Mortality in dementia is predicted by older age of onset and cognitive presentation

Global burden of young-onset Alzheimer's disease and other dementias: a secondary analysis of the global burden of disease study, 2019

The aging of the world population has led to an increase in the epidemiology and burden of Alzheimer's disease and other dementias.

Objective

To describe the global burden of young-onset Alzheimer's disease and other dementias by world region and income through a secondary analysis of the Global Burden of Disease Study 2019.

Methods

This is a descriptive cross-sectional ecological study. Data by sex and five-year age groups from 40 to 64 years were extracted from the Global Burden of Disease Study results tool. We performed a descriptive analysis of prevalence, incidence, deaths, disability-adjusted life years, years of life lost, and years lived with disability.

Results

In 2019, young-onset Alzheimer's disease and other dementias presented a prevalence of 2.67 cases and an incidence of 0.44 per 1,000 inhabitants globally. It carried a significant burden, resulting in 1.16 disability-adjusted life years per 1,000 inhabitants, primarily due to years of life lost, and to a lesser extent due to years lived with disability. East Asia & the Pacific, Latin America & the Caribbean, and North America are the most affected regions. Burden rates are consistently higher among women; no gradient was observed by country income. Smoking was the most relevant risk factor, presenting a broad difference by country income level.

Conclusion

The global burden of young-onset Alzheimer's disease and other dementias may reshape healthcare requirements and the societal impact of dementias, and its understanding is relevant to inform decisions related to service offerings and research agendas.

Dementia subtypes, cognitive decline and survival among older adults attending a memory clinic in Cape Town, South Africa: a retrospective study

BACKGROUND

There are no published longitudinal studies from Africa of people with dementia seen in memory clinics. The aim of this study was to determine the proportions of the different dementia subtypes, rates of cognitive decline, and predictors of survival in patients diagnosed with dementia and seen in a memory clinic.

METHODS

Data were collected retrospectively from clinic records of patients aged ≥ 60 seen in the memory clinic at Groote Schuur Hospital, Cape Town, South Africa over a 10-year period. Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria were used to identify patients with Major Neurocognitive Disorders (dementia). Additional diagnostic criteria were used to determine the specific subtypes of dementia. Linear regression analysis was used to determine crude rates of cognitive decline, expressed as mini-mental state examination (MMSE) points lost per year. Changes in MMSE scores were derived using mixed effects modelling to curvilinear models of cognitive change, with time as the dependent variable. Multivariable cox survival analysis was used to determine factors at baseline that predicted mortality.

RESULTS

Of the 165 patients who met inclusion criteria, 117(70.9%) had Major Neurocognitive Disorder due to Alzheimer's disease (AD), 24(14.6%) Vascular Neurocognitive Disorder (VND), 6(3.6%) Dementia with Lewy Bodies (DLB), 5(3%) Parkinson disease-associated dementia (PDD), 3(1.8%) fronto-temporal dementia, 4(2.4%) mixed dementia and 6(3.6%) other types of dementia. The average annual decline in MMSE points was 2.2(DLB/PDD), 2.1(AD) and 1.3(VND). Cognitive scores at baseline were significantly lower in patients with 8 compared to 13 years of education and in those with VND compared with AD. Factors associated with shorter survival included age at onset greater than 65 (HR = 1.82, 95% C.I. 1.11, 2.99, p = 0.017), lower baseline MMSE (HR = 1.05, 95% C.I. 1.01, 1.10, p = 0.029), Charlson's comorbidity scores of 3 to 4 (HR = 1.88, 95% C.I. 1.14, 3.10, p = 0.014), scores of 5 or more (HR = 1.97, 95% C.I. 1.16, 3.34, p = 0.012) and DLB/PDD (HR = 3.07, 95% C.I. 1.50, 6.29, p = 0.002). Being female (HR = 0.59, 95% C.I.0.36, 0.95, p = 0.029) was associated with longer survival.

CONCLUSIONS

Knowledge of dementia subtypes, the rate and factors affecting cognitive decline and survival outcomes will help inform decisions about patient selection for potential future therapies and for planning dementia services in resource-poor settings.

