人体高硒负荷与视力状况的关系

Relationship between high body selenium load and eyesight

[目的]硒的生物效应具有两面性,适量硒摄入可维持眼组织营养代谢及视功能正常所需,硒摄入缺乏或过量时也会导致眼组织功能异常。研究发现硒摄入不足可增加患近视的风险,但关于过量硒摄入对近视影响的研究尚不足。本研究旨在探讨适量硒和过量硒摄入人群的视力状况与其血、尿、发中硒含量及血清硒蛋白P(SEPP-1)水平之间的关系。[方法]应用横断面研究方法,选择湖北恩施某土壤高硒地区常住居民作为暴露组,湖北仙桃某土壤适硒地区常住居民作为对照组,根据整群随机抽样原则以及纳入条件要求,最终纳入研究对象303名,其中暴露组154人,对照组149人。通过问卷调查收集研究对象基本情况,应用国际标准视力表检测两组人群视力,采集研究对象血、尿、发并测定其中硒含量及血清SEPP-1水平。比较两组人群视力情况及硒负荷水平,并应用二元logistic回归分析探索血、尿、发中硒元素含量和血清SEPP-1水平与近视发生之间的关系。[结果]暴露组血、尿、发硒含量高于对照组(P<0.05),但SEPP-1水低于对照组(P<0.05)。暴露组与对照组血硒含量在不同血硒等级间的分布不同(Z=-11.42,P<0.05)。两组人群视力检测结果发现,对照组149名调查对象中有40人近视(26.8%),暴露组154名调查对象中有80人近视(51.9%),暴露组人群近视的发生率高于对照组(P<0.001)。研究人群血、尿、发硒含量之间呈中度相关(0.4<r<0.7,P<0.001),但SEPP-1水平与血、尿、发硒含量之间均无明显相关(P>0.05)。近视人群血、尿、发硒含量高于视力正常人群(P<0.01),且调查对象血、尿、发硒含量在不同视力等级间的分布存在差异,随着视力损伤程度的加重而升高(r值分别为0.207、0.160和0.171,P值分别为<0.001、0.006和0.003)。二元logistic回归分析结果显示,在调整了性别、年龄、文化程度、体重指数、吸烟、饮酒因素后,血、尿、发硒含量越高,近视的患病风险也将随之增加,其OR及95%CI分别为7.838(2.533～24.252)、2.431(1.148～5.146)和6.896(2.080～22.831)(P<0.05)。[结论]高硒负荷可能增加人群患近视的风险,视力损伤程度随硒负荷的升高而加重。

[Objective]The biological effects of selenium have two sides.Proper intake of selenium maintains nutrient metabolism and visual function of eyes,but insufficient or excessive intake results in visual dysfunction.Studies have found that insufficient intake of selenium increases the risk of shortsightedness,but there are few reports on the effects of excessive selenium intake on shortsightedness.This study is designed to investigate the relationship of eyesight with selenium levels in blood,urine,and hair,as well as serum selenoprotein P(SEPP-1)level in populations with proper and excessive intake of selenium.[Methods]A cross-sectional study was used to select residents living in Enshi of Hubei Province with a high soil selenium level(exposed group)and Xiantao of Hubei Province with normal soil selenium level(control group).According to the principle of cluster random sampling and the inclusion criteria,the study finally recruited 303 subjects,including 154 residents in the exposed group and 149 residents in the control group.The basic information of subjects were collected through questionnaire.Eyesight was detected with international standard visual acuity chart.Blood,urine,and hair samples were collected to measure respective selenium levels and serum SEPP-1 level.The eyesight and selenium load were compared between the exposed and control groups.Binary logistic regression analysis was applied to explore the relationships of selenium in blood,urine,and hair and serum SEPP-1 with eyesight.[Results]The selenium levels in blood,urine,and hair in the exposed group were significantly higher than those in the control group(P<0.05),but the serum SEPP-1 level was significantly lower(P<0.05).There was a significant difference in the distribution of blood selenium grades between the two groups(Z=-11.42,P<0.05).The results of visual acuity test showed that there were 40 cases with shortsightedness out of 149 subjects(26.8%)in the control group and 80 cases with shortsightedness out of 154 subjects(51.9%)in the exposed group,and the rate of shortsightedness in the exposed group was higher than that in the control group(P<0.001).The levels of selenium in blood,urine,and hair were moderately correlated between each other(0.4<r<0.7,P<0.001),but had no significant relationship with the level of serum SEEP-1(P>0.05).The levels of selenium in blood,urine,hair were significantly higher in the shortsightedness group than those in the normal eyesight group(P<0.01).Moreover,there was a significant difference in the distributions of selenium in blood,urine,and hair among different eyesight grades,and the selenium levels increased with the severity of eyesight impairment(r values were 0.207,0.160,and 0.171,and P values were<0.001,0.006,and 0.003,respectively).The binary logistic regression analysis results turned out that the risk of shortsightedness was higher with the increase of the levels of selenium in blood,urine,and hair(ORs were 7.838,2.431,and 6.896,and 95%CIs were 2.533-24.252,1.148-5.146,and 2.080-22.831 respectively)after adjusting for factors such as sex,age,education level,body mass index,smoking,and drinking.[Conclusion]High selenium load will increase the risk of shortsightedness,and higher selenium load is associated with more severe eyesight impairment.