Phenotypic expressions of Alzheimer’s disease: A gender perspective

Introduction. Dementia is one of the main diseases linked to aging and leading to disability. The gender per-spective of this disease has not been studied in a complete and dedicated way and this constitutes a great limitation because dementia, like other diseases, appears to have a gender-related expression. The aim of this research is to contribute to the study of gender differences in a large cohort of patients affected by Alzheimer’s disease. Methods and patients. The study population included the clinical records of 1925 patients with Alzheimer’s disease, diagnosed according to NINCDS-ADRDA criteria and to NIA-AA, from the e-database of the Neurogenetic Regional Centre (NRC) of Lamezia Terme (Southern Italy). The mean age of the sample was 71.5 ± 8.9 years and follow-up was an average of 4 years. The variables included in the analysis and differentiated for gender were the prevalence and the onset of the disease, the time elapsed between the onset and the first consultation, duration of follow-up, duration of the disease, education, cardiovascular and metabolic risk factors. A check list of symptoms and signs was compiled from the cognitive and behavioral history and categorized in 12 clusters. Statistical analysis was performed using IBM SPSS 20 (significance was given by p <0.05). Results. Women were more numerically represented in the sample (67.1%). There were no differences according to gender in the time elapsed between onset of symptoms and the first con-sultation, in the follow-up period and in the duration of dis-ease. Women were more cognitively impaired at baseline (MMSE score 15.9 ± 5.9 vs 17 ± 6.5), had a lower level of education (5.6 years vs 6.51 years) and presented higher comor-bidity and incidence of depression (p = 0.000) and anxiety (p = 0.002). Men displayed a more rapid decline at the end of the follow-up, losing 3.85 ± 4.66 points vs 2.93 ± 4.39 at MMSE; they showed a statistically significant prevalence in behavioral symptoms (p = 0.009), including irritability (p = 0.000) and agitation (p = 0.041), and some cognitive deficits, such as language impairments (p = 0.000), apraxia (p = 0.005), spatial disorientation (p = 0.006) and acalculia (p = 0.035). APOE results were not representative in terms of gender differences but confirmed a possible impact of the ε4 allele on cognitive decline. Discussion. Behind the classical memory impairment and temporal disorientation, that are present in about all men and woman, a different AD phenotype between the two gen-ders emerges from this work. Our results revealed a poorly-educated female sample, with a worse cognitive impairment and mood disorders. Men showed a more rapid cognitive impairment and an aggressive behavioral picture. The identification of specific gender aspects, cognitive and behav-ioral, could be a valuable aid for a faster identification of Al-zheimer’s disease and its better management.