Incidence of dementia: evidence for an effect modification by gender. The ILSA Study

Age at Onset of Heart Failure and Subsequent Risk of Dementia: A Longitudinal Cohort Study

BACKGROUND

The average age at onset of heart failure (HF) shows a progressive decrease in recent years; however, the association between age at onset of HF and risk of subsequent dementia remains undetermined.

OBJECTIVES

The study sought to examine whether younger onset age of HF is associated with a higher risk of incident dementia.

METHODS

Individual-level data from the UK Biobank cohort study were analyzed in the present study. Cox regression models and the propensity score matching method were used to analyze the associations of HF and its onset age with subsequent all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VD).

RESULTS

Compared with 442,791 participants without HF, those with HF had a higher risk of all-cause dementia (HR: 1.14). Among 14,413 participants with HF, multivariable-adjusted HRs for all-cause dementia, AD, and VD were 1.18, 1.64, and 1.27, respectively, per 10-year decrease in age at HF onset. The propensity score matching analyses found that the strength of association between HF and all-cause dementia increased with decreasing onset age of HF (≥75 years, HR: 1.05; 65-74 years, HR: 1.10; <65 years, HR: 1.67) after multivariable adjustment. Similarly, participants with onset age of HF <65 years had the greatest HRs for incident AD and VD, compared with their matched control subjects.

CONCLUSIONS

Younger age at HF onset was associated with increased risk of dementia. Individuals with an onset age of HF before 65 years of age may represent a particularly vulnerable population for dementia irrespective of subtypes and need careful monitoring and timely intervention to attenuate subsequent risk of incident dementia.

Predicting Alzheimer's Disease and Related Dementias in Heart Failure and Atrial Fibrillation

BACKGROUND

The Framingham Heart Study Dementia Risk Score (FDRS) was developed in a general population of older persons. It is unknown how the FDRS variables predict Alzheimer's disease and Alzheimer's disease-related dementias (AD/ADRD) in heart failure and atrial fibrillation populations. We aimed to evaluate the predictive ability of the FDRS variables in population-based cohorts of heart failure and atrial fibrillation and to determine whether the addition of other comorbidities and risk factors improves risk prediction for AD/ADRD.

METHODS

Residents aged ≥50 years from 7 southeastern Minnesota counties with a first diagnosis of heart failure or atrial fibrillation between January 1, 2013, and December 31, 2017, were identified. Patients with AD/ADRD before or within 6 months after index atrial fibrillation or heart failure and patients who died within 6 months after index were excluded. For both cohorts, models were constructed to predict AD/ADRD after index including the variables in the FDRS. Additional comorbidities and risk factors were added to the models. For all models, c-statistics using 5-fold cross-validation were calculated.

RESULTS

Among 3052 patients with heart failure (mean age 75 years, 53% male), 626 developed AD/ADRD; among 4107 patients with atrial fibrillation (mean age 74 years, 57% male), 736 developed AD/ADRD. Among patients with heart failure, the FDRS variables predicted AD/ADRD with c-statistic = 0.69. Adding comorbidities and risk factors improved the c-statistic slightly to 0.70. The FDRS variables also performed well (c-statistic = 0.73) in patients with atrial fibrillation; adding comorbidities and risk factors slightly improved performance (c-statistic = 0.75).

CONCLUSIONS

The variables from the FDRS predict AD/ADRD well in both heart failure and atrial fibrillation populations. The addition of comorbidities and risk factors only modestly improved prediction, indicating that the FDRS variables are appropriate to predict AD/ADRD in patients with heart failure and atrial fibrillation.

Sauver J, Bielinski SJ, Chamberlain AM, Weston SA, Jiang R, Roger VL. Alzheimer's disease and related dementias and heart failure: A community study

BACKGROUND

Cognitive function is essential to effective self-management of heart failure (HF). Alzheimer's disease and Alzheimer's disease-related dementias (AD/ADRD) can coexist with HF, but its exact prevalence and impact on health care utilization and death are not well defined.

METHODS

Residents from 7 southeast Minnesota counties with a first-ever diagnosis code for HF between January 1, 2013 and December 31, 2018 were identified. Clinically diagnosed AD/ADRD was ascertained using the Centers for Medicare and Medicaid (CMS) Chronic Conditions Data Warehouse algorithm. Patients were followed through March 31, 2020. Cox and Andersen-Gill models were used to examine associations between AD/ADRD (before and after HF) and death and hospitalizations, respectively.

