Age-specific childhood obesity and adult cholelithiasis: association and shared transcriptomic bases.

Objectives: The association between obesity and cholelithiasis has been identified. However, the causal relationship between age-specific childhood obesity and adult cholelithiasis remains unclear. In addition, the biological basis for the association between childhood obesity and adult cholelithiasis is poorly understood, which poses a challenge for preventing adult cholelithiasis in specific biological pathways.

Methods: Summary statistics of genome-wide association studies (GWASs) of childhood age-specific body mass index (BMI) at 12 time points and adult cholelithiasis derived from FinnGen were used in this study, with the former covering data from birth to 8 years. Linkage disequilibrium score regression (LDSC) analyses were used to assess the genetic correlations of age-specific childhood BMI to cholelithiasis. Two-sample Mendelian randomization (MR) and multivariable Mendelian randomization (MVMR) analyses were utilized to explore the causal associations. As downstream analyses, summary-based Mendelian randomization (SMR) analyses, transcriptome-wide association studies (TWAS), and Bayesian colocalization were conducted to discover the shared transcriptomic signals. The GWAS summary statistics of cholelithiasis from the UK Biobank were used for sensitivity analyses.

Results: LDSC analyses revealed significant genetic correlations between 11 age-specific childhood BMIs and adult cholelithiasis (except for birth BMI). Two-sample MR and MVMR analyses indicated causal relationships between birth BMI and BMI at 8 months, 1.5 years, 7 years, and 8 years after birth and adult cholelithiasis. SMR, TWAS, and colocalization analyses identified MLXIPL as the strongest overlapping signal between age-specific BMI and adult cholelithiasis.

Conclusion: This study provides new evidence on the relationships between childhood obesity and adult cholelithiasis, highlighting the role of early intervention for obesity in childhood at key time points. MLXIPL gene expression was identified as a potential biological pathway, suggesting potential therapeutic targets and precise intervention strategies for childhood obesity and adult cholelithiasis.