METHODS: In this 6-week, multicenter, open-label, parallel-group trial, patients with type 2 DM whose BG level was not adequately controlled with glibenclamide monotherapy (glycosylated hemoglobin [HbA1c] 8%-13%) were randomized either to replace glibenclamide with BIAsp 30 (individually titrated dosages starting with 6-8 U BID) plus rosiglitazone (4 mg once daily) (BIAsp 30 + ROS group) or to add rosiglitazone (4 mg once daily) to their pretrial doses of glibenclamide (GLIB + ROS group). Patients measured their BG levels immediately before each of the 3 main meals, 90 minutes after the start of each meal, and at bedtime, and mean BG levels were calculated at weeks 0 (baseline), 1, 2, 4, 6, and at 2-week follow-up (week 8). The primary end point was change in mean daily BG level during treatment. Secondary end points included preprandial, postprandial, and bedtime BG levels, serum fructosamine level HbA, and fasting BG level, which were measured at each study visit. Tolerability was assessed using hematologic and biochemical parameters, vital signs, and physical examination.

RESULTS: Forty-nine patients (32 men, 17 women; mean [SD] age, 59.1 [8.9] years; mean [SD] body mass index, 27.7 [3.7] kg/m2) participated in the study. A significant difference was found between treatments in the change in mean daily BG level from baseline to week 6 (P=0.01). After the 6-week treatment period, change in mean serum fructosamine level was significantly greater for BIAsp 30 + ROS compared with GLIB + ROS (P=0.02). HbA1c decreased in both treatment groups from baseline to study end, but the difference between groups was nonsignificant. The changes in fasting BG from baseline to study end also were nonsignificant between groups. Both combinations were well tolerated.

CONCLUSIONS: This short-term study in patients with type 2 DM whose BG level was poorly controlled with glibenclamide monotherapy suggests that switching to a combination of BIAsp 30 + ROS was efficacious and well tolerated and provided an alternative to adding rosiglitazone to existing glibenclamide treatment. The study also suggests that BIAsp 30 may be associated with greater improvements in short-term metabolic control.

13. Influence of treatment with acarbose or glibenclamide on insulin sensitivity in type 2 diabetic patients.

Diabetes Obes Metab. 2003 Jan;5(1):38-44. Fischer S, Patzak A, Rietzsch H, Schwanebeck U, Kohler C, Wildbrett J, Fuecker K, Temelkova-Kurktschiev T, Hanefeld M. Institute and Outpatient Department of Clinical Metabolic Research, Medical Faculty 'Carl Gustav Carus' of the Technical University Dresden, Germany.

AIM: The aim of our double-blind, placebo-controlled study was to compare the effect of acarbose and glibenclamide on the insulin sensitivity in type 2 diabetes.

METHODS: We investigated 77 patients (mean age 58.7 years, mean BMI 27.3 kg/m2), treated by diet alone for at least 4 weeks. The subjects were randomized into three treatment groups for 16 weeks: 100 mg t.i.d. acarbose (n = 25) or 1 mg t.i.d. glibenclamide (n = 27) or one t.i.d. placebo (n = 25). Before and after therapy, the levels of fasting plasma glucose, glycosylated haemoglobin, fasting insulin, plasma glucose and insulin 1 h after a standardized breakfast were measured and insulin sensitivity determined by euglycaemic hyperinsulinaemic clamp test.

RESULTS: After the treatment period, BMI in the acarbose and placebo group decreased significantly, whereas in the glibenclamide group a significant increase was observed. Fasting plasma glucose was only significant reduced under glibenclamide. The postprandial glucose decreased significantly after acarbose (13.8 vs. 11.4 mmol/l, p<0.05) and glibenclamide treatment (14.6 vs. 11.4 mmol/l, p < 0.05) and was unchanged under placebo (13.8 vs. 13.7 mmol/l). The fasting insulin levels remained unchanged in all three groups, whereas postprandial insulin values increased significantly under glibenclamide. Neither acarbose nor glibenclamide significantly changed insulin sensitivity [acarbose: glucose disposal rate before treatment 2.3 mg/kg body weight/min/insulin, after treatment 3.2; glibenclamide 2.2 vs. 2.1; placebo 2.6 vs. 3.0].

