Faculty Bibliography

Chronic inflammation drives many obesity-associated conditions, including atherosclerosis. GlycA, a marker of systemic inflammation with lower intraindividual variability than hsCRP, is independently associated with incident cardiovascular events and mortality. Although GlycA is elevated in obesity, correlations with anthropometric measures are modest and the effect of weight loss on GlycA is untested. Obese (BMI 44.6±6.6kg/m² ), non-diabetic women (33.7±8.2 years) undergoing Roux-en-Y gastric bypass (n=23) or sleeve gastrectomy (n=31) were prospectively studied at baseline, 6 and 12 months post-procedure. Women with normal BMI (n=14) served as controls. Bariatric surgery significantly reduced GlycA by 6 months (451±47umol/L vs 383±50umol/L; p<0.001) with further reduction at 12 months (348±41umol/L; p<0.001) and no difference between procedures. At 12 months, despite 41% of surgical subjects maintaining BMI >30kg/m² , GlycA levels did not differ between surgical and control subjects (p=0.13). Increased HDL particle size was strongly associated with reduced GlycA (r=-0.49; p<0.001) and was found to mediate up to 43% of its weight-loss-associated fall. This is the first study to demonstrate that surgical weight loss markedly reduces levels of GlycA.

Mechanisms explaining the relationship between obesity and cardiovascular disease (CVD) are needed. Despite growing recognition of the importance of the anucleate platelet transcriptome, low levels of RNA in platelets make assessment difficult. We sought to perform unbiased platelet RNA profiling in obesity by performing a prospective study of severe obesity and weight loss via bariatric surgery on platelet characteristics and mRNA profile in 26 pre-menopausal, non-diabetic women (31.6 ± 8.4 years; BMI 43.0 ± 6.5 kg/m²) who underwent sleeve gastrectomy. Totally, 10 women of similar age with normal BMI served as controls. Platelet activation via flow cytometry was assessed before and after surgery. RNA-sequencing (RNAseq) was performed on platelet isolates from a subset of 13 subjects (eight obese women and five normal-BMI subjects). Platelet count, size, and age did not differ between control and obese women. However, platelet surface P-selectin and CD40 were higher in obesity. RNAseq demonstrated 629 differentially abundant transcripts in obesity. Notably, S100A9 and AGER, established markers of cardiovascular risk, were two of the most highly upregulated transcripts (each > 2.5 fold). At 6 months post-operatively, subjects lost 26.1 ± 5.8% body weight and inducible platelet P-selectin expression was reduced. Expression of 170 transcripts was affected by surgery, but only a small fraction (46/629) were genes found altered in obesity. We demonstrate that obesity is associated with an altered platelet transcriptome and increased platelet activation, which is partly attenuated by bariatric surgery. These observations suggest that platelets may contribute to increased cardiovascular risk in obesity through a variety of mechanisms.

Perforated duodenal ulcer following RYGB is an unusual clinical situation that may be a diagnostic challenge. Only 23 cases have previously been reported. We present five cases. The hallmark of visceral perforation, namely pneumoperitoneum, was not seen in three of the four cases that underwent cross sectional imaging. This is perhaps due to the altered anatomy of the RYGB that excludes air from the duodenum. Our cases had more free fluid than expected. The bariatric surgeon should not wait for free intraperitoneal air to suspect duodenal perforation after RYGB.

The following review is being published by the American Society for Metabolic and Bariatric Surgery in response to numerous inquiries made to the Society by patients, physicians, society members, hospitals, and others regarding one-anastomosis gastric bypass as a primary treatment for obesity or metabolic disease. The review is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The review is not intended as, and should not be construed as, stating or establishing a local, regional, or national standard of care.

BACKGROUND: Bariatric surgery is frequently recommended prior to total joint arthroplasty (TJA) for morbidly obese patients with end-stage arthropathy. Current published data on the efficacy of bariatric surgery for preoperative medical optimization has yielded mixed results, and the effect of time from bariatric surgery to TJA on the preoperative risk profile is not well defined. Our study evaluated the effect of time from bariatric surgery to TJA on 90-day complication and readmission rates. METHODS: We utilized the Healthcare Cost and Utilization Project (HCUP) California State Inpatient Database (SID) to identify patients who underwent TJA following bariatric surgery between 2007 and 2011. Primary endpoints were 90-day complication rates and all-cause 90-day readmission rates following TJA. RESULTS: We identified 330 cases of bariatric surgery followed by total hip arthroplasty (THA) and 1017 cases followed by total knee arthroplasty (TKA). There were no significant demographic differences among patients who underwent TJA greater than or less than 6 months after bariatric surgery. Patients undergoing THA more than 6 months after bariatric surgery were significantly less likely to be readmitted within 90 days for any cause. There was no association between time from bariatric surgery to THA or TKA and 90-day complications. DISCUSSION: Delaying THA at least 6 months after bariatric surgery may help reduce the rate of 90-day readmissions in this high-risk patient population. Arthroplasty surgeons recommending bariatric surgery as preoperative risk modification should consider the patient's overall nutritional status, medical comorbidities, and overall response to surgery prior to booking for TJA.

