Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.
Department of Biomedical Engineering and Technomathematics, Aachen University of Applied Sciences, Juelich, Germany.
Microvasc Res. 2020 Mar;128:103937. doi: 10.1016/j.mvr.2019.103937. Epub 2019 Oct 20.
Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults.
We included 112 black and 143 white healthy normotensive adults (20-30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected.
The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8%; p < .001).
Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation.
在全球范围内，一些黑人群体报告称心血管疾病风险因素发生了不利转变，死亡率水平更高。视网膜微血管为系统性血管疾病的发病机制提供了早期认识，但尚不清楚年轻健康的黑人和白人成年人之间视网膜血管直径和急性视网膜血管功能反应是否存在差异。
我们纳入了 112 名黑人健康的血压正常成年人和 143 名白人健康的血压正常成年人（年龄 20-30 岁）。从视网膜图像中计算视网膜血管直径（中央视网膜动脉和静脉当量（CRAE 和 CRVE）），并确定对闪烁光诱导激发（FLIP）的血管直径反应。此外，还收集了动态血压（BP）、人体测量学和血液样本。
两组人群的 24 小时 BP 谱和人体测量学特征相似（均 P>.24）。与白人组相比，黑人组的 CRAE 更小（158±11 比 164±11 MU，P<.001），而 CRVE 相似（P=.57）。在 FLIP 反应中，黑人组的动脉最大扩张大于白人组（5.6±2.1 比 3.3±1.8%；P<.001）。
健康的黑人成年人在年轻时视网膜动脉就比白人人群狭窄。正在进行后续研究以表明这是否与高血压发展风险增加有关。黑人人群对 FLIP 的血管扩张反应更大的原因尚不清楚，需要进一步研究。
