The association of DNA methylation with body mass index: distinguishing between predictors and biomarkers

Clinical Epigenetics

Table 4 Associations between methylation score and BMI

Time points	N	Unadjusted for current BMI/birthweight				Adjusted for current BMI/birthweight
Time points	N	Effect size	CI	p value	Adjusted R-squared¹	Effect size	CI	p value
Model: Earlier methylation score predicting later BMI²
Methylation score at birth predicting BMI in childhood	830	− 0.03	− 0.18, 0.13	0.72	− 0.0004	− 0.07	− 0.22, 0.07	0.36
Methylation score at birth predicting BMI in adolescence	712	0.06	− 0.25, 0.36	0.70	− 0.001	− 0.05	− 0.35, 0.25	0.73
Methylation score in childhood predicting BMI in adolescence	762	0.41	0.13, 0.69	0.004	0.005	0.13	− 0.07, 0.34	0.20
Antenatal methylation score predicting BMI in middle-age	765	0.80	0.44, 1.17	1.92E−05	0.02	0.19	− 0.06, 0.44	0.13
Model: Earlier birthweight or BMI predicting later methylation score³
Birthweight predicting methylation score in childhood	814	− 0.0001	− 0.0002, 0.00004	0.17	0.003	− 0.0002	− 0.0003, − 0.00006	0.006
Birthweight predicting methylation score in adolescence	812	0.000003	− 0.0001, 0.0001	0.96	0.002	− 0.00008	− 0.0002, 0.00005	0.22
BMI in childhood predicting methylation score in adolescence	891	0.09	0.06, 0.12	3.05E−09	0.02	0.06	0.04, 0.09	1.52E−06
Antenatal BMI predicting methylation score in middle-age	851	0.07	0.05, 0.08	1.42E−16	0.06	0.05	0.03, 0.05	5.48E−11

¹Adjusted R-squared obtained from model with only the methylation score and no other covariates
²From model adjusting for age (except at birth), sex (where applicable), sample type (where applicable) and cell type proportions (B cell, CD4T, CD8T, Gran, Mono and NK). Units are standard deviation in DNA methylation score per kg/m²
³From model adjusting for age (except at birth), sex (where applicable), sample type (where applicable) and cell type proportions (B cell, CD4T, CD8T, Gran, Mono and NK). Units are kg/m² per standard deviation in DNA methylation score for all models not including birthweight, where the units for these models are grams per standard deviation in DNA methylation score

ISSN: 1868-7083