Study Links Three Midlife Health Factors to 13 Additional Dementia-Free Years

A long-term study of 12,409 U.S. participants published in Neurology Open Access reveals that maintaining normal blood pressure, avoiding diabetes, and not smoking during midlife is associated with nearly 13 additional dementia-free years. Led by NYU Langone Health researchers, the study showed that individuals with none of these risk factors at age 55 lived an average of 30.1 years dementia-free, compared to just 17.5 years for those with all three. Demographic disparities were also observed, as women and white participants lived longer without dementia than men and Black participants.

Midlife vascular risk factors

• ▪In the Atherosclerosis Risk in Communities study, hypertension was defined as systolic blood pressure ≥130 or ≥140 mm Hg, diastolic blood pressure ≥80 or ≥90 mm Hg, or the use of blood pressure medication.
• ▪In the Atherosclerosis Risk in Communities study, diabetes was defined by fasting glucose ≥126 mg/dL, non-fasting glucose ≥200 mg/dL, an HbA1c of 6.5% or higher, a physician's diagnosis, or medication use.
• ▪A prospective cohort study of 12,409 U.S. participants showed that maintaining normal blood pressure, avoiding diabetes, and not smoking during midlife was associated with nearly 13 additional dementia-free years.

Dementia-free survival years

• ▪Participants with all three midlife vascular risk factors had a 2.69-fold higher hazard of dementia and a 5.61-fold higher hazard of dying before a dementia diagnosis compared to those with no risk factors.
• ▪By age 85, only 7% of individuals with all three midlife vascular risk factors remained dementia-free, compared with 35% of those with no risk factors.
• ▪At age 55, study participants with none of the three vascular risk factors lived an average of 30.1 additional years without dementia, compared to 17.5 years for those with all three risk factors.

Demographic disparities in outcomes

• ▪White study participants lived more years free of dementia than Black participants at all risk levels, averaging 19.6 dementia-free years with all three risk factors compared to 16.0 years for Black participants.
• ▪Carriers of the APOE4 gene variant had shorter dementia-free survival than noncarriers in the Atherosclerosis Risk in Communities study cohort.
• ▪Women lived longer without dementia than men at all risk levels, averaging 18.1 dementia-free years from age 55 with all three risk factors compared to 16.6 years for men.

Vascular damage to brain

• ▪High blood pressure, diabetes, and smoking cause damage to cerebral blood vessels, which can lead to chronic cerebrovascular injury, neuroinflammation, and cumulative oxidative stress.
• ▪Vascular damage in the brain accelerates atherosclerosis, increases stroke risk, and may facilitate Alzheimer's disease pathology by promoting amyloid plaques and tau tangles.

Midlife prevention strategies

• ▪Senior investigator Josef Coresh recommends that individuals determine their blood pressure and HbA1c levels by their 40s to focus on prevention rather than treatment alone.
• ▪Experts note that the study was observational and cannot prove direct cause and effect, and that risk factors were measured only once at baseline.

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