RESULTS

Among 6336 patients with HF (mean age [SD] 75 years [14], 48% female), 644 (10%) carried a diagnosis of AD/ADRD at index HF diagnosis. The 3-year cumulative incidence of AD/ADRD after HF diagnosis was 17%. During follow-up (mean [SD] 3.2 [1.9] years), 2618 deaths and 15,475 hospitalizations occurred. After adjustment, patients with AD/ADRD before HF had nearly a 2.7 times increased risk of death, but no increased risk of hospitalization compared to those without AD/ADRD. When AD/ADRD was diagnosed after the index HF date, patients experienced a 3.7 times increased risk of death and a 73% increased risk of hospitalization compared to those who remain free of AD/ADRD.

CONCLUSIONS

In a large, community cohort of patients with incident HF, the burden of AD/ADRD is quite high as more than one-fourth of patients with HF received a diagnosis of AD/ADRD either before or after HF diagnosis. AD/ADRD markedly increases the risk of adverse outcomes in HF underscoring the need for future studies focused on holistic approaches to improve outcomes.

Sex Differences in the Association Between Midlife Cardiovascular Conditions or Risk Factors With Midlife Cognitive Decline

BACKGROUND AND OBJECTIVES

The prevalence of midlife cardiovascular conditions and risk factors is higher in men than women. Associations between midlife cardiovascular conditions or risk factors and midlife cognitive decline have been reported, but few studies have assessed sex differences in these associations.

METHODS

We included 1,857 participants enrolled in the population-based Mayo Clinic Study of Aging who were 50 to 69 years of age at baseline. Participants were evaluated every 15 months by a coordinator, including neurologic evaluation and neuropsychological testing. The neuropsychological testing used 9 tests to calculate global cognitive and domain-specific (memory, language, executive function, and visuospatial skills) z scores. Nurse abstractors reviewed participant medical records to determine the presence of cardiovascular conditions (coronary heart disease, arrhythmias, congestive heart failure) and risk factors (hypertension, diabetes, dyslipidemia, obesity, ever smoking). Linear mixed-effect models evaluated the association between baseline cardiovascular conditions or risk factors and global and domain-specific cognitive decline. Multivariable models adjusted for demographics, APOE genotype, depression, and other medical conditions. Interactions between sex and each cardiovascular condition or risk factor were examined, and results were stratified by sex.

RESULTS

Overall, 1,465 (78.9%) participants had at least 1 cardiovascular condition or risk factor; the proportion of men was higher than women (767 [83.4%] vs 698 [74.5%], p < 0.0001). Cross-sectionally, coronary heart disease and ever smoking were associated with a lower visuospatial z score in multivariable models. Longitudinally, several cardiovascular conditions and risk factors were associated with declines in global and domain-specific z scores but not visuospatial z scores. Most cardiovascular conditions were more strongly associated with cognition among women: coronary heart disease and other cardiovascular conditions were associated with global cognitive decline only in women (all p < 0.05). In addition, diabetes, dyslipidemia, and coronary heart disease were associated with language z score decline only in women (all p < 0.05). However, congestive heart failure was associated with language z score decline only in men (all p < 0.05).

DISCUSSION

Midlife cardiovascular conditions and risk factors are associated with midlife cognitive decline. Moreover, specific cardiovascular conditions and risk factors have stronger associations with cognitive decline in midlife for women than men despite the higher prevalence of those conditions in men.

Cognitive decline and risk of dementia in individuals with heart failure: A systematic review and meta-analysis

AIM

To determine the association between heart failure (HF) and cognitive change and dementia.

METHODS AND RESULTS

Systematic search of three electronic databases was performed and 29 eligible studies involving approximately 3 million participants were identified. Twelve studies examined dementia and 20 cognitive change, but only a subset of studies could be included in the meta-analysis. These findings indicated that HF was not significantly associated with dementia (n=8, hazard ratio [HR] 1.18, 95% confidence interval [CI] [0.93, 1.50]), but increased the risk of cognitive impairment (n=3, HR 1.80, 95%CI [1.14,2.86]) . Additionally, HF was associated with poorer mean cognitive performance in global cognition (Hedges' g -0.73, 95%CI [-1.12, -0.35]), memory (Hedges' g -0.57, 95%CI [-0.72, -0.42]), executive function (Hedges' g -0.58, 95%CI [-0.72, -0.43]), attention/speed (Hedges' g -0.50, 95%CI [-0.63, -0.37]) and language (Hedges' g -0.61, 95%CI [-1.05, -0.17]).

