安徽省2周岁内母乳与非母乳喂养儿童血清维生素A水平比较分析

目的了解母乳与非母乳喂养儿童中血清维生素A水平是否存在差异以及造成差异可能原因。方法研究数据来自人群为基础的儿童维生素A营养状况横断面调查,共调查401名 0-23月龄儿童。采用改良的荧光方法测定血清中视黄醇含量来反映维生素A水平,通过问卷方法调查儿童的家庭社会经济、围产期保健、2周内患病情况;半定量膳食频率问卷调查前1周内儿童膳食情况。利用SAS 8．1软件进行统计分析。结果 401名2岁内儿童中,母乳喂养率为50．37％;非母乳喂养组维生素A平均水平为(30．67±0．57)μg／dl,母乳喂养组为(27．60±0．56)μg/dl,两组差异有统计学意义(P<0．01);在控制其他因素影响后,调整后的非母乳喂养组均值为(31．82±0．98)μg／dl, 母乳喂养组为(29．46±0．96)μg／dl,差异有统计学意义(P<0．01)。按年龄组分层分析显示,0月龄～、6月龄～、12月龄～和18月龄～组的母乳喂养率分别92．1％、70．1％、32．0％和17．1％。各年龄组内两组间(非母乳喂养组-母乳喂养组)维生素A均值差值及其95％可信区间(CI)分别为4．70 (-2．52-1.92)、0．82(-2.32-3．95)、2．95(-0．68-6．58)和6．05(2．34-9．77)μg／dl;控制其他混杂因素后,调整后的两组均值差值及其95％CI分别为0．00(-7．18-7．19)、1．35(-1．76-4．45)、 2．92(-0．82-6．65)和4.26(0．71-7．81)μg/dl;调整前、后只有18月龄组非母乳喂养组和母乳喂养组维生素A水平差异有统计学意义(P<0．01)。趋势x2检验表明12月龄以后母乳喂养儿童辅食添加频率均比非母乳喂养儿童低。结论与非母乳喂养儿童相比,母乳喂养儿童的体内维生素A水平有所降低,但差别只是局限在18月龄以后儿童中。母乳中维生素A含量不足以及辅食添加不充分可能是造成这种差异潜在原因。控制人群中维生素A缺乏应该采取综合干预措施。

Differences in serum retinol level between the breastfed and non-breastfed children aged 0 to 23 months

OBJECTIVE: Some recent studies found that high prevalence of vitamin A deficiency in the breastfed children. This study aimed to understand the differences in serum retinol level between breastfed and bottle-fed children aged 0 to 23 months and the possible causes of low level of serum retinol for the breastfed children. METHODS: Data for children aged 0 to 23 months were extracted from a population-based cross sectional study for vitamin A nutrition status. Fluorescence method was used to measure the serum retinol. Mothers or caregivers were asked to answer a pre-designed questionnaire and socioeconomic status, peri-natal care, breastfeeding status, morbidity histories and other related factors were collected. Semi-quantitative food frequency questionnaire was used to investigate the child's dietary intake one week prior to the survey. Data were analyzed using SAS 8.1. RESULTS: Of 401 children aged 0 to 23 months, the breastfeeding rate was 50.37%. The means of the serum retinol level between bottle-fed (30.67 +/- 0.57) microg/dl and the breastfed children (27.60 +/- 0.56) microg/dl was significantly different (P < 0.01). The corresponding figures were (31.82 +/- 0.98) microg/dl and (29.46 +/- 0.96) microg/dl after adjustment for confounders, which also showed significant difference (P < 0.01). After stratified by age groups, the breastfeeding rates in the 0-, 6-, 12- and 18-months groups were 92.1%, 70.1%, 32.0% and 17.1%, respectively. We calculated the difference in means of the serum retinol level between the bottle-fed and breastfed children for each of four age groups, and the 95% confidence limits of the differences. The differences in means and the 95% confidence limits for 0-, 6-, 12- and 18-months group were 4.70 microg/dl (-2.52-1.92), 0.82 microg/dl (-2.32-3.95), 2.95 microg/dl (-0.68-6.58) and 6.05 microg/dl (2.34-9.77), respectively. After adjustment for confounders and covariates, the adjusted figures were 0.00 microg/dl (-7.18-7.19), 1.35 microg/dl (-1.76-4.45), 2.92 microg/dl (-0.82-6.65) and 4.26 microg/dl (0.71-7.81), respectively. The significant difference in means of serum retinol level was only found in the 18-months group before or after adjustments (P < 0.01 for both). The Cochrane-Atmitage chi square trend test showed that the breastfed children tended to have lower frequencies of complementary dietary intakes than that of the bottle-fed aged 12 months and above. CONCLUSIONS: The breastfed children aged 0 to 23 months had relative low serum retinol level while compared with the bottle-fed. However, the significant differences seemed to be only confined to those aged 18 months and above. Low level of vitamin A in breast milk and low frequent complimentary food supplements might have served as the potential for the differences.