OBJECTIVE: The objective of this study was to determine whether the DiaRem, a score that predicts type 2 diabetes (T2D) remission following roux-en-y gastric bariatric surgery (RYGB), also predicts remission following laparoscopic adjustable gastric banding (LAGB) and laparoscopic sleeve gastrectomy (LSG) in white and Hispanic patients. BACKGROUND: While bariatric surgery is highly effective in reversing insulin resistance, there are patients for whom surgery will not lead to remission. To date, there is no score for predicting remission following LAGB or LSG surgery. Additionally, there is little known about how to predict whether Hispanic patients will experience remission. METHODS: We conducted a retrospective cohort study of white and Hispanic patients with T2D who received bariatric surgery. There were 361 white and 130 Hispanic patients among whom 328 had RYGB surgery, 107 had LSG surgery, and 56 had LAGB surgery. We used age, diabetes treatment, and hemoglobin A1c to calculate DiaRem scores. Mann-Whitney U test was used to determine the association between DiaRem scores and remission. Area under the receiver operant curve (AUC) was used to assess the ability of the DiaRem to discriminate between patients who did and did not remit. RESULTS: The DiaRem was associated with partial remission in all surgery types for white and Hispanic patients (Mann-Whitney, p < 0.001). The DiaRem had moderate to high discriminant ability (AUC > 0.70) for all surgical and racial/ethnic groups. CONCLUSIONS: The DiaRem distinguishes between patients likely and unlikely to experience remission, informing expectations of patients making T2D treatment decisions.

OBJECTIVE: High-density lipoprotein cholesterol efflux capacity (CEC) is inversely associated with incident cardiovascular events, independent of high-density lipoprotein cholesterol. Obesity is often characterized by impaired high-density lipoprotein function. However, the effects of different bariatric surgical techniques on CEC have not been compared. This study sought to determine the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on CEC. APPROACH AND RESULTS: We prospectively studied severely obese, nondiabetic, premenopausal Hispanic women not using lipid medications undergoing RYGB (n=31) or SG (n=36). Subjects were examined before and at 6 and 12 months after surgery. There were no differences in baseline characteristics between surgical groups. Preoperative CEC correlated most strongly with Apo A1 (apolipoprotein A1) concentration but did not correlate with body mass index, waist:hip, high-sensitivity C-reactive protein, or measures of insulin resistance. After 6 months, SG produced superior response in high-density lipoprotein cholesterol and Apo A1 quantity, as well as global and non-ABCA1 (ATP-binding cassette transporter A1)-mediated CEC (P=0.048, P=0.018, respectively) versus RYGB. In multivariable regression models, only procedure type was predictive of changes in CEC (P=0.05). At 12 months after SG, CEC was equivalent to that of normal body mass index control subjects, whereas it remained impaired after RYGB. CONCLUSIONS: SG and RYGB produce similar weight loss, but contrasting effects on CEC. These findings may be relevant in discussions about the type of procedure that is most appropriate for a particular obese patient. Further study of the mechanisms underlying these changes may lead to improved understanding of the factors governing CEC and potential therapeutic interventions to maximally reduce cardiovascular disease risk in both obese and nonobese patients.

BACKGROUND: At our medical center, female patients who have undergone bariatric surgery are advised to defer pregnancy for 2 years after surgery to avoid the following complications and their potential consequences for the fetus: inadequate gestational weight gain, inadequate postsurgical weight loss, hyperemesis gravidarum, nutritional deficiencies, gestational diabetes, and gestational hypertension. OBJECTIVES: To examine the effect of time from surgery to conception on pregnancy course and outcomes in bariatric patients. SETTING: University. METHODS: We identified 73 pregnancies in 54 women who became pregnant after undergoing bariatric surgery. Surgery to conception interval was compared between pregnancies that were carried to delivery and 8 pregnancies that resulted in spontaneous abortion. Of 41 pregnancies that were carried to delivery, 26 occurred in women who had undergone surgery less than 2 years before conception, and 15 occurred in women who had undergone surgery greater than 2 years before conception. Gestational age at delivery, number of neonatal intensive care unit admissions, gestational weight gain, hyperemesis gravidarum, nutritional deficiencies, gestational diabetes, and gestational hypertension during pregnancy were compared for the 2 groups. RESULTS: Eight patients who had spontaneous abortion had a significantly shorter time from surgery to conception. There were no significant differences between our 2 groups in rates of preterm deliveries, neonatal intensive care unit admission, gestational weight gain, hyperemesis, nutritional deficiencies, gestational diabetes, or gestational hypertension. CONCLUSIONS: Becoming pregnant within the first 2 years after bariatric surgery appears to have no effect on pregnancy course and outcomes. Women who miscarried had a significantly lower mean surgery to conception interval. These results fail to show an increased rate of pregnancy complications during the first 2 years after bariatric surgery.