Epigenome-wide association study of level and change in cognitive abilities from midlife through late life

Clinical Epigenetics

Table 2 The association between DNA methylation and longitudinal trajectories of cognitive abilities from latent growth-curve models

Cognitive domain and CpG site	CpG on intercept			CpG on linear change			CpG on quadratic change			LRT CpG	Cohen’s d equivalent
Cognitive domain and CpG site	Estimate	SE	p value	Estimate	SE	p value	Estimate	SE	p value	p value	Intercept	Change 65–75
Processing speed
cg18064256	− 1.35	0.32	2.90e−05	− 0.38	0.26	0.15	0.03	0.15	0.85	1.01e−05	0.14	0.04
Spatial ability
cg04549090	1.37	0.35	1.11e−04	0.24	0.22	0.27	− 0.15	0.16	0.34	5.25e−04	0.14	0.01
cg18064256	− 1.71	0.35	1.41e−06	− 0.35	0.23	0.13	0.10	0.17	0.54	8.53e−07	0.17	0.03
Working memory
cg09988380	− 1.61	0.37	1.48e−05	0.30	0.21	0.16	–	–	–	9.93e−05	0.16	0.03
cg25651129	1.83	0.35	2.80e−07	− 0.85	0.21	4.03e−05	–	–	–	2.63e−07	0.18	0.09
cg08011941	1.41	0.37	1.38e−04	− 0.11	0.22	0.61	–	–	–	4.22e−04	0.14	0.01

Mean cognitive level, 10-year linear change, and 10-year quadratic change in cognitive abilities in relation to DNA methylation at sites significant in EWAS analyses. Regression estimates, standard errors, and p values were obtained from full latent growth-curve models, simultaneously modeling the association between DNA methylation and intercept level, linear, and quadratic change in cognitive abilities. Age (in decades) was used as the underlying timescale, centered at age 65 for all domains. The models were further adjusted for sex, smoking at the time of blood sample, and methylation array. The model fit was compared to a null model not including DNA methylation to assess the significance of the effect of DNA methylation on cognitive level and change. Standardized mean differences (Cohen’s d equivalents) by 1 standard deviation higher DNA methylation at respective site was calculated for the intercept level and for 10-year change in cognitive abilities
SE standard error, LRT likelihood ratio test

ISSN: 1868-7083