Merete Frandsen

Impact of metformin versus repaglinide on non-glycaemic cardiovascular risk markers related to inflammation and endothelial dysfunction in non-obese patients with type 2 diabetes

OBJECTIVE In patients with type 2 diabetes mellitus (T2DM), biomarkers reflecting inflammation and endothelial dysfunction have been linked to cardiovascular disease (CVD biomarkers) and metabolic regulation. In T2DM patients, metformin and insulin secretagogues have demonstrated equal anti-hyperglycaemic potency. Here, we report the effect of metformin versus an insulin secretagogue, repaglinide, on CVD biomarkers in non-obese T2DM patients. DESIGN AND METHODS Single-centre, double-masked, double-dummy, crossover study during 2x4 months involving 96 non-obese (body mass index< or =27 kg/m(2)) insulin-naïve T2DM patients. At enrolment, previous oral hypoglycaemic agents were stopped and the patients entered a 1-month run-in on diet-only treatment. Hereafter, patients were randomized to either 2 mg repaglinide thrice daily followed by 1 g metformin twice daily or vice versa each during 4 months with a 1-month washout between interventions. RESULTS Levels of tumour necrosis factor-alpha, plasminogen activator inhibitor-1 antigen, tissue-type plasminogen activator antigen, von Willebrand factor, soluble intercellular adhesion molecule-1 and soluble E-selectin were significantly lower during metformin versus repaglinide treatments. In contrast, Amadori albumin and heart rate were higher during metformin versus repaglinide. Levels of interleukin-6, fibrinogen, soluble vascular cell adhesion molecule-1, asymmetric dimethylarginine and advanced glycation end products as well as glycaemic levels (previously reported) and 24-h blood pressure were similar between treatments. Adjustment for known macrovascular disease did not affect the between-treatment effects. CONCLUSIONS In non-obese T2DM patients, metformin was more effective in reducing selected biomarkers reflecting inflammation and endothelial dysfunction compared with repaglinide despite similar glycaemic levels between treatments.

Effect of Adjunct Metformin Treatment in Patients with Type-1 Diabetes and Persistent Inadequate Glycaemic Control. A Randomized Study

Background Despite intensive insulin treatment, many patients with type-1 diabetes (T1DM) have longstanding inadequate glycaemic control. Metformin is an oral hypoglycaemic agent that improves insulin action in patients with type-2 diabetes. We investigated the effect of a one-year treatment with metformin versus placebo in patients with T1DM and persistent poor glycaemic control. Methodology/Principal Findings One hundred patients with T1DM, preserved hypoglycaemic awareness and HaemoglobinA1c (HbA1c) ≥8.5% during the year before enrolment entered a one-month run-in on placebo treatment. Thereafter, patients were randomized (baseline) to treatment with either metformin (1 g twice daily) or placebo for 12 months (double-masked). Patients continued ongoing insulin therapy and their usual outpatient clinical care. The primary outcome measure was change in HbA1c after one year of treatment. At enrolment, mean (standard deviation) HbA1c was 9.48% (0.99) for the metformin group (n = 49) and 9.60% (0.86) for the placebo group (n = 51). Mean (95% confidence interval) baseline-adjusted differences after 12 months with metformin (n = 48) versus placebo (n = 50) were: HbA1c, 0.13% (−0.19; 0.44), p = 0.422; Total daily insulin dose, −5.7 U/day (−8.6; −2.9), p<0.001; body weight, −1.74 kg (−3.32; −0.17), p = 0.030. Minor and overall major hypoglycaemia was not significantly different between treatments. Treatments were well tolerated. Conclusions/Significance In patients with poorly controlled T1DM, adjunct metformin therapy did not provide any improvement of glycaemic control after one year. Nevertheless, adjunct metformin treatment was associated with sustained reductions of insulin dose and body weight. Further investigations into the potential cardiovascular-protective effects of metformin therapy in patients with T1DM are warranted. Trial Registration ClinicalTrials.gov NCT00118937

Targeting hyperglycaemia with either metformin or repaglinide in non-obese patients with type 2 diabetes: results from a randomized crossover trial

Aim:  Metformin is the ‘drug‐of‐first‐choice’ in obese patients with type 2 diabetes mellitus (T2DM) due to its antihyperglycaemic and cardiovascular protective potentials. In non‐obese patients with T2DM, insulin secretagogues are empirically used as first choice. In this investigator‐initiated trial, we evaluated the effect of metformin vs. an insulin secretagogue, repaglinide on glycaemic regulation and markers of inflammation and insulin sensitivity in non‐obese patients with T2DM.

