Objective To evaluate the effects of saxagliptin on β cell function of type 2 diabetic patients. Methods The Cochrane Library, PubMed, EMbase, CBM, VIP, and CNKI were searched from their establishment to November, 2011, for relevant randomized controlled trials on the effects of saxagliptin on β cell function in type 2 diabetic patients. Language was limited to Chinese and English only. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and evaluated and cross-checked the methodological quality. Then meta-analysis was conducted using RevMan 5.0 software. Results Five RCTs were included. The results of meta-analysis showed that: HOMA-B was significantly increased in the saxagliptin (or saxagliptin plus routine treatment) 2.5 mg, 5 mg, and 10 mg groups (MD=8.03, 95%CI 4.57 to 11.48, Plt;0.000 01; MD=7.50, 95%CI 4.27 to 10.73, Plt;0.000 01; MD=17.45, 95%CI 13.93 to 20.97, Plt;0.000 01); HOMA-IR was similar between saxagliptin 2.5 or 10 mg group, and control group (MD= –0.05, 95%CI –0.18 to 0.08, P=0.47; MD= –0.18, 95%CI –0.60 to 0.24, P=0.4). Conclusion Current evidence shows that saxagliptin is effective in improving β cell function and insulin resistance. Due to short follow-up and small sample size, this conclusion has to be further proved by more high-quality RCTs.
目的:观察二甲双胍对慢性暴露于高糖和高游离脂肪酸的大鼠离体胰岛细胞胰岛素分泌功能的影响。方法:将大鼠离体胰岛细胞培养于5.5~16.7 mmol/L葡萄糖或5.5 mmol/L软脂酸中48 h,再加入不同浓度二甲双胍(0~5 mg/L)培养24 h。收集各组胰岛细胞,加入5.5~16.7 mmol/L葡萄糖刺激培养1 h。收集培养液,用放免法测定其基础及葡萄糖刺激的胰岛素分泌(GSIS)水平。结果:低糖组(5.5 mmol/L葡萄糖)用不同浓度二甲双胍(0~5 mg/L)处理后的β细胞基础及葡萄糖刺激的胰岛素分泌无显著性差异(Pgt;0.05);高糖(16.7 mmol/L葡萄糖)及高脂(0.5 mmol/L棕榈酸)组β细胞基础胰岛素分泌较对照组明显增高(Plt;0.01),GSIS较对照组明显降低(Plt;0.01);用2.5~5 mg/L二甲双胍干预后,高糖及高脂组β细胞基础胰岛素分泌较未治疗组明显降低(Plt;0.01),GSIS较未治疗组明显增高(Plt;0.01)。结论:低糖环境下,二甲双胍对β细胞胰岛素分泌功能无明显影响;慢性高糖及高脂可致β细胞胰岛素分泌功能受损;而2.5~5 mg/L二甲双胍能改善糖脂毒性所致β细胞胰岛素分泌功能异常。提示二甲双胍降糖效果除了其外周作用外,可能对糖脂中毒的β细胞具有直接保护作用。