Aim: We performed an epigenome-wide association study within the Finnish Health in Teens cohort to identify differential DNA methylation and its association with BMI in adolescents.
Materials & methods: Differential DNA methylation analyses of 3.1 million CpG sites were performed in saliva samples from 50 lean and 50 heavy adolescent girls by genome-wide targeted bisulfite-sequencing.
Results: We identified 100 CpG sites with p-values < 0.000524, seven regions by 'bumphunting' and five CpG islands that differed significantly between the two groups. The ten CpG sites and regions most strongly associated with BMI substantially overlapped with obesity- and insulin-related genes, including MC2R, IGFBPL1, IP6K1 and IGF2BP1.
Conclusion: Our findings suggest an association between the saliva methylome and BMI in adolescence.
Keywords: BMI; DNA methylation; adolescents; epigenome-wide association study; girls; insulin; melanocortin; obesity; saliva; targeted bisulfite-sequencing.