Long-term effects of pioglitazone and metformin on insulin sensitivity in patients with Type 2 diabetes mellitus.

AIM: Despite their comparable glycaemic effects in patients with Type 2 diabetes mellitus (T2DM), pioglitazone and metformin may have different effects on insulin sensitivity because they have different mechanisms of action. We studied the changes in insulin sensitivity, as assessed by the Quantitative Insulin Sensitivity Check Index (QUICKI), in patients with T2DM who used metformin or pioglitazone as monotherapy or in combination therapy with sulphonylurea. METHODS: Data in this report are from two multicentre, randomized, double-blind, double-dummy studies conducted in Europe (monotherapy) or in Europe and Canada (combination therapy study). Patients were randomized to 52 weeks of treatment consisting of a 12-week forced titration period and a 40-week maintenance period. HbA(1c), fasting plasma glucose (FPG) and fasting serum insulin (FSI) were quantified from a single blood sample at weeks 0, 8, 16, 24, 32, 42 and 52. Insulin sensitivity was assessed with QUICKI, which is calculated from FSI and fasting blood glucose (FBG) concentrations using the formula 1/(log(10) FSI + log(10) FBG). Time course effects of the treatments were compared by repeated measures analysis of covariance. RESULTS: As monotherapy, pioglitazone and metformin increased QUICKI compared with baseline (baseline vs. end point [mean +/- sem]; pioglitazone [0.303 +/- 0.001 vs. 0.321 +/- 0.001; P < 0.001] and metformin [0.304 +/- 0.001 vs. 0.315 +/- 0.001; P < 0.001]). Pioglitazone increased insulin sensitivity more than metformin from week 4 through week 52. There were significant increases in QUICKI from baseline in both combination therapy groups (baseline vs. end point; pioglitazone + sulphonylurea [0.305 +/- 0.001 vs. 0.319 +/- 0.001; P < 0.001] and metformin + sulphonylurea [0.306 +/- 0.001 vs. 0.317 +/- 0.001; P < 0.001]). Overall, pioglitazone + sulphonylurea significantly increased insulin sensitivity more than metformin + sulphonylurea. CONCLUSION: Pioglitazone differed from metformin in its effects on insulin sensitivity despite both drugs having comparable glycaemic effects.     

Management of newly diagnosed non-insulin-dependent (type 2) diabetes mellitus: a retrospective audit

A retrospective survey of the case records of 130 patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM) was performed to assess the effect of 1 year of clinical attendance on blood glucose control, body weight, lipid profile and blood pressure. The mean age of these patients was 63 +/- (SE) 0.1 years and 45% were 65 years or older. Body mass index (BMI) was 28.3 +/- 0.49 kg m-2 and 72% were overweight or obese. Sixty-seven percent of the patients were hypertensive (WHO criteria). Serum cholesterol was 6.0 +/- 0.2 mmol/l, HDL cholesterol 1.0 +/- 0.0 mmol/l and triglycerides 3.14 +/- 0.29 mmol/l (non-fasting). Seventy-two percent of the patients were managed on diet alone and 23% by diet plus sulphonylurea. The remaining 5% were treated by metformin or a combination of metformin plus sulphonylurea. After one year, glycated haemoglobin (HbA1) decreased from 10.7 +/- 0.3% to 8.2 +/- 0.2% (P less than 0.01; normal less than 7.5%). The sulphonylurea groups showed similar decreases in HbA1. Overall there was a small but significant fall in BMI (-0.5 +/- 0.2 kg m-2; P less than 0.05). However, the diet treated patients showed a significant decrease in BMI (-0.8 +/- 0.3 kg m-2; P less than 0.01) whilst BMI increased in the sulphonylurea treated group (+0.7 +/- 0.2 kg m-2; P less than 0.01). Serum lipid concentrations remained unchanged in both groups. The proportion of patients with hypertension remained the same. Hence after one year of clinical attendance, HbA1 improved but there was minimal change in the associated cardiovascular risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rosiglitazone RECORD study: glucose control outcomes at 18 months.

