西藏不同海拔地区人群红细胞代谢相关血清学指标分析

  目的  探讨西藏不同海拔地区藏族人群红细胞代谢相关血清学指标特征，并建立各指标的参考区间。  方法  2016年9月—2018年8月，采用整群抽样法随机抽取西藏阿里地区(海拔Ⅰ，海拔4298~4352 m)、拉萨市和日喀则市(海拔Ⅱ，海拔3670~3835 m)、林芝市(海拔Ⅲ，海拔约2900 m)常住人群为研究对象。采集其血液测定全血细胞计数、血清铁(serum iron，SI)、未饱和铁结合力(unsaturated iron binding capacity，UIBC)、转铁蛋白(transferrin，TRF)、铁蛋白(ferritin，FER)、叶酸(folic acid，FA)、维生素B₁₂(vitamin B₁₂，Vit B₁₂)，计算转铁蛋白饱和度(transferrin saturation，TSAT)。采用多元线性回归和方差成分分析比较不同性别/年龄/海拔藏族人群各指标差异，采用转换参数法建立各指标的参考区间。  结果  共纳入藏族人群1128例，其中937例用于参考区间建立。男性SI、TSAT、FER水平显著高于女性，TRF、FA、UIBC显著低于女性(P均 < 0.001)；TRF和UIBC随人群年龄增长而逐渐降低，FER随人群年龄增长而逐渐升高，Vit B₁₂以30~39岁年龄组最高；SI、TSAT、FER和Vit B₁₂随海拔升高而逐渐升高(P均 < 0.001)；TRF、UIBC在海拔Ⅱ人群中最高，海拔Ⅲ人群中最低。各指标参考区间如下:SI在女性中为4.5~35.6 μmol/L，男性为10.6~41.1 μmol/L；UIBC在女性中为19.9~79.5 μmol/L，男性为16.4~63.9 μmol/L；TRF为1.90~3.64 g/L；TSAT在女性中为5.3%~58.2%，男性为16.4%~68.8%；FER在海拔Ⅰ、Ⅱ女性中为4.81~953.15 μg/L，海拔Ⅲ女性为4.85~459.53 μg/L，海拔Ⅰ、Ⅱ男性为50.55~1677.28 μg/L，海拔Ⅲ男性为48.68~1239.30 μg/L；FA为1.96~9.76 μg/L；Vit B₁₂为176.3~1162.3 ng/L。  结论  西藏不同海拔地区人群红细胞代谢相关指标存在性别/年龄/海拔差异，与平原地区居民存在不同，应针对西藏地区建立其人群特异参考区间。

Analysis on Serological Parameters Related to Erythrocyte Metabolism of People in Areas at Different High-altitude in Tibet

  Objective  To explore the characteristics of serological parameters related to erythrocyte metabolism in Tibetans living at different altitudes in Tibet, and to establish the reference intervals of each parameter.  Methods  The cluster-sampling method was used to randomly select residents from Ngari (altitude Ⅰ, 4298-4352 m), Lhasa and Xigaze (altitudeⅡ, 3670-3835 m), and Nyingchi (altitude Ⅲ, about 2900 m) in Tibet from September 2016 to August 2018. Blood samples were collected for the determination of the whole blood-cell count, serum iron (SI), unsaturated ironbinding capacity (UIBC), transferrin (TRF), ferritin (FER), folic acid (FA), and vitamin B₁₂(Vit B₁₂). Transferrin saturation (TSAT) was calculated. Multiple linear regression and variance component analysis were used to compare the differences in gender, age, and altitude for various laboratory parameters among Tibetan population. The reference intervals of the laboratory parameters were established by the transformed parameter method.  Results  A total of 1128 Tibetans were included in this study, of which 937 subjects were used to establish the reference intervals. The levels of SI, TSAT and FER in males were significantly higher than those in females (all P < 0.001). TRF, FA and UIBC in males were significantly lower than those in females (all P < 0.001). TRF and UIBC decreased with age; FER increased with age; the highest Vit B₁₂ was in the 30-39 age group; SI, TSAT, FER and Vit B₁₂ increased with altitude (all P < 0.001); the highest TRF and UIBC were at the altitude Ⅱ and the lowest at the altitude Ⅲ. The reference intervals of each index is shown as follows: 4.5-35.6 μmol/L in females and 10.6-41.1 μmol/L in males for SI; 19.9-79.5 μmol/L in females and 16.4-63.9 μmol/L in males for UIBC; 1.90-3.64 g/L for TRF; 5.3%-58.2% in females and 16.4%-68.8% in males for TSAT; 4.81-953.15 μg/L in females at the altitude Ⅰ and Ⅱ, 4.85-459.53 μg/L in females at the altitude Ⅲ, 50.55-1677.28 μg/L in males at altitude Ⅰ and Ⅱ, and 48.68-1239.30 μg/L in males at altitude Ⅲ for FER; 1.96-9.76 μg/L for FA; 176.3-1162.3 ng/L for Vit B₁₂.  Conclusions  There are gender/age/altitude differences in serological parameters related to erythrocyte metabolism among residents in areas at the high altitude. The distribution is also different from that in plain areas. Therefore, it is necessary to establish specific reference intervals for the population in Tibet.