IMPACT OF ALZHEIMER’S DISEASE DEVELOPMENT ON THE HEART: FOCUS ON INFLUENCE OF PHYSICAL AND MENTAL ACTIVITY AGAINST THE DELETERIOUS EFFECT OF SOCIAL ISOLATION AND PROTEIN MALNUTRITION

Abstract

Alzheimer's disease (AD) represents a pressing worldwide health problem. Social isolation (SI) is harmful to brain health especially for elderly; it plays a leading role in exacerbates the risk and prevalence of neurological diseases as well as heart disease. Protein malnutrition (PM) can predict the development of AD and may predict cardiac diseases. It is suggested that heart-healthy eating may also help to protect brain. Moreover, physical and mental exercises have been approved for cardiovascular benefits and can be considered as amazing strategy for lowering the risk of cognitive decline. The study was performed in two sets according to time of the experiment (3 or 5 weeks). Each set contain 2 groups; one was socialized and normally-fed (S&NF) while the other was isolated and protein malnourished (SI&PM). All groups were subdivided into 4 subgroups; two received saline and served as control while two received ALCl3 (70mg/kg IP) every day and served as AD subgroups. One control and AD subgroups were weekly exposed to physical and mental activities (Ph&M) using Swimming and Y-maze tests while the other was not. Biochemical parameters as AChE, Aβ, Tau, β-secretase, monoamins, oxidative stress and inflammatory markers were estimated in the brain. Moreover, brain derived neurotrophic factor (BDNF), DNA fragmentation and histopathological changes in different brain regions were also measured. In addition, serum CKMB, PTX-3, Troponin, AST, HDL, LDL and Cholesterol were also measured as well as histopathological changes in the heart. During AD development, SI&PM induced deleterious effect on the heart which was more sever by progression of AD at 5 weeks as indicated by the increase in serum CKMB, PTX-3, troponin, AST, LDL and Cholesterol together with decrease in HDL. However, Ph&M showed higher protection against the risk of SI&PM especially in AD-associated groups. Histopathological examinations confirmed the biochemical ones in all groups. The deleterious effect of SI&PM on the heart was more pronounced with AD progression. However, Ph&M can provide marked protection against hazards of, SI&PM especially in AD-associated groups. Consequently, Socialization and adequate nutrition with regular Ph&M are advised especially in elderly and during AD progression.