CONCLUSION

Patients with HF perform worse on all cognitive tests, and have an increased risk of cognitive impairment. These findings highlight the need for clinicians to consider cognition as part of routine care for patients with HF.

Cognitive Reserve Characteristics and Occupational Performance Implications in People with Mild Cognitive Impairment

The Cognitive Reserve hypothesis suggests that there are individual differences in the ability to cope with the pathologic changes in Alzheimer's Disease. The proportion of elderly individuals has increased in recent years; this increase emphasizes the importance of early detection of mild cognitive impairment and the promotion of healthy ageing. The purpose of our study is to characterize cognitive reserve and occupational performance implications in people with mild cognitive impairment. 125 patients with mild cognitive impairment were enrolled. The Montreal Cognitive Assessments (MoCA) was used to evaluate cognitive status and the Cognitive Reserve Index Questionnaire (CRIq) as an indicator of cognitive reserve. Higher level of education was associated with higher MoCA scores (r = 0.290, p = 0.001). Positive significant correlations were observed between MoCA and total CRIq (r = 0.385, p < 0.001) as well as its three sub-domains, education (r = 0.231, p = 0.010), working activity (r = 0.237, p = 0.008) and leisure time (r = 0.319, p < 0.001). This study findings provide the importance of considering socio-behavioral factors in cognitive status. This research helps to describe the importance of engaging occupationally along the whole life-course as a potential protective factor in ageing, and includes a perspective of occupational therapy regarding the hypothesis of cognitive reserve.

Sex-Specific Associations Between Depressive Symptoms and Risk for Subsequent Dementia

BACKGROUND

An association between depression and an increased risk for subsequent dementia is well-established. Sexspecific associations are understudied yet.

OBJECTIVE

We aimed to investigate sex-specific associations between depressive symptoms and dementia risk.

METHODS

Longitudinal analyses were conducted in a pooled data set (n = 4,255, mean age = 80 years) of two prospective cohort studies (LEILA 75+, AgeCoDe). Depressive symptoms were harmonized by dichotomized scores of two different depression screening scales using established cutoffs. Transition to dementia was used as outcome in Cox proportional hazards models.

RESULTS

Depressive symptoms at baseline were associated with an increased risk for subsequent dementia, and this association was more pronounced in males (interaction of depressive symptoms × sex: HR = 1.64, 95% CI: 1.02-2.64, p = 0.042) in a model adjusted for study, age, and education. After additional adjustment for subjective and objective cognition, depressive symptoms and their interaction with sex (HR = 1.38, 95% CI: 0.85-2.23, p = 0.188) were no longer significantly associated with the risk for subsequent dementia. Sex-stratified analyses showed stronger and significant associations between depressive symptoms and subsequent dementia in men (e.g., HR= 2.10, 95% CI: 1.36-3.23, p = 0.001, compared to HR= 1.28, 95% CI: 1.04-1.58, p = 0.020, in women).

CONCLUSIONS

Overall, we provide evidence for a stronger association between depression and dementia in men compared to women. Depressive symptoms should be diagnosed, monitored, and treated, not only due to depression, but also with respect to the risk for subsequent dementia, especially in elderly men.

Associations between coronary heart disease and risk of cognitive impairment: A meta-analysis

BACKGROUND

Several studies have demonstrated that coronary heart disease (CHD) is a high risk factor for cognitive impairment, whereas other studies showed that there was no association between cognitive impairment and CHD. The relationship between CHD and cognitive impairment is still unclear based on these conflicting results. Thus, it is of importance to evaluate the association between CHD and cognitive impairment. The present study made a meta-analysis to explore the association between CHD and risk of cognitive impairment.

METHODS

Articles exploring the association between CHD and cognitive impairment and published before November 2020 were searched in the following databases: PubMed, Web of Science, Medline, EMBASE, and Google Scholar. We used STATA 12.0 software to compute the relative risks (RRs), odds ratios (ORs), or hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The meta-analysis showed a positive association between CHD and risk of all-cause cognitive impairment with a random effects model (RR = 1.27, 95% CI 1.18 to 1.36, I²  = 82.8%, p < .001). Additionally, the study showed a positive association between myocardial infraction (MI) and risk of all-cause cognitive impairment with a random effects model (RR = 1.49, 95% CI 1.20 to 1.84, I²  = 76.0%, p < .001). However, no significant association was detected between angina pectoris (AP) and risk of all-cause cognitive impairment with a random effects model (RR = 1.23, 95% CI 0.95 to 1.58, I²  = 79.1%, p < .001). Subgroup studies also showed that CHD patients are at higher risk for vascular dementia (VD), but not Alzheimer's disease (AD) (VD: RR = 1.34, 95% CI: 1.28-1.39; AD: RR = 0.99, 95% CI: 0.92-1.07).

