PDM: Prediabetes (2013)


Caiazzo R, Arnalsteen L, Pigeyre M, Dezfoulian G, Verkindt G, Kirkby-Bott J, Mathurin P, Fontaine P, Romon M, Pattou F. Long-term metabolic outcome and quality of life after laparoscopic adjustable gastric banding in obese patients with type 2 diabetes mellitus or impaired fasting glucose. Br J Surg. 2010; 97(6): 884-891.

PubMed ID: 20473998
Study Design:
Prospective Cohort Study
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To assess metabolic outcome and quality of life (QoL) five years after laparoscopic adjustable gastric banding (LAGB) in severely obese patients with type 2 diabetes and in patients with impaired fasting glucose (IFG) levels.

Inclusion Criteria:

LAGB between May 1997 and December 2002.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:


Consecutive patients receiving LAGB between May 1997 and December 2002.


Longitudinal cohort 

Blinding Used

Implied with measurements.


Laparoscopic adjustable gastric banding (LAGB).

Statistical Analysis

  • Data were expressed as mean values and analyzed by paired and unpaired T-tests and by the Mann-Whitney U-test as appropriate.
  • Repeated measures were compared using a one- or two-way ANOVA dedicated to repeated measures, completed by post-hoc analysis with Tukey-Kramer test when appropriate.
  • Categorical variables were compared with the ×2 test for distribution assessment and the McNemar ×2 test  for repeated-measure comparisons. 
Data Collection Summary:

Timing of Measurements

Baseline, one, three, six, 12, 24 and 60 months.

Dependent Variables

  • Weight loss, hypertension, sleep apnea, diabetes treatment, QoL assessed at baseline, one year and five years after surgery
  • Fasting and postprandial glucose and insulin, HbA1c and lipid profile at baseline, one year and five years after surgery
  • Liver steatosis: Considered severe when if affected 60% or more of the sampled hepatocytes from liver biopsy during surgery and at one- and five- year follow-up.

Independent Variables

Laparoscopic adjustable gastric banding (LAGB).  

Description of Actual Data Sample:
  • Initial N: 143 (21 males, 122 females)
    • 23 had type 2 diabetes
    • 53 had IFG
    • 67 had normal fasting glucose
  • Attrition (final N): 73 included in the analysis after five years
    • 22 with type 2 diabetes
    • 51 with IFG
  • Age: 39.9 (8.5 SD) years
  • Location: France.


Summary of Results:

Other Findings

  • Diabetes was diagnosed  5.1 years before surgery. T2DM was significantly associated with male sex (P=0.001), older age (P=0.001), more frequent hypertension (P=0.048), the metabolic syndrome (P<0.001), more severe liver steatosis (P<0.001), higher basal insulinemia (P=0.038) and lower HDL-C (P=0.005), compared with subjects with IFG
  • None of the patients with T2DM and only two of  IFG patients developed serious complication after LABG (P=0.038). The mean excess weight loss (EWL) at five years after LABG reached 45.5% in all patients. The patients with T2DM had highly significant weight loss at one year but it was slightly less so than in non-diabetic patients. T2DM patients EWL reached 41% at five years compared with 46% in non-diabetics (P = 0.417)
  • The difference in weight loss was explained in multi-variable analysis by older age (P=0.035) and lower baseline BMI (P=0.013) rather than by diabetic status (P=0.197)
  • LAGB was also associated with a significant improvement in QoL at one and five years
  • Overall need for oral anti-diabetic drugs (number of medications per patient) and exogenous insulin use decreased markedly after LAGB.  Steatosis remained necessary in 16 of 22 patients (P=0.009)
  • All biological metabolic parameters were significantly improved at five years in the diabetic patients, but the metabolic syndrome rate did not decrease. Severe steatosis as present at baseline in 14 of these patients, but persisted in three of 19 patients who had a liver biopsy at five years (P=0.003 vs. baseline)
  • Insulin sensitivity, β-cell function and  β-cell sensitivity improved at five years and also at one year for β-cell function (P=0.05 vs. baseline)
  • Of the 51 IFG patients, the sustained weight loss of 41% of excess BMI was associated with a significant improvement in HbA1c (from 6.0%±0.5% to 5.5%±0.5%, P<0.05), fasting blood glucose (from 6.1±0.6 to 5.2±1.1mmol per L, P<0.05), postprandial blood glucose (from 6.4±1.7 to 5.5±0.9mmol per L, P<0.05), triglycerides (from 1.8±0.8 to 1.0±0.4mmol per L, P<0.05), HDL cholesterol (from 0.52±0.21 to 0.57±0.17mmol per L, P<0.05) and systolic blood pressure (from 134±17 to 128±13mm Hg, P<0.05). Diastolic blood pressure values were not reported.
  • Of the 51 IFG patients, 34 (67%) achieved normal glucose regulation and two (4%) progressed towards T2DM. β-cell function was normal at baseline and remained stable. The sustained weight loss of 41% of excess BMI was associated with a significant improvement in fasting and postprandial hyperinsulinism (10.6 and 26.8mmol per L, respectively) and liver steatosis (13%)
  • Longer duration of T2DM, pre-operative insulin treatment, higher FBG, impaired β-cell function and disposition index at inclusion were significantly associated with poor long-term metabolic outcome after LAGB (HbA1c higher than 7%).
Author Conclusion:

LAGB improved metabolic outcomes and QoL in patients with grade three obesity with IFG or T2DM but rarely led to prolonged remission in long-standing diabetes.

Funding Source:
Government: French Ministry of Health, Conseil Regional Nord-Pas de Calais
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes