端粒长度介导老年人膳食n-3 PUFAs摄入量与认知功能之间的关联性：一项横断面研究

Telomere length mediates the association between dietary n-3 PUFAs intake and cognitive function： A cross-sectional study

摘要

目的 本研究旨在探讨老年人膳食n-3多不饱和脂肪酸（n-3 polyunsaturated fatty acids,n-3 PUFAs）摄入量与认知功能之间的关联,并探索白细胞端粒长度的中介作用。方法 利用1999—2002年美国国家健康与营养调查（National Health and Nutrition Examination Survey,NHANES）数据库开展横断面研究,最终分析了2 228例符合纳入标准的参与者,通过24 h膳食回忆访谈评估n-3 PUFAs摄入量,采用定量聚合酶链反应量化白细胞端粒长度,借助韦氏成人智力量表Ⅲ数字符号替换测试测定认知功能。运用多元线性回归模型和亚组模型分析膳食n-3 PUFAs摄入量、白细胞端粒长度与认知功能之间的关联性,限制性立方样条分析膳食n-3 PUFAs摄入量与认知功能、白细胞端粒长度的剂量-反应关系,建立中介模型分析白细胞端粒长度在其中的中介作用。结果 多元线性回归结果显示膳食n-3 PUFAs摄入量（P<0.001）与白细胞端粒长度（P=0.044）是认知功能的影响因素。限制性立方样条模型分析显示膳食n-3 PUFAs摄入量与认知功能呈显著非线性正相关（P<0.001）;白细胞端粒长度与认知功能未检测到显著非线性趋势（P=0.516）。亚组分析显示,膳食n-3 PUFAs与认知功能的正向关联在年龄（P<0.001）、性别（P>0.05）等亚组中均显著且无交互作用;与白细胞端粒长度的关联仅在饮酒史（是）、无高血压亚组中显著,各分层变量无交互作用（P>0.05）。中介模型显示,白细胞端粒长度在膳食n-3 PUFAs摄入量与认知功能之间起部分中介作用,贡献率为1.400%。结论 白细胞端粒长度介导了老年人膳食n-3 PUFAs摄入与认知功能之间的关联性。

Abstract

Objective To investigate the association between dietary intake of n-3 polyunsaturated fatty acids （n-3 PUFAs） and cognitive function in elderly individuals, and to explore the mediating role of leukocyte telomere length. Methods A cross-sectional study was conducted using data from the 1999—2002 National Health and Nutrition Examination Survey （NHANES）. Finally, 2 228 participants who met the inclusion criteria were analyzed. A 24-hour dietary recall interview was used to evaluate the dietary intake of n-3 PUFAs. Quantitative polymerase chain reaction （qPCR） was used to quantify leukocyte telomere length. The Wechsler Adult Intelligence Scale-Ⅲ Digit Symbol Substitution Test was used to measure cognitive function. Mutiple linear regression models and subgroup models were used to analyze the association of dietary intake of n-3 PUFAs and leukocyte telomere length with cognitive function. Restricted cubic spline analysis was used to examine the dose-response relationship of dietary intake of n-3 PUFAs with cognitive function and leukocyte telomere length. A mediation model was established to analyze the mediating role of leukocyte telomere length in this relationship. Results The multiple linear regression results showed that dietary n-3 PUFAs intake （P<0.001） and leukocyte telomere length （P=0.044） were influencing factors of cognitive function. Restricted cubic spline model analysis revealed that dietary intake of n-3 PUFAs showed a significant nonlinear positive correlation with cognitive function （P<0.001）, but no significant nonlinear trend was detected between leukocyte telomere length and cognitive function （P=0.516）. Subgroup analysis revealed that the positive association between dietary n-3 PUFAs and cognitive function remained significant across all subgroups stratified by age and gender, with no significant interaction （P<0.001, P>0.050）. The association with leukocyte telomere length was significant only in subgroups with a history of alcohol consumption and without hypertension, with no significant interactions across stratification variables （P>0.050）. The mediation model indicated that leukocyte telomere length partially mediated the relationship between dietary intake of n-3 PUFAs and cognitive function, with a contribution rate of 1.400%. Conclusion The findings indicate that leukocyte telomere length mediates the association between dietary intake of n-3 PUFAs and cognitive function in elderly individuals.

关键词

脂肪酸类,ω3 / 白细胞端粒长度 / 认知功能

Key words

fatty acids,omega-3 / leukocyte telomere length / cognitive function