.001) upon adjustment to previously reported risk factors of CRC.

CONCLUSION

Pre-procedural SMO is associated with increased risk of colorectal adenomas after bariatric surgery compared to obese and morbidly obese individuals. Pre-operative BMI should be incorporated into post-operative screening plan in this population.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort

BACKGROUND AND AIM

While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence.

METHODS

Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA.

RESULTS

During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm² increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm² increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA.

CONCLUSION

Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Incidence of polyp formation following bariatric surgery

BACKGROUND

Multiple studies have linked obesity to an increased risk of cancer. The correlation is so strong that the national cancer prevention guidelines recommend weight loss for patients with obesity to reduce their risk of cancer. Bariatric surgery has been shown to be very effective in sustained weight loss. However, there have been mixed findings about bariatric surgery and its effects on the risk of colorectal cancer.

OBJECTIVE

This study sought to examine bariatric surgery patients and their risk of pre-cancerous or cancerous polyps to elucidate any risk factors or associations between bariatric surgery and colorectal cancer.

SETTING

A retrospective review of the academic medical center's bariatric surgery database was performed from January 2010 to January 2017. Patients who underwent medical or surgical weight loss and had a subsequent colonoscopy were included in the study. Positive colonoscopy findings were described as malignant or premalignant polyps.

METHODS

A total of 1777 patients were included, with 1360 in the medical group and 417 in the surgical group. Data analysis included patient demographics, co-morbidities, procedure performed, surgical approach, weight loss, and colonoscopy findings. A multivariate analysis was used to determine whether an association exists between weight loss and incidence of colorectal polyps, and if so, whether the association different for medical versus surgical weight loss.

RESULTS

A higher percentage of body mass index (BMI) reduction was seen in the surgical group. An overall comparison showed average reductions in BMI of 27.7% in the surgical group and 3.5% in the medical group (P < .0001). Patients with the greatest reduction in BMI, regardless of medical or surgical therapy, showed a lower incidence of precancerous and cancerous polyps (P = .041).

CONCLUSION

This study offers a unique approach in examining the incidence of colorectal polyps related to obesity. Patients with the greatest reduction in their BMI, more common in the surgical group, had a lower incidence of precancerous and cancerous polyps.

Obesity, Cancer, and Risk Reduction with Bariatric Surgery

The prevalence of noncommunicable diseases has increased dramatically in North America and throughout the world and is expected to continue increasing in coming years. Obesity has been linked to several types of cancers and is associated with increased morbidity and mortality following cancer diagnosis. Bariatric surgery has emerged as the prominent model to evaluate the effects of intentional weight loss on cancer incidence and outcomes. Current literature, comprising prospective cohort investigations, indicates site-specific reductions in cancer risk with select bariatric procedures. Future research is required to establish evidence-based indications for bariatric surgery in the context of cancer prevention.

Self-Reported Smoking Compared to Serum Cotinine in Bariatric Surgery Patients: Smoking Is Underreported Before the Operation

BACKGROUND

Smoking has been associated with postoperative complications and mortality in bariatric surgery. The evidence for smoking is based on self-report and medical charts, which can lead to misclassification and miscalculation of the associations. Determination of cotinine can objectively define nicotine exposure. We determined the accuracy of self-reported smoking compared to cotinine measurement in three phases of the bariatric surgery trajectory.

METHODS

Patients in the phase of screening (screening), on the day of surgery (surgery), and more than 18 months after surgery (follow-up) were consecutively selected. Self-reported smoking was registered and serum cotinine was measured. We evaluated the accuracy of self-reported smoking compared to cotinine, and the level of agreement between self-report and cotinine for each phase.

RESULTS

In total, 715 patients were included. In the screening, surgery, and follow-up group, 25.6%, 18.0%, and 15.5%, respectively, was smoking based on cotinine. The sensitivity of self-reported smoking was 72.5%, 31.0%, and 93.5% in the screening, surgery, and follow-up group, respectively (p < 0.001). The specificity of self-report was > 95% in all groups (p < 0.02). The level of agreement between self-report and cotinine was 0.778, 0.414, and 0.855 for the screening, surgery, and follow-up group, respectively.

CONCLUSIONS

Underreporting of smoking occurs before bariatric surgery, mainly on the day of surgery. Future studies on effects of smoking and smoking cessation in bariatric surgery should include methods taking into account the issue of underreporting.

Nutritional prevention of colorectal cancer

The preventability estimate for colorectal cancer (CRC) is approximately 50%, highlighting the huge potential for altering modifiable lifestyle factors (including diet and body fatness) in order to reduce risk of this common malignancy. There is strong evidence that dietary factors (including intake of wholegrains, fibre, red and processed meat and alcohol) affect CRC risk. The lack of positive intervention trials and limited mechanistic understanding likely explain limited public health impact of epidemiological observations, to date. An alternative strategy for nutritional prevention of CRC is use of supplements that provide higher individual nutrient exposure than obtained through the diet (chemoprevention). There are positive data for calcium and/or vitamin D and the n-3 fatty acid EPA from polyp prevention trials using colorectal adenoma as a CRC risk biomarker. Although CRC is an obesity-related malignancy, there remains a paucity of observational data supporting intentional weight loss for CRC risk reduction. Some types of obesity surgeries (Roux-en-Y gastric bypass) might actually increase subsequent CRC risk due to alteration of local intestinal factors. There is intense interest in nutritional therapy of patients after diagnosis of CRC, in order to impact on recurrence and overall survival (now often termed cancer interception). In conclusion, nutritional prevention of CRC continues to hold much promise. Increased mechanistic understanding of the role of individual nutrients (linked to intestinal microbiota), as well as a precision medicine approach to CRC chemoprevention and interception based on both tumour and host factors, should enable translation of nutritional interventions into effective CRC risk reduction measures.

