Nomura Sarah Jo, Robien Kim, Zota Ami R
Office of Minority Health and Health Disparities Research, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC; and
Department of Exercise and Nutrition Sciences and.
J Nutr. 2017 Apr;147(4):538-548. doi: 10.3945/jn.116.243162. Epub 2017 Mar 8.
Leukocyte telomere length (LTL) is a biomarker of the aging process and is associated with the risk of chronic disease. Higher exposure to cadmium may be associated with shorter LTL, and adequate nutrient concentrations may be associated with longer LTL; however, the potential interaction between metals and nutrients on LTL has yet to be examined. The objective of this study was to evaluate whether serum concentrations of vitamins and carotenoids were associated with LTL, and whether they modified the association between blood cadmium and LTL in the US NHANES (1999-2002). We evaluated cross-sectional associations between LTL and serum concentrations of vitamin A, γ-tocopherol, α-tocopherol, folate, and vitamin B-12 (1999-2002; = 7458) and α-carotene, β-carotene, β-cryptoxanthin, lutein + zeaxanthin, and lycopene (2001-2002; = 4018) in a nationally representative sample of US adults (≥20 y of age) with the use of multivariable linear regression. We further investigated whether vitamin and carotenoid concentrations modified associations between blood cadmium and LTL with models stratified by serum nutrient concentrations and the inclusion of an interaction term. Blood cadmium was inversely associated with LTL (percentage of LTL difference per 1 μg/L = -3.74; 95% CI: -5.35, -2.10). Serum vitamin A was positively associated (percentage of LTL difference per 1 μg/L = 4.01; 95% CI: 0.26, 7.90) and γ-tocopherol was inversely associated (percentage of LTL difference per 1 μg/dL = -2.49; 95% CI: -4.21, -0.73) with LTL. Serum folate (-trend = 0.06) and α-tocopherol (-trend = 0.10) were marginally positively associated with LTL, whereas vitamin B-12 (-trend = 0.78) was not associated with LTL. Serum carotenoids were generally positively associated with LTL. Serum vitamin and carotenoid concentrations did not modify blood cadmium and LTL associations (-interaction > 0.10). Results from this cross-sectional study suggest that exposure to cadmium and certain nutrients may be associated with LTL in US adults, but the serum concentrations of the vitamins and carotenoids evaluated did not modify cross-sectional associations between cadmium exposure and LTL.
白细胞端粒长度（LTL）是衰老过程的生物标志物，与慢性病风险相关。更高的镉暴露可能与较短的LTL相关，充足的营养素浓度可能与较长的LTL相关；然而，金属与营养素对LTL的潜在相互作用尚未得到研究。本研究的目的是评估美国国家健康与营养检查调查（1999 - 2002年）中维生素和类胡萝卜素的血清浓度是否与LTL相关，以及它们是否改变血液镉与LTL之间的关联。我们使用多变量线性回归评估了美国成年人（≥20岁）全国代表性样本中LTL与维生素A、γ - 生育酚、α - 生育酚、叶酸和维生素B - 12（1999 - 2002年；n = 7458）以及α - 胡萝卜素、β - 胡萝卜素、β - 隐黄质、叶黄素 + 玉米黄质和番茄红素（2001 - 2002年；n = 4018）血清浓度之间的横断面关联。我们进一步通过按血清营养素浓度分层并纳入交互项的模型，研究维生素和类胡萝卜素浓度是否改变血液镉与LTL之间的关联。血液镉与LTL呈负相关（每1μg/L的LTL差异百分比 = -3.74；95%CI：-5.35，-2.10）。血清维生素A与LTL呈正相关（每1μg/L的LTL差异百分比 = 4.01；95%CI：0.26，7.90），γ - 生育酚与LTL呈负相关（每1μg/dL的LTL差异百分比 = -2.49；95%CI：-4.21，-0.73）。血清叶酸（-趋势 = 0.06）和α - 生育酚（-趋势 = 0.10）与LTL呈微弱正相关，而维生素B - 12（-趋势 = 0.78）与LTL无关。血清类胡萝卜素通常与LTL呈正相关。血清维生素和类胡萝卜素浓度未改变血液镉与LTL之间的关联（-交互作用 > 0.10）。这项横断面研究的结果表明，在美国成年人中，镉暴露和某些营养素可能与LTL相关，但所评估的维生素和类胡萝卜素的血清浓度并未改变镉暴露与LTL之间的横断面关联。
