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. 2008 Dec 10;36(4):183–191. [Article in Spanish] doi: 10.1157/13078602

Metformina para la diabetes mellitus tipo 2. Revisión sistemática y metaanálisis☆

Metformin for type 2 diabetes mellitus. Systematic review and meta-analysis

A Sáenz Calvo a,⁎, I Fernández Esteban b, A Mataix Sanjuán b, M Ausejo Segura c, M Roqué d, D Moher e
PMCID: PMC7684484  PMID: 16153370

Abstract

Objective

To evaluate the efficacy of metformin against placebo, diet, oral antidiabetics, or insulin in type 2 diabetes mellitus.

Design

Systematic review.

Data sources

MEDLINE (1966-2003), EMBASE (1974-2003), LILACS (1986- 2003), Cochrane library (Issue 3, 2003).

Selection of studies

29 randomized clinical trials of metformin in monotherapy, with results on mortality, morbility, and biochemistry.

Extraction of data

RevMan 4 computer program. Two reviewers extracted the data and evaluated the quality. Main variables: any clinical event related to diabetes (mortality, coronary disease, stroke, arterial disease, and retinopathy). Secondary variables: weight and biochemistry.

Results

29 clinical studies with 37 comparisons of metformin were analyzed (13 with sulphonylureas, 12 with placebo, 3 with diet, 3 with thiazolidinediones, 2 with α-glucosidase inhibitors, 2 with insulin, and 2 with meglitinides). Metformin was more beneficial than the sulphonylureas or insulin for any clinical event associated with diabetes (relative risk [RR]=0.78; 95% confidence interval [CI], 0.65-0.94) and than diet (RR=0.74; 95% CI, 0.60-0,90). Metformin decreased glycosylated hemoglobin A1 (weighted mean difference, -1.21%; 95% CI, −1.48 to −0.94), low density lipoprotein cholesterol (weighted mean difference, −0.24; 95% CI, −0.40 to −0.09), and weight (standardized mean difference, −0.11; 95% CI, −0.18 to −0.04). Metformin was more beneficial than the placebo, diet or the thiazolidinediones on glycosylated hemoglobin A1, and than the sulphonylureas or insulin on weight.

Conclusions

In the long term metformin reduces the risks of clinical events associated with diabetes. There are no long term clinical trials which compare α-glucosidase inhibitors, meglitinides, and thiazolidinediones with metformin, in primary results. The different treatments compared with metformin did not obtain more benefit for the secondary results evaluated.

Key words: Metformin, Biguanides, Type 2 diabetes mellitus, Systematic review, Metaanalyses

Footnotes

☆

Farma Roche obtuvo para nosotros los textos completos de las referencias potencialmente relevantes. La Agencia Laín Entralgo de la Comunidad Autónoma de Madrid realizó para nosotros una actualización de la búsqueda bibliográfica. La Colaboración Cochrane Iberoamericana nos ayudó en el estudio estadístico. En 2002 el Dr. Sáenz recibió un premio a la investigación financiado por Novartis. La revisión completa se puede consultar en la colaboración Cochrane 2005 (issue 3).

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