Comparing survival and mortality in patients with late-onset and young-onset vascular dementia

OBJECTIVES

Vascular dementia (VD) is one of the more common types of dementia. Much is known about VD in older adults in terms of survival and associated risk factors, but comparatively less is known about VD in a younger population. This study aimed to investigate survival in people with young-onset VD (YO-VD) compared to those with late-onset VD (LO-VD) and to investigate predictors of mortality.

DESIGN

Retrospective file review from 1992 to 2014.

SETTING

The inpatient unit of a tertiary neuropsychiatry service in Victoria, Australia.

PARTICIPANTS

Inpatients with a diagnosis of VD.

MEASUREMENTS AND METHODS

Mortality information was obtained from the Australian Institute of Health and Welfare. Clinical variables included age of onset, sex, vascular risk factors, structural neuroimaging, and Hachinksi scores. Statistical analyses used were Kaplan-Meier curves for median survival and Cox regression for predictors of mortality.

RESULTS

Eighty-four participants were included with few clinical differences between the LO-VD and YO-VD groups. Sixty-eight (81%) had died. Median survival was 9.9 years (95% confidence interval 7.9, 11.7), with those with LO-VD having significantly shorter survival compared to those with YO-VD (6.1 years and 12.8 years, respectively) and proportionally more with LO-VD had died (94.6%) compared to those with YO-VD (67.5%), χ2(1) = 9.16, p = 0.002. The only significant predictor of mortality was increasing age (p = 0.001).

CONCLUSION

While there were few clinical differences, and older age was the only factor associated with survival, further research into the effects of managing cardiovascular risk factors and their impact on survival are recommended.

Exploring the mechanism of Ginkgo biloba L. leaves in the treatment of vascular dementia based on network pharmacology, molecular docking, and molecular dynamics simulation

BACKGROUND

Ginkgo biloba L. leaves (GBLs) play a substantial role in the treatment of vascular dementia (VD); however, the underlying mechanisms of action are unclear.

OBJECTIVE

This study was conducted to investigate the mechanisms of action of GBLs in the treatment of VD through network pharmacology, molecular docking, and molecular dynamics simulations.

METHODS

The active ingredients and related targets of GBLs were screened using the traditional Chinese medicine systems pharmacology, Swiss Target Prediction and GeneCards databases, and the VD-related targets were screened using the OMIM, DrugBank, GeneCards, and DisGeNET databases, and the potential targets were identified using a Venn diagram. We used Cytoscape 3.8.0 software and the STRING platform to construct traditional Chinese medicine-active ingredient-potential target and protein-protein interaction networks, respectively. After gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis of potential targets using the DAVID platform, the binding affinity between key active ingredients and targets was analyzed by molecular docking, and finally, the top 3 proteins-ligand pairs with the best binding were simulated by molecular dynamics to verify the molecular docking results.

RESULTS

A total of 27 active ingredients of GBLs were screened and 274 potential targets involved in the treatment of VD were identified. Quercetin, luteolin, kaempferol, and ginkgolide B were the core ingredients for treatment, and AKT1, TNF, IL6, VEGFA, IL1B, TP53, CASP3, SRC, EGFR, JUN, and EGFR were the main targets of action. The main biological processes involved apoptosis, inflammatory response, cell migration, lipopolysaccharide response, hypoxia response, and aging. PI3K/Akt appeared to be a key signaling pathway for GBLs in the treatment of VD. Molecular docking displayed strong binding affinity between the active ingredients and the targets. Molecular dynamics simulation results further verified the stability of their interactions.

CONCLUSION SUBSECTIONS

This study revealed the potential molecular mechanisms involved in the treatment of VD by GBLs using multi-ingredient, multi-target, and multi-pathway interactions, providing a theoretical basis for the clinical treatment and lead drug development of VD.

Survival in Huntington's disease and other young-onset dementias

OBJECTIVES

To compare survival and risk factors associated with mortality in common young-onset dementias (YOD) including Huntington's disease.

