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

Area of Science:

• Pediatric Endocrinology
• Genetics
• Public Health

Background:

• Childhood obesity is a growing concern with suspected links to pubertal development.
• Observational studies suggest a connection, but causal evidence is limited due to confounding factors.

Purpose of the Study:

• To investigate the potential causal relationship between childhood obesity and pubertal development outcomes (delayed puberty and height).
• To explore potential reverse causation between height and childhood obesity.

Main Methods:

• Utilized Mendelian randomization (MR) with inverse-variance weighted (IVW) analysis.
• Employed various MR methods including weighted median, weighted mode, and MR-Egger regression.
• Conducted sensitivity analyses (MR-Egger, MR-PRESSO, Cochran's Q, leave-one-out) and reverse MR analysis.

Main Results:

• No significant genetic causal effect of childhood obesity on delayed puberty or height was detected (p>0.05).
• A significant causal association was found between height and childhood obesity (OR=0.85, 95% CI=0.76-0.96).
• Heterogeneity was noted for childhood obesity and height (Cochran's Q, p<0.05), but sensitivity analyses ruled out pleiotropic bias.

Conclusions:

• Childhood obesity does not appear to have a direct genetic causal impact on delayed puberty or height.
• Height demonstrates a causal influence on childhood obesity.
• Further research using advanced methods is recommended to elucidate pubertal development determinants.