Three Midlife Vascular Risk Factors Linked to 13 Fewer Dementia-Free Years in New Study

Hypertension, diabetes, and current smoking in midlife were associated with a stepwise reduction in dementia-free survival in a prospective analysis of the Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study. Among 12 409 adults who were alive and free of dementia at age 55, those with none of the 3 vascular risk factors lived an average of 30.1 years without dementia between ages 55 and 95. Dementia-free survival declined to 26.3 years with 1 risk factor, 21.0 years with 2, and 17.5 years with all 3 - a 12.6-year difference between the lowest- and highest-risk groups.

The analysis followed participants for a median of 26.3 years, during which 3008 developed dementia and 5238 died without dementia. Compared with participants who had no vascular risk factors, those with all 3 had a 2.69-fold higher hazard of dementia and a 5.61-fold higher hazard of death without dementia. Accounting for that competing mortality was central to the study: participants with the greatest vascular burden sometimes appeared to have a lower cumulative incidence of dementia at the oldest ages because fewer survived long enough to develop it.

In this video, corresponding author Josef Coresh, MD, PhD, explains why the research team used dementia-free survival to capture the combined effects of dementia and premature death in an understandable measure. He also discusses the strengths and limitations of measuring vascular risk at a single midlife visit, why the analysis focused on only 3 factors, and how differences by sex and race should be interpreted. Coresh emphasizes that the findings are observational but offer another way for clinicians to frame the long-term value of preventing or delaying vascular risk factors. He also addresses why late-life dementia prevention remains important for people who survive to older ages with better cardiovascular health.