Halazun K J, Bofkin K A, Asthana S, Evans C, Henderson M, Spark J I
Leeds Vascular Institute, Leeds General Infirmary, Leeds, West Yorkshire, UK.
Eur J Vasc Endovasc Surg. 2007 Apr;33(4):391-4; discussion 395-6. doi: 10.1016/j.ejvs.2006.10.022. Epub 2006 Dec 11.
Previous literature has suggested an association between AAA and the presence of elevated plasma homocysteine levels (HCY). Homocysteine can stimulate elastolysis in the arterial media via activation of elastase and matrix metalloproteinases. No evidence in the literature exists correlating aneurysm expansion and HCY. The study objective is to identify whether the rate of AAA expansion is related to HCY.
108 patients undergoing surveillance for AAA were identified at our vascular surgical unit. AAA size and growth rate were assessed by serial ultrasonographic measurements. Fasting total HCY levels were measured using fluorescence polarisation immunoassays. Demographic details and atherosclerotic risk factors were noted all AAA patients. A multivariate analysis was performed for growth rate vs. HCY, hypertension and hypercholesterolaemia. The correlation between AAA growth rate, AAA size and HCY levels were calculated.
60% of patients with AAA had some degree of hyperhomocysteinaemia (> 15 micromol/l). Multivariate analysis showed HCY to be the only significant factor affecting AAA growth rate. A positive correlation was demonstrated between HCY levels and AAA growth rate using a linear regression model (R=0.28, p=0.003). Median growth rate among patients with hyperHCY was double that of patients with normal HCY (0.5 mm/month vs. 0.25 mm/month, p=0.003). A growth rate of > 10 mm/year was seen in 25% of hyper HCY patients and in only 2% of patients with normal HCY. In addition patients with hyper HCY and larger AAAs (> 4 cm) had a growth rate twice as fast as patients with hyper HCY and AAAs < 4 cm.
A correlation between HCY and growth rate exists, although this is weak due to the multifactorial aetiology of AAAs. HyperHCY patients have faster expansion rates than patients with normal HCY, with significant numbers demonstrating rapid expansion (> 10 mm/year) and therefore an increased risk of rupture.
既往文献提示腹主动脉瘤（AAA）与血浆同型半胱氨酸水平（HCY）升高之间存在关联。同型半胱氨酸可通过激活弹性蛋白酶和基质金属蛋白酶刺激动脉中层的弹性蛋白溶解。文献中没有证据表明动脉瘤扩张与HCY相关。本研究的目的是确定AAA的扩张速率是否与HCY有关。
在我们的血管外科病房确定了108例接受AAA监测的患者。通过系列超声测量评估AAA大小和生长速率。使用荧光偏振免疫分析法测量空腹总HCY水平。记录所有AAA患者的人口统计学细节和动脉粥样硬化危险因素。对生长速率与HCY、高血压和高胆固醇血症进行多变量分析。计算AAA生长速率、AAA大小与HCY水平之间的相关性。
60%的AAA患者有一定程度的高同型半胱氨酸血症（>15微摩尔/升）。多变量分析显示HCY是影响AAA生长速率的唯一重要因素。使用线性回归模型显示HCY水平与AAA生长速率之间存在正相关（R = 0.28，p = 0.003）。高HCY患者的中位生长速率是HCY正常患者的两倍（0.5毫米/月对0.25毫米/月，p = 0.003）。25%的高HCY患者生长速率>10毫米/年，而HCY正常的患者中只有2%生长速率>10毫米/年。此外，AAA较大（>4厘米）的高HCY患者的生长速率是AAA<4厘米的高HCY患者的两倍。
HCY与生长速率之间存在相关性，尽管由于AAA的多因素病因，这种相关性较弱。高HCY患者的扩张速率比HCY正常的患者快，大量患者表现出快速扩张（>10毫米/年），因此破裂风险增加。
