中年女性每日铁摄入量与痴呆的相关性研究

目的:分析中年女性每日铁摄入量与痴呆的相关性。方法:收集2764份美国妇女健康研究(SWAN)资料,该资料通过参与者或其家属自评问卷的方式评估痴呆,根据评估结果将其分为痴呆组(n=974)和非痴呆对照组(n=1790)。通过1995年版饮食频率调查问卷估算膳食摄入量,比较两组年龄、运动量、家庭收入、种族/国家、血压、血脂、能量摄入等差异,Logistic回归分析膳食中铁摄入量与痴呆的关系,限制性三次样条分析铁摄入量与痴呆的非线性关系。结果:痴呆组与对照组在种族、TG上有差异。此外,痴呆组每日铁摄入量高于对照组(P<0.01),且痴呆组高于推荐铁摄入量(RDA,20mg/天)的人群多于对照组(P<0.01),但总热量、蛋白质、碳水化合物脂肪摄入量在两组之间差异无统计学意义(P>0.05)。总铁摄入量与痴呆呈正相关,这种正相关关系在调整了年龄和充分调整潜在混杂因素的模型中仍然存在。每日铁摄入量>20mg/天者患痴呆风险增加,这种关系在调整了年龄以及整协变量年龄、种族和TG后仍然存在。限制性三次样条回归表明随着铁摄入量的增高,痴呆风险先趋于平稳,而后逐渐升高,当每日铁最大摄入量超过50mg后,风险增加速度明显加快。结论:中年女性每日铁摄入量与痴呆呈正相关关系,但不能断定铁摄入量与痴呆的因果关系。

The Relationship between Daily Iron Intake and Dementia in Middle-aged Women

Objective:To study the relationship between daily iron intake and dementia in middle-age women.Method:The 2764 data were from study of somen's health across the nation(SWAN)in the present study.Dietary intake was estimated by the 1995 dietary frequency questionnaire.According to the evaluation results,they were divided into dementia group(n=974)and non-dementia control group(n=1790).The difference of mean values between the two groups were compared by Mann-Whitney U.Logistic regression was used to analyze the relationship between dietary iron intakes and dementia.The non-linear relationship between them was analyzed by restricted cubic spline.Results:There were differences in race and TG in dementia group.In addition,daily iron intake in dementia group was higher than that in control group(P<0.01),and more people in dementia group had higher iron intake than that recommended by RDA(P<0.01).However,there were no differences in total calories,protein,carbohydrate fat intake(P>0.05).Total iron intake was positively correlated with dementia.With iron intake as the control group,the risk of dementia was significantly increased(P<0.01).This positive correlation still exists in model adjusted for age and model adequately adjusted for potential confounding factors.Daily iron intake higher than RDA(20mg/d)was more likely to suffer from dementia than below RDA.This relationship still exists after adjusting the age.After adjusting the covariate age,race and TG,this relationship still exists.Restricted cubic spline regression showed that the increase of iron intake,the risk of dementia tended to stabilize at first,and then gradually increased.After exceeding the maximum daily iron intake of 50mg,the risk increased rapidly.Conclusion:There was a positive correlation between daily iron intake and dementia in middle-aged women.However,the causal relationship between iron intake and dementia can not be determined.