中国南北两县810名老年人红细胞叶酸营养状况及其地区差异调查

Folate status in the red blood cell and related geographical differences among 810 with 65- to 74- year-old population of two counties in Southern and Northern China

目的了解中国南北方部分地区老年人的红细胞叶酸水平，评价红细胞叶酸与血浆叶酸水平的相关性。方法在江苏省张家港市（南方）和河北省石家庄市元氏县（北方）募集810名65—74岁老年人，采集空腹静脉血标本，应用96孔板微生物法检测红细胞叶酸水平，经自然对数转换后，用t检验进行红细胞叶酸平均水平的比较；用x2检验进行红细胞叶酸缺乏率的比较。结果南方老年人群红细胞叶酸平均水平为1083．3nm01／L（95％CI：1034．1。1134．8），北方为489．1nmol／L（95％CI：466．7—512．6），南方是北方的2．2倍（t=23．684，P〈0．001）。南方老年人群红细胞叶酸缺乏率为1．O％，北方为28．9％，南北方差异有统计学意义（x2=124．06，P〈0．001）。红细胞叶酸水平与血浆叶酸水平呈正相关，相关系数为0．49（P〈0．001）；在控制了地区、性别、年龄组、BMI分组、文化程度、吸烟及饮酒暴露情况后，调整相关系数为0．38（P〈0．001）。结论中国65～74岁老年人群的红细胞叶酸营养状况有显著地区差异，南方老年人红细胞叶酸水平高于北方，但缺乏率却低于北方，红细胞叶酸水平与血浆叶酸水平呈正相关。

Objective To assess the red blood cell （RBC） folate status among Chinese elderly population and its geographical differences between Southern and Northern regions, and to evaluate the correlation between RBC and plasma folate. Methods This study was conducted in two counties of Jiangsu and Hebei provinces of China. A total of 810 individuals aged 65-74 years were recruited. RBC folate in blood samples was measured by microbiological assay. Data on RBC folate was log-transformed before analysis. Means of RBC folate concentration were compared by t-test, and the prevalence rates of RBC folate deficiency for different characteristics were compared by Z2 test. Results The geometric mean ofRBC folate concentration was 1083.3 nmol/L（95%CI： 1034.1- 1134.8） among the Southerners and 489.1 nmol/L （95%CI： 466.7-512.6） among the Northerners, with the former being 2.2 times of the latter （t=23.684, P〈0.001）. The prevalence rates of RBC folate deficiency were 1.0% in the South and 28.9% in the North （x2=124.06, P〈0.001）. The concentrations of RBC folate were positively correlated with plasma folate （r = 0.49, P〈 0.001 ）. After adjustment for region, sex, age, BMI, education, exposure to tobacco smoking and alcohol consumption, the correlation remained significant （r=0.38, P〈0.001）. Condusion In 810 Chinese elderly population aged 65-74 from the two counties, Southerners had a higher RBC folate concentration and a lower deficiency prevalence than those in the Northerners. The RBC folate concentration was positively associated with plasma folate.