AIMS: To compare glucose control over 18 months between rosiglitazone oral combination therapy and combination metformin and sulphonylurea in people with Type 2 diabetes. METHODS: RECORD, a multicentre, parallel-group study of cardiovascular outcomes, enrolled people with an HbA(1c) of 7.1-9.0% on maximum doses of metformin or sulphonylurea. If on metformin they were randomized to add-on rosiglitazone or sulphonylurea (open label) and if on sulphonylurea to rosiglitazone or metformin. HbA(1c) was managed to < or = 7.0% by dose titration. A prospectively defined analysis of glycaemic control on the first 1122 participants is reported here, with a primary outcome assessed against a non-inferiority margin for HbA(1c) of 0.4%. RESULTS: At 18 months, HbA(1c) reduction on background metformin was similar with rosiglitazone and sulphonylurea [difference 0.07 (95% CI -0.09, 0.23)%], as was the change when rosiglitazone or metformin was added to sulphonylurea [0.06 (-0.09, 0.20)%]. At 6 months, the effect on HbA(1c) was greater with add-on sulphonylurea, but was similar whether sulphonylurea was added to rosiglitazone or metformin. Differences in fasting plasma glucose were not statistically significant at 18 months [rosiglitazone vs. sulphonylurea -0.36 (-0.74, 0.02) mmol/l, rosiglitazone vs. metformin -0.34 (-0.73, 0.05) mmol/l]. Increased homeostasis model assessment insulin sensitivity and reduced C-reactive protein were greater with rosiglitazone than metformin or sulphonylurea (all P < or = 0.001). Body weight was significantly increased with rosiglitazone compared with sulphonylurea [difference 1.2 (0.4, 2.0) kg, P = 0.003] and metformin [difference 4.3 (3.6, 5.1) kg, P < 0.001]. CONCLUSIONS: In people with diabetes, rosiglitazone in combination with metformin or sulphonylurea was demonstrated to be non-inferior to the standard combination of metformin + sulphonylurea in lowering HbA(1c) over 18 months, and produces greater improvements in C-reactive protein and basal insulin sensitivity but is also associated with greater weight gain.     

The contribution of metformin to glycaemic control in patients with Type 2 diabetes mellitus receiving combination therapy with insulin

Combination therapy of oral hypoglycaemic agents and insulin is a therapeutic option for those who have deterioration in glycaemic control. We examined the contribution of metformin by withdrawing it from Type 2 diabetic patients who had been stabilised on combination therapy. Fifty-one subjects with Type 2 diabetes and secondary oral hypoglycaemic agent failure were studied in a randomised, open and parallel study. In the first phase of 36 weeks, subjects were stabilised on combined therapy of sulphonylureas and nocturnal insulin, with or without metformin. During the second phase, metformin was withdrawn. The primary variables for efficacy were HbA(1c), fasting plasma glucose and 3-point capillary blood glucose profiles. After stabilisation with combination therapy, those subjects on metformin used less insulin to maintain glycaemic control (13.7+/-6.8 vs. 23.0+/-9.4 U/day, P=0.001) and had lower HbA(1c) values (8.13+/-0.89 vs. 9.05+/-1.30%, P=0.003) compared with those not given metformin. Withdrawal of metformin therapy caused deterioration in HbA(1c) (P=0.001). This study confirms that metformin plays an important role in the success of the combination therapy. The rational use of metformin and sulphonylurea together with insulin will help to improve metabolic control in Type 2 diabetes patients who have secondary drug failure.     

Comparison of pioglitazone and metformin efficacy using homeostasis model assessment.

AIMS: To compare clinical efficacy of two different insulin sensitizers, pioglitazone and metformin, and to reveal factors that influence the clinical efficacy. METHODS: Seventy-eight Japanese subjects with Type 2 diabetes mellitus poorly controlled with sulphonylureas [38 men and 40 women, aged 57 +/- 9 years, body mass index 25.2 +/- 1.4 kg/m2, and HbA1c 8.3 +/- 0.6% (means +/- SD)] were randomly assigned to groups for the addition of either pioglitazone or metformin and followed up for 4 months. A decrease in HbA1c levels was compared with baseline factors including homeostasis model assessment of insulin sensitivity (HOMA-R) and beta-cell function (HOMA-beta) with 71 subjects who completed the study. RESULTS: The overall decrease in HbA1c levels was similar for the pioglitazone (-1.2 +/- 0.2%) and metformin (-1.3 +/- 0.1%) groups. In the pioglitazone group, the decrease in HbA1c levels was negatively correlated with baseline HOMA-R (r=-0.698, P<0.0001) and HOMA-beta (r=-0.680, P<0.0001). In contrast, the decrease was positively correlated with baseline HOMA-beta (r=0.556, P=0.0004) in the metformin group. Multivariate analysis revealed that either HOMA-R or HOMA-beta was a main determinant of the decrease in HbA1c levels in the pioglitazone group. In the metformin group, baseline levels of fasting glucose were also included as an independent determinant in addition to HOMA-beta. The subjects with greater HOMA-R (> or =4.0) or HOMA-beta (> or =40%) displayed better response to pioglitazone than to metformin, and vice versa. CONCLUSIONS: In Type 2 diabetic subjects poorly controlled with sulphonylureas, addition of pioglitazone or metformin resulted in a comparable reduction in HbA1c levels. Subjects with greater insulin resistance or preserved beta-cell function displayed better response to pioglitazone, whereas subjects with reduced beta-cell function displayed better response to metformin.     

