Bariatric Surgery and LDL Cholesterol

Background:

Observational studies have shown that gastric bypass is superior to sleeve gastrectomy in terms of LDL cholesterol improvement. If these results are confirmed in randomized controlled trials, pre-surgical LDL cholesterol status should be a point to consider in the surgical procedure election.

Objective:

The primary objective is to compare 1-year LDL cholesterol remission after gastric bypass and sleeve gastrectomy in morbid obese patients.

Methods:

Phase 3, uni-centric, randomized clinical trial, with intention-to-treat analysis to compare LDL cholesterol remission between gastric bypass and sleeve gastrectomy with a 12 months follow-up. The inclusion criteria will be patients aged between 18-60 years old with a body mass index ≥40 or ≥35 kg/m2 with a significant obesity related comorbidity and high LDL cholesterol levels. Patients will be evaluated preoperatively (2 months before surgery) and at 3, 6 and 12 months after bariatric surgery. Examinations will include routine blood chemistry, anthropometric measures, food intake recall, physical activity questionnaires,intima media thickness, fecal samples for microbiota examinations, fat tissue samples and serum samples for lipidomics and hormonal analyses.

In the preoperative period, patients will follow a standard nutritional intervention that includes 6 monthly group sessions focused on achieving changes in dietary habits and hence ease adaptation after surgery.

In addition, lipid-lowering treatment will be adjusted and standardized following the Institut Català de la Salut clinical practice guidelines. Cholesterol-lowering drugs will be withdrawn immediately after the surgical intervention to asses LDL cholesterol remission during follow-up.

After surgery, a standardized protocol will be followed for the two groups in relation to dietary recommendations and physical activity, as well as the initiation of lipid-lowering medication after the intervention, in order to avoid the bias that may arise due to an open study.

Eligibility Criteria:
Inclusion Criteria:

* Body mass index (BMI) ≥40 or BMI ≥35 kg/m2 with a significant obesity related comorbidities.
* Age 18 - 60 years.
* Previous successfully instituted and supervised but failed adequate diet and exercise program.
* Elevated LDL cholesterol defined as LDL cholesterol concentration \>130 mg/dL or treatment with cholesterol-lowering drugs.

Exclusion Criteria:

* BMI \>60 kg/m2.
* Previous BS.
* Exclusion criteria for BS:

  * Significant psychiatric disorder.
  * Severe eating disorder, active alcohol or substance abuse.
  * Contraindications for major abdominal surgery.
  * Active gastric ulcer disease.
  * Severe hepatic diseases.
  * Pregnancy or breastfeeding.
* Cases in whom SG or GB are preferred:

  * Severe symptomatic gastro esophageal reflux disease despite medication.
  * Large hiatal hernia.
  * Expected dense adhesions at the level of the small bowel.
  * Need for endoscopic follow-up of the duodenum, history of inflammatory bowel disease.
  * History of renal transplantation in which drug malabsorption can be caused with a GB.
* Cholesterol lowering drugs will be withdrawn immediately after the surgical intervention to asses LDL cholesterol remission during follow-up. Cases in whom perioperative statins withdrawn cannot be adequate will be excluded:

  * Established cardiovascular disease or subclinical cardiovascular disease (atheroma plaque detection in carotid ultrasonography exam) in which LDL cholesterol objectives are more aggressive or statins can be prescribed independently of LDL cholesterol levels.
  * LDL cholesterol \>190 mg/dL or history of familial hypercholesterolemia.