Effect of adjunct metformin treatment on levels of plasma lipids in patients with type 1 diabetes

Background: In addition to its glucose‐lowering effect, metformin treatment has been suggested to improve lipidaemia in patients with type 2 diabetes. In contrast, in patients with type 1 diabetes (T1DM), information about the effect of metformin treatment on lipidaemia is limited. In this study, we report the effect of a 1‐year treatment with metformin vs. placebo on plasma lipids in T1DM patients and persistent poor glycaemic control.

Combining insulin with metformin or an insulin secretagogue in non-obese patients with type 2 diabetes: 12 month, randomised, double blind trial

Objectives To study the effect of insulin treatment in combination with metformin or an insulin secretagogue, repaglinide, on glycaemic regulation in non-obese patients with type 2 diabetes. Design Randomised, double blind, double dummy, parallel trial. Setting Secondary care in Denmark between 2003 and 2006. Participants Non-obese patients (BMI ≤27) with preserved beta cell function. Interventions After a four month run-in period with repaglinide plus metformin combination therapy, patients with a glycated haemoglobin (HbA1c) concentration of 6.5% or more were randomised to repaglinide 6 mg or metformin 2000 mg. All patients also received biphasic insulin aspart 70/30 (30% soluble insulin aspart and 70% intermediate acting insulin aspart) 6 units once a day before dinner for 12 months. Insulin dose was adjusted aiming for a fasting plasma glucose concentration of 4.0-6.0 mmol/l. The target of HbA1c concentration was less than 6.5%. Treatment was intensified to two or three insulin injections a day if glycaemic targets were not reached. Main outcome measure HbA1c concentration. Results Of the 459 patients who were eligible, 102 were randomised, and 97 completed the trial. Patients had had type 2 diabetes for approximately 10 years. At the end of treatment, HbA1c concentration was reduced by a similar amount in the two treatment groups (insulin plus metformin: mean (standard deviation) HbA1c 8.15% (1.32) v 6.72% (0.66); insulin plus repaglinide: 8.07% (1.49) v 6.90% (0.68); P=0.177). Total daily insulin dose and risk of hypoglycaemia were also similar in the two treatment groups. Weight gain was less with metformin plus biphasic insulin aspart 70/30 than with repaglinide plus biphasic insulin aspart 70/30 (difference in mean body weight between treatments −2.51 kg, 95% confidence interval −4.07 to −0.95). Conclusions In non-obese patients with type 2 diabetes and poor glycaemic regulation on oral hypoglycaemic agents, overall glycaemic regulation with insulin in combination with metformin was equivalent to that with insulin plus repaglinide. Weight gain seemed less with insulin plus metformin than with insulin plus repaglinide. Trial registration NCT00118963

Impact of metformin versus the prandial insulin secretagogue, repaglinide, on fasting and postprandial glucose and lipid responses in non-obese patients with type 2 diabetes

OBJECTIVE Non-obese patients with type 2 diabetes (T2DM) are characterized by predominant defective insulin secretion. However, in non-obese T2DM patients, metformin, targeting insulin resistance, is non-inferior to the prandial insulin secretagogue, repaglinide, controlling overall glycaemia (HbA1c). Whether the same apply for postprandial glucose and lipid metabolism is unknown. Here, we compared the effect of metformin versus repaglinide on postprandial metabolism in non-obese T2DM patients. DESIGN Single-centre, double-masked, double-dummy, crossover study during 2x4 months involving 96 non-obese (body mass index < or = 27 kg/m2) insulin-naïve T2DM patients. At enrolment, patients stopped prior oral hypoglycaemic agents therapies and after a 1-month run-in period on diet-only treatment, patients were randomized to repaglinide (2 mg) thrice daily followed by metformin (1 g) twice daily or vice versa each during 4 months with 1-month washout between interventions. METHODS Postprandial metabolism was evaluated by a standard test meal (3515 kJ; 54% fat, 13% protein and 33% carbohydrate) with blood sampling 0-6 h postprandially. RESULTS Fasting levels and total area under the curve (AUC) for plasma glucose, triglycerides and free fatty acids (FFA) changed equally between treatments. In contrast, fasting levels and AUC of total cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol and serum insulin were lower during metformin than repaglinide (mean (95% confidence intervals), LDL cholesterol difference metformin versus repaglinide: AUC: -0.17 mmol/l (-0.26; -0.08)). AUC differences remained significant after adjusting for fasting levels. CONCLUSIONS In non-obese T2DM patients, metformin reduced postprandial levels of glycaemia, triglycerides and FFA similarly compared to the prandial insulin secretagogue, repaglinide. Furthermore, metformin reduced fasting and postprandial cholesterolaemia and insulinaemia compared with repaglinide. These data support prescription of metformin as the preferred drug in non-obese patients with T2DM targeting fasting and postprandial glucose and lipid metabolism.

