Incident ischaemic heart disease in persons with Alzheimer's disease in a Finnish nationwide exposure-matched cohort

Burden of Illness in People with Alzheimer's Disease: A Systematic Review of Epidemiology, Comorbidities and Mortality

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide, and an updated quantification of its impact on morbidity, disability, and mortality is warranted. We conducted a systematic literature review, focusing on the past decade, to characterize AD and assess its impact on affected individuals.

METHODS

Searches of Embase, MEDLINE, and the Cochrane Library were conducted on August 7, 2020 and updated on November 10, 2021. Observational studies from any country reporting incidence, prevalence, comorbidities, and/or outcomes related to disability and mortality/life expectancy, in people with mild cognitive impairment (MCI) due to AD, or mild, moderate, or severe AD dementia, were considered relevant.

RESULTS

Data were extracted from 88 studies (46 incidence/prevalence; 44 comorbidities; 25 mortality-/disability-related outcomes), mostly from Europe, the USA, and Asia. AD dementia diagnosis was confirmed using biomarkers in only 6 studies. Estimated 5-year mortality in AD was 35%, and comorbidity prevalence estimates varied widely (hypertension: 30.2-73.9%; diabetes: 6.0-24.3%; stroke: 2.7-13.7%). Overall, people with AD dementia were more likely to have cardiovascular disease or diabetes than controls, and 5-year mortality in people with AD dementia was double that in the age- and year-matched general population (115.0 vs 60.6 per 1,000 person-years).

CONCLUSIONS

AD is associated with excess morbidity and mortality. Future longitudinal studies of population aging, incorporating biomarker assessment to confirm AD diagnoses, are needed to better characterize the course of MCI due to AD and AD dementia.

Folic Acid and Folinic Acid Protect Hearts of Aging Triple-transgenic Alzheimer's Disease mice via IGF1R/PI3K/AKT and SIRT1/AMPK Pathways

Patients with Alzheimer's disease have increased risk of developing heart disease, which therefore highlights the need for strategies aiming at reducing Alzheimer's disease-related cardiovascular disease. Folic acid and folinic acid are beneficial to the heart. We aimed to investigate the benefits of folic acid and folinic acid in heart of patients with late-stage Alzheimer's disease. Twelve 16-month-old mice of triple-transgenic late-stage Alzheimer's disease were divided into three groups: Alzheimer's disease group, Alzheimer's disease + folic acid group, and Alzheimer's disease + folinic acid group. The mice were administered 12 mg/kg folic acid or folinic acid once daily via oral gavage for 3 months. In the folic acid and folinic acid treatment groups, the intercellular space was reduced, compared with the Alzheimer's disease group. TUNEL assay and western blot images showed that the number of apoptotic cells and the apoptosis-related protein expression were higher in the Alzheimer's disease group than in other two treated groups. Folic acid and folinic acid induced the IGF1R/PI3K/AKT and SIRT1/ AMPK pathways in the hearts of mice with Alzheimer's disease. Our results showed that folic acid and folinic acid treatment increased survival and SIRT1 expression to reduce apoptotic proteins in the heart. The aging mice treated with folinic acid had more IGF1R and SIRT1/AMPK axes to limit myocardial cell apoptosis. In conclusion, folic acid and folinic acid promote cardiac cell survival and prevent apoptosis to inhibit heart damage in aging mice with triple-transgenic late-stage Alzheimer's disease. In particular, folinic acid provides a better curative effect than folic acid.

Edible folic acid and medicinal folinic acid produce cardioprotective effects in late-stage triple-transgenic Alzheimer's disease model mice by suppressing cardiac hypertrophy and fibrosis

Some clinical studies have indicated the patients with Alzheimer's disease (AD) display an increased risk of cardiovascular disease (CVD). Here, to examine the relationship between AD and CVDs, we investigated the changes in heart function in triple-transgenic late-stage AD model mice (3× Tg-AD; APPSwe, PS1M146V, and tauP301L). We fed the AD mice folic acid (FA) or folinic acid (FN) and analyzed the protective effects of the compounds on the heart; specifically, 20-month-old triple-transgenic AD mice, weighing 34-55 g, were randomly allocated into three groups-the AD, AD + FA, and AD + FN groups-and subject to gastric feeding with FA or FN once daily at 12 mg/kg body weight (BW) for 3 months. Mouse BWs were assessed throughout the trial, at the end of which the animals were sacrificed using carbon dioxide suffocation. We found that BW, whole-heart weight, and left-ventricle weight were reduced in the AD + FA and AD + FN groups as compared with the measurements in the AD group. Furthermore, western blotting of excised heart tissue revealed that the levels of the hypertrophy-related protein markers phospho(p)-p38 and p-c-Jun were markedly decreased in the AD + FA group, whereas p-GATA4, and ANP were strongly reduced in the AD + FN group. Moreover, the fibrosis-related proteins uPA, MMP-2, MEK1/2 and SP-1 were decreased in the heart in both AD + FN group. In summary, our results indicate that FA and FN can exert anti-cardiac hypertrophy and fibrosis effects to protect the heart in aged triple-transgenic AD model mice, particular in FN.