CONCLUSIONS: Our results show a more substantial improvement of glucose control under glibenclamide than under acarbose which, however, was not associated with an increase of insulin sensitivity.

14. Rosiglitazone reduces urinary albumin excretion in type II diabetes.

J Hum Hypertens. 2003 Jan;17(1):7-12.

Comment in: J Hum Hypertens. 2003 Jan;17(1):5-6. Bakris G, Viberti G, Weston WM, Heise M, Porter LE, Freed MI. Rush University, Hypertension/Clinical Research Center, Department of Preventive Medicine, Rush Presbyterian-St Luke's Medical Center, Chicago, IL 60612, USA. gbakris@rush.edu

This study examines the effect of rosiglitazone on urinary albumin excretion (UAE) in patients with type II diabetes. Urinary albumin: creatinine ratio (ACR) was measured in a 52-week, open-label, cardiac safety study comparing rosiglitazone and glyburide. Patients were randomised to treatment with rosiglitazone 4 mg b.i.d. or glyburide.

ACR was measured at baseline and after 28 and 52 weeks of treatment. Statistically significant reductions from baseline in ACR were observed in both treatment groups at week 28. By week 52, only the rosiglitazone group showed a significant reduction from baseline.

Similar results were observed for the overall study population and for the subset of patients with baseline microalbuminuria. For patients with microalbuminuria at baseline, reductions in ACR did not correlate strongly with reductions in glycosylated haemoglobin, or fasting plasma glucose, but showed strong correlation with changes in mean 24-h systolic and diastolic blood pressure for rosiglitazone-treated patients (deltaACR vs deltamean 24-h systolic blood pressure, r=0.875; deltaACR vs deltamean 24-h diastolic blood pressure, r=0.755; P<0.05 for both). No such correlation was observed for glyburide-treated patients.

In conclusion, rosiglitazone treatment was associated with a decrease in urinary albumin excretion. These findings suggest a potential beneficial effect of rosiglitazone in the treatment or prevention of renal and vascular complications of type II diabetes.

15. The effect of oral folic acid on glutathione, glycaemia and lipids in Type 2 diabetes.

Diabetes Nutr Metab. 2004 Apr;17(2):95-102.

Child DF, Hudson PR, Jones H, Davies GK, De P, Mukherjee S, Brain AM, Williams CP, Harvey JN. Department of Medicine, Gladstone Centre, Maelor Hospital, Wrexham, North Wales, United Kingdom. sharon.langford@new-tr.wales.nhs.uk

Plasma homocysteine is an established risk factor for vascular disease and precursor of the anti-oxidant glutathione. This study was designed to investigate the relationship of changes in homocysteine (Hcy) induced by oral folate to glutathione and measures of glycaemia and lipid metabolism in Type 2 diabetes (T2DM).

Twenty-seven patients (26 male, 1 female, aged 48-68 years) with T2DM and microalbuminuria were treated with folic acid 10 mg daily for 3 months. During the study, diastolic blood pressure (p=0.04), HbA1c (p=0.04), serum triglycerides (p=0.04) and serum total/HDL-cholesterol ratio (p=0.004) all increased and serum HDL-cholesterol fell (p=0.006).

The increased red cell folate correlated with a reduction in microalbuminuria (p=0.001). Overall, plasma glutathione increased (p=0.016) despite reduction in its precursor Hcy (p<0.001). Change in glutathione correlated inversely with change in HbA1c (p<0.02), total cholesterol (p=0.003) and triglycerides (p<0.02) and positively with HDL-cholesterol (p=0.033). Increase in glutathione correlated with levels of vitamin B6 (p<0.05). Metformin treatment protected against the rise in blood pressure (BP) (p=0.02), independently of changes in plasma glutathione.

In summary, oral folic acid supplementation in T2DM reduced plasma Hcy and increased glutathione levels. HbA1c, triglycerides and HDL-cholesterol deteriorated during the trial: their levels correlated inversely with changes in glutathione. The increase in glutathione may depend on an adequate supply of B6, as changes in glutathione correlated with vitamin B6 levels. Reduced Hcy and increased glutathione may both mediate improvement in vascular function and outcome. Some aspects of the response to folate may be different in patients on metformin.

16. Serum homocysteine levels are increased in women with gestational diabetes mellitus.