Agreement Between Fasting and Postprandial LDL Cholesterol Measured with 3 Methods in Patients with Type 2 Diabetes Mellitus

BACKGROUND LDL cholesterol (LDL-C) is a modifiable cardiovascular disease risk factor. We used 3 LDL-C methods to study the agreement between fasting and postprandial LDL-C in type 2 diabetes (T2DM) patients. METHODS We served 74 T2DM patients a standardized meal and sampled blood at fasting and 1.5, 3.0, 4.5, and 6.0 h postprandially. We measured LDL-C by use of modified β quantification (MBQ), the Friedewald equation (FE), and a direct homogeneous assay (DA). We evaluated agreement using 95% limits of agreement (LOA) within ±0.20 mmol/L (±7.7 mg/dL). RESULTS LDL-C concentrations at all postprandial times disagreed with those at fasting for all methods. In 66 patients who had complete measurements with all LDL-C methods, maximum mean differences (95% LOA) in postprandial vs fasting LDL-C were -0.16 mmol/L (-0.51; 0.19) [-6.2 mg/dL (-19.7; 7.3)] with MBQ at 3 h; -0.36 mmol/L (-0.89; 0.17) [-13.9 mg/dL (-34; 6.6)] with FE at 4.5 h; and -0.24 mmol/L (-0.62; 0.05) [-9.3 mg/dL (-24; 1.9)] with DA at 6.0 h. In postprandial samples, FE misclassified 38% of patients (two-thirds of statin users) into lower Adult Treatment Panel III (ATP III) risk categories. Greater disagreement between fasting and postprandial LDL-C was observed in individuals with postprandial triglyceride concentrations >2.08 mmol/L (>184 mg/dL) and in women (interactions: P ≤ 0.038). CONCLUSIONS Differences up to 0.89 mmol/L (34 mg/dL) between fasting and postprandial LDL-C concentrations, with postprandial LDL-C concentrations usually being lower, were found in T2DM by 3 different LDL-C methods. Such differences are potentially relevant clinically and suggest that, irrespective of measurement method, postprandial LDL-C concentrations should not be used to assess cardiovascular disease risk.

Sustained postprandial decrease in plasma levels of LDL cholesterol in patients with type-2 diabetes mellitus

Objective. Low density lipoprotein cholesterol (LDL‐C) is an independent and modifiable risk factor for development of cardiovascular disease (CVD). Postprandial lipid metabolism has been linked to CVD, but little is known about the postprandial LDL‐C profile in patients with type‐2 diabetes (T2DM). We aimed to study the postprandial levels of LDL‐C in T2DM patients. Material and methods. After an overnight fast, 74 T2DM patients, mean age approximately 60 years, were served a standard fat‐rich meal of 3,515 kJ containing 54 % fat, 13 % protein and 33 % carbohydrates. Only drinking water was allowed postprandially. Blood samples were drawn at times 0 (fasting), 1.5, 3.0, 4.5 and 6.0 h (postprandial). In all samples, LDL‐C was measured with modified beta quantification (separation by ultracentrifugation followed by measurement of infranate high density lipoprotein cholesterol (HLD‐C) using a homogeneous assay). Results. At all postprandial times, levels of LDL‐C showed highly significant (p<0.005) decreases compared to time 0 (mean [95 % CI] maximum change in LDL‐C levels at 3.0 h: −0.16 mmol/L [−0.12; −0.20]; p<0.001). Independently of fasting LDL‐C levels and ongoing statin therapy, LDL‐C decreased significantly more in female compared to male patients postprandially (mean [95 % CI] maximum unadjusted change versus time 0 in LDL‐C for men [n = 56] at 3.0 h: −0.14 mmol/L [−0.19; −0.10], p<0.001; for women [n = 18] at 4.5 h: −0.26 mmol/L [−0.35; −0.18], p<0.001; −0.14 mmol/L [−0.24; −0.05], p = 0.005 between genders for the mean [95 % CI] fasting adjusted difference at 4.5 h in the change versus time 0 in LDL‐C; gender by time interaction: p = 0.007 (repeated measures mixed model)). Conclusions. In T2DM patients served a fat‐rich meal, levels of LDL‐C decreased significantly more in women compared to men postprandially, irrespective of fasting levels or ongoing statin therapy. This might have implications in the atherosclerotic process and on any difference in the risk of CVD between genders.