Midlife vascular risk factors were connected to a greater likelihood of dementia among blacks and whites, according to research recently published in JAMA Neurology.
“While some studies use careful rigorous dementia ascertainment methods, few studies combine such ascertainment with longitudinal associations in a racially diverse population...” Rebecca F. Gottesman, MD, PhD, of the department of neurology at Johns Hopkins University and colleagues wrote. “We examined [Atherosclerosis Risk in Communities] participants in midlife, when vascular risk assessment appears to be most critical.”
Midlife hypertension alone is the reason for 425,000 cases of Alzheimer’s disease in the United States each year, according to researchers
Gottesman and colleagues gathered data on vascular and demographic risk factors from 15,744 participants of the previously conducted Atherosclerosis Risk in Communities study. The participants ranged in age from 44 to 66 years old, and 72.9% were white. Researchers analyzed information from cognitive evaluations, death certificates, ICD-9 codes from hospital visits, interviews, telephone calls and five in-person visits.
The researchers identified 1,516 cases of dementia, 43% of which were among men and 65.1% among whites. Risk factors for dementia included diabetes (HR = 1.77; 95% CI, 1.53-2.04); less than a high school education (HR = 1.61; 95% CI, 1.28-2.03); midlife smoking (HR = 1.41; 95% CI, 1.23-1.61); hypertension (HR = 1.39; 95% CI, 1.22-1.59); and prehypertension (HR = 1.31; 95% CI, 1.14-1.51). In addition, older age (HR = 8.06; 95% CI, 6.69-9.72 for participants aged between 60 and 66 years), APOE 4 genotype (HR = 1.98; 95% CI, 1.78-2.21), black race (HR = 1.36; 95% CI, 1.21-1.54) were also linked to increased dementia risk, and the HR for dementia for diabetes was almost as high as that for APOE 4 genotype.
“Our study adds to the existing literature by avoiding many of the biases caused by incomplete case ascertainment or use of memory clinic cohorts and by evaluating a racially diverse population over decades,” Gottesman and colleagues wrote. “Future studies need to evaluate the mechanism of this racial disparity in dementia rates and assess subclinical vascular disease (systemic and cerebrovascular) as a risk factor for dementia.” – by Janel Miller
Gottesman reports serving as associate editor of Neurology. Please see the study for a full list of the other authors’ relevant financial disclosures.