Department of Endocrinology, Metabolism and Diabetes, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan.
Geriatr Gerontol Int. 2011 Jan;11(1):55-62. doi: 10.1111/j.1447-0594.2010.00635.x.
The maximum dosage of metformin allowed for clinical use in Japan is much less than half that in Western countries, making it difficult to apply the results of clinical trials in Western countries to Japanese patients. In particular, the efficacy and safety of metformin in elderly patients are largely unknown.
Among 1508 patients who were newly prescribed metformin at our hospital from 2000-2006, patients with sufficient clinical data were retrospectively studied for the safety (n=1132) and efficacy (n=568) of the drug. Of 568 patients in whom the efficacy of metformin was analyzed, 180 patients (31.7%) were elderly, aged 65 years or over.
Metformin was effective for the treatment of type 2 diabetes in Japanese patients, with significant improvement in HbA1c level at all time-points after 1 month, with the largest decrease by approximately 0.9% in patients treated with 750 mg/day and approximately 0.7% in those treated with 500 mg/day, at 4 months. Metformin improved glycemic control in elderly patients as well as non-elderly patients. The efficacy was independent of age, sex, degree of obesity and concomitant use of other drugs. No significant difference was observed in elevated lactic acid levels between elderly and non-elderly patients. No case of lactic acidosis was observed.
These results suggest that the efficacy of metformin in Japanese elderly patients with type 2 diabetes is not different from that in non-elderly patients, and that its safety might be linked to specific and well-documented contraindications rather than age itself.
日本允许临床使用的最大剂量的二甲双胍比西方国家少一半以上，这使得难以将西方国家的临床试验结果应用于日本患者。特别是，二甲双胍在老年患者中的疗效和安全性在很大程度上尚不清楚。
在 2000 年至 2006 年期间，我院新开出二甲双胍处方的 1508 例患者中，对有足够临床数据的患者进行回顾性研究，以评估二甲双胍的安全性（n=1132）和疗效（n=568）。在分析了 568 例患者的二甲双胍疗效的患者中，180 例（31.7%）为老年患者，年龄在 65 岁及以上。
二甲双胍治疗日本 2 型糖尿病患者有效，治疗 1 个月后所有时间点的 HbA1c 水平均显著改善，750mg/天治疗组的最大降幅约为 0.9%，500mg/天治疗组的最大降幅约为 0.7%，在 4 个月时。二甲双胍改善了老年患者和非老年患者的血糖控制。疗效与年龄、性别、肥胖程度和同时使用其他药物无关。老年患者和非老年患者乳酸水平升高无显著差异。未观察到乳酸性酸中毒病例。
这些结果表明，二甲双胍在日本老年 2 型糖尿病患者中的疗效与非老年患者无差异，其安全性可能与特定的、有充分记录的禁忌症有关，而不是与年龄本身有关。
