Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
J Formos Med Assoc. 2012 Feb;111(2):109-12. doi: 10.1016/j.jfma.2012.01.007. Epub 2012 Feb 13.
Glycated hemoglobin A1c (HbA1c) is an important indicator of glycemic control. The current recommendation for glycemic control based on HbA1c values has been widely accepted. However, HbA1c values depend on the lifespan of erythrocytes and the assay methods used. Here, we report the case of a patient with type 2 diabetes with unusual falling of HbA1c due to interference from dapsone treatment for leukocytoclastic vasculitis. He was a 52-year-old man, who was diagnosed with type 2 diabetes mellitus 5 years previously and who had been treated in our hospital in the past 3 years. Glycemia was controlled by sulfonylurea and metformin. During the 3-years follow-up period, HbA1c dropped significantly during the addition of dapsone treatment, although plasma glucose levels remained stable. HbA1c levels were raised after discontinuation of dapsone. With rechallenge of dapsone usage, HbA1c decreased again. We conclude that dapsone may be the cause of artificially low HbA1c. Other measurements to monitor glycemic control should be considered when dapsone is used for the treatment of concurrent disorders, such as autoimmune disease and pneumocystis jiroveci pneumonia.
糖化血红蛋白 A1c（HbA1c）是血糖控制的重要指标。目前基于 HbA1c 值的血糖控制推荐已被广泛接受。然而，HbA1c 值取决于红细胞的寿命和所用的检测方法。在这里，我们报告了一例 2 型糖尿病患者因白细胞碎裂性血管炎的治疗而出现 HbA1c 异常下降的情况。患者为 52 岁男性，5 年前被诊断为 2 型糖尿病，过去 3 年在我院治疗。血糖通过磺酰脲类药物和二甲双胍控制。在 3 年的随访期间，尽管血糖水平保持稳定，但加用氨苯砜治疗后 HbA1c 显著下降。停用氨苯砜后 HbA1c 升高。重新使用氨苯砜后，HbA1c 再次下降。我们得出结论，氨苯砜可能是导致 HbA1c 人为降低的原因。当氨苯砜用于治疗自身免疫性疾病和卡氏肺孢子虫肺炎等并发疾病时，应考虑其他监测血糖控制的方法。