Comparison of basal and prandial insulin therapy in patients with secondary failure of sulphonylurea therapy.

A group of 35 normal weight patients with secondary failure of sulphonylurea therapy (fasting plasma glucose greater than 8.0 mmol l-1 on maximal dose of sulphonylurea) were randomly assigned to receive either a single injection of a basal insulin supplement (human ultralente insulin, n = 16) or three or four injections of a preprandial insulin supplement (human unmodified insulin, n = 19). Patients performed self-monitoring of capillary blood glucose and adjusted their insulin doses in an effort to achieve fasting and preprandial capillary glucose concentrations of less than 7.0 mmol l-1. Blood glucose control after 16 weeks of insulin therapy was improved to a similar extent by both regimens (HbA1 basal insulin group 12.5 +/- 1.2 (+/- SD) falling to 10.7 +/- 2.2%; preprandial group 12.0 +/- 1.6 falling to 9.5 +/- 1.6%). Preprandial insulin gave better control of daytime blood glucose levels but fasting plasma glucose did not differ between the two regimens (basal group 10.6 +/- 3.6, preprandial group 11.1 +/- 3.6 mmol l-1). Insulin dose was greater in the preprandial group (44.1 +/- 17.9 U day-1) than in the basal group (26.7 +/- 12.5 U day-1 (p less than 0.005), but there was no difference in the frequency or severity of hypoglycaemia between the two treatments. Only the preprandial therapy group showed significant weight gain (2.7 +/- 3.0 kg). While both regimens led to improvement of blood glucose control, these results suggest that neither basal nor preprandial insulin alone can achieve ideal blood glucose control through 24 h in patients with fairly severe failure of control on sulphonylurea therapy.     

Effects of metformin on glucose, insulin and lipid metabolism in patients with mild hypertriglyceridaemia and non-insulin dependent diabetes by glucose tolerance test criteria.

The effect of metformin treatment was studied in nine patients with mild (fasting plasma glucose concentration less than 7.5 mmol.l-1) non-insulin-dependent diabetes mellitus (NIDDM) and fasting plasma triglyceride (TG) concentration greater than 2.0 mmol.l-1. Individuals were studied before and three months after receiving 2.5 g/day of metformin. Mean hourly plasma glucose concentration from 8 AM to 4 PM (7.5 +/- 0.5 vs 6.5 +/- 0.4 mmol.l-1, p less than 0.001), as well as glycosylated hemoglobin levels (7.0 +/- 0.5 vs 6.2 +/- 0.2%, p less than 0.02) were significantly lower following metformin treatment. The improvement in glycaemic control was not associated with an improvement in insulin stimulated glucose disposal as measured by the glucose clamp technique. Mean hourly day-long concentrations of plasma insulin (519 +/- 81 vs 364 +/- 64 pmol.l-1, p less than 0.001), FFA (502 +/- 45 vs 460 +/- 35 mu mol.l-1, p less than 0.01), and triglyceride (3.60 +/- 0.33 vs 3.02 +/- 0.31 mmol.l-1, p less than 0.001) concentrations were significantly lower following three months of metformin treatment. Finally, fasting plasma TG concentration, very low density lipoprotein (VLDL)-TG, and VLDL-cholesterol concentrations were significantly decreased, while high density lipoprotein (HDL)-cholesterol concentration was significantly increased following metformin therapy. Thus, metformin administration to individuals with NIDDM, who did not have significant fasting hyperglycaemia, led to a decrease in plasma glucose, insulin, FFA, and TG concentration, and an increase in plasma HDL-cholesterol concentration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metformin as additional therapy in adolescents with poorly controlled type 1 diabetes: randomised placebo-controlled trial with aspects on insulin sensitivity

