title: Effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetic rats on different diets.
abstract: BACKGROUND
  The aim of the study was to investigate the effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetes after different diets.
  
  
  METHODS
  Seventy Male Sprague Dawley rats were fed with a high fat diet followed by streptozotocin treatment to induce type 2 diabetes. Then all rats were randomly divided into a control group, a metformin group (200 mg/kg), and a sitagliptin group (10 mg/kg). Each group was further divided into 4 groups receiving one load of high carbohydrate diet (45% glucose, 4.5 ml/kg), high fat diet (20% lipid emulsion, 4.5 ml/kg), high protein diet (20% whey protein, 10 ml/kg) or mixed meal, respectively. The caloric densities were all 33 kJ/kg. Postprandial blood glucose (P2BG), triglyceride (TG), glucagon-like peptide-1 (GLP-1), glucagon and insulin levels were measured.
  
  
  RESULTS
  In the high carbohydrate group, sitagliptin was more efficient in lowering P2BG compared with metformin (p < 0.05). In the high-fat group, metformin was more powerful in lowering TG (p < 0.05) and P2BG (p < 0.05) levels because of its improvement of insulin sensitivity. In the high protein diet group, metformin did not reduce the P2BG level (p > 0.05), although it did reduce the TG level (p < 0.05). In the mixed diet group, metformin was more efficient in lowering P2BG (p < 0.05) but had a similar effect on TG (p > 0.05) compared with sitagliptin.
  
  
  CONCLUSIONS
  In the type 2 diabetic model, metformin and sitagliptin have different effects on glycolipid metabolism after different diets. If it is proved in type 2 diabetic patients, then different medicines may be recommended according to different diets in order to improve glycolipid metabolism.
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Juhong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Tu
authors.initials: T
authors.lastname: Ba
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Shan
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Miaoyan
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Huizhu
authors.initials: H
authors.lastname: Ren
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Jingli
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Yang
authors.affiliation: Key Laboratory of Hormone and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Disease, Tianjin Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.
authors.forename: Baocheng
authors.initials: B
authors.lastname: Chang
keywords: diet intervention; glycolipid metabolism; metformin; sitagliptin; type 2 diabetes