ß-amyloid pathology is not associated with depression in a large community sample autopsy study.

BACKGROUND: Depression has been associated with dementia. This study aimed to verify if ß-amyloid Alzheimer's disease-type burden was associated with lifetime major depressive disorder (MDD) and with current depressive symptoms in a large population-based autopsy study. METHODS: We included 1013 deceased subjects submitted to autopsy (mean age=74.3±11.6 years, 49% men) in a community sample. ß-amyloid burden was measured in all cases based on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria for presence and density of neuritic plaques. Lifetime MDD was defined when at least one previous episode according to the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders - DSM (SCID). Depressive symptoms and cognitive impairment were determined using the depression item of the Neuropsychiatric Inventory (D-NPI>0) and the Clinical Dementia Rating scale (CDR>0.5) respectively. RESULTS: Lifetime MDD, late life depression (LLD) and current depressive symptoms were associated with cognitive impairment (p<0.001). Additionally, neuritic plaques were associated with cognitive impairment (p<0.001). Moderate or frequent neurite plaque density was not associated with MDD, LLD or current depressive symptoms in multiple logistic models adjusted for age, gender, and cognitive impairment. LIMITATIONS: In this cross-sectional study, all neuropsychiatric and cognitive assessment were based on informant-report of deceased participants. CONCLUSIONS: Different clinical depictions of depression were associated with dementia in this large community sample of elderly individuals with multiethnic backgrounds. Notwithstanding, they were unrelated to ß-amyloid pathology in the brain areas studied. The link between depression and dementia might be complex and determined by multiple factors.

Association between diabetes and causes of dementia: Evidence from a clinicopathological study.

BACKGROUND: Diabetes mellitus is a risk factor for dementia, especially for vascular dementia (VaD), but there is no consensus on diabetes as a risk factor for Alzheimer's disease (AD) and other causes of dementia. OBJECTIVE: To explore the association between diabetes and the neuropathological etiology of dementia in a large autopsy study. METHODS: Data were collected from the participants of the Brain Bank of the Brazilian Aging Brain Study Group between 2004 and 2015. Diagnosis of diabetes was reported by the deceased's next-of-kin. Clinical dementia was established when CDR ≥ 1 and IQCODE > 3.41. Dementia etiology was determined by neuropathological examination using immunohistochemistry. The association of diabetes with odds of dementia was investigated using multivariate logistic regression. RESULTS: We included 1,037 subjects and diabetes was present in 279 participants (27%). The prevalence of dementia diagnosis was similar in diabetics (29%) and non-diabetics (27%). We found no association between diabetes and dementia (OR = 1.22; 95%CI = 0.81-1.82; p = 0.34) on the multivariate analysis. AD was the main cause of dementia in both groups, while VaD was the second-most-frequent cause in diabetics. Other mixed dementia was the second-most-common cause of dementia and more frequent among non-diabetics (p = 0.03). CONCLUSION: Diabetes was not associated with dementia in this large clinicopathological study.

INTRODUÇÃO: Diabetes mellitus é um fator de risco para a demência, especialmente para a demência vascular (DV), mas ainda não há consenso sobre diabetes como fator de risco para a doença de Alzheimer (DA) e outras causas de demência. OBJETIVO: Verificar a associação entre diabetes e demência e sua etiologia neuropatológica em um grande estudo de autópsia. Métodos: Os dados foram coletados do Banco de Encéfalos Humanos do Grupo de Estudos em Envelhecimento Cerebral da FMUSP entre 2004 e 2015. O diagnóstico de diabetes foi relatado por pelos parentes do falecido. A demência clínica foi estabelecida quando CDR ≥ 1 e IQCODE > 3,41. A etiologia da demência foi determinada pelo exame neuropatológico com imuno-histoquímica. A associação de diabetes com probabilidades de demência foi investigada usando regressão logística multivariada. RESULTADOS: Foram incluídos 1.037 sujeitos, diabetes esteve presente em 279 participantes (27%). A frequência de diagnóstico de demência foi semelhante entre diabéticos (29%) e não diabéticos (27%). Não encontramos associação entre diabetes e demência (OR = 1,22; IC 95% = 0,81-1,82; p = 0,34) na análise multivariada. DA foi a principal causa de demência em ambos os grupos, DV foi a segunda causa em diabéticos. A frequência de outra demência mista foi a segunda causa de demência e mais frequente entre os não diabéticos (p = 0,03). CONCLUSÃO: A diabetes não foi associada à demência neste grande estudo clínico-patológico.

Diabetes is Not Associated with Alzheimer's Disease Neuropathology.

BACKGROUND: Previous evidence linking diabetes to Alzheimer's disease (AD) neuropathology is mixed and scant data are available from low- and middle-income countries. OBJECTIVE: To investigate the association between diabetes and AD neuropathology in a large autopsy study of older Brazilian adults. METHODS: In this cross-sectional study, diabetes was defined by diagnosis during life or use of antidiabetic medication. A standardized neuropathological examination was performed using immunohistochemistry. The associations of diabetes with Consortium to Establish and Registry for Alzheimer Disease (CERAD) scores for neuritic plaques and Braak-Braak (BB) scores for neurofibrillary tangles were investigated using multivariable ordinal logistic regression. We investigated effect modification of education, race, and APOE on these associations. RESULTS: Among 1,037 subjects (mean age = 74.4±11.5 y; mean education = 4.0±3.7 y; 48% male, 61% White), diabetes was present in 279 subjects. Diabetes was not associated with BB (OR = 1.12, 95% CI = 0.81-1.54, p = 0.48) or with CERAD (OR = 0.97, 95% CI = 0.68-1.38, p = 0.86) scores on analyses adjusted for sociodemographic and clinical variables. We observed effect modification by the APOE allele ɛ4 on the association between diabetes mellitus and BB scores. CONCLUSION: No evidence of an association between diabetes and AD neuropathology was found in a large sample of Brazilians; however, certain subgroups, such as APOE allele ɛ4 carriers, had higher odds of accumulation of neurofibrillary tangles.