OBJECTIVE: Metabolic control often deteriorates during puberty in children with type 1 diabetes. The aim of the present study was to investigate whether addition of metformin for 3 Months improves metabolic control and insulin sensitivity. DESIGN: Twenty-six of 30 randomised adolescents with type 1 diabetes (18 females, eight males) completed a double-blind placebo-controlled trial. Their mean age was 16.9+/-1.6 (s.d.) Years, mean glycated haemoglobin (HbA(1c)) 9.5+/-1.1% and daily insulin dosage 1.2+/-0.3 U/kg. The participants were randomised to receive oral metformin or placebo for 3 Months. HbA(1c) was measured Monthly, and peripheral insulin sensitivity was assessed by a euglycaemic hyperinsulinaemic clamp at baseline and at the end of the study. RESULTS: HbA(1c) decreased significantly in the group treated with metformin, from 9.6 to 8.7% (P<0.05), but was unchanged in the placebo group (9.5 vs 9.2%). Peripheral glucose uptake divided by mean plasma insulin concentration was increased in the metformin group (P<0.05) but not in the placebo group. Initial insulin sensitivity was inversely correlated to changes in HbA(1c) (r=-0.62; P<0.05) and positively correlated to changes in insulin sensitivity (r=0.77; P<0.01). CONCLUSIONS: In this double-blind placebo-controlled study we found that metformin improves metabolic control in adolescents with type 1 diabetes. The effect seems to be associated with an increased insulin-induced glucose uptake.     

Improvement in C-reactive protein and advanced glycosylation end-products in poorly controlled diabetics is independent of glucose control

We studied the efficacy of four different treatment regimens (sulphonylurea and metformin+/-acarbose versus glimepiride and rosiglitazone versus glimepiride and bedtime NPH insulin versus multiple actrapid and NPH insulin injections) in poorly controlled type 2 diabetes subjects on hs-CRP, VCAM-1 and AGE at 4, 8 and 12 weeks of treatment. Multiple insulin injections rapidly improved HbA(1c) by 0.6+/-0.9% (p<0.005), 1.2+/-1.3% (p<0.0005) and 1.3+/-1.4% (p<0.0005) at week 4, at week 8 and week 12, respectively. Subjects who continued their existing combination treatment of sulphonylurea, metformin+/-acarbose also showed a significant reduction in HbA(1c) (p<0.05). Although effective in reducing glycemic parameters, there was no reduction in CRP levels in either treatment group. The treatment regimen consisting of rosiglitazone and glimepiride significantly lowered hs-CRP by -2.6 (3.9) mg/L (p<0.05) at week 12 in spite of no improvement in blood glucose. AGE improved in all groups irrespective of type of treatment, glycaemic control and CRP levels. Our data indicate rapid glycaemic control alone does not necessarily result in improvement in markers of inflammation in type 2 diabetes patients.     

Effect of metformin treatment on multiple cardiovascular disease risk factors in patients with type 2 diabetes mellitus

In light of the conflicting results of the recent United Kingdom Prospective Study (UKPDS), where diabetic patients on metformin monotherapy had lower all-cause mortality and the addition of metformin in sulfonylurea-treated patients was associated with an increased risk of diabetes-related death, we sought to compare the effects on cardiovascular disease (CVD) risk factors of metformin monotherapy with metformin treatment when added to a sulfonylurea compound in patients with type 2 diabetes. Thirty-one volunteers with type 2 diabetes mellitus, 16 on dietary therapy and 15 on sulfonylurea monotherapy (SU), were treated with metformin for 12 weeks. Measurements were made of (1) fasting plasma glucose, hemoglobin A(1c) (HbA(1c)), lipid, remnant lipoprotein cholesterol (RLP-C) levels, and low-density lipoprotein (LDL) particle size; (2) daylong plasma glucose, insulin, free fatty acid (FFA), triglyceride (TG), and RLP-C concentrations; and (3) fasting levels of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and soluble E-selectin (sE-selectin). Fasting plasma glucose concentrations decreased to a similar degree after treatment with metformin in both the metformin monotherapy group (12.45 +/- 0.48 v 9.46 +/- 0.47 mmol/L, P <.001) and the combined SU and metformin therapy group (14.09 +/- 0.51 v 10.57 +/- 0.85 mmol/L, P =.001). Fasting plasma lipid concentrations and LDL particle size did not significantly change in either treatment group, whereas fasting RLP-C concentrations were significantly lower in the metformin monotherapy group (0.43 +/- 0.09 v 0.34 +/- 0.07 mmol/L, P =.02). Daylong concentrations of plasma glucose, FFA, TG, and RLP-C were lower to a similar degree in both treatment groups, whereas daylong plasma insulin concentrations were unchanged. Fasting plasma sVCAM-1 levels were significantly lower in both the metformin monotherapy group (484 +/- 19 v 446 +/- 18 ng/mL, P =.02) and the combined SU and metformin therapy group (496 +/- 29 v 456 +/- 31 ng/mL, P =.05), whereas fasting plasma sICAM-1 and sE-selectin levels were essentially unchanged. Administration of metformin, either as monotherapy or in combination with a sulfonylurea drug, improved glycemic control and led to a decrease in several CVD risk factors in patients with type 2 diabetes.     

