Influence of the physical growth indicators of primary and middle school students on hemoglobin in different economic zones of Ningxia

Abstract

Objective To estimate the detection rate of low hemoglobin among primary and middle school students in Ningxia, and to explore association between physical growth indicators with level of hemoglobin in different economic zones from both the student and school levels, and to provide an effective basis for anemia prevention of primary and secondary school students.

Methods The stratified random cluster sampling method was used to measure 5 447 primary and middle school students physical growth indicators and hemoglobin values. Prevalence of low hemoglobin was described and its association with physical growth indicators were analyzed through HLM models.

Results The detection rate of low hemoglobin among primary and middle school students was 12.7%, of which 13.0% were boys and 12.4% were girls, without significant gender differences (χ ² = 0.43, P>0.05). Low hemoglobin in rural areas was higher than urban areas, as well as in the low-age group which was 18.5%, 12.6%, 8.3%, 11.5% in the 7, 9, 12, and 14-year-old groups, respectively, and the differences between the groups were statistically significant (χ ² = 43.49, 68.13, P<0.05) . The wasting group had the highest detection rate of low hemoglobin, and low hemoglobin in obesity and overweight was lower than that of the normal group, with significant differences between groups ( Z= 2. 08 P<0.05) . Positive association between height and weight with hemoglobin was observed (γ ₃₀ =0.13, γ ₄₀ =0.06), and the association of hip circumference with hemoglobin was negative (γ ₅₀ = -0.02). Body weight had a significant associated with the hemoglobin value in different economic film in- tervals ( P<0.05).

Conclusion The detection rate of low hemoglobin is relatively high among primary and middle school students in rural areas, low-age groups, and wasting groups in Ningxia. The differences between school groups are significant, and it is necessary to mine school-level variables.

Abstract

【摘要】 目的 分析中小学生身体形态指标在不同经济片区间对血红蛋白的影响, 为改善中小学生低血红蛋白状况提供 有效依据。 方法 采用分层随机整群抽样法, 测量宁夏地区 5 447 名中小学生身体形态指标及血红蛋白, 描述低血红蛋白 检出情况, 并通过多层线性模型 (HLM模型) 分析身体形态指标在不同经济片区间对血红蛋白的影响。 结果 中小学生低 血红蛋白检出率为12.7%, 其中男生为 13.0%, 女生为 12.4%, 差异无统计学意义 (χ ²=0.43, P>0.05)。农村髙于城市;低年 龄组的检出率较髙, 7,9, 12, 14岁组分别为 18.5%, 12.6%, 8.3%, 11.5%, 差异均有统计学意义 (χ ² 值分别为 43.49,68.13, P 值均<0.05); 消瘦组学生低血红蛋白检出率最髙, 肥胖、超重组检出率低于正常组, 差异有统计学意义 ( Z = 2.08, P<0.05)。 身髙、体重对学生血红蛋白呈正向影响 (γ ₃₀ = 0.13, γ ₄₀= 0.06), 臀围对学生血红蛋白呈负向影响 (γ ₅₀ = -0.02)。体重在不同 经济片区间对血红蛋白的影响有统计学意义 ( P<0.05)。 结论 宁夏地区农村、低年龄组、消瘦组中小学生的低血红蛋白 检出率偏髙。学校群组之间存在差异, 需要对学校层面的变量进行挖掘。