IGF2 methylation is associated with lipid profile in obese children.

OBJECTIVE

Our aim was to investigate the relationships between the degree of IGF2 methylation and the metabolic status in obese children and adolescents.

METHODS

Eighty-five obese subjects aged 11.6 ± 2.1 years were studied. Anthropometry, metabolic parameters, blood pressure and body composition were assessed. DNA methylation analysis was performed by restriction enzyme digestion assay. The study population was subdivided into two groups according to the percentage of IGF2 cytidine-guanosine (CpG) island methylation.

RESULTS

Twenty-two subjects showed intermediate methylation (a percentage of CpG site methylation comprised between 10 and 60%), 56 were hypomethylated (percentage of methylation lower than 10%), and only 1 showed a high rate of hypermethylation (percentage of methylation above 60%). Children with intermediate methylation showed significantly higher levels of triglycerides (107.6 ± 41.99 vs. 76.6 ± 30.18 mg/dl, p < 0.005) and a higher triglyceride/high-density lipoprotein-cholesterol ratio (2.23 ± 0.98 vs. 1.79 ± 0.98, p < 0.02) compared with hypomethylated children.

CONCLUSIONS

These preliminary findings show for the first time a relationship between IGF2 methylation pattern and lipid profile in obese children. Although the correlation does not imply causation, if our findings are confirmed in further studies, IGF2 methylation might represent an epigenetic marker of metabolic risk.