Effect of short term intensive multitherapy on carotid intima-media thickness in patients with newly diagnosed type 2 diabetes mellitus.

BACKGROUND: Controlling plasma glucose levels, blood pressure and lipid levels is proven to reduce the risk of vascular complications in patients with type 2 diabetes mellitus. This has prompted intensive multitherapy targeted at several macrovascular risk factors. Carotid intima-media thickness (cIMT) is a reliable measure of early atherosclerosis. We sought to determine whether a 6-month intensive mutiltherapy program resulted in better goal attainment than usual care and its effect on the development of cIMT among patients with newly diagnosed type 2 diabetes mellitus. METHODS: The study randomly assigned 220 patients with newly diagnosed type 2 diabetes mellitus to intensive or traditional therapy groups. The clinical parameters, such as fasting plasma glucose, total cholesterol, triglyceride, blood pressure, body weight and insulin were assessed at the baseline and after the 6-month therapy. cIMT of the patients was also obtained. RESULTS: The average levels of fasting plasma glucose, hemoglobin A1c, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the intensive group were significantly lower than those in the control group at the end of 6-month treatment. By 6 months, a higher proportion of patients in the intensive therapy group than in the control group attained goals for fasting plasma glucose (FPG), TC, LDL-C and hemoglobin A1c. With intensive multherapy the level of carotid intima-media thickness in the intensive therapy group was lower than that in the control group ((0.88 +/- 0.26) mm vs (0.96 +/- 0.22) mm, P < 0.01). CONCLUSIONS: The evidence from this clinical trial demonstrates that intensive glucose, lipid and blood pressure control in patients with newly diagnosed type 2 diabetes is associated with diabetic macrovascular benefits. Intensive multitherapy allows more patients to achieve aims of control and may reduce macrovascular complications and delay disease progression.

[Improvement of the function of islet beta and alpha cells by intervention against glucotoxicity: experiment with rats].

OBJECTIVE: To investigate the effects of intervention against glucotoxicity on improvement of the function and pathological changes of islet beta and alpha cells. METHODS: Thirty-six male Sprague Dawley rats were randomly divided into four equal groups: normal control (NC) group, fed with standard chow, high-fat (HF) group, fed with extra high-fat chow; diabetes mellitus (DM) control group, fed with high-fat chow for 8 weeks followed by 30 mg/kg streptozotocin injection to establish DM models; and insulin (INS) group, treated with subcutaneous injection of long-acting insulin (glargine, 0.5 U x kg(-1) x d(-1)) for 4 weeks after the establishment of DM models. 48 h, 2 weeks, and 4 weeks after the STZ injection to the 2 DM groups oral glucose tolerance test (OGTT) was performed to all rats. Peripheral blood samples were collected from the caudal vein. Serum insulin level was assayed by radioimmunoassay. Total serum cholesterol (TC) and triglyceride (TG) were measured by enzyme-colorimetric method. By the end of experiment the rats were killed with their pancreases taken out. Immunohistochemistry was used to observe the morphological changes of the islet beta and alpha cells. Beta cell and alpha cell masses were calculated by the proportions of positive area in the islet. Proinsulin mRNA level was detected by RT-PCR. Insulin protein content in islets was detected by Western blotting. RESULTS: Four weeks after the insulin intervention against glucotoxicity, the fasting blood glucose and blood glucose 2 h after sugar-taking of the INS group were both significantly lower than those of the DM group (both P < 0.01). The relative beta cell mass of the INS group was 0.38 +/- 0.08, significantly bigger, 2.45 times, that of the DM group (0.11 +/- 0.05, P < 0.01). The relative alpha cells mass in islets of the INS group was 0.16 +/- 0.04, significantly lower, by 43%, than that of the DM group (0.28 +/- 0.15, P < 0.01). The insulin contents in beta cells of the INS group was 0.58 +/- 0.03, significantly higher, by 70.6%, than that of the DM group (0.34 +/- 0.14, P < 0.01). The proinsulin mRNA level of the INS group was 1.52 +/- 0.14, significantly higher, by 20.6%, than that of the DM group. CONCLUSION: The morphology of islet beta, alpha cells in diabetic rats was improved by four weeks of Intervention against glucotoxicity improves the pathology of islet beta and alpha cells in diabetic and insulin synthesis.

Effects of timely insulin treatment on protection of beta cells in a rat model of type 2 diabetes mellitus.

BACKGROUND: Insulin treatment plays a key role in management of diabetes mellitus. Clinical researches showed that extra improvements in restoration of insulin secretion of pancreatic beta cells were found in patients with newly diagnosed type 2 diabetes. The purpose of this study was to investigate the effects of early insulin treatment on insulin mRNA expression and morphological alterations of beta cells in a Sprague Dawley (SD) rat model of type 2 diabetes. METHODS: A rat model of type 2 diabetes mellitus (T2DM) was induced by a high fat diet (high energy, HE) and low doses of streptozotoxin (STZ, 40 mg/kg). A group of diabetic rats was then injected with protamine zinc insulin [PZI, 1 - 2 U x kg(-1) x d(-1)] for one week. Insulin mRNA expression, morphological features of pancreatic islets, and metabolic parameters were examined in rats using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and other techniques. RESULTS: In insulin-treated diabetic rats, insulin mRNA levels prominently increased by 81.3% (P < 0.05), as compared with untreated diabetic rats. Moreover, timely insulin treatment noticeably improved the insulin content of beta cells, with an increase of 10.2% (P < 0.05), despite a slight reduction in fasting blood glucose (FBG), triglyceride (TG), and free fatty acid (FFA) levels, as compared to an untreated diabetic group. CONCLUSION: Insulin treatment at the onset of T2DM effectively improves insulin synthesis, as confirmed by morphological changes to beta cells in a rat model of type 2 diabetes.