Sex- and Age-Specific Associations of Blood Lead Levels with Child Growth and Haemoglobin in Bangladesh: A Nationally Representative Study

Evidence on sex- and age-specific associations between lead levels and childhood growth remains limited. We analyzed 10,324 children aged 12–59 months from the Bangladesh Multiple Indicator Cluster Survey 2025 using survey-weighted multivariable linear regression to examine sex- and age-specific associations of blood lead level (BLL) with anthropometric measures and haemoglobin levels. The geometric mean BLL was 4.43 µg/dL, and 66.3% of children had concentrations above the Centers for Disease Control and Prevention (CDC) threshold (≥3.5 µg/dL). Higher BLL was associated with lower height-for-age z-score (HAZ) (β = −0.129, 95% CI: −0.182 to −0.076), weight-for-age z-score (WAZ) (β = −0.108, 95% CI: −0.156 to −0.060), and weight-for-height z-score (WHZ) (β = −0.052, 95% CI: −0.101 to −0.002). Higher BLL was also associated with lower HAZ and WAZ among boys (HAZ: β = −0.114, 95% CI: −0.188 to −0.040; WAZ: β = −0.113, 95% CI: −0.179 to −0.046) and girls (HAZ: β = −0.150, 95% CI: −0.225 to −0.075; WAZ: β = −0.104, 95% CI: −0.171 to −0.036), while higher BLL was associated with lower WHZ among boys (β = −0.076, 95% CI: −0.144 to −0.007). Higher BLL was associated with lower HAZ (β = −0.266, 95% CI: −0.408 to −0.125) and WAZ (β = −0.206, 95% CI: −0.326 to −0.086) among boys aged 24–35 months, while among girls aged 36–59 months, corresponding estimates were −0.211 (95% CI: −0.310 to −0.113) and −0.106 (95% CI: −0.191 to −0.022). The findings suggest that longitudinal studies are needed to clarify the temporal and developmental patterns underlying these associations.