Wang Ying, Chung Sang-Jin, McCullough Marjorie L, Song Won O, Fernandez Maria Luz, Koo Sung I, Chun Ock K
Department of Nutritional Sciences, University of Connecticut, Storrs, CT Epidemiology Research Program, American Cancer Society, Atlanta, GA.
Department of Foods and Nutrition, Kookmin University, Seoul, Korea; and.
J Nutr. 2014 Jul;144(7):1067-74. doi: 10.3945/jn.113.184317. Epub 2014 Apr 17.
Hyperlipidemia and elevated circulating C-reactive protein (CRP) and total homocysteine (tHcy) concentrations are cardiovascular disease (CVD) risk factors. Previous studies indicated that higher serum carotenoid concentrations were inversely associated with some of these biomarkers. However, whether dietary carotenoid intake is inversely associated with these CVD risk biomarkers is not well known. We assessed the associations between individual dietary carotenoid intake and CVD risk biomarkers and tested whether the serum carotenoid concentrations explain (mediate) or influence the strength of (moderate) the associations, if any association exists. Dietary data collected from 2 24-h dietary recalls and serum measurements in adult men (n = 1312) and women (n = 1544) from the NHANES 2003-2006 were used. Regression models designed for survey analysis were used to examine the associations between individual dietary carotenoids and log-transformed blood cholesterol, CRP, and tHcy. The corresponding individual serum carotenoid concentration was considered as mediator (and moderator if applicable). After adjustment for covariates, significant inverse associations with LDL cholesterol were observed for dietary β-carotene (P < 0.05) and lutein + zeaxanthin (P < 0.001), and with tHcy for dietary β-carotene (P < 0.05), lycopene (P < 0.05), and total carotenoids (P < 0.05). Dietary lutein + zeaxanthin intake was also positively associated with HDL cholesterol concentrations (P < 0.01). Most of these associations were null after additional adjustment for corresponding serum carotenoid concentrations, indicating the complete mediation effects of serum carotenoids. Serum β-carotene significantly moderated the associations between dietary β-carotene and CRP (P-interaction < 0.05), and quartile 4 of dietary β-carotene was associated with lower CRP concentrations only among participants with serum β-carotene > 0.43 μmol/L. In this population-based cross-sectional study, serum carotenoids were mediators of dietary carotenoids and CVD risk biomarker associations. Serum β-carotene was also a moderator of the dietary β-carotene and CRP association. These findings may help in the design of future intervention studies on dietary carotenoids in the prevention of CVD.
高脂血症以及循环中C反应蛋白（CRP）和总同型半胱氨酸（tHcy）浓度升高是心血管疾病（CVD）的危险因素。先前的研究表明，较高的血清类胡萝卜素浓度与其中一些生物标志物呈负相关。然而，饮食中类胡萝卜素的摄入量是否与这些CVD风险生物标志物呈负相关尚不清楚。我们评估了个体饮食中类胡萝卜素摄入量与CVD风险生物标志物之间的关联，并测试了血清类胡萝卜素浓度是否解释（介导）或影响（调节）这些关联的强度（如果存在任何关联）。使用了从2003 - 2006年美国国家健康与营养检查调查（NHANES）中成年男性（n = 1312）和女性（n = 1544）收集的2次24小时饮食回忆数据和血清测量数据。用于调查分析的回归模型用于检验个体饮食类胡萝卜素与对数转换后的血胆固醇、CRP和tHcy之间的关联。相应的个体血清类胡萝卜素浓度被视为中介变量（以及适用时的调节变量）。在调整协变量后，观察到饮食中的β - 胡萝卜素（P < 0.05）和叶黄素 + 玉米黄质（P < 0.001）与低密度脂蛋白胆固醇呈显著负相关，饮食中的β - 胡萝卜素（P < 0.05）、番茄红素（P < 0.05）和总类胡萝卜素（P < 0.05）与tHcy呈负相关。饮食中叶黄素 + 玉米黄质的摄入量也与高密度脂蛋白胆固醇浓度呈正相关（P < 0.01）。在对相应血清类胡萝卜素浓度进行额外调整后，这些关联大多无效，表明血清类胡萝卜素具有完全的中介作用。血清β - 胡萝卜素显著调节了饮食中的β - 胡萝卜素与CRP之间的关联（P交互作用 < 0.05），并且仅在血清β - 胡萝卜素> 0.43 μmol/L的参与者中，饮食中β - 胡萝卜素的第4四分位数与较低的CRP浓度相关。在这项基于人群的横断面研究中，血清类胡萝卜素是饮食类胡萝卜素与CVD风险生物标志物关联的中介变量。血清β - 胡萝卜素也是饮食中的β - 胡萝卜素与CRP关联的调节变量。这些发现可能有助于设计未来关于饮食类胡萝卜素预防CVD的干预研究。
