DNA methylation age and trajectories in physical and mental health functioning
|Day:||Thu 4 Jul|
Recent developments have enabled the measurement of biological age based on the epigenetic measure, DNA methylation and there has been interest the correlates of being ‘epigenetically older’ than chronological age (so-called ‘accelerated ageing’). Studies in this area have shown significant associations between accelerated ageing and all-cause mortality, cardiovascular disease and cancer. However, it is unclear whether there is a relationship between this measure of accelerated ageing and measures of health that decline with age, such as physical functioning. We examined the association of accelerated ageing and functioning in the Understanding Society dataset using methylation and functioning data collected at wave 3, and change in functioning between waves 3 and 6. We used regression and linear mixed effects models to examine the association of accelerated ageing, using two separate measures (the Horvath and Hannum clocks) derived from DNA methylation, ‘objective’ measures of functioning, (lung function, hand grip strength and cognitive performance) and subjective functioning assessed with the SF-12 at three time points in UKHLS (n=992, mean age 57.6y). Accelerated ageing was not associated with objective measures of functioning in general. The results show a small significant association between epigenetic age, measured using the Hannum algorithm, and changes in physical functioning (coefficient -0.163, standard error, 0.08, p<0.05). The association with a different clock was similar but not significant (Horvath: coefficient -0.115, standard error, 0.07). We conclude that accelerated age is not generally associated with functioning. The finding with changes in SF-12 require further investigation with additional follow up of the participants.