Predictors of progression of cognitive decline in Alzheimer’s disease: the role of vascular and sociodemographic factors

Abstract

Rates of disease progression differ among patients with Alzheimer's disease, but little is known about prognostic predictors. The aim of the study was to assess whether sociodemographic factors, disease severity and duration, and vascular factors are prognostic predictors of cognitive decline in Alzheimer's disease progression. We conducted a longitudinal clinical study in a specialized clinical unit for the diagnosis and treatment of dementia in Rome, Italy. A total of 154 persons with mild to moderate Alzheimer's disease consecutively admitted to the dementia unit were included. All patients underwent extensive clinical examination by a physician at admittance and all follow-ups. We evaluated the time-dependent probability of a worsening in cognitive performance corresponding to a 5-point decrease in Mini-Mental State Examination (MMSE) score.Survival analysis was used to analyze risk of faster disease progression in relation to age, education, severity and duration of the disease, family history of dementia, hypertension, hypercholesterolemia, and type 2 diabetes. Younger and more educated persons were more likely to have faster Alzheimer's disease progression. Vascular factors such as hypertension and hypercholesterolemia were not found to be significantly associated with disease progression. However, patients with diabetes had a 65% reduced risk of fast cognitive decline compared to Alzheimer patients without diabetes. Sociodemographic factors and diabetes predict disease progression in Alzheimer's disease. Our findings suggest a slower disease progression in Alzheimer's patients with diabetes. If confirmed, this result will contribute new insights into Alzheimer's disease pathogenesis and lead to relevant suggestions for disease treatment.

Rationale for Combined Exercise and Cognition-Focused Interventions to Improve Functional Independence in People with Dementia

“…The review by Fillit et al [49] has collated evidence to show that the relative risk of dementia may be more than 4 times higher in patients with a systolic blood pressure of 1 160 mmHg compared to those with a systolic blood pressure of 110-139 mmHg [49] ; having diabetes almost doubles the risk of dementia [49] . Hypertension was found to occur in a third of Alzheimer disease patients (34%), with hypercholesterolaemia occurring in 18% and diabetes in 14% in a recent Italian study of Alzheimer disease patients [51] . Being overweight or obese was found to increase the risk of dementia/Alzheimer's disease by 35-90%; smoking increases the risk by 8-203%, whilst exercise or high levels of physical activity decreased the risk by 37-62% in several longitudinal studies [49] .…”

“…Many of the CVD risk factors have recently been shown to serve as risk factors for developing both Alzheimer's disease and vascular dementia, with the risk of developing dementia being increased in the presence of multiple CVD risk factors [49] . These factors may also predict the progression of cognitive decline [51] . The main CVD risk factors for dementia include hypertension, dyslipidaemia and type II diabetes mellitus.…”

“…However, it has been suggested that the various vascular factors have different roles in the progression of cognitive decline [50] . Type II diabetes may also assist in slowing further decline in cognition in people who already have dementia [51] . Although the mechanisms for this are unclear, the treatment of diabetes may be behind this observation [51] .…”

“…Type II diabetes may also assist in slowing further decline in cognition in people who already have dementia [51] . Although the mechanisms for this are unclear, the treatment of diabetes may be behind this observation [51] .…”

Effects of Blood Pressure Changes on Alzheimer’s Disease

“…This subject has been analyzed in only few studies, with inconclusive results [46][47][48][49][50][51] . It is likely that the heterogeneity of the populations included and the high incidence of hypotension in the advanced stages of Alzheimer's disease are relevant factors that may explain differences in the outcome of neurodegenerative disease found in different studies.…”