Allan S. Brett, MD reviewing Hirst JA et al. Diabetes Care 2012 Feb .
On average, by about 1% more than various alternatives.
How much lowering of glycosylated hemoglobin (HbA1c) levels should we expect when we prescribe metformin to patients with diabetes? To answer this question, researchers performed a meta-analysis of 35 randomized metformin trials of ≥12 weeks' duration. Key findings are as follows:
In comparisons between metformin monotherapy and placebo (or no drug treatment), metformin reduced mean HbA1c level by 1.1%.
In comparisons involving metformin plus another oral agent versus the other agent alone, addition of metformin reduced mean HbA1c level by 1.0%.
In comparisons involving metformin plus insulin versus insulin alone, addition of metformin reduced mean HbA1c level by 0.8% in patients with type 2 diabetes. In patients with type 1 diabetes receiving insulin, add-on metformin therapy had no HbA1c-lowering effect.
In comparisons between low-dose and high-dose metformin (usually 1000 vs. 2000 mg daily), HbA1c level was 0.3% lower with high-dose therapy.
COMMENT
These useful data can guide our expectations when we initiate metformin therapy. We should remember, however, that these are average results, with individual patients experiencing better or worse responses — and that outcomes in any given patient will be influenced by adherence to lifestyle changes. To me, the most surprising finding was that escalating the metformin dose from 1000 mg to 2000 mg daily resulted in only a modest 0.3% additional average lowering of HbA1c levels.
CITATION(S):
Hirst JA et al. Quantifying the effect of metformin treatment and dose on glycemic control. Diabetes Care 2012 Feb; 35:446. (dx.doi.org/10.2337/dc11-1465)
______________________________________
NEJM Journal Watch is produced by NEJM Group, a division of the Massachusetts Medical Society.
rvmasalvd: They took data of ONLY controlled experiments where questions about diet become superficial/ irrelevant. In other words, scientific fact is that oral medicine improves by JUST 31 mg/dl
rvmasalvd: They took data of ONLY controlled experiments where questions about diet become superficial/ irrelevant. In other words, scientific fact is that oral medicine improves by JUST 31 mg/dl
RESEARCH DESIGN AND METHODS MEDLINE, EMBASE, and the Cochrane Library were searched from 1950 to June 2010 for trials of at least 12 weeks’ duration in which diabetic patients were treated with either metformin monotherapy or as an add-on therapy. Data on change in HbA1c were pooled in a meta-analysis. Data from dose-comparison trials were separately pooled.
RESULTS A total of 35 trials were identified for the main analysis and 7 for the dose-comparison analysis. Metformin monotherapy lowered HbA1c by 1.12% (95% CI 0.92–1.32; I2 = 80%) versus placebo, metformin added to oral therapy lowered HbA1c by 0.95% (0.77–1.13; I2 = 77%) versus placebo added to oral therapy, and metformin added to insulin therapy lowered HbA1c by 0.60% (0.30–0.91; I2 = 79.8%) versus insulin only. There was a significantly greater reduction in HbA1c using higher doses of metformin compared with lower doses of metformin with no significant increase in side effects.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.