Metformin as Treatment for Overweight and Obese Adults: A Systematic Review

Kara M. Levri; Elizabeth Slaymaker; Allen Last; Julie Yeh; Jonathan Ference; Frank D’Amico; Stephen A. Wilson

doi:10.1370/afm.343

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Metformin use in obese subjects with pre-diabetes.
Edoardo Cervoni

Published on: 03 January 2006
What Information to Report in Systematic Reviews
David L Nordstrom

Published on: 13 December 2005
Metformin as Treatment for Overweight and Obese Adults
Samuel N Grief

Published on: 20 October 2005
Choosing patients wisely
Kenneth N. Woliner

Published on: 02 October 2005
Metformin for Obesity
John G. Scott

Published on: 29 September 2005

Published on: (3 January 2006)
Page navigation anchor for Metformin use in obese subjects with pre-diabetes.
Metformin use in obese subjects with pre-diabetes.
Edoardo Cervoni, Southport, UK
Dr Grief suggested glucose intolerance as a potential category for using metformin as treatment for overweight and obese individuals. It makes clinical sense that obese patients with prediabetes (fasting glucose 110-125 mg/dl)may benefit from metformin and there is some evidence that this may well be the case (see article below).
Qvigstad-Elisabeth.Forebygging av type 2-diabetes--en oversikt. Tidsskrift for den...
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Dr Grief suggested glucose intolerance as a potential category for using metformin as treatment for overweight and obese individuals. It makes clinical sense that obese patients with prediabetes (fasting glucose 110-125 mg/dl)may benefit from metformin and there is some evidence that this may well be the case (see article below).
Qvigstad-Elisabeth.Forebygging av type 2-diabetes--en oversikt. Tidsskrift for den Norske laegeforening, {Tidsskr-Nor-Laegeforen}, 2 Dec 2004, vol. 124, no. 23, p. 3047-50.
Competing interests: None declared
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Competing Interests: None declared.
Published on: (13 December 2005)
Page navigation anchor for What Information to Report in Systematic Reviews
What Information to Report in Systematic Reviews
David L Nordstrom, Minneapolis USA
The authors' systematic review is a rare and welcome contribution to the family medicine literature.
However, the report lacks some important information: the rationale for choosing the Jadad scale; the basis for excluding studies with scores under 7; and the meaning of "insufficient" evidence in the discussion.
Competing interests: None declared

Competing Interests: None declared.
Published on: (20 October 2005)
Page navigation anchor for Metformin as Treatment for Overweight and Obese Adults
Metformin as Treatment for Overweight and Obese Adults
Samuel N Grief, Chicago, USA
Thank you for the article. I have been using Metformin as treatment for obesity for years and wondered myself how others were doing.
I would also ask you to consider the concomitant condition of glucose intolerance (pre-diabetes) as a potential category for using metformin as treatment for overweight and obese individuals.
The more treatment options that exist for obesity, the more likely doctors will t...
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Thank you for the article. I have been using Metformin as treatment for obesity for years and wondered myself how others were doing.
I would also ask you to consider the concomitant condition of glucose intolerance (pre-diabetes) as a potential category for using metformin as treatment for overweight and obese individuals.
The more treatment options that exist for obesity, the more likely doctors will take the initiative in treating this growing epidemic.
Sincerely,
Dr. Samuel N. Grief, MD, FCFP University of Illinois at Chicago
Competing interests: None declared
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Competing Interests: None declared.
Published on: (2 October 2005)
Page navigation anchor for Choosing patients wisely
Choosing patients wisely
Kenneth N. Woliner, Boca Raton, FL
Unfortunately, from this paper, it is not easy to detect baseline HOMA scores for insulin resistance, or other surrogate measures such as Hemoglobin A1c levels, Triglyceride/HDL ratio, etc. It would be interesting to see this information on the patients cited by each study, as I suspect that only "insulin resistant" patients would benefit from Metformin.
From my own research on insulin resistance as well as...
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Unfortunately, from this paper, it is not easy to detect baseline HOMA scores for insulin resistance, or other surrogate measures such as Hemoglobin A1c levels, Triglyceride/HDL ratio, etc. It would be interesting to see this information on the patients cited by each study, as I suspect that only "insulin resistant" patients would benefit from Metformin.
From my own research on insulin resistance as well as clinical experience as a private practice physician treating many overweight and obese patients I have come to the following conclusions:
1. The main defect in insulin resistance is in "non-oxidative" glucose metabolism - i.e. - putting glucose into mucles to form glycogen.
2. Metformin and other insulin sensitizing vitamins / minerals, and herbals help glucose enter muscle cells with less insulin needed by the body. This leads to less body weight, while also increasing muscle strength and endurance due to the higher concentration of glycogen available. (BTW, the other insulin sensitizing nutraceuticals I use are Chromium Picolinate 500 mcg BID, Vanadyl Sulfate 120 mcg QD, Cinnamon 1000 - 5000 mg QD, and Alpha Lipoic Acid 300 mg - 600 mg BID.)
3. If someone, even if they are overweight, is insulin sensitive, metformin will have neglible effects, if any, for weight loss.
4. Lacking a clear measure of insulin resistance (a 2 hour Glucose Tolerance Test with insulin levels drawn in addition to Glucose) - I use the Hemoglobin A1c as a 3-month average indicator. My ranges are: Hemoglobin A1c:
4.0 - 4.9% normal - insulin sensitive
5.0 - 5.9% high normal - insulin resistant
6.0 - 6.9% likely diabetes, higher risk for CV events
> 7.0% diabetes in poor control, additional
risk for microvesascular events
5. Those with higher Hemoglobin A1c values will have more dramatic weight reduction effects. Those with Hemoglobin A1c < 5.0% rarely have any weight reducing effect with Metformin as they are already "insulin senstive".
A similar analogy - if a patient was anemic, but had high Serum Iron, %transferrin saturation, and ferritin levels (and low TIBC) - would iron have any chance at helping their anemia? So my conclusion is: CHOOSE YOUR PATIENTS WISELY.
Kenneth N. Woliner, MD, ABFP Holistic Family Medicine, LLC 2499 Glades Road #106A Boca Raton, FL 33431
Competing interests: None declared
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Competing Interests: None declared.
Published on: (29 September 2005)
Page navigation anchor for Metformin for Obesity
Metformin for Obesity
John G. Scott, USA
The idea that metformin, an inexpensive and relatively safe drug, could be used for weight loss in obese patients is both intriguing and seductive. Although the thorough systematic review by Levri, et al. does not support the current use of metformin for weight loss, it also makes clear that a definitive study is yet to be done. No pharmaceutical company is likely to invest in such a study for a drug available gene...
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The idea that metformin, an inexpensive and relatively safe drug, could be used for weight loss in obese patients is both intriguing and seductive. Although the thorough systematic review by Levri, et al. does not support the current use of metformin for weight loss, it also makes clear that a definitive study is yet to be done. No pharmaceutical company is likely to invest in such a study for a drug available generically, but this review should be helpful to anyone seeking funding from NIH for a large clinical trial of metformin in very obese (BMI>35) patients. This is the group most at risk of increased morbidity and mortality, and also the group theoretically most likely to lose weight with metformin.
Even if metformin were to turn out to be useful for weight loss, however, we should not allow ourselves to be seduced by it or any other weight loss drug that comes down the pike. While such medicines, along with diet and exercise may help individual patients, they will do nothing to get at the root causes of the U.S. obesity epidemic. Those causes are societal and structural and require policy and legislative solutions. We will be doing a disservice to our patients if we focus only on treating individual obese patients and fail to use our medical knowledge to promote “intelligent design” of our work places and our communities, as well as some reasonable regulation of the food industry.
Competing interests: None declared
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Competing Interests: None declared.