Improved glycaemic control by addition of glimepiride to metformin monotherapy in type 2 diabetic patients.

AIM: To compare the effect of glimepiride in combination with metformin with monotherapy of each drug on glycaemic control in Type 2 diabetic patients. DESIGN AND METHODS: Randomized, double-blind, double-dummy, parallel-group multicentre study conducted in France. Type 2 diabetic patients aged 35-70 years inadequately controlled by metformin monotherapy 2550 mg daily for at least 4 weeks were randomized to either metformin, glimepiride or metformin and glimepiride. RESULTS: Three hundred and seventy-two patients aged 56 +/- 8 years were treated for 5 months. Combination treatment was significantly more efficient in controlling HbA1c (% change + 0.07 +/- 1.20 for metformin, + 0.27 +/- 1.10 for glimepiride, -0.74 +/- 0.96 for combination treatment, P < 0.001), fasting blood glucose (FBG) (mmol/l change + 0.8 +/- 0.4 for metformin, + 0.7 +/- 3.1 for glimepiride and -1.8 +/- 2.2 for combination treatment, P < 0.001) and post-prandial blood glucose (PPBG) (mmol/l change + 1.1 +/- 5.9 for metformin, + 0.1 +/- 5.1 for glimepiride and -2.6 +/- 3.9 for combination treatment, P < 0.001) than either glimepiride or metformin alone. There was no significant difference between metformin or glimepiride monotherapy with respect to the change in HbA1c or FBG; however, glimepiride was significantly more effective than metformin in reducing PPBG. The incidence of symptomatic hypoglycaemia was higher in the combination group than in either monotherapy group (P = 0.039). CONCLUSIONS: Addition of glimepiride to metformin in Type 2 diabetic patients inadequately controlled by metformin alone resulted in superior glycaemic control compared with glimepiride or metformin monotherapy.     

Combination therapy for type 2 diabetes: repaglinide plus rosiglitazone.

AIMS: This 24-week, randomized, multicentre, open-label, parallel-group clinical trial compared efficacy and safety of repaglinide monotherapy, rosiglitazone monotherapy, and combination therapy (repaglinide plus rosiglitazone) in Type 2 diabetes after unsatisfactory response to sulphonylurea or metformin monotherapy. METHODS: Enrolled patients (n = 252) were adults having Type 2 diabetes for at least 1 year, with HbA(1c) values > 7.0% after previous monotherapy (sulphonylurea or metformin, >/= 50% maximal dose). Prior therapy was withdrawn for 2 weeks, followed by randomization to repaglinide, rosiglitazone, or repaglinide/rosiglitazone. Study treatments were initiated with a 12-week dose optimization period (doses optimized according to labelling), followed by a 12-week maintenance period. Efficacy endpoints were changes in HbA(1c) values (primary) or fasting plasma glucose values (secondary). RESULTS: Baseline HbA(1c) values were comparable (9.3% for repaglinide, 9.0% for rosiglitazone, 9.1% for combination). Mean changes in HbA(1c) values at the end of treatment were greater for repaglinide/rosiglitazone therapy (-1.43%) than for repaglinide (-0.17%) or rosiglitazone (-0.56%) monotherapy. Reductions of fasting plasma glucose values were also greater for combination therapy (-5.2 mmol/l, -94 mg/dl) than for repaglinide monotherapy (-3.0 mmol/l, -54 mg/dl) or rosiglitazone monotherapy (-3.7 mmol/l, -67 mg/dl). Minor hypoglycaemic events occurred in 9% of combination therapy patients, vs. 6% for repaglinide and 2% for rosiglitazone. Individual weight gains for combination therapy were correlated to HbA(1c) response. CONCLUSIONS: The combination therapy regimen was well tolerated. In patients previously showing unsatisfactory response to oral monotherapy, glycaemic reductions were greater for the repaglinide/rosiglitazone combination regimen than for use of either repaglinide or rosiglitazone alone.     