CONCLUSION

In a word, CHD was significantly associated with an increased risk of developing cognitive impairment.

What does (low) education mean in terms of dementia risk? A systematic review and meta-analysis highlighting inconsistency in measuring and operationalising education

Low education is considered an important modifiable risk factor for dementia worldwide, despite the lack of a formal consensus definition of low education. The primary aim of this systematic review was to document and address the inconsistency in measuring and operationalising education in dementia studies. A secondary aim was to consider the dose of education required to reduce dementia risk. The protocol was registered at PROSPERO with registration ID CRD42018096168. CINAHL, Cochrane, PsycInfo, and Pubmed databases were searched using terms related to education, dementia and/or MCI, and incidence. Studies were eligible for inclusion if a risk ratio for education and any dementia, Alzheimer's Disease (AD), Vascular Dementia (VaD) or Mild Cognitive Impairment (MCI) was reported in a population cognitively healthy at baseline. Sample sizes for 65 studies meeting selection criteria ranged from 152 to 12,881, representing populations from 24 countries. Risk of bias, assessed using a tool designed specifically for dementia risk studies, was found to be medium or low for all studies. There were 23 continuous, 29 dichotomous, and 31 categorical operationalisations of education reported. Random effects meta-analyses from continuous operationalisations suggested each year of education reduced risk by eight percent for AD (95% CI:5-12%) and seven percent for any dementia (95% CI:6-9%). Dichotomous operationalisations indicated an increased risk for low education of 45% (95% CI:29-63%) for any dementia and 85% (95% CI:56-118%) for AD, however definitions of low education were heterogeneous, ranging from zero to 12 years. There were too few studies to produce summary ratios for VaD or MCI. We conclude that, while the evidence of an association between low education and dementia incidence is robust, inconsistency in the definition, measurement and operationalisation of education hinders the translation of this evidence into practical policy recommendations to reduce dementia risk.

Pathways Connecting Late-Life Depression and Dementia

Late-life depression is associated with significant cognitive impairment. Meta-analyses showed that depression is associated with an increased risk for Alzheimer’s disease (AD) and it might be an etiological factor for AD. Since late-life depression is often connected with cognitive impairment and dementia is usually associated with depressive symptoms, a simple diagnostic approach to distinguish between the disorders is challenging. Several overlapping pathophysiological substrates might explain the comorbidity of both syndromes. Firstly, a stress syndrome, i.e., elevated cortisol levels, has been observed in up to 70% of depressed patients and also in AD pathology. Stress conditions can cause hippocampal neuronal damage as well as cognitive impairment. Secondly, the development of a depression and dementia after the onset of vascular diseases, the profile of cerebrovascular risk factors in both disorders and the impairments depending on the location of cerebrovascular lesions, speak in favor of a vascular hypothesis as a common factor for both disorders. Thirdly, neuroinflammatory processes play a key role in the etiology of depression as well as in dementia. Increased activation of microglia, changes in Transforming-Growth-Factor beta1 (TGF-beta1) signaling, production of pro-inflammatory cytokines as well as reduction of anti-inflammatory molecules are examples of common pathways impaired in dementia and depression. Fourthly, the neurotrophin BDNF is highly expressed in the central nervous system, especially in the hippocampus, where it plays a key role in the proliferation, differentiation and the maintenance of neuronal integrity throughout lifespan. It has been associated not only with antidepressant properties but also a reduction of cognitive impairment and therefore could be involved also in AD. Another etiologic factor is amyloid accumulation, as plasma amyloid beta-42 independently predicts both late-onset depression and AD. Higher plasma amyloid beta-42 predicts the development of late onset depression and conversion to possible AD. However, clinical trials with antibodies against beta amyloid recently failed, i.e., Solanezumab, Aducanumab, and Crenezumab. An overproduction of amyloid-beta might simply reflect a form of synaptic plasticity to compensate for neuronal dysfunction in different kind of neurological and psychiatric diseases of multiple etiologies. The tau hypothesis, sex/gender specific differences, epigenetics and the gut microbiota-brain axis imply other potential common pathways connecting late-life depression and dementia. In conclusion, different potential pathophysiological links between dementia and depression highlight several specific synergistic and multifaceted treatment possibilities, depending on the individual risk profile of the patient.

