Hypertension, a dementia polygenic risk score, APOE genotype, and incident dementia.

Introduction: There is inconsistent evidence on whether genetic risk for dementia modifies the association between hypertension and dementia.

Methods: In 198,965 dementia-free participants aged ≥60 years, Cox proportional-hazards models were used to investigate the association between hypertension and incident dementia. A polygenic risk score (PRS) based on 38 non-apolipoprotein E (APOE) single nucleotide polymorphisms and APOE ε4 status were used to determine genetic risk for dementia.

Results: Over 15 years follow-up, 6270 participants developed dementia. Hypertension was associated with a 19% increased risk of dementia (hazard ratio = 1.19, 95% confidence interval 1.11-1.27). The associations remained similar when stratifying by genetic risk, with no evidence for multiplicative interaction by dementia PRS (P = 0.20) or APOE ε4 status (P = 0.16). However, the risk difference between those with and without hypertension was larger among those at higher genetic risk.

Discussion: Hypertension was associated with an increased risk of dementia regardless of genetic risk for dementia.