Abnormal amyloid beta metabolism in systemic abnormalities and Alzheimer's pathology: Insights and therapeutic approaches from periphery

Alzheimer's disease (AD) is an age-associated, multifactorial neurodegenerative disorder that is incurable. Despite recent success in treatments that partially improve symptomatic relief, they have failed in most clinical trials. Re-holding AD for accurate diagnosis and treatment is widely known as a challenging task. Lack of knowledge of basic molecular pathogenesis might be a possible reason for ineffective AD treatment. Historically, a majority of therapy-based studies have investigated the role of amyloid-β (Aβ peptide) in the central nervous system (CNS), whereas less is known about Aβ peptide in the periphery in AD. In this review, we provide a comprehensive summary of the current understanding of Aβ peptide metabolism (anabolism and catabolism) in the brain and periphery. We show that the abnormal metabolism of Aβ peptide is significantly linked with central-brain and peripheral abnormalities; the interaction between peripheral Aβ peptide metabolism and peripheral abnormalities affects central-brain Aβ peptide metabolism, suggesting the existence of significant communication between these two pathways of Aβ peptide metabolism. This close interaction between the central brain and periphery in abnormal Aβ peptide metabolism plays a key role in the development and progression of AD. In conclusion, we need to obtain a full understanding of the dynamic roles of Aβ peptide at the molecular level in both the brain and periphery in relation to the pathology of AD. This will not only provide new information regarding the complex disease pathology, but also offer potential new clues to improve therapeutic strategies and diagnostic biomarkers for the successful treatment of AD.

The Protective Effects of Clams on Hypercholesterolemia in Late-Stage Triple-Transgenic Alzheimer's Diseased Mice Hearts

To investigate a high cholesterol diet in Alzheimer’s disease (AD) mice, they were fed with (2% cholesterol) in five groups with a control group, AD mice group, AD mice plus Meretrix lusoria group, AD mice plus Geloina eros group, and, AD mice plus Corbicula fluminea group for three months, and treated with the fatty acid profiles of clams by gas chromatography (GC). The results showed that treatment with clams for three months reduced Fas/L and Caspase-3 in the Meretrix lusoria and Geloina eros groups, but Fas-associated death domain (FADD) and Caspase-8 were strongly reduced in the Geloina eros group. For the mitochondria-dependent apoptotic pathway, the reduction of apoptosis proteins were observed in the hearts of clams-treated AD mice. BAK and Caspase-9 was reduced in the Meretrix lusoria group, but Caspase-3 and Cytochrome-c were reduced in Geloina eros group. Enhancement of survival proteins p-AKT, p-IGF1R, p-PI3K, Bcl-XL, Bcl2, and the longevity SIRT1 signaling proteins, p-AMPK-α, SIRT1, PGC1-α, p-FOXO3 were observed in clams-treated mice and even more strongly enhanced in the Meretrix lusoria, Geloina eros and Corbicula fluminea groups. This study observed that the ingestion of clams caused a reduction of apoptosis proteins and enhancement of survival and SIRT1 signaling proteins in the hearts.

