【作者】 王伟；

【导师】 张万起；

【作者基本信息】 天津医科大学 ， 营养与食品卫生学， 2019， 博士

【摘要】 目的1)观测健康妊娠期妇女达到“零点平衡”时碘的摄入量,探讨符合我国不同妊娠期妇女的碘推荐摄入量,为我国妊娠期妇女的碘参考摄入量的标准修订提供数据资料;2)观测中国健康妊娠期妇女24小时尿肌酐排出量的范围,探索尿碘/肌酐比值数据应用于评价妊娠期妇女碘营养的可能方式,为准确简便地评估妊娠期妇女碘营养状况提供方法学支持。方法碘平衡研究以我国健康妊娠期妇女为研究对象,纳入山东、天津以及河北三个地区的妊娠早、中、晚期妇女进行碘平衡实验研究。采用双份饭法收集连续七日24小时食物、饮用水样、记录每日饮水量、采集24小时尿液、粪便样品。检测各样本中碘含量,估算每日吸气碘摄入量、呼气碘排出量、汗液碘排出量,计算每日总碘摄入量和每日总碘排出量。根据碘平衡值=碘摄入量?碘排出量,通过模型拟合计算达到“零点平衡”时的碘摄入量。结合不同碘摄入量的动物干预模型实验,探讨妊娠期妇女碘平衡实验过程中发现的“零点平衡”随碘摄入量升高而升高现象的可能解释。妊娠期妇女尿碘/肌酐比值研究,以不同碘营养状况下的健康妊娠期妇女为研究对象,采用双份饭法收集连续七日24小时食物、饮用水样、记录每日饮水量、采集24小时尿液,并收集两次随机尿样本。检测样本碘含量及尿样肌酐含量,计算妊娠期妇女每日总碘摄入量、24小时尿碘排出量和24小时尿肌酐排出量。通过拟合数学模型,讨论UI/Cr合理的应用方式。结果共收集130名妊娠期妇女志愿者平衡实验样本,其中122例志愿者数据纳入分析:妊娠早期30人,妊娠中期54人,妊娠晚期38人。志愿者平均年龄29.8岁,平均孕周22.0周。纳入分析的数据包括773天次平衡试验样本信息,包括妊娠早中晚期各182、354、237天次的双份饭样本3092份,饮水量773例,24小时尿样773份,粪便样本559份。碘适宜的妊娠早、中、晚期妇女每日总碘摄入量分别为271.2μg/d、274.9μg/d、315.6μg/d,差异无统计学意义(P=0.05);每日总碘排出量分别为220.0μg/d、293.2μg/d、287.5μg/d,差异亦无统计学意义(P=0.06)。不同妊娠期的碘平衡值总体上无统计学上的差异(P=0.66)。妊娠早中晚期对应碘的“零点平衡”值,即拟合线X轴的截距分别为353.0μg、310.6μg、314.4μg。总体零点平衡值为313.2μg。分析发现,长期生活在高水碘地区的妊娠期妇女,每日总碘摄入量和总碘排出量均要高于生活在一般环境下的妊娠期妇女,并且计算所得碘的“零点平衡”值同样高于生活在一般环境下的妊娠期妇女的该值。这一人群结果在动物模型实验中得到了验证。妊娠期大鼠经灌胃干预后每日分别摄入7.53μg、62.69μg、308.68μg碘,所计算每日碘平衡值均值分别为3.39μg、18.57μg、87.85μg。可知受孕大鼠的碘平衡值同样受每日碘摄入总量的影响。妊娠期妇女24小时尿肌酐排出量为1.17(95%CI 1.11,1.22)g。不同妊娠期妇女24小时尿肌酐排出量差异无统计学意义(P=0.119)。24小时尿碘排出量全距为(33,2022)μg/d;尿碘/肌酐比值全距为(32,1203)μg/g;每日碘摄入量全距为(26,2139)μg/d。相比尿碘浓度,尿碘/肌酐比值与24小时尿碘排出量、每日碘摄入量均具有更高的相关性(P<0.05)。尿碘/肌酐比值比尿碘浓度可以更好地反映24小时尿碘排出量和每日碘摄入量。以尿碘/肌酐比值5μg/g为组距,制定尿碘/肌酐比值相对应的24小时尿碘排出量和每日碘摄入量理论值,绘制查询对照表,方便查询。结论1)妊娠期妇女总体计算零点平衡值为313.2μg/day;2)妊娠期妇女长期摄入过量碘,计算所得碘平衡值会升高;3)妊娠期妇女24小时尿肌酐排出量为1.17 g,制定与UI/Cr相对应的24小时尿碘排出量和每日碘摄入量理想值,可用于妊娠期妇女碘营养评价。更多还原

