Ray Joel G, Kearon Clive, Yi Qilong, Sheridan Patrick, Lonn Eva
Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
Ann Intern Med. 2007 Jun 5;146(11):761-7. doi: 10.7326/0003-4819-146-11-200706050-00157. Epub 2007 Apr 30.
Elevated total homocysteine levels are associated with a higher risk for venous thromboembolism. Whether decreasing homocysteine levels with vitamin therapy reduces the risk for venous thromboembolism is not known.
To determine whether decreasing homocysteine levels alters the risk for symptomatic venous thromboembolism.
Secondary analysis of data from the randomized, placebo-controlled Heart Outcomes Prevention Evaluation 2 (HOPE-2) trial.
145 clinical centers in 13 countries.
5522 persons 55 years of age or older with known cardiovascular disease or diabetes mellitus and at least 1 other risk factor for vascular disease.
A daily supplement of 2.5 mg of folic acid, 50 mg of vitamin B(6), and 1 mg of vitamin B(12) or matching placebo for 5 years.
Prospectively diagnosed and confirmed symptomatic deep venous thrombosis or pulmonary embolism.
The geometric mean homocysteine level decreased by 2.2 micromol/L in the vitamin therapy group and increased by 0.80 micromol/L in the placebo group. Venous thromboembolism occurred in 88 participants during a mean follow-up of 5 years. The incidence rate of venous thromboembolism was the same in the vitamin therapy group and the placebo group (0.35 per 100 person-years; hazard ratio, 1.01 [95% CI, 0.66 to 1.53]). Vitamin therapy did not reduce the risk for deep venous thrombosis (hazard ratio, 1.04 [CI, 0.63 to 1.72]), pulmonary embolism (hazard ratio, 1.14 [CI, 0.57 to 2.28]), or unprovoked venous thromboembolism (hazard ratio, 1.21 [CI, 0.66 to 2.23]).
The proportion of patients with a previous episode of venous thromboembolism at enrollment was not known, and venous thromboembolism events were not centrally adjudicated.
Decreasing homocysteine levels with folic acid and vitamins B6 and B12 did not reduce the risk for symptomatic venous thromboembolism.
总同型半胱氨酸水平升高与静脉血栓栓塞风险较高相关。维生素疗法降低同型半胱氨酸水平是否能降低静脉血栓栓塞风险尚不清楚。
确定降低同型半胱氨酸水平是否会改变有症状静脉血栓栓塞的风险。
对随机、安慰剂对照的心脏结局预防评估2（HOPE - 2）试验的数据进行二次分析。
13个国家的145个临床中心。
5522名55岁及以上患有已知心血管疾病或糖尿病且至少有1项其他血管疾病风险因素的人。
每日补充2.5毫克叶酸、50毫克维生素B6和1毫克维生素B12或匹配的安慰剂，持续5年。
前瞻性诊断并确诊的有症状深静脉血栓形成或肺栓塞。
维生素治疗组的同型半胱氨酸几何平均水平下降了2.2微摩尔/升，安慰剂组上升了0.80微摩尔/升。在平均5年的随访期间，88名参与者发生了静脉血栓栓塞。维生素治疗组和安慰剂组静脉血栓栓塞的发生率相同（每100人年0.35；风险比，1.01 [95%可信区间，0.66至1.53]）。维生素治疗并未降低深静脉血栓形成（风险比，1.04 [可信区间，0.63至1.72]）、肺栓塞（风险比，1.14 [可信区间，0.57至2.28]）或不明原因静脉血栓栓塞（风险比，1.21 [可信区间，0.66至2.23]）的风险。
入组时曾有静脉血栓栓塞发作的患者比例未知，且静脉血栓栓塞事件未进行集中判定。
叶酸及维生素B6和B12降低同型半胱氨酸水平并不能降低有症状静脉血栓栓塞的风险。