The preventive effects of edible folic acid on cardiomyocyte apoptosis and survival in early onset triple-transgenic Alzheimer's disease model mice

In recent years, neuropathological and epidemiological studies have indicated an association between Alzheimer's disease (AD) and several cardiovascular risk factors. In this study, the cardio-protective effects of folic acid (FA) in early stage AD was elucidated using a triple-transgenic (3xTg) Alzheimer's mouse model. Eleven-month-old C57BL/6 mice and 3xTg mice were assigned to five groups. During the four-month treatment period, the low-FA treatment group received FA through their diet, and the high-FA treatment groups received 3 mg/dl folate in drinking water and were also gastric-fed 1.2 mg/kg folate every day. In the C57B1/6J mice, treatment with high doses of FA (HFA) did not show any considerable effect compared to the control group or the low-dose dietary FA treatment group. However, Alzheimer's mice treated with HFA showed enhanced cardio-protection. Western blot analysis revealed that FA treatment restored SIRT1 expression, which was suppressed in 3xTg mice, through enhanced AMPK expression. FA significantly enhanced the IGF1 receptor survival mechanism in the hearts of the 3xTg mice and suppressed the expression-intrinsic and extrinsic apoptosis-associated proteins. The results suggest that FA intake may significantly alleviate cellular pathological events in the heart associated with AD.

The coverage of elective revascularisation procedure codes in the National Finnish Hospital Discharge Register

INTRODUCTION

Administrative registers provide an attractive data source for real-life effectiveness studies. The validity of coronary artery disease diagnoses in the Finnish National Hospital Discharge Register (HDR) is high but the validity of revascularization procedure codes (percutaneous coronary intervention; PCI and coronary artery bypass grafting; CABG) are unknown.

METHODS

All elective PCIs (n = 1771) and CABGs (n = 1819), performed at the Heart Center, Kuopio University Hospital, Finland between years 2007 and 2014 were identified from the unit's Special Electronic Medical Records (sEMR). Personal identity codes were used to link these data to the HDR. Sensitivity was estimated as proportion of operations recorded in sEMR and HDR.

RESULTS

With the strictest assumption of exactly the same intervention day in HDR and sEMR, the sensitivity for procedure codes were 84.6% for PCI and 97.1% for CABG, respectively. When a one-day difference was allowed in the dates, the sensitivity increased to 87.6% for PCI and 98.0% for CABG. Altogether 62.1% of elective PCIs and 69.2% of CABGs were correctly classified as elective procedures in the HDR.

CONCLUSION

The potential of the research application of the HDR extends beyond traditionally used diagnostic codes. One feasible application is the assessment of real-life effectiveness of different procedures. KEY MESSAGES The majority of PCIs (87.6%) and CABGs (98.0%), performed in the Heart Center, Kuopio University Hospital responsible for the treatment of approximately one fifth of the Finnish population, were captured by the Finnish National Hospital Discharge Register. However, only 62.1% of elective PCIs and 69.2% of CABGs were correctly classified as elective procedures in the HDR. Electivity data were missing from approximately one third of the procedures. This study produces new information of the potential use of HDR for real-life effectiveness studies to support evidence-based decision making in health care.

30-Day Mortality after Cardiovascular Events in Persons with or without Alzheimer's Disease

BACKGROUND AND OBJECTIVES

Persons with Alzheimer's disease (AD) have been suggested to receive suboptimal treatment. We studied the 30-day mortality after ischemic stroke, hemorrhagic stroke, or myocardial infarction in individuals with or without AD.

METHODS

An exposure matched cohort of all Finnish community-dwellers diagnosed with clinically verified AD in 2005-2012 (n = 73,005) and 1-4 matched comparison persons/AD-affected person (n = 215,449). Data on 30-day mortality after ischemic stroke (n = 16,419; deaths: n = 2,748), hemorrhagic stroke (n = 3,570; deaths: n = 1,224), and myocardial infarction (n = 15,304; deaths: n = 3,804) were obtained from the National Hospital Discharge register. The main analyses were restricted to first-ever events.

RESULTS

Persons with AD had slightly higher 30-day mortality after ischemic stroke (adjusted HR 1.36, 95% Confidence interval (CI) 1.24,1.49), hemorrhagic stroke (adjusted HR 1.11, 95% CI 0.98,1.25), or myocardial infarction (adjusted HR, 1.40, 9% CI 1.30,1.51). The associations were not affected by age, gender, or co-morbidities and remained similar when patients with previous ischemic strokes or infarctions were included. The absolute risk increase in 30-day mortality after ischemic or hemorrhagic stroke and myocardial infarction were 4.9% (95% CI 3.3,6.5), 3.3% (95% CI - 1.6,8.2), and 7.5% (95% CI 5.0,10.0), respectively.

CONCLUSIONS

Although the 30-day mortality was somewhat higher in the AD cohort, the absolute differences were small indicating that acute treatment was not notably inferior in AD patients. The slightly higher mortality was not explained by co-morbidities but may reflect the higher mortality of AD persons in general, or treatment practice of patients with severe cognitive impairment.