Markus H, Kapozsta Z, Ditrich R, Wolfe C, Ali N, Powell J, Mendell M, Cullinane M
Department of Clinical Neuroscience, St George's Hospital Medical School, Guy's, King's and St Thomas' School of Medicine, London, UK.
Stroke. 2001 Nov;32(11):2465-71. doi: 10.1161/hs1101.098152.
Individuals of African Caribbean descent who live in the United Kingdom have an increased risk of stroke. The reasons for this are not fully understood, but differences in genetic predispositions or other novel stroke risk factors could play a role. US blacks have been reported to have increased common carotid artery wall thickness, or intima-media thickness (IMT), measured by ultrasound. We measured carotid IMT in UK African Caribbeans compared with UK whites and determined whether different distributions of polymorphisms in potential candidate vascular genes or differences in measures of chronic inflammation or infection could account for any difference.
In a population study, common carotid artery IMT was measured in 202 white men and 89 African Caribbean men. The distribution of polymorphisms in ACE, paraoxonase 1, paraoxonase 2, and methylenetetrahydrofolate reductase genes was determined. Serum C-reactive protein and Helicobacter pylori seropositivity were determined.
Carotid IMT was increased in African Caribbeans even after controlling for cardiovascular risk factors, including homocysteine and social class: beta=0.113, 95% CI 0.036 to 0.189, P=0.004. There was a significant interaction with smoking and mean IMT (P=0.022), and the difference in both measures of IMT between ethnic groups was largely limited to individuals who had never smoked. There were significant ethnic differences in the distributions of 3 of the 4 candidate genes studied (ACE, paraoxonase 1, and methylenetetrahydrofolate reductase). H pylori seropositivity was increased in African Caribbeans (78.7% versus 53% in UK whites). However, neither the genetic polymorphisms nor H pylori seropositivity was related to IMT, and ethnic differences in their distribution did not account for the increased IMT seen in African Caribbeans.
Carotid IMT is increased in UK African Caribbeans even after controlling for conventional risk factors. There are highly significant ethnic differences in the distribution of many potential cerebrovascular candidate genes. Although those we examined did not explain the ethnic differences in IMT, other genetic predispositions or environmental exposures could account for these differences.
生活在英国的非洲裔加勒比人中风风险增加。其原因尚未完全明确，但遗传易感性差异或其他新的中风风险因素可能起了作用。据报道，美国黑人经超声测量的颈总动脉壁厚度增加，即内膜中层厚度（IMT）增加。我们比较了英国非洲裔加勒比人和英国白人的颈动脉IMT，并确定潜在候选血管基因多态性的不同分布、慢性炎症或感染指标的差异是否能解释任何差异。
在一项人群研究中，测量了202名白人男性和89名非洲裔加勒比男性的颈总动脉IMT。确定了血管紧张素转换酶（ACE）、对氧磷酶1、对氧磷酶2和亚甲基四氢叶酸还原酶基因多态性的分布。测定了血清C反应蛋白和幽门螺杆菌血清阳性率。
即使在控制了包括同型半胱氨酸和社会阶层在内的心血管危险因素后，非洲裔加勒比人的颈动脉IMT仍增加：β=0.113，95%可信区间为0.036至0.189，P=0.004。吸烟与平均IMT之间存在显著交互作用（P=0.022），种族间IMT的两种测量差异在很大程度上仅限于从不吸烟的个体。在所研究的4个候选基因中的3个（ACE、对氧磷酶1和亚甲基四氢叶酸还原酶）分布存在显著种族差异。非洲裔加勒比人的幽门螺杆菌血清阳性率增加（78.7%，而英国白人中为53%）。然而，基因多态性和幽门螺杆菌血清阳性率均与IMT无关，其分布的种族差异也不能解释非洲裔加勒比人IMT增加的现象。
即使在控制了传统危险因素后，英国非洲裔加勒比人的颈动脉IMT仍增加。许多潜在脑血管候选基因的分布存在高度显著的种族差异。虽然我们研究的这些基因不能解释IMT的种族差异，但其他遗传易感性或环境暴露可能解释这些差异。
