Long-term effect of metformin on blood glucose control in non-obese patients with type 2 diabetes mellitus.
BACKGROUND
We aimed to investigate the long-term effect of metformin on the blood glucose control in non-obese patients with type 2 diabetes mellitus.


METHODS
A retrospective study was performed in 213 patients with type 2 diabetes mellitus under the administration of metformin for more than one year. The clinical parameters were investigated for 3 years. The obese and non-obese individuals were defined as a body mass index (BMI) of 25 kg/m2 or over (n = 105) and a BMI of less than 25 kg/m2 (n = 108), respectively.


RESULTS
HbA1c levels were significantly decreased compared with those at the baseline time. The course of HbA1c was similar between the non-obese and the obese groups, while the dose of metformin required to control blood glucose was significantly lower in the non-obese group than in the obese group. The reductions in HbA1c were 1.2% and 1.1% at 12 months, 0.9% and 0.9% at 24 months, and 0.8% and 1.0% at 36 months in the non-obese and obese groups, respectively. BMI did not change during the observation periods. Approximately half of all patients required no additional antidiabetic agents or a reduction in other treatments after the initiation of metformin in either of the two groups.


CONCLUSIONS
The present study demonstrated the long-term beneficial effect of metformin in non-obese (BMI < 25 kg/m2) diabetic patients. This effect appears to be maintained even after the observation period of this study, because metformin was limited to a relatively low dose in the non-obese group and the observed worsening in glycemic control over time can probably be attenuated by increasing the dose of metformin.
Department of Diabetes, Metabolism and Kidney Disease, Edogawa Hospital, Tokyo 133-0052, Japan. ito@edogawa.or.jp.
Hiroyuki
H
Ito
Hidenori
H
Ishida
Yuichiro
Y
Takeuchi
Shinichi
S
Antoku
Mariko
M
Abe
Mizuo
M
Mifune
Michiko
M
Togane