Association of Anemia with Dementia and Cognitive Decline among Community-Dwelling Elderly

Abstract

<b><i>Introduction:</i></b> The association of anemia with dementia in elders is controversial. We examined the potential association of anemia with dementia in a large population of elders. <b><i>Methods:</i></b> Historical-prospective registry-based study. Included 36,951 community-dwelling elders (65–113 years) that were followed during 2002–2012. Anemia of all kinds was defined according to Clalit Health Services (CHS) definitions: hemoglobin (HGB) <14 g/dL men, <12 g/dL women; and World Health Organization (WHO): HGB <13 g/dL men, <12 g/dL women. Anemia was categorized as mild (HGB 11–13 g/dL men, 11–12 g/dL women) or moderate-severe (HGB <8–10.9 g/dL men and women). Background data, laboratory values, and diagnosis of dementia and cognitive decline (DCD) were reviewed. <b><i>Results:</i></b> During the 10-year follow-up period, DCD was newly diagnosed in 7,180 subjects (19.4%). Subjects with DCD had a higher rate of anemia than those without DCD. Time to development of DCD was 1.5 years shorter in those with than without anemia. On multivariate Cox regression analysis adjusted for age and sex, the hazard ratio (HR) for DCD was 1.45 (95% CI: 1.37–1.54) by CHS and 1.51 (95% CI: 1.41–1.61) WHO anemia criteria. The more severe the anemia, the greater the risk of DCD development (HGB 13–14 g/dL [men only], HR = 1.20 [95% CI: 1.09–1.32]; mild anemia, HR = 1.38 [95% CI: 1.28–1.49]; moderate-severe anemia, HR = 1.64 [CI: 1.41–1.90]). Every decrease in 1 standard deviation of HGB (1.4 g/dL) increased the DCD risk by 15%. A competing risk model has weakened the association of anemia with DCD risk. <b><i>Conclusions and implications:</i></b> Anemia in community-dwelling elders appears to be associated with an increased DCD risk in a dose-response manner. Application of the WHO anemia criteria in men may miss patients with mild anemia that places them at DCD risk. Further research should look at anemia as a cause of reversible dementia.

Associations of blood cell indices and anemia with risk of incident dementia: A prospective cohort study of 313,448 participants

“…Our findings showed alignment with previous studies that low HGB and anemia were significantly associated with increased dementia risk. 11,12,[30][31][32][33] We also found a moderate increase in dementia risk as HGB grew beyond 17.8 g/dL, and genetically determined HGB was correlated with risk of AD according to our MR analysis. Pathologic changes of mature and immature eryth rocytes in aspects of their counts, volumes, fractions, distributions, and total mass could result in the decreased oxygen-carrying capacity of the blood, thus contributing to the pathogenesis of dementia.…”

A nomogram incorporating red blood cell indices to predict post-stroke cognitive impairment in the intracerebral hemorrhage population

“…HGB is the carrier of oxygen and participates in oxygen transport. HGB abnormalities will deprive oxygen delivery to the brain and thus attenuate neuronal energy metabolism ( Weiss et al, 2022 ). Deficient oxygen transport may trigger hypoperfusion, cerebral blood flow changes, and disorder of cerebral auto-regulation, which may further lead to cerebral degenerative abnormalities, such as cognitive dysfunction ( Wan et al, 2020 ).…”

Data-driven health deficit assessment improves a frailty index’s prediction of current cognitive status and future conversion to dementia: results from ADNI

“…Neutrophils are hypothesized to contribute to AD progression through systemic inflammation and disturbance of the blood–brain barrier [ 41 ]. RBC is one of several red blood cell indices associated with AD and cognitive decline [ 42 ], and may reflect an array of pathological disturbances affecting brain function, i.e., B-vitamin deficiencies [ 43 ], anemia [ 44 ], and chronic kidney disease [ 45 ].…”

“…The survival probabilities indicate the probability of remaining stable MCI at time of follow-up, and vertical lines through each line indicate censoring. D Estimated mean AUC(t) for prediction of AD conversion in subjects with MCI at baseline plotted over 5 years of follow-up for the three rival continuous FI variables in development and validation cohorts ◂ blood cell indices associated with AD and cognitive decline [42], and may reflect an array of pathological disturbances affecting brain function, i.e., B-vitamin deficiencies [43], anemia [44], and chronic kidney disease [45].…”