Addition of rosiglitazone to glimepirid and metformin combination therapy in type 2 diabetes

The study was planned to determine the efficacy and safety of adding rosiglitazone to a combination of glimepiride and metformin therapy with insufficiently controlled type 2 diabetes. This was an open-label study with a follow-up period of 26 weeks. Thirty patients were taking 3 mg glimepiride two times and 850 mg metformin two times per day. Patients were told to take one rosiglitazone 4 mg tablet before breakfast additionally. The primary efficacy measure was the mean change in HbA1c from baseline to the end of the study. Secondary efficacy parameters included the mean changes from baseline to the end of the study in fasting plasma glucose (FPG) and insulin levels, as well as total cholesterol, HDL-C, LDL-C, triglycerides, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Mean HbA1c levels decreased significantly from 7.54 +/- 0.9% to 6.57 +/- 0.7% (p < 0.001) at 26th week. FPG levels fell from 169.39 +/- 37.8 mg/dl to 135.69 +/- 28.0 mg/dl (p < 0.001), respectively. Insulin levels decreased from 19.60 +/- 9.8 U/L to 14.66 +/- 11.6 U/L (p = 0.026) at 26th week. No one experienced elevations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels greater than 2.5 times the upper limit of the reference range. This study confirms that the addition of rosiglitazone (4 mg/day) to sulphonylurea and metformin treatment for patients with type 2 diabetes improves glycemic control, is safe, and generally well tolerated.     

The effect of metformin on glycaemic control, intermediary metabolism and blood pressure in non-insulin-dependent diabetes mellitus

Fourteen non-insulin-dependent diabetics (9 female, 5 male), aged 46 to 64 years, uncontrolled by diet (fasting plasma glucose greater than or equal to 8 mmol/l), were treated with metformin, 1-3 g daily, and followed prospectively at 1 week, then at 2-weekly intervals for 6 months. The fasting plasma glucose fell significantly (p less than 0.01) after 1 week of therapy and HbA1 showed a significant reduction, 13.4 +/- 2.5% (mean +/- SD) to 10.7 +/- 1.8% (normal range 5.1-9.3%) at 8 weeks (p less than 0.001). There was no significant change in body weight, plasma insulin, serum cholesterol or triglycerides, blood lactate, pyruvate, glycerol, alanine, 3-hydroxybutyrate or acetoacetate concentration. Systolic, diastolic, and mean arterial blood pressures, along with resting heart rate remained unchanged. This study shows that metformin effectively lowers plasma glucose without hyperinsulinism or significant rise in fasting blood lactate and other gluconeogenic precursors.     

Comparison of insulin lispro mixture 25/75 with insulin glargine during a 24-h standardized test-meal period in patients with Type 2 diabetes.

AIM: To compare insulin lispro mixture (25% insulin lispro and 75% NPL; Mix 25/75) twice-daily plus oral glucose-lowering medications (metformin and/or sulphonylurea) with once-daily insulin glargine plus oral agents with respect to postprandial glycaemic control and other glucose and lipid parameters in patients with Type 2 diabetes inadequately controlled with insulin and/or oral glucose-lowering agents. METHODS: This was a randomized, open-label, crossover study. Prestudy oral agents were continued and patients not already on oral agents were treated with metformin. Mix 25/75 and insulin glargine were adjusted over 3 months to attain premeal plasma glucose (PG) < 6.0 mmol/l and were then given during a 24-h in-patient test meal period with frequent PG, serum triglyceride (TG) and free fatty acid (FFA) measurements. RESULTS: Twenty patients (10 F/10 M; mean +/-sd age 54.0 +/- 10.7 years, body mass index 37.0 +/- 8.6 kg/m2, HbA1c 8.4 +/- 1.01%) participated. Mean doses were 23 U before the morning and 37 U before the evening meal for Mix 25/75 and 44 U for insulin glargine. The combined 2-h morning and evening meal postprandial plasma glucose (PPG) was not different between groups (9.2 +/- 2.04 vs. 9.9 +/- 1.66 mmol/l, P = 0.161). Mix 25/75 was associated with a lower mean 2-h PPG for all meals combined (9.0 +/- 1.88 vs. 9.9 +/- 1.80 mmol/l, P < 0.05) and lower mean 24-h PG (6.7 +/- 1.00 vs. 7.5 +/- 1.32 mmol/l, P < 0.01). Eight patients experienced mild hypoglycaemia (PG < 3.5 mmol/l) with Mix 25/75 and 3 with insulin glargine. The endpoint HbA1c was lower with Mix 25/75 (6.9 +/- 0.52% vs. 7.3 +/- 0.81%, P < 0.05). CONCLUSIONS: In a 24-h test-meal setting in 20 patients, Mix 25/75 insulin plus oral glucose-lowering agents was associated with lower mean PPG and 24-h PG, more mild hypoglycaemia and similar TG, FFA and fasting PG concentrations. HbA1c was lower with Mix 75/25 plus oral agents, although it may not have reached steady state due to ongoing dose adjustment.     

