THE COURSE AND END-POINTS OF ALZHEIMER’S DISEASE ACCORDING TO SOCIODEMOGRAPHICS, APOLIPOPROTEIN E GENOTYPE AND COGNITIVE ABILITY

Abstract

The prognosis of Alzheimer's disease (AD) might be influenced by many sociodemographic and clinical factors. Previous studies have investigated the main effects of critical predictors but few have analyzed potential interactions. We have studied the long-term cognitive outcome, nursing home placement (NHP) and mortality by interactions between factors in cholinesterase inhibitor (ChEI)-treated AD patients. The Swedish Alzheimer Treatment Study (SATS) is a prospective, observational, multicenter study for longitudinal evaluation of ChEI treatment in clinical practice. This presentation includes 224 deceased SATS participants diagnosed with mild-to-moderate AD (Mini-Mental State Examination score (MMSE), 10–26 at the start of ChEI therapy, i.e., time of diagnosis) who were admitted to nursing homes (NHs) during the study. Cognitive abilities were evaluated at baseline and semiannually over 3 years. Dates of NHP and death were recorded. Patients were divided into two groups by age at AD diagnosis, cut-off median 78 years. Younger females exhibited lower cognitive ability at NHP (mean MMSE score (95% confidence interval), 16.3 (14.9–17.7) points vs. 18.7 (17.6–19.7) points, p=0.018), and a longer time to NHP (22.1 (19.9–24.2) months vs. 15.6 (13.6–17.7) months, p<0.001), than older females. Females ≤77 years old had longer survival times in NHs, (5.4 (4.7–6.0) years), compared with the other groups: ≥78-year-old females, (4.1 (3.4–4.7) years); ≤77-year-old males, (2.8 (1.7–3.8) years); and ≥78-year-old males, (2.8 (2.0–3.5 years), p<0.001). Younger apolipoprotein E (APOE) ε4-carriers demonstrated lower cognitive ability at NHP, (16.3 (14.9–17.7) points vs. 19.0 (17.9–20.1) points, p=0.021), longer time to NHP, (22.8 (20.8–24.8) months vs. 17.7 (15.4–19.9) months, p=0.006), longer survival time in NHs, (5.0 (4.4–5.7) years vs. 3.8 (3.2–4.5) years, p=0.030), and longer life-span from AD diagnosis, (6.9 (6.3–7.6) years vs. 5.3 (4.6–6.0) years, p=0.002), than older ε4-carriers. In the ≤77-year-old group, a longer survival time in NHs (∼5 years) and thus higher cost of care might be expected in females, mild AD or APOE ε4-carriers. Younger patients with moderate AD showed remarkably low cognitive ability at NHP (mean MMSE score 12); these individuals might need increased support.