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NJ BCBS Announces Bariatric Surgery Coverage in Patients with Diabetes and Body Mass Index Less than 35

Background

Bariatric surgery is an established treatment for morbid obesity in patients with a body mass index (BMI) equal to or greater than 40 kg/m2, or BMI equal to or greater than 35 in the presence of weight-related comorbidities.   Some experts have recommended broadening of the eligibility criteria for bariatric surgery, in order to reach more patients who might benefit.  The population of patients with nonmorbid obesity (i.e., BMI 30-35 kg/m2) represents a very large number of patients with a high overall burden of weight-related comorbidities.

There is particular interest in bariatric surgery as a treatment for diabetes, given the high remission rates reported for morbidly obese patients with diabetes following bariatric surgery.  Remission of diabetes is likely mediated both through weight loss and through metabolic changes induced by intestinal bypass or gastric resection.  Purely restrictive procedures such as laparoscopic adjustable gastric banding (LAGB) may result in lower rates of diabetes remission compared to procedures such as gastric bypass that include gastric resection and intestinal bypass.

Objective 

The overall objective of this Assessment is to determine whether bariatric surgery improves outcomes for diabetic patients with BMI less than 35 kg/m2.  A second objective is to determine the comparative efficacy of different bariatric surgery procedures in this population of patients.

Search Methods:  A literature search was performed through MEDLINE® (via PubMed) for the period of January 2008 through May 2012 using the search terms “bariatric” “LAGB,” “lap-band,” “gastric banding” and “diabetes.”  These terms were cross-referenced with the terms “obesity,” “obese,” and “overweight.”  Electronic search was supplemented with a hand search of relevant bibliographies and the “related articles” search of selected citations in PubMed.

Selection Criteria

Studies were selected that used bariatric surgery to treat diabetic patients with BMI less than 35 kg/m2:  1) randomized, controlled trials or observational studies comparing bariatric surgery to nonsurgical treatment or to another bariatric procedure; 2) cohort studies or case series that enrolled at least 12 patients receiving a particular procedure; and 3) reported on one or more relevant outcomes related to the remission or change in severity of diabetes.

Main Results

There were no randomized trials comparing bariatric surgery to medical treatment for diabetic subjects with BMI less than 35 kg/m2.  There was only one randomized trial comparing 2 bariatric procedures.  Therefore, studies were categorized by procedure type and presented as case series, regardless of the underlying study type.

Nine studies reported diabetes remission rates and other outcomes in subjects undergoing gastric bypass.  Diabetes remission rates varied between 48% and 100% at follow-up times of 1 year and beyond.  One of the studies was a randomized clinical trial of gastric bypass versus sleeve gastrectomy; in this study, diabetes remission associated with gastric bypass was 93% versus 47% for sleeve gastrectomy at 1 year.

Two studies reported outcomes of sleeve gastrectomy.  The diabetes remission rates were 55% and 47% at 1 year.

One study was selected that reported outcomes of ileal interposition. The diabetes remission rate at a mean follow-up time of 39.1 months was 78.3%.

Two studies reported outcomes of gastric banding.  The outcomes reported in this study were not considered to be rigorous, as the only measure of diabetes outcome was withdrawal of diabetes medication.  The reported remission rates were 27.5% and 50% at variable follow-up times.

One study of biliopancreatic diversion reported a remission rate of 67% for subjects with BMI between 30 and 35, and 27% for subjects with BMI between 25 and 30 kg/mat 12 months’ follow-up.

One study reported outcomes of duodenal-jejunal exclusion.  The subjects in this study had more severe diabetes than the subjects enrolled in other studies; 100% were on insulin treatment and the duration of diabetes was between 5 and 15 years.  The diabetes remission rate was 17% at 6 months.