Associations between heart failure and risk of dementia: A PRISMA-compliant meta-analysis

BACKGROUND

There are differences among the outcomes regarding cognitive impairment in heart failure (HF) because the evidence is fragmented and sample size is small. Therefore we aimed to systematically review and analyze the available evidence about the association between HF and dementia.

METHODS

In the present study, we searched for articles published until August 2019 in the following databases: PubMed, Web of Science, EMBASE, Medline and Google Scholar. The pooled multivariate odds ratio (OR) or relative risk (RR) and 95% confidence intervals (CI) were obtained by the use of STATA 12.0 software.

RESULTS

The meta-analysis showed a positive association between HF and risk of all-cause dementia (OR/RR = 1.28, 95% CI 1.15 to 1.43, I = 70.0%, P < 0.001). Additionally, the study showed no significant association between HF and risk of Alzheimer's disease (AD) (OR/RR = 1.38, 95% CI 0.90 to 2.13, I = 74.8%, P = 0.008).

CONCLUSION

In conclusion, HF was associated with an increased risk of developing dementia. In addition, large scale prospective studies are essential to explore the associations between HF and risk of AD.

Stroke and dementia risk: A systematic review and meta-analysis

INTRODUCTION

Stroke is an established risk factor for all-cause dementia, though meta-analyses are needed to quantify this risk.

METHODS

We searched Medline, PsycINFO, and Embase for studies assessing prevalent or incident stroke versus a no-stroke comparison group and the risk of all-cause dementia. Random effects meta-analysis was used to pool adjusted estimates across studies, and meta-regression was used to investigate potential effect modifiers.

RESULTS

We identified 36 studies of prevalent stroke (1.9 million participants) and 12 studies of incident stroke (1.3 million participants). For prevalent stroke, the pooled hazard ratio for all-cause dementia was 1.69 (95% confidence interval: 1.49-1.92; P < .00001; I2 = 87%). For incident stroke, the pooled risk ratio was 2.18 (95% confidence interval: 1.90-2.50; P < .00001; I2 = 88%). Study characteristics did not modify these associations, with the exception of sex which explained 50.2% of between-study heterogeneity for prevalent stroke.

DISCUSSION

Stroke is a strong, independent, and potentially modifiable risk factor for all-cause dementia.

Sex Differences in Cardiovascular Risk Factors for Dementia

Dementia, characterized by a progressive cognitive decline and a cumulative inability to behave independently, is highly associated with other diseases. Various cardiovascular disorders, such as coronary artery disease and atrial fibrillation, are well-known risk factors for dementia. Currently, increasing evidence suggests that sex factors may play an important role in the pathogenesis of diseases, including cardiovascular disease and dementia. Recent studies show that nearly two-thirds of patients diagnosed with Alzheimer’s disease are women; however, the incidence difference between men and women remains vague. Therefore, studies are needed to investigate sex-specific differences, which can help understand the pathophysiology of dementia and identify potential therapeutic targets for both sexes. In the present review, we summarize sex differences in the prevalence and incidence of dementia by subtypes. This review also describes sex differences in the risk factors of dementia and examines the impact of risk factors on the incidence of dementia in both sexes.

Detecting spatiotemporal clusters of dementia mortality in the United States, 2000-2010

Based on national death certificate data during 2000 and 2010, we employed the space-time scan statistic to identify spatiotemporal clusters of dementia mortality in the contiguous United States. Results revealed that, for both Alzheimer's disease and all-cause dementia mortality in the total population, the most likely clusters occurred in the Northeast region, with lower than average relative risk. The most likely excess mortality clusters were in the Pacific Northwest and Ohio River Valley and Carolinas. Temporal information of clusters suggested reduction in the relative risk of Alzheimer's disease and all-cause dementia mortality in most of the highly likely clusters. The results should propel public health agencies to evaluate the capacity of local health and social care to meet dementia patients' needs before death in the high-risk cluster areas. Further investigation of causal factors of these clusters is needed.