Role of bariatric surgery in reducing the risk of colorectal cancer: a meta-analysis

BACKGROUND

Obesity increases the risk of multiple co-morbidities such as type 2 diabetes, cardiovascular disease and most cancers, including colorectal cancer. Currently, the literature presents conflicting results regarding the protective effects of bariatric surgery on the incidence of colorectal cancer. This meta-analysis was conducted to investigate the effect of bariatric surgery on the risk of developing colorectal cancer in obese individuals.

METHODS

Ovid Embase, Ovid MEDLINE, Cochrane CENTRAL and Web of Science were searched for relevant articles. Articles published by the end of December 2018 were retrieved; data were extracted according to evidence-based PICO (population, intervention, control, outcome) model and analysed using a random-effects model to estimate the pooled relative risk (RR) and its 95 per cent confidence interval. The heterogeneity of studies was tested and quantified using Cochran's Q and I² statistics. Meta-regression was used to investigate the association of year of study, region, mean length of follow-up and sample size with RR.

RESULTS

Seven articles, involving a total of 1 213 727 patients, were included in the meta-analysis. The pooled estimate of the RR was 0·64 (95 per cent c.i. 0·42 to 0·98). The test of asymmetry found no significant publication bias. Meta-regression showed that sample size was a statistically significant factor (P = 0·037), but year of publication, region and mean duration of follow-up were not significant.

CONCLUSION

Patients who underwent bariatric surgery had a greater than 35 per cent reduction in the risk of developing colorectal cancer compared with obese individuals who had no surgery.

Suppressive effects of metformin on colorectal adenoma incidence and malignant progression

BACKGROUND

The linear progression from normal colonic epithelium to adenoma initiation, carcinoma transformation and metastasis is considered the classical model of colorectal cancer (CRC) development. Although metformin has been extensively reported to be negatively related to cancer incidence, the effect of metformin on CRC development remains unclear. We aimed to evaluate the role of metformin in the entire CRC linear progression.

METHODS

Systematic searches and data extraction were performed in the PubMed, Embase, and Cochrane Library databases on Jan 31, 2019. The combined relative ratios (RRs) of colorectal tumor incidence and the hazard ratios (HRs) of overall survival (OS) and cancer-specific survival (CSS) were evaluated by a random-effects model. Then, the effects of metformin were further assessed through stratified analyses by population, medication duration and dosage, dose-response analysis and comparison with other antidiabetic agents.

RESULTS

A total of 50 studies consisting of 238,540 cases of diabetes mellitus (DM) were included in this study. Metformin use was negatively associated with the incidence of colorectal adenoma (RR: 0.75, 95% CI: 0.65-0.86) and CRC (RR: 0.73, 95% CI: 0.58-0.90). Moreover, CRC patients benefited from metformin in terms of both OS (HR: 0.73, 95% Cl: 0.63-0.84) and CSS (HR: 0.60, 95% Cl: 0.50-0.73). Stratified analyses suggested that a long duration of high-dose metformin (RR: 0.52, 95% Cl: 0.36-0.83) was more effective than a short duration in Asian populations against colorectal adenoma (RR: 0.66, 95% Cl: 056-0.70) and CRC (RR: 0.45, 95% Cl: 0.29-0.70). Interestingly, metformin use decreased CRC risk in a dose-dependent manner (RR: 0.91, 95% CI: 0.87-0.95). In addition, the benefit of metformin on CRC was more significant than that of other antidiabetic agents, including insulin.

CONCLUSIONS

The use of metformin is associated with a lower incidence of adenoma and CRC and a better prognosis, especially in Asian populations.

Bariatric surgery is independently associated with a decrease in the development of colorectal lesions

BACKGROUND

Obesity is a risk factor for colorectal cancer and possibly the formation of precancerous, colorectal polyps . Bariatric surgery is very effective for long-term weight loss; however, it is not known whether bariatric surgery decreases the risk of subsequent colonic neoplasia. We hypothesized that bariatric surgery would decrease the risk of developing colorectal lesions (new cancer and precancerous polyps).

METHODS

We reviewed all patients (n = 3,676) who underwent bariatric surgery (gastric bypass, sleeve gastrectomy, or gastric banding) at the University of Virginia (Charlottesville, VA) 1985-2015. Obese, nonoperative patients (n = 46,873) from an institutional data repository were included as controls. Cases and controls were propensity score matched 1:1 by demographics, comorbidities, body mass index, and socioeconomic factors. The matched cohort was compared by univariate analysis and conditional logistic regression.

RESULTS

A total of 4,462 patients (2,231 per group) with a median follow-up of 7.8 years were well-matched with no statistically significant baseline differences in initial body mass index (48 vs 49 kg/m²), sex, and age in addition to other comorbidities (all P > .05). The operative cohort had more weight loss (55.5% vs -1.4% decrease in excess body mass index, P < .0001). The operative cohort developed fewer colorectal lesions (2.4% vs 4.8%, P < .0001). We observed no differences in polyp characteristics or staging for patients who developed cancer (all P > .05). After risk adjustment, bariatric surgery was independently associated with a decrease in new colorectal lesions (OR 0.62, 95% CI 0.42-0.91, P = .016).

CONCLUSION

Bariatric surgery was associated with lesser, risk-adjusted incidence of new colorectal lesions in this large population of propensity matched patients undergoing bariatric surgery compared with a control group not undergoing bariatric surgery. These results suggest the benefits of bariatric surgery may extend beyond weight loss and mitigation of comorbidities.