RT Journal Article
SR Electronic
T1 Hemoglobin level in older persons and incident Alzheimer disease
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 219
OP 226
DO 10.1212/WNL.0b013e318225aaa9
VO 77
IS 3
A1 Shah, R.C.
A1 Buchman, A.S.
A1 Wilson, R.S.
A1 Leurgans, S.E.
A1 Bennett, D.A.
YR 2011
UL http://n.neurology.org/content/77/3/219.abstract
AB Objective: To test the hypothesis that level of hemoglobin is associated with incident Alzheimer disease (AD). Methods: A total of 881 community-dwelling older persons participating in the Rush Memory and Aging Project without dementia and a measure of hemoglobin level underwent annual cognitive assessments and clinical evaluations for AD. Results: During an average of 3.3 years of follow-up, 113 persons developed AD. In a Cox proportional hazards model adjusted for age, sex, and education, there was a nonlinear relationship between baseline level of hemoglobin such that higher and lower levels of hemoglobin were associated with AD risk (hazard ratio [HR] for the quadratic of hemoglobin 1.06, 95% confidence interval [CI] 1.01–1.11). Findings were unchanged after controlling for multiple covariates. When compared to participants with clinically normal hemoglobin (n = 717), participants with anemia (n = 154) had a 60% increased hazard for developing AD (95% CI 1.02–2.52), as did participants with clinically high hemoglobin (n = 10, HR 3.39, 95% CI 1.25–9.20). Linear mixed-effects models showed that lower and higher hemoglobin levels were associated with a greater rate of global cognitive decline (parameter estimate for quadratic of hemoglobin = −0.008, SE −0.002, p < 0.001). Compared to participants with clinically normal hemoglobin, participants with anemia had a −0.061 z score unit annual decline in global cognitive function (SE 0.012, p < 0.001), as did participants with clinically high hemoglobin (−0.090 unit/year, SE 0.038, p = 0.018). Conclusions: In older persons without dementia, both lower and higher hemoglobin levels are associated with an increased hazard for developing AD and more rapid cognitive decline.