The aim of this study was to investigate whether epigenetic changes in the DNA of the APOE gene affects the risks of dementia, Alzheimers disease (AD) or cardiovascular disease (CVD). By the use of two NEAR population-based studies: the Swedish Adoption/Twin Study of Aging (SATSA) and the Screening Across the Lifespan of Twins (SALT), this was investigated in 447 Swedish Twins (mean age 78 years).
Epigenetic changes of the DNA in the APOE gene increase the risk of dementia but not cardiovascular diseases.
Epigenetic changes in the APOE gene were related with dementia and AD independently of sex, age at blood draw, education, and smoking, potentially through lowering protein expression. We did not detect any relationship between epigenetic changes in APOE and CVD. Results were similar when comparing within discordant twin pairs and did not differ as a function of APOE genotype, indicating that the associations are not explained by genetic factors. In conclusion, the findings highlight the importance of epigenetic changes in APOE in dementia, and that lower levels of the protein may be linked to long-term disease risk.
Photo of Ida Karlsson, first author of the study.
Karlsson IK, Ploner A, Wang Y, Gatz M, Pedersen NL, Hägg S. Apolipoprotein E DNA methylation and late-life disease. Int J Epidemiol. 2018;47(3):899-907. doi: 10.1093/ije/dyy025.