Homocysteine and dementia risk

To examine the association between serum total homocysteine levels (tHcy) and dementia risk.

A total of 1588 Japanese adults aged ≥60 years without dementia were prospectively followed from 2002 to 2012.

During the follow-up, 372 subjects developed all-cause dementia; 247 had Alzheimer's disease (AD) and 98 had vascular dementia (VaD).

High serum tHcy levels are associated with an elevated risk of dementia, AD and VaD in a non-linear manner, such that an exposure-response association is present only within a relatively high range of tHcy levels. Non-genetic factors affecting serum tHcy concentrations may play important roles in tHcy-dementia associations irrespective of the genetic susceptibility for raised tHcy.