Author’s Conclusions and Comments

Except for gastric bypass, there is insufficient evidence to come to firm conclusions regarding the efficacy of bariatric procedures for diabetes in patients with BMI less than 35 kg/m2.  Despite the variation in remission rates between 9 case series, a large proportion of subjects in each study obtain remission of diabetes without medications.  Given the natural history of diabetes, it is very difficult to achieve a remission of diabetes with lifestyle and dietary changes.  With medication, it is difficult to achieve a level of diabetes control that is otherwise the equivalent of remission in terms of achieved HbA1c levels, lipid levels, and glucose levels.  Although the long-term outcomes of gastric bypass in terms of occurrence of complications of diabetes has not been directly observed, knowledge of long-term outcomes of gastric bypass in the morbidly obese make it likely that the improvement of diabetes status is durable and patients’ health outcomes will improve.  Gastric bypass is a well-established procedure for the morbidly obese, in whom the risk/benefit profile has been deemed acceptable for appropriately selected morbidly obese subjects.  The risk/benefit profile for diabetic subjects is likely to be similar.

Based on the available evidence, the Blue Cross and Blue Shield Association Medical Advisory Panel made the following judgments about whether bariatric surgery or which specific bariatric procedures as a treatment for diabetes in subjects with BMI less than 35 kg/m2 meet the Blue Cross and Blue Shield Association Technology Evaluation Center (TEC) criteria:

1.    The technology must have final approval from the appropriate governmental regulatory bodies.

Surgical procedures are not subject to U.S. Food and Drug Administration (FDA) approval, although devices used as part of the surgical procedure may be.  Procedures such as gastric bypass, or sleeve gastrectomy, are not subject to FDA approval.  Some bariatric surgery procedures involve placement of a device, such as laparoscopic adjustable gastric banding (LAGB) or duodenal sleeve, and these devices require FDA approval.

LAGB has been FDA approved since 2001 for patients with a BMI greater than 40 kg/m2, or a BMI of equal to or greater than 35-40 kg/m2 in the presence of weight-related comorbidities.  In February 2011, the FDA granted approval for LAGB in patients with a BMI of 30-35 kg/m2 in the presence of at least one weight-related comorbidity.  The FDA labeling indicates that this procedure should be reserved for patients who have been unsuccessful in achieving weight loss by nonsurgical methods and for patients who are at the highest risk for weight-related complications.

2.    The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes.

There is adequate evidence only for the gastric bypass procedure.  Nine studies of gastric bypass report outcomes of diabetic subjects in this BMI category, either as single case series, arms of a randomized trial, or observational comparison to nonsurgical treatment.  There is insufficient evidence for the other procedures—sleeve gastrectomy, ileal interposition, laparoscopic gastric banding, biliopancreatic diversion, and duodenal-jejunal exclusion.  The number of studies and rigor of those studies are insufficient to make conclusions.

3.    The technology must improve the net health outcome; and

4.    The technology must be as beneficial as any established alternatives.

In the 9 studies evaluating gastric bypass as a treatment for diabetes, the diabetes remission rate at approximately 1 year after surgery varied between 48 and 100%.  Differences between studies are likely to due to differences in patient selection and criteria for diabetes remission.  Most of the studies used a rigorous definition of diabetes remission, which included withdrawal of diabetic medications in addition to meeting a threshold level for HbA1c.  There were also large average declines in low-density lipoprotein (LDL) levels and triglyceride levels.  Although direct benefit of this improved diabetic status in such subjects in terms of the long-term outcomes of diabetes has not been observed, it is likely that this magnitude of improvement translates to a reduction in complications of diabetes.

Whether the use of sleeve gastrectomy, ileal interposition, gastric banding, biliopancreatic diversion, or duodenal-jejunal exclusion for the treatment of type 2 diabetes in patients with a body mass index less than 35 kg/m2improves the net health outcome or is as beneficial as other procedures has not been demonstrated.

5.    The improvement must be attainable outside the investigational settings.

Gastric bypass is an established treatment for obesity among morbidly obese subjects for the indication of weight loss.  Performing gastric bypass for this indication does not involve any particular additional expertise.

Whether the use of sleeve gastrectomy, ileal interposition, gastric banding, biliopancreatic diversion, or duodenal-jejunal exclusion for the treatment of type 2 diabetes in patients with a body mass index less than 35 kg/m2 improves the net health outcome in the investigational setting has not been demonstrated.

Therefore, gastric bypass for the treatment of type 2 diabetes in patients with a body mass index less than 35 kg/mmeets the TEC criteria.  The use of sleeve gastrectomy, ileal interposition, gastric banding, biliopancreatic diversion, or duodenal-jejunal exclusion for the treatment of type 2 diabetes in patients with a body mass index less than 35 kg/mdoes not meet the TEC criteria.