The Association Between Anemia of Chronic Inflammation and Alzheimer's Disease and Related Dementias

Background: Dementia is a spectrum of neurological diseases characterized by memory impairment and cognitive decline with the pathogenesis and effective management remaining elusive. Several studies have identified a correlation between anemia and Alzheimer's disease and related dementias (ADRD); however, anemia subtypes and association with ADRD have yet to be studied conclusively. Objective: To study an association between ADRD and anemia of chronic inflammation. Methods: We conducted a retrospective case-control study of the patients, diagnosed with ADRD at Brookdale Hospital. Pair-wise comparisons between means of controls and cases in terms of iron studies and laboratory results were performed using a Mann-Whitney U test. Pair-wise comparisons between anemia subgroups (moderate and severe) were performed using a Two Sample proportion Z-Test, where for each couple of normally distributed population. Results: There was a total of 4,517 (1,274 ADRD group; 3,243 Control group) patients. There was significant difference in hemoglobin 10.15 versus 11.04 [p-value <0.001]. Iron studies showed a significant difference in ferritin 395 +/- 488.18 versus 263 +/- 1023.4 [p < 0.001], total iron binding capacity 225 +/- 84.08 versus 266 +/- 82.30 [p < 0.001] and serum iron level 64 +/- 39.34 versus 53 +/- 41.83 [p < 0.001]. Folic acid and vitamin B12 levels were normal in both groups. Severe and moderate anemia in the ADRD group were respectively 6.2% [95% CI: 4.2-8.4] and 13% [95% CI: 9.8-16.2] higher. Overall, incidence of moderate-to-severe anemia was found to be 19% higher in ADRD group [95% CI: 15.8-22.1]. Conclusion: We demonstrated an association between ADRD and anemia of chronic inflammation independent of age, renal function, and HgbA1C levels.