METHODS

This retrospective cohort study included inpatients from an Australian specialist neuropsychiatry service, over 20 years. Dementia diagnoses were based on consensus criteria and Huntington's disease (HD) was confirmed genetically. Mortality and cause of death were determined using linkage to the Australian Institute of Health and Welfare National Death Index.

RESULTS

There were 386 individuals with YOD included. The dementia types included frontotemporal dementia (FTD) (24.5%), HD (21.2%) and Alzheimer's disease (AD) (20.5%). 63% (n = 243) individuals had died. The longest median survival was for those who had HD, 18.8 years from symptom onset and with a reduced mortality risk compared to AD and FTD (hazard ratio 0.5). Overall, people with YOD had significantly increased mortality, of 5-8 times, compared to the general population. Females with a YOD had higher standardised mortality ratio compared to males (9.3 vs. 4.9) overall. The most frequent cause of death in those with HD was reported as HD, with other causes of death in the other YOD-subtypes related to dementia and mental/behavioural disorders.

DISCUSSION

This is the first Australian study to investigate survival and risk factors of mortality in people with YOD. YOD has a significant risk of death compared to the general population. Our findings provide useful clinical information for people affected by YOD as well as future planning and service provision.

Young-onset dementia diagnosis, management and care: a narrative review

Young-onset dementia comprises a heterogeneous range of dementias, with onset at less than 65 years of age. These include primary dementias such as Alzheimer disease, frontotemporal and vascular dementias; genetic/familial dementias; metabolic disorders; and secondary dementias such as those that result from alcohol use disorder, traumatic brain injury, and infections. The presentation of young-onset dementia is varied and may include cognitive, psychiatric and neurological symptoms. Diagnostic delay is common, with a frequent diagnostic conundrum being, "Is this young-onset dementia or is this psychiatric?". For assessment and accurate diagnosis, a thorough screen is recommended, such as collateral history and investigations such as neuroimaging, lumbar puncture, neuropsychology, and genetic testing. The management of young-onset dementia needs to be age-appropriate and multidisciplinary, with timely access to services and consideration of the family (including children).

Recent research advances in young-onset dementia

PURPOSE OF REVIEW

Young-onset dementia (YOD) refers to a dementia for which symptom onset occurs below the age of 65. This review summarizes the recent literature in this area, focusing on updates in epidemiology, diagnosis and service provision.

RECENT FINDINGS

In the last year, internationally, the prevalence of YOD was reported as 119 per 100 000, but this may vary according to population types. Although the commonest causes of YOD are Alzheimer's disease (AD) and frontotemporal dementia (FTD), there is increasing recognition that YOD is diagnostically and phenotypically broader than AD and FTD. YOD may be due to many other diseases (e.g. Huntington's disease, vascular dementia) whereas accumulation of the same protein (e.g. amyloid protein) may lead to different phenotypes of Alzheimer's disease (such as posterior cortical atrophy and behavioural-variant/frontal-variant AD). This heterogeneity of phenotypic presentation is also seen in YOD due to known genetic mutations. Biomarkers such as plasma and cerebrospinal fluid proteins, neuroimaging and genetics have shown promise in the early identification of YOD as well as providing further understanding behind the overlap between psychiatric and neurodegenerative conditions occurring in younger people. The management of YOD needs to consider age-specific issues for younger people with dementia and their family networks together with better integration with other health services such as aged, disability and improved access to services and financial assistance.

SUMMARY

These findings emphasize the need for early identification and appropriate age-specific and person-centred management for people with young-onset dementia.

Outcomes and Predictors of In-Hospital Mortality among Older Patients with Dementia

