中文摘要：

目的分析广州居民膳食n-3脂肪酸摄入水平与血脂的关系。方法志愿者形式招募40～75岁广州市民,采用定量食物频数问卷调查研究对象每日食物摄入种类及数量,计算能量及营养素,特别是n-3脂肪酸含量。检测空腹血脂4项。将膳食n-3脂肪酸摄入量四分位分组分析其与血脂的相关关系。结果共招募3974名研究对象,其膳食总能量摄入量为（7.68±2.24）MJ/d、脂肪供能比为（33.1±7.8）%,饱和脂肪酸供能比为（8.3±2.2）%。膳食n-3脂肪酸摄入量为（1.29±1.02）g/d,其中α-亚麻酸（ALA）为（1.18±0.99）g/d[（0.58±0.42）%energy],二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）为（99.50±103.09）mg/d。校正年龄、性别、BMI、总能量、饱和脂肪酸及膳食n-6脂肪酸摄入量等混杂因素后,膳食ALA摄入量与空腹血清总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）及低密度脂蛋白胆固醇（LDL-C）呈剂量依赖的负相关关系（P〈0.05）,Q4（2.23g/d）的TC、HDL-C及LDL-C显著低于Q1（0.47g/d）（P〈0.05）;膳食EPA＋DHA摄入量与TG及HDL-C也呈线性负相关关系（P﹤0.05）,Q1（26.40 mg/d）的TG及HDL-C水平显著高于其他3组（P〈0.05）。结论与ALA和EPA＋DHA摄入量分别为0.47 g/d和26.40 mg/d相比,摄入量达到2.23 g/d和200.30 mg/d时有利于将血脂维持在较低水平。

英文摘要：

Objective To investigate the associations betweens dietary n-3 fatty acid consumption and serum lipids in middle-aged and older adults in Guangzhou. Methods In this cross-sectional study, 3974 Guangzhou residents aged between 40-75 years were enrolled. Dietary n-3 fatty acids and other nutrients intakes were assessed by quantitative food frequency questionnaire（FFQ）. Fasting serum total cholesterol（TC）, triglycerides（TG）, low density lipoprotein cholesterol（LDL-C）, high density lipoprotein cholesterol（HDL-C） were detected. Results The daily dietary energy intake was（7.68±2.24） MJ. Fat energy ratio was（33.1±7.8）%, and saturated fat energy ratio was（8.3±2.2）%. Total daily dietary n-3 fatty acid consumption was（1.29±1.02）g, in which linolenic acid（ALA） intake was（1.18±0.99）g [（0.58±0.42）% energy] and eicosapntemacnioc acid（EPA）＋docosehexaenoic acid（DHA） was（99.50±103.09） mg. After adjustment for age, sex, BMI, total energy, saturated fatty acids and n-6 fatty acids intakes and other confounders, dietary ALA was inversely associated with serum TC, TG, HDL-C, and LDL-C（P〈0.05）. Compared with the lowest quartile（0.47 g/d）, subjects in the highest quartile（2.23 g/d） had lower levels of TC, HDL-C, and LDL-C（P〈0.05）. Dietary EPA＋DHA was also inversely associated with TG and HDL-C（P〈0.05）. The levels of TG and HDL-C were significantly decreased in the higher three quartiles than that in the lowest quartile（26.40 mg/d）（P〈0.05）. Conclusion Subjects with higher consumptions of ALA（2.23 g/d） and EPA＋DHA （200.30 mg/d） had lower levels of serum lipids than those with lower consumptions of ALA（0.47 g/d） and EPA＋DHA（26.40 mg/d）.