Journal Watch—June 2015

| June 1, 2015

A quick look at the noteworthy articles in bariatric and metabolic research

Resting-state brain connectivity after surgical and behavioral weight loss.
Lepping RJ, Bruce AS, Francisco A, et al. Obesity (Silver Spring). 2015 Jun 5. [Epub ahead of print]
Synopsis: Changes in food-cue neural reactivity associated with behavioral and surgical weight loss interventions have been reported. Resting functional connectivity represents tonic neural activity that may contribute to weight loss success. This study explores whether intervention type is associated with differences in functional connectivity after weight loss.

Fifteen participants with obesity were recruited prior to adjustable gastric banding surgery. Thirteen demographically matched participants with obesity were selected from a separate behavioral diet intervention. Resting-state functional magnetic resonance imaging was collected 3 months after surgery/behavioral intervention. ANOVA was used to examine post-weight loss differences between the two groups in connectivity to seed regions previously identified as showing differential cue-reactivity after weight loss.

Following weight loss, behavioral dieters exhibited increased connectivity between left precuneus/superior parietal lobule (SPL) and bilateral insula pre- to postmeal and bariatric patients exhibited decreased connectivity between these regions pre- to postmeal (Pcorrected <0.05).

Behavioral dieters showed increased connectivity pre- to postmeal between a region associated with processing of self-referent information (precuneus/SPL) and a region associated with interoception (insula) whereas bariatric patients showed decreased connectivity between these regions. This may reflect increased attention to hunger signals following surgical procedures and increased attention to satiety signals following behavioral diet interventions.

Bariatric surgery in cancer survivorship: does a history of cancer affect weight loss outcomes?
Philip EJ, Torghabeh MH, Strain GW. Surg Obes Relat Dis. 2015 Jan 1. pii: S1550-7289(14)00510-3. [Epub ahead of print]
Synopsis: The authors conducted a  retrospective chart review of 1013 patients identified 29 bariatric surgery patients with a history of cancer who were then matched to patients without a history of cancer.
At 1-year postsurgical follow-up, individuals with a history of cancer had lost less weight than those without a history of cancer (14.2 versus 14.8); however, this difference was not significant (P = .76).

The authors concluded that cancer survivors appear to draw similar benefit from bariatric surgery as those without a history of cancer, although a larger study with greater statistical power to detect differences is needed to confirm these results. These preliminary results are encouraging in light of the increasing focus on weight loss among this population.
PMID: 26048524

Revised sleeve gastrectomy (re-sleeve).
Nedelcu M, Noel P, Iannelli A, Gagner M. Surg Obes Relat Dis. 2015 Feb 14. pii: S1550-7289(15)00040-4. [Epub ahead of print]
Synopsis: In this article, the researches sought to evaluate the safety and the efficiency of revisional sleeve gastrectomy (ReSG).
From October 2008 to October 2014, 61 patients underwent ReSG. All patients with failure after primary LSG underwent radiologic evaluation, and an algorithm of treatment was proposed.

Sixty-one patients (54 women, 7 men; mean age 40.8 yr) with a body mass index (BMI) of 39.4 kg/m² underwent ReSG. The primary LSG was performed for mean BMI of 46.2 kg/m² (range 35.4-77.9). The mean interval time from the primary LSG to ReSG was of 37.5 months (9-80 mo). The indication for ReSG was insufficient weight loss in 28 patients (45.9%), weight regain in 29 patients (47.5%), and gastroesophageal reflux disease (GERD) in 4 patients. In 42 patients the gastrografin swallow results were interpreted as primary dilation and in the remaining 19 cases as secondary dilation. The computed tomography (CT) scan volumetry was obtained in 38 patients with mean gastric volume of 436.3 cc (275–1056 cc). All cases were completed by laparoscopy with no intraoperative incidents. The mean operative time was 39 minutes (range 29–70 min) and the mean hospital stay was 3.5 days (range 3–16 d). One perigastric hematoma and 2 cases of gastric stenosis were recorded. The mean BMI decreased to 29.2 kg/m2 (range 20.2–37.5); the mean percentage of excess weight loss (%EWL) was 58.5% (±25.3) (P<.0004) for a mean follow-up of 20 months (range 6–56 mo).

The researchers concluded that ReSG may be a valid option for failure of primary LSG. Further prospective clinical trials are required to compare the outcomes of ReSG with those of laparoscopic Roux-en-Y gastric bypass or duodenal switch for weight loss failure after LSG.
PMID: 26048518

Predictors of hospital readmission after bariatric surgery.
Abraham CR, Werter CR, Ata A, et al. J Am Coll Surg. 2015 Feb 28. pii: S1072-7515(15)00154-4. [Epub ahead of print]
Synopsis: The authors conducted a study to identify comorbidities, surgical variables, and postoperative complications associated with readmission.
Patients with bariatric surgery as their primary procedure were identified from the 2012 American College of Surgeons (ACS) NSQIP database. Patient variables, operative times, and major postoperative complications were analyzed for predictors of readmission. The ACS NSQIP estimated probability of morbidity (MORBPROB) was also considered. Chi-square tests and Poisson regression were used for statistical analysis to identify significant predictors.

There were 18,186 patients who met inclusion criteria. There were 1,819 who had a laparoscopic gastric band, 9,613 who had laparoscopic Roux-en-Y gastric bypass (RYGB), 6,439 who had gastroplasties (vertical banded gastroplasty and sleeve), and 315 who had open RYGB. Age, sex, BMI, American Society of Anesthesiologists (ASA) class, diabetes, hypertension, steroid use, type of procedure, and operative time all were significantly associated with readmission within 30 days of operation. All major postoperative complications were significant predictors of readmission. Patients expected to be at high risk based on the ACS NSQIP MORBPROB had a significantly higher rate of readmissions. The overall readmission rate for patients undergoing bariatric surgery was 5%. The readmission rate among patients with any major complication was 31%.

The authors concluded that bariatric surgery is a low-risk procedure. Complexity of operation, ASA class, prolonged operative time, and major postoperative complications are important determinants of high risk for readmission. The ACS NSQIP MORBPROB may be a useful tool to identify and target patients at risk for readmission.
PMID: 26047761

Bile acid signaling: Mechanism for bariatric surgery, cure for NASH?
Kohli R, Myronovych A, Tan BK, et al. Dig Dis. 2015;33(3):440–446. Epub 2015 May 27.
Synopsis: In this article, the authors discuss bariatric surgery and nonalcoholic steatohepatitis (NASH). They review their preclinical studies on experimental procedures such as “ileal transposition” or bile diversion and established procedures, such as Roux-en-Y gastric bypass and the adjustable gastric band. Their data show that the resolution of NASH and increase in serum bile acids are not seen in rodents that lose an equivalent amount of weight via food restriction. In particular, they discuss their studies on the role of altered bile acid signaling, in the potent impact vertical sleeve gastrectomy (VSG). They describe key bile acid signaling elements that may provide potential therapeutic targets for “bariatric-mimetic technologies” that could produce benefits similar to bariatric surgery without surgery. They conclude that bariatric surgeries can be used as “laboratories” to dissect the mechanisms by which these procedures work to improve obesity and fatty liver disease.
PMID: 26045281


Category: Journal Watch, Past Articles

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