Dementia is associated with high rates of admission to hospital, due to acute illness, and in-hospital mortality. The study aimed to investigate the impact of dementia on in-hospital mortality and identify the predictors of in-hospital mortality in these patients. This was a retrospective study evaluating all the patients ≥65 years consecutively admitted to our Emergency Department (ED). We compared the clinical outcomes of the patients with dementia at ED admission with those who did not have dementia, using a propensity score-matched (PSM) paired cohort of controls. The patients were matched for age, sex, Charlson Comorbidity Index value, and clinical severity at presentation (based on NEWS ≥ 5). The primary study endpoint was all-cause in-hospital death. After the PSM, a total of 7118 patients, 3559 with dementia and 3559 in the control group, were included in the study cohort. The mean age was 84 years, and 59.8% were females. The overall mortality rate was higher for the demented patients compared with the controls (18.7% vs. 16.0%, p = 0.002). The multivariate-adjusted hazard ratio (HR) showed that dementia was an independent risk factor for death (HR 1.13 [1.01−1.27]; p = 0.033). In the patients with dementia, respiratory failure (HR 3.08 [2.6−3.65]), acute renal failure (HR 1.64 [1.33−2.02]; p < 0.001), hemorrhagic stroke (HR 1.84 [1.38−2.44]; p < 0.001), and bloodstream infection (HR 1.41 [1.17−1.71]; p = 0.001) were significant predictors of worse outcomes. Finally, the comorbidities and severity of illness at ED admission negatively influenced survival among the patients with dementia (CCI HR 1.05 [1.01−1.1] p = 0.005; NEWS ≥ 5 HR 2.45 [1.88−3.2] p < 0.001). In conclusion, among the hospitalized older patients, dementia was associated with a higher risk of mortality. Furthermore, among the older patients with dementia, respiratory failure and bloodstream infections were independently associated with an increased risk of in-hospital mortality.

Huntington's disease: Mortality and risk factors in an Australian cohort

INTRODUCTION

There has not been any examination of the risk factors associated with mortality in Huntington's Disease (HD) in an Australian cohort.

METHOD

This retrospective study included inpatients admitted to a specialist neuropsychiatry service in Melbourne, Australia. HD status was based on genetic testing. Risk factors included age of onset, CAG repeat length and neuroimaging. Mortality data was acquired through the Australian Institute of Health and Welfare National Death Index.

RESULTS

The cohort included 83 participants, with 44 (53%) deceased. The median age of death was 59 years and median survival was 18.8 years from onset age (median 41.0 years). CAG repeat length (median 44.0, IQR 42.5, 47.0) was inversely correlated with age of onset (r = -0.73) and age at death (r = -0.80) but was not correlated with mortality status. There was no difference in functional and cognitive assessments, nor brain volumes, in the alive group compared to the deceased group. There were more people who were alive who had a positive family history of a psychiatric condition (p = 0.006) or dementia (p = 0.009). Standardised mortality ratios demonstrated a 5.9× increased risk of death for those with HD compared to the general population.

CONCLUSIONS

This is the first study to examine risk factors of mortality in HD in an Australian cohort. Median survival in our cohort is consistent with previous studies in HD, and markedly reduced compared to the general Australian population. CAG repeat length was not associated with mortality suggesting that non-genetic factors contribute to mortality status and warrant further investigation.

Risk factors to mortality and causes of death in frontotemporal dementia: An Australian perspective

OBJECTIVES

Frontotemporal dementia (FTD) is a common cause of dementia in younger people. There is less information known about risk factors to mortality such as the type of symptom onset and cause of death in this group.

METHOD

This was a retrospective file review of inpatients with FTD admitted to a tertiary neuropsychiatry unit located in Australia from 1992 to 2014. Mortality information including linkage of names and causes of death were obtained from the Australian Institute Health and Welfare National Death Index.

RESULTS

One hundred inpatients were diagnosed with FTD, including behavioural-variant, language-variant FTDs and FTD-motor neuron disease (FTD-MND). Mean age was 52.8 years (SD = 10, range 31-76 years). Sixty-seven of them had died at linkage. Median survival of the sample was 10.5 years and FTD-MND had the shortest survival, 3.5 years. Increasing age of onset and FTD-MND were found to be significant predictors of association for mortality. Compared to the general population, having a FTD had an 8× increased risk of death. Females had double the standardised mortality ratio compared to males.

DISCUSSION

This study provides important prognostic information for people diagnosed with FTD living in Australia. It highlights the importance of obtaining a definitive diagnosis as early as possible for future planning. More investigation into the relationship of symptom onset type and sex differences in FTD is required.