title: Preoperative Fasting Plasma C-Peptide Levels as Predictors of Remission of Type 2 Diabetes Mellitus after Bariatric Surgery: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  The study evaluated the predictive role of preoperative fasting C-peptide, hemoglobin (Hb)A1c, fasting plasma glucose (FPG), and body mass index (BMI) levels on diabetes remission in patients with type 2 diabetes following bariatric surgery.
  
  
  METHODS
  Medline, PubMed, Central, and Google Scholar databases of up to September 7, 2016 were searched using the following terms: type 2 diabetes mellitus, gastric bypass, Roux-en-Y, anastomosis, C-peptide, weight loss, HbA/HbA1c, predictive/predictor.
  
  
  RESULTS
  Meta-analysis of the pooled data indicated that fasting C-peptide was predictive of increased chance of remission of type 2 diabetes (pooled difference in means = 0.93, 95% confidence interval [CI] = 0.61 to 1.25, p < .001). The analysis also found that FPG (pooled standardized mean difference = -0.42, 95% CI: -0.64 to -0.20, p < .004) and HbA1c levels (pooled difference in means = -1.05, 95% CI: -1.48 to -0.62, p < .001) were associated with reduced odds of type 2 diabetes remission. BMI was not found to be associated with remission (pooled difference in means = 0.29, 95% CI: 0.30 to 0.88, p = .343). In general, subgroup analysis, which evaluated the pooled data from the retrospective and prospective studies separately, gave similar results.
  
  
  CONCLUSIONS
  Preoperative fasting plasma C-peptide was associated with increased type 2 diabetes remission after bariatric surgery, whereas baseline HbA1c and FPG levels were associated with reduced chance of remission. These parameters may be used as a guideline in weighing the risks and benefits for surgical intervention in patients with type 2 diabetes.
authors.affiliation: a Department of General Surgery , Beijing Tian Tan Hospital, Capital Medical University , 6 Tiantan Xili, Dongcheng District, Beijing , China.
authors.forename: Wenmao
authors.initials: W
authors.lastname: Yan
authors.affiliation: a Department of General Surgery , Beijing Tian Tan Hospital, Capital Medical University , 6 Tiantan Xili, Dongcheng District, Beijing , China.
authors.forename: Rixing
authors.initials: R
authors.lastname: Bai
authors.affiliation: a Department of General Surgery , Beijing Tian Tan Hospital, Capital Medical University , 6 Tiantan Xili, Dongcheng District, Beijing , China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: a Department of General Surgery , Beijing Tian Tan Hospital, Capital Medical University , 6 Tiantan Xili, Dongcheng District, Beijing , China.
authors.forename: Maomin
authors.initials: M
authors.lastname: Song
mesh_terms: D050110:Bariatric Surgery; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology* / Q000601:surgery; D005215:Fasting / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D009767:Obesity, Morbid / Q000601:surgery*; D011237:Predictive Value of Tests; D018570:Risk Assessment; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D006442:Glycated Hemoglobin
keywords: C-peptide; bariatric; diabetes; meta-analysis; remission; surgery