【Abstract】 Objective: 1)To observe the iodine intake of healthy pregnant women at zero iodine balance,and to explore the recommended iodine intake of Chinese women with different gestational stages.2)To explore the range of 24 hour urinary creatinine excretion in healthy Chinese pregnant women,and a possible method for evaluating iodine nutritional status in pregnant women by using the data of urinary iodinecreatinine ratio.Method: The iodine balance study took healthy Chinese pregnant women as the object including the early,middle and late pregnancy in three regions of Shandong province,Tianjin City and Hebei Province.For seven consecutive days,duplicate diets,drinking water,24-hour urine samples,and daily feces of the pregnant women were collected and record the daily water intakewas recorded.The iodine content of each sample was detected and estimate daily iodine intake by inspiration and iodine excretion by both expiration and sweat.Calculate the daily total iodine intake and excretion.According to the iodine balance value is equal to the iodine intake minus the iodine output,the iodine intake at the zero iodine balance is calculated by the model fitting.Experimental animal models with different iodine intakes were established to explore the possible explanation of the phenomenon that the zero iodine balance value increased with the iodine intake in pregnant women during the iodine balance experiment.The urinary iodine-creatinine ratio using to evaluating iodine nutrional status on pregnant women was studied in healthy Chinese pregnant women recruited in the iodine balance experment with different iodine nutrition status.The rational application of urinary iodine-creatinine ratio was discussed by calculating the mathematical model.Results: Data from 122 volunteers were included in the analysis.The average age of the volunteers was 29.8 years and the average gestational age was 22.0 weeks.The analysis data included balanced experiment samples at 773 days,including data of 3092 double meal samples,773 drinking water samples,773 24 hour urine samples and 559 fecal samples.Total daily iodine intake in early,middle and late pregnancy was 271.2μg/d,274.9μg/d and 315.6μg/d,respectively,and there was no statistical significance(P=0.05).Total daily iodine output was 220.0μg/d,293.2μg/d and 287.5μg/d,respectively,and there was no statistical significance(P=0.06).There was no statistically significant difference in iodine balance between different gestation periods(P=0.66).The corresponding zero-iodine balance value of early,middle and late pregnancy,namely the intercept of fitted line and X axis,was 353.0 μg/d,310.6 μg/d and 314.4 μg/d,respectively.The total zero iodine balance value is 313.2 μg.The analysis found that the daily total iodine intake and total iodine output of pregnant women who lived in areas with high water iodine for a long time were higher than those who lived in general environment and the calculated iodine zero iodine balance is also higher than that of pregnant women living in the general environment.The results for this population were confirmed in animal models.In the present study,the average 24 hour urinary creatinine excretion in pregnant women was 1.17(95%CI 1.11,1.22)g.The 24 hour urinary creatinine excretion in different gestation periods was no statistical significance(P=0.119).The range of 24-hour urinary iodine excretion was(33,2022)μg/d,the range of urinary iodinecreatinine ratio was(32,1203)μg/g,the range of daily iodine intake was(26,2139)μg/d.Compared with urinary iodine concentration,urinary iodine-creatinine ratio has a greater correlation with 24 hour urinary iodine output and daily iodine intake(P<0.05).Urinary iodine-creatinine ratio can better reflect 24 hour urinary iodine output and daily iodine intake than urinary iodine concentration.The ideal values of 24 hour urinary iodine output and daily iodine intake were determined with the urinary iodine-creatinine ratio of 5μg/g as the interval,and the comparison table was drawn to facilitate the query.Conclusions: 1)The total calculated zero-iodine balance value for pregnant women was 313.2μg/d.2)The calculated iodine balance value increases in pregnant women who consume excessive iodine over a long period of time.3)The 24 hour urinary creatinine excretion in healthy Chinese pregnant women was 1.17 g,the ideal values of 24-hour urinary iodine excretion and daily iodine intake corresponding to the urinary iodine-creatinine ratio were calculated and listed out.更多还原