Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa.
Heart Lung Circ. 2020 Dec;29(12):1823-1831. doi: 10.1016/j.hlc.2020.05.093. Epub 2020 Jun 13.
Leptin is a vasoactive peptide that has been linked to diseases associated with macrovascular deterioration. What is still uncertain is its involvement in the microvasculature. Since microvascular changes are presumed to precede macrovascular deterioration, we examined whether measures of the retinal microvasculature are associated with leptin in healthy, young Black and White individuals.
We included 283 Black and 289 White men and women (aged 20-30 years). We determined serum leptin, calculated central retinal artery and vein equivalents and arterio-venous ratio. We also measured retinal vessel responses to light flicker provocation.
Black men were leaner and had lower leptin than White men, whereas Black women had increased adiposity and leptin compared to White women (all p<0.001). Black groups had narrower retinal arteries, and greater maximum arteriolar and venular dilations in response to light flicker than the White groups (p<0.001). Arterio-venous ratio associated negatively with leptin (all p≤0.044) in all groups (except Black women), but was lost upon adjustment for body mass index and other covariates. We found an inverse association between maximal venular dilation and leptin only in Black men in single and multiple regression analyses (Std β= -0.22; R=0.05; p=0.035). No associations were found between other retinal measures with leptin in the other groups.
We found an independent, negative association between retinal vein dilation with leptin in healthy, young Black men, suggesting a potential detrimental role for leptin in regulating microvascular responses in a population group known to be at greater risk of cardiovascular disease development.
瘦素是一种血管活性肽，与大血管恶化相关疾病有关。但其在微血管中的作用仍不确定。由于微血管变化被认为先于大血管恶化，我们研究了健康的年轻黑人和白人个体中视网膜微血管的测量值是否与瘦素有关。
我们纳入了 283 名黑人男性和 289 名白人男性和女性（年龄 20-30 岁）。我们测定了血清瘦素，计算了视网膜中央动脉和静脉等效物以及动静脉比。我们还测量了视网膜血管对光闪烁刺激的反应。
黑人男性比白人男性更瘦，瘦素水平更低，而黑人女性比白人女性体脂增加，瘦素水平更高（均 p<0.001）。与白人组相比，黑人组的视网膜动脉更窄，对光闪烁刺激的最大动脉和静脉扩张更大（均 p<0.001）。动静脉比与所有组（除黑人女性外）的瘦素呈负相关（均 p≤0.044），但经体重指数和其他协变量调整后，这种相关性消失。我们在单因素和多因素回归分析中仅发现黑人男性的最大静脉扩张与瘦素呈负相关（标准化β=-0.22；R=0.05；p=0.035）。在其他组中，没有发现其他视网膜测量值与瘦素之间存在相关性。
我们发现健康的年轻黑人男性中视网膜静脉扩张与瘦素之间存在独立的负相关，这表明瘦素在调节已知心血管疾病发病风险更高的人群的微血管反应方面可能具有潜在的有害作用。
