OBJECTIVE: To evaluate the prevalence of vitamin B12 deficiency in Chinese patients with type 2 diabetes mellitus receiving metformin treatment and to investigate the effects of metformin daily dose and treatment duration on the prevalence of vitamin B12 deficiency and peripheral neuropathy (PN).
METHODS: In this multicenter cross-sectional study, 1027 Chinese patients who had been taking ≥1000 mg/day metformin for ≥1 year were enrolled using proportionate stratified random sampling based on daily dose and treatment duration. Primary measures included the prevalence of vitamin B12 deficiency (<148 pmol/L), borderline B12 deficiency (148 pmol/L-211 pmol/L), and PN.
RESULTS: The prevalence of vitamin B12 deficiency, borderline deficiency, and PN were 2.15%, 13.66%, and 11.59%, respectively. Patients receiving ≥1500 mg/day metformin had significantly higher prevalence of borderline vitamin B12 deficiency (16.76% vs. 9.91%, p = .0015) and serum B12 ≤221 pmol/L (19.25% vs. 11.64%, p < .001) than patients receiving <1500 mg/day metformin. No difference was found in prevalence of borderline vitamin B12 deficiency (12.58% vs. 15.49%, p = .1902) and serum B12 ≤221 pmol/L (14.91% vs. 17.32%, p = .3055) between patients receiving metformin for ≥3 and <3 years. Patients with vitamin B12 deficiency had numerically higher PN prevalence (18.18% vs. 11.27%, p = .3192) than patients without it. Multiple logistic analyses revealed that HbA1c and metformin daily dose were associated with the prevalence of borderline B12 deficiency and B12 ≤221 pmol/L.
CONCLUSIONS: High daily dosage (≥1500 mg/day) played an important role in metformin-associated vitamin B12 deficiency while not contributing to the risk of PN.
目的:了解中国接受二甲双胍治疗的2型糖尿病患者维生素B12缺乏症的患病率, 探讨二甲双胍日剂量和治疗时间对维生素B12缺乏症患病率和周围神经病变(PN)的影响。 方法:在这项多中心横断面研究中, 采用基于日剂量和治疗时间的比例分层随机抽样, 纳入了1027例服用二甲双胍≥1000 mg/d≥1年的中国患者。主要指标包括维生素B12缺乏症(<148 pmol/L), B12临界缺乏(148 pmol/L-211 pmol/L)和PN的患病率。 结果:维生素B12缺乏, 临界缺乏和PN的患病率分别为2.15%, 13.66%和11.59%。接受≥1500mg /d二甲双胍治疗的患者与接受<1500mg /d二甲双胍治疗的患者相比, 维生素B12临界缺乏(16.76%vs.9.91%, p = 0.0015)和血清B12≤221 pmol/L(19.25%vs.11.64%, p<0.001)的患病率显著较高。服用二甲双胍≥3年和<3年的患者之间, 维生素B12临界缺乏(12.58%vs.15.49%, p = 0.1902)和血清B12≤221 pmol/L(14.91%vs.17.32%, p =0.3055)的患病率没有差异。与无维生素B12缺乏的患者相比, 缺乏维生素B12的患者PN患病率较高(18.18%vs.11.27%, p = 0.3192)。多元logistic回归分析显示, HbA1c 和二甲双胍日剂量与B12临界缺乏和B12≤221 pmol/L的患病率相关。 结论:高日剂量(≥1500mg /天)在二甲双胍相关的维生素B12缺乏症中起重要作用, 但不会增加PN的风险。.