[Association of lead exposure with stunting and underweight among children aged 3-5 years in China].

<b>Objective:</b> To evaluate the association of lead exposure with stunting and underweight among children aged 3-5 years in China. <b>Methods:</b> Data was collected from China National Human Biomonitoring (CNHBM) between January 2017 and December 2018. A total of 3 554 children aged 3-5 years were included. Demographic characteristic, lifestyle and nutritional status were collected through questionnaires. Height and weight were measured by standardized method. Stunting and underweight status were determined by calculating height for age <i>Z</i>-score and weight for age <i>Z</i>-score. Blood and urine samples were collected to detect the concentrations of blood lead, urinary lead and urinary creatinine. Children were stratified into 4 groups (<i>Q</i>₁ to <i>Q</i>₄) by quartiles of blood lead level and corrected urinary lead level, respectively. Complex sampling logistic regression models were applied to evaluate the association of the blood lead level, urinary lead level with stunting and underweight. <b>Results:</b> Among 3 554 children, the age was (4.09±1.06) years, of which 1 779 (80.64%) were female and 1 948 (55.84%) were urban residents. The prevalence of stunting and wasting was 7.34% and 2.96%, respectively. The <i>M (Q</i>₁<i>, Q</i>₃<i>)</i> for blood lead levels and urinary lead levels in children was 17.49 (12.80, 24.71) μg/L, 1.20 (0.61, 2.14) μg/g Cr, respectively. After adjusting for confounding factors, compared with the lowest blood lead concentration group <i>Q</i>₁, the risk of stunting gradually increased in the <i>Q</i>₃ and <i>Q</i>₄ group (<i>P_trend</i>=0.010), with <i>OR</i> (95%<i>CI</i>) values of 1.40 (0.80-2.46) and 1.80 (1.07-3.04), respectively. Compared with the lowest urinary lead concentration group <i>Q</i>₁, the risk of stunting still increased in the <i>Q</i>₃ and <i>Q</i>₄ group (<i>P_trend</i>=0.012), with <i>OR</i> (95%<i>CI</i>) values of 1.69 (1.01-2.84) and 1.79 (1.05-3.06), respectively. The correlation between the lead exposure and underweight was not statistically significant (<i>P</i>>0.05). <b>Conclusion:</b> Lead exposure is positively associated with the risk of stunting among children aged 3-5 years in China.