METHODS: In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score).
RESULTS: B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively).
CONCLUSIONS: The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.
方法:在此前瞻性中,双盲,安慰剂对照试验,90例接受二甲双胍治疗至少4年的2型糖尿病患者以及外周和自主性DN患者被随机分为接受B12的积极治疗组(n=44)和接受安慰剂的对照组(n=46)。所有患者的B12水平均低于400pmol/L。受试者接受腓肠神经传导速度(SNCV)的测量,腓肠神经动作电位(振幅)(SNAP),和振动感知阈值(VPT),他们进行了心血管自主神经反射测试(CART:平均循环结果(MCR),Valsalva测试,姿势指数,和直立性低血压)。通过SUDOSCAN评估手和脚的电化学皮肤电导(ESCH和ESCF,分别)。我们还使用了密歇根神经病筛查仪器问卷和检查(MNSIQ和MNSIE,分别)和问卷调查,以评估生活质量(QoL)和疼痛程度(疼痛评分)。
结果:B12水平从基线时的232.0±71.8增加到随访时的776.7±242.3pmol/L,p<0.0001,在活性组中但在对照组中没有。VPT,MNSIQ,QoL,疼痛评分,SNCV,SNAP,和ESCF在活性组中明显改善(分别为p<0.001,p=0.002,p<0.0001,p<0.000,p<0.0001,p<0.0001和p=0.014),而CARTS和MNSIE改善但不显著。MCR,MNSIQ,SNCV,SNAP,对照组疼痛评分显著恶化(p=0.025,p=0.017,p=0.045,p<0.0001,p<0.0001)。
结论:用1mg口服甲基钴胺治疗DN患者12个月可增加血浆B12水平,改善所有神经生理参数,sudomotor功能,疼痛评分,和QoL,但它并没有改善CARTS和MNSIE。