A tricyclic antidepressant, amoxapine, reduces amyloid-β generation through multiple serotonin receptor 6-mediated targets

Alzheimer’s disease (AD) is a major and devastating neurodegenerative disease, and the amyloid-β (Aβ) hypothesis is still the central theory for AD pathogenesis. Meanwhile, another major mental illness, depression, is one of the risk factors for AD. From a high-throughput screening (HTS), amoxapine, a typical secondary amine tricyclic antidepressant (TCA), was identified to reduce Aβ production. A follow-up investigation on antidepressants showed that most of the TCAs harbour similar activity. Previous studies have indicated that TCAs improve cognitive function in AD mouse models as well as in preliminary clinical data; however, the underlying mechanism is controversial, and the effect on Aβ is elusive. Thus, we developed a secondary screening to determine the molecular target of amoxapine, and serotonin receptor 6 (HTR6) was identified. Knockdown of HTR6 reduced the amoxapine’s effect, while the HTR6 antagonist SB258585 mimicked the activity of amoxapine. Further mechanistic study showed that amoxapine and SB258585 reduced Aβ generation through multiple HTR6-mediated targets, including β-arrestin2 and CDK5. Taken together, our study suggests that amoxapine, though no longer a first-line drug for the treatment of depression, may be beneficial for AD and further structural modification of TCAs may lead to desirable therapeutic agents to treat both AD and depression.

Temporal trend in dementia incidence since 2002 and projections for prevalence in England and Wales to 2040: modelling study

Objective To forecast dementia prevalence with a dynamic modelling approach that integrates calendar trends in dementia incidence with those for mortality and cardiovascular disease.Design Modelling study.Setting General adult population of England and Wales.Participants The English Longitudinal Study of Ageing (ELSA) is a representative panel study with six waves of data across 2002-13. Men and women aged 50 or more years, selected randomly, and their cohabiting partners were recruited to the first wave of ELSA (2002-03). 11392 adults participated (response rate 67%). To maintain representativeness, refreshment participants were recruited to the study at subsequent waves. The total analytical sample constituted 17 906 people. Constant objective criteria based on cognitive and functional impairment were used to ascertain dementia cases at each wave.Main outcome measures To estimate calendar trends in dementia incidence, correcting for bias due to loss to follow-up of study participants, a joint model of longitudinal and time-to-event data was fitted to ELSA data. To forecast future dementia prevalence, the probabilistic Markov model IMPACT-BAM (IMPACT-Better Ageing Model) was developed. IMPACT-BAM models transitions of the population aged 35 or more years through states of cardiovascular disease, cognitive and functional impairment, and dementia, to death. It enables prediction of dementia prevalence while accounting for the growing pool of susceptible people as a result of increased life expectancy and the competing effects due to changes in mortality, and incidence of cardiovascular disease.Results In ELSA, dementia incidence was estimated at 14.3 per 1000 person years in men and 17.0/1000 person years in women aged 50 or more in 2010. Dementia incidence declined at a relative rate of 2.7% (95% confidence interval 2.4% to 2.9%) for each year during 2002-13. Using IMPACT-BAM, we estimated there were approximately 767 000 (95% uncertainty interval 735 000 to 797 000) people with dementia in England and Wales in 2016. Despite the decrease in incidence and age specific prevalence, the number of people with dementia is projected to increase to 872 000, 1 092 000, and 1 205 000 in 2020, 2030, and 2040, respectively. A sensitivity analysis without the incidence decline gave a much larger projected growth, of more than 1.9 million people with dementia in 2040.Conclusions Age specific dementia incidence is declining. The number of people with dementia in England and Wales is likely to increase by 57% from 2016 to 2040. This increase is mainly driven by improved life expectancy.

Gender differences in risk factors for transition from mild cognitive impairment to Alzheimer's disease: A CREDOS study

BACKGROUND

Women are subject to a disproportionate burden from Alzheimer's disease (AD) and sex differences exist in treatment response and prognosis of the disease. Yet gender-specific risk factors have not been widely studied. We aimed to investigate gender-specific risk factors for AD in subjects with mild cognitive impairment (MCI).

METHODS

Participants (n=294) with MCI were recruited from a nationwide, prospective cohort study of dementia and were followed for a median (range) of 13.8 (6.0-36.0) months. Sex-stratified associations of progression to AD with baseline characteristics were explored.

RESULTS

Seventy-four individuals (25.2%) developed incident dementia (67 AD) during follow-up. Significant risk factors for probable AD differed by sex. In men, the significant risk factors were severe periventricular white matter hyperintensities, and poorer global cognitive function. In women, older age, clinically significant depressive symptoms at baseline, and positive APOE ε4 alleles were the significant risk factors.

CONCLUSIONS

Risk factors for progression from MCI to probable AD differed in men and women. These results may translate to gender-specific preventative or therapeutic strategies for patients with MCI.