Guallar Eliseo, Silbergeld Ellen K, Navas-Acien Ana, Malhotra Saurabh, Astor Brad C, Sharrett A Richey, Schwartz Brian S
Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
Am J Epidemiol. 2006 Apr 15;163(8):700-8. doi: 10.1093/aje/kwj090. Epub 2006 Feb 16.
Homocysteine levels are associated with peripheral arterial disease (PAD) in observational studies. Lead and cadmium are risk factors for PAD that affect thiol metabolism, and they may partly explain the association of homocysteine with PAD. To evaluate the roles of lead and cadmium exposure in confounding the association between homocysteine and PAD, the authors performed a cross-sectional study among 4,447 persons aged > or = 40 years who participated in the 1999-2002 National Health and Nutrition Examination Survey (NHANES). PAD was defined as an ankle-brachial blood pressure index less than 0.90 in at least one leg. After adjustment for sociodemographic variables, the odds ratio for PAD in the highest quintile of homocysteine compared with the lowest was 1.92 (p(trend) = 0.004). Adjusting for blood lead and cadmium levels reduced this odds ratio to 1.37 (p(trend) = 0.13), and further adjusting for estimated glomerular filtration rate and smoking reduced it to 0.89 (p(trend) = 0.87). Adjustment for other risk factors did not affect this association. In the general population, the association of homocysteine level with PAD can be completely explained by confounding due to smoking, increased blood lead and cadmium levels, and impaired renal function. The association of lead and cadmium with PAD risk deserves further investigation.
在观察性研究中，同型半胱氨酸水平与外周动脉疾病（PAD）相关。铅和镉是影响硫醇代谢的PAD风险因素，它们可能部分解释了同型半胱氨酸与PAD之间的关联。为了评估铅和镉暴露在混淆同型半胱氨酸与PAD之间关联中的作用，作者对参加1999 - 2002年国家健康和营养检查调查（NHANES）的4447名年龄≥40岁的人进行了一项横断面研究。PAD被定义为至少一条腿的踝臂血压指数小于0.90。在对社会人口统计学变量进行调整后，同型半胱氨酸最高五分位数组与最低五分位数组相比，患PAD的优势比为1.92（趋势p值 = 0.004）。对血铅和镉水平进行调整后，该优势比降至1.37（趋势p值 = 0.13），进一步对估计肾小球滤过率和吸烟情况进行调整后，该优势比降至0.89（趋势p值 = 0.87）。对其他风险因素进行调整并未影响这种关联。在一般人群中，同型半胱氨酸水平与PAD之间的关联可完全由吸烟、血铅和镉水平升高以及肾功能受损导致的混杂因素来解释。铅和镉与PAD风险之间的关联值得进一步研究。