Efficacy of berberine in patients with type 2 diabetes mellitus

Berberine has been shown to regulate glucose and lipid metabolism in vitro and in vivo. This pilot study was to determine the efficacy and safety of berberine in the treatment of type 2 diabetes mellitus patients. In study A, 36 adults with newly diagnosed type 2 diabetes mellitus were randomly assigned to treatment with berberine or metformin (0.5 g 3 times a day) in a 3-month trial. The hypoglycemic effect of berberine was similar to that of metformin. Significant decreases in hemoglobin A1c (from 9.5%+/-0.5% to 7.5%+/-0.4%, P<.01), fasting blood glucose (from 10.6+/-0.9 mmol/L to 6.9+/-0.5 mmol/L, P<.01), postprandial blood glucose (from 19.8+/-1.7 to 11.1+/-0.9 mmol/L, P<.01), and plasma triglycerides (from 1.13+/-0.13 to 0.89+/-0.03 mmol/L, P<.05) were observed in the berberine group. In study B, 48 adults with poorly controlled type 2 diabetes mellitus were treated supplemented with berberine in a 3-month trial. Berberine acted by lowering fasting blood glucose and postprandial blood glucose from 1 week to the end of the trial. Hemoglobin A1c decreased from 8.1%+/-0.2% to 7.3%+/-0.3% (P<.001). Fasting plasma insulin and homeostasis model assessment of insulin resistance index were reduced by 28.1% and 44.7% (P<.001), respectively. Total cholesterol and low-density lipoprotein cholesterol were decreased significantly as well. During the trial, 20 (34.5%) patients experienced transient gastrointestinal adverse effects. Functional liver or kidney damages were not observed for all patients. In conclusion, this pilot study indicates that berberine is a potent oral hypoglycemic agent with beneficial effects on lipid metabolism.     

Comparison of fixed-dose rosiglitazone/metformin combination therapy with sulphonylurea plus metformin in overweight individuals with Type 2 diabetes inadequately controlled on metformin alone.

AIM: This 52-week, randomized, double-blind, parallel-group study was designed to compare rosiglitazone/metformin fixed-dose combination therapy with combination sulphonylurea plus metformin therapy in overweight individuals with inadequately controlled type 2 diabetes mellitus. METHOD: Individuals with inadequate glycaemic control (HbA (1c)> or =7%) while on metformin monotherapy (> or =0.85 g/day) entered a 4-week run-in period during which they received metformin 2 g/day. At the end of the run-in, individuals with fasting plasma glucose > or =7.0 mmol/l were randomized to treatment with metformin (2 g/day) and either rosiglitazone (4 mg/day; RSG+MET [N=294]) or a sulphonylurea (glibenclamide 5 mg/day or gliclazide 80 mg/day; SU+MET [N=302]). Medications were up-titrated to maximum tolerated doses (rosiglitazone 8 mg, glibenclamide 15 mg or gliclazide 320 mg plus metformin 2 g/day) during the first 12 weeks of double-blind treatment. The primary efficacy end point was the change in HbA (1c) from baseline after 52 weeks of treatment. RESULTS: RSG+MET was non-inferior to SU+MET with respect to changes in HbA (1c) after one year of treatment (DeltaHbA (1c)= -0.78% and -0.86%, respectively; treatment difference =0.09%, 95% CI=-0.08, 0.25). The HbA (1c) reductions with RSG+MET, but not SU+MET, were accompanied by significant improvements in measures of beta-cell function including proinsulin:insulin ratio. The degree of beta-cell failure was significantly greater with SU+MET compared to RSG+MET as measured by the coefficient of failure (0.543 vs. 0.055 HbA (1c)%/year, respectively, p=0.0002). The proportion of individuals who experienced hypoglycaemic events was significantly (p<0.0001) lower with RSG+MET (6%) than with SU+MET (30%). Diastolic ambulatory blood pressure and cardiovascular biomarkers (high-sensitivity C-reactive protein and plasminogen activator inhibitor-1) were also reduced following one year of treatment with RSG+MET but not SU+MET. Both treatments were generally well tolerated. CONCLUSION: Fixed-dose combination therapy with rosiglitazone/metformin is non-inferior to sulphonylurea plus metformin combination therapy in reducing HbA (1c) over one year of treatment. Improvements in measures of beta-cell function suggest that the improvements in glycaemic control may be better maintained in long-term therapy with the rosiglitazone/metformin combination.     

