Association between urinary methylparaben level and bone mineral density in children and adolescents aged 8-19 years

Previous epidemiological study has explored a positive association between methylparaben (Mep) and bone mineral density (BMD) in adults. Evidence linking Mep and BMD in children and adolescents is very limited. This study examined the association between Mep and BMD in children and adolescents aged 8-19 years. In this cross-sectional study, 1830 children and adolescents aged 8-19 years from NHANES 2011-2016 were analyzed. Mep was ln-transformed for analysis of the skewed distribution. Multiple linear regression analyses were performed to evaluate Mep's association with BMD (containing total BMD, trunk bone BMD, pelvis BMD, lumbar spine BMD, and thoracic spine BMD). Moreover, a generalized additive model (GAM) and a fitted smoothing curve (penalized spline method) were conducted to explore the exact shape of curve between them. In the fully adjusted model, ln- transformed Mep and BMD showed an independent and positive association (total BMD (beta = 0.003, 95% CI (0.001, 0.005), P = 0.01), trunk bone BMD (beta = 0.002, 95% CI (0.000, 0.005), P = 0.04), pelvis BMD (beta = 0.004, 95% CI (0.001, 0.008), P = 0.02), lumbar spine BMD (beta = 0.005, 95% CI (0.001, 0.008), P = 0.01), thoracic spine BMD (beta = 0.003, 95% CI (0.001, 0.005), P = 0.02)) and a linear association. Subgroup analysis showed positive association between ln-transformed Mep and BMD. Furthermore, the positive association was significant in females and children aged 12-19 years (P for trend < 0.05). This study is the first study to find evidence demonstrating that exposure to Mep may be positively associated with BMD in children and adolescents aged 8-19 years. Validation of our findings will need further research.

Automated summary

Previous studies have found a positive association between methylparaben (Mep) and bone mineral density (BMD) in adults, but limited research has been conducted in children and adolescents. This study examined 1830 individuals aged 8-19 years and found a positive association between Mep and BMD. The association was particularly significant in females and children aged 12-19 years.