Causal associations between childhood obesity and delayed puberty or height: a bidirectional two-sample Mendelian randomization study.

Objectives: Childhood obesity is thought to influence pubertal development, according to observational studies. However, the exact causal relationship remains unclear due to the complexity of factors affecting pubertal development.

Methods: To explore the association between exposure (childhood obesity) and outcome (delayed puberty, height), we utilized various methods, including inverse-variance weighted (IVW), weighted median, weighted mode, and MR Egger regression. Additionally, sensitivity analyses were conducted using MR-Egger, MR-PRESSO, Cochran's Q, and leave-one-out techniques to ensure the robustness of the results. Additionally, reverse MR analysis was conducted to explore potential reverse causation.

Results: The IVW analysis revealed no significant genetic causal link between childhood obesity and delayed puberty or height (all p>0.05). In the reverse analysis, height had a causal association with childhood obesity (OR=0.85, 95 % CI=0.76-0.96). The Cochran's Q test highlighted heterogeneity in the results concerning childhood obesity and height (p<0.05). But the MR-Egger intercept and MR-PRESSO test confirmed no impact the results pleiotropic bias, supported by leave-one-out sensitivity analysis.

Conclusions: Our study found no significant genetic causal association between childhood obesity and delayed puberty or height. However, height was causally associated with childhood obesity. Future research should utilize advanced analytical methods to better understand the determinants of pubertal development.