Combination treatment with metformin and glibenclamide versus single-drug therapies in type 2 diabetes mellitus: a randomized,double-blind,comparative study

To compare efficacy and tolerability of combination treatment with metformin and sulfonylurea with each of these drugs alone in the treatment of type 2 diabetes, 88 type 2 diabetic subjects (hemoglobin A1c [HbA1c] levels, 8.0%+/-1.0%; age, 57.3+/-7.1 years; body mass index [BMI]. 27.0+/-2.6 kg/m2; diabetes duration, 9.8+/-8.2 years; means +/- SD) were randomly assigned to double-blind treatment with metformin (500 to 3,000 mg/d), glibenclamide (5 to 15 mg/d), or their combination (metformin 400 to 2,400 mg/d + glibenclamide 2.5 to 15 mg/d) for 6 months. Thereafter, groups were crossed over for the following 6 months. Thus, each patient received metformin or glibenclamide alone, and the combination treatment. Doses were titrated to obtain HbA1c levels < or = 6.0% and fasting plasma glucose levels less than 140 mg/dL. Eighty patients concluded both treatment periods and were included in the analysis of treatment efficacy. In patients receiving metformin or glibenclamide alone, the maximal dose was reached in 21 and 25 patients, respectively; 8 and 15 of these subjects, respectively, required the maximal dose when they were on the combination treatment. During the study, 4 (10.0%) subjects receiving metformin, 7 (17.1%) receiving glibenclamide, and 31 (39.2%) receiving the combination treatment reached HbA1c levels < or = 6.0%. Moreover, when efficacy of the combination treatment on glycemic control was compared with that of single-drug therapies in each individual patient, the combination was significantly more effective than either metformin or glibenclamide (HbA1c after treatment, 6.1%+/-1.1% v 7.3%+/-1.4%, and 6.5%+/-0.7% v 7.6%+/-1.5%, respectively, both P<.0001). In conclusion, combination treatment with metformin and sulfonylurea is more effective than these drugs alone in improving glycemic control in type 2 diabetes, while also allowing a reduction of the dosage of each drug.     

Glycemic control with glyburide/metformin tablets in combination with rosiglitazone in patients with type 2 diabetes: a randomized, double-blind trial

PURPOSE: To assess the efficacy and safety of adding rosiglitazone to an established regimen of glyburide/metformin in patients with type 2 diabetes who had not achieved adequate glycemic control (glycosylated hemoglobin [HbA1C] levels >7.0% and < or =10.0%). METHODS: Following an open-label, lead-in phase to optimize the dosing of glyburide/metformin tablets, 365 patients randomly received additive therapy comprising rosiglitazone (4 mg once daily) or placebo for 24 weeks. Based on glycemic response, rosiglitazone dose was maintained or increased to 4 mg twice daily. Glyburide/metformin dose was maintained or reduced by 2.5/500 mg for symptomatic hypoglycemia. The primary endpoint was the change in HbA1C level from baseline to week 24. The proportions of patients achieving HbA1C levels <7% and a fasting plasma glucose level <126 mg/dL were also assessed. RESULTS: After 24 weeks, therapy with glyburide/metformin plus rosiglitazone resulted in a greater reduction in HbA1C levels (-1.0%, P<0.001) compared with combination therapy that included placebo, and in a larger proportion of patients (42% vs. 14%) who attained levels <7%. The difference in fasting plasma glucose levels between groups was -48 mg/dL (P<0.001), favoring glyburide/metformin plus rosiglitazone. The adverse event profile in the rosiglitazone-treated group included mild-to-moderate edema (8%), hypoglycemia (22%), and weight gain of 3 kg. No patient experienced hypoglycemia requiring third-party assistance. CONCLUSION: In patients with inadequate glycemic control despite established glyburide/metformin therapy, the addition of rosiglitazone improves glycemic control, allowing more patients to achieve an HbA1C level <7% and perhaps delaying the need for insulin treatment.