title: Preoperative carbohydrate loading for elective surgery: a systematic review and meta-analysis.
abstract: OBJECTIVE
  It is unclear whether the preoperative administration of oral carbohydrates (CHO) is safe and effective, and therefore we herein evaluated the efficacy and adverse events associated with CHO for elective surgery.
  
  
  METHODS
  Comprehensive searches were conducted to identify randomized controlled trials (RCTs), which evaluated preoperative CHO for elective surgery. Two reviewers independently selected the trials, extracted data, and assessed the methodological qualities and evidence levels. The data were analyzed by the RevMan 5.0 software program.
  
  
  RESULTS
  CHO increased the insulin and glucose levels on the first day after surgery higher than those in overnight fasting group (fifteen RCTs) and i.v. glucose infusion group (three RCTs). The pooled results of thirteen RCTs showed greater declines in the insulin level at the induction of anesthesia and a smaller increase in the glucose level at the end of surgery, and fewer decreases in the postoperative insulin sensitivity index in the CHO group were observed as compared to the placebo group. No aspiration was observed in any of the included studies.
  
  
  CONCLUSIONS
  CHO appears to be safe, and may attenuate postoperative insulin resistance as compared to placebo. However, the quality of most of the published trials has been poor, and the evidence levels for most outcomes were low, so rigorous and larger RCTs are needed in the future.
authors.affiliation: Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Dong Gang West Road No. 199, Lanzhou, 730000, Gansu, China. guo19880101@163.com
authors.forename: Lun
authors.initials: L
authors.lastname: Li
authors.forename: Zehao
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiangji
authors.initials: X
authors.lastname: Ying
authors.forename: Jinhui
authors.initials: J
authors.lastname: Tian
authors.forename: Tiantian
authors.initials: T
authors.lastname: Sun
authors.forename: Kang
authors.initials: K
authors.lastname: Yi
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Zhang
authors.initials: Z
authors.lastname: Jing
authors.forename: Kehu
authors.initials: K
authors.lastname: Yang
mesh_terms: D000284:Administration, Oral; D001786:Blood Glucose / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000009:adverse effects; D017558:Elective Surgical Procedures; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007362:Intensive Care Units; D007902:Length of Stay; D011183:Postoperative Complications / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D012107:Research Design / Q000592:standards
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin