Vascular risk factors and cognitive decline in a population sample

Sex Differences in the Association Between Vascular Risk Factors and Cognitive Decline: A UK Biobank Study

Background

Age-related cognitive decline is accelerated by vascular risk factors for cerebral small vessel disease. However, the association of vascular risk factors with cerebral small vessel disease contributing to the sex differences in cognitive decline remains unclear.

Objectives

The purpose of this study was to evaluate sex differences in cognitive decline and the association between vascular risk factors and cognitive decline by sex.

Methods

We used data from the UK Biobank (>55 years of age; n = 19,067) to assess cognitive tests (executive function, processing speed, and memory) while adjusting for baseline measurements to examine how vascular risk factors affect cognition. A univariate regression analysis was used to assess sex differences at the first time point (2014). A repeated measure analysis with a mixed effect model was used to determine cognitive decline (between 2014 and 2019). Any significant interaction between vascular risk factors and sex was investigated.

Results

Females had lower scores in all 3 domains at the first cognitive tests (2014). We found a significant sex-by-time interaction over a 5-year period in matrix pattern completion (P = 0.03). After adjusting for vascular risk factors, this interaction was reduced (P = 0.08). High low-density lipoprotein, low education, and high blood pressure had a greater effect on the rate of cognitive decline in the executive function for females compared to males for the sex∗vascular risk factor interaction (P < 0.05).

Conclusions

The rate of cognitive decline did not differ significantly between males and females. However, the impact of several vascular risk factors on cognitive decline was greater in females than in males.

Benzodiazepine use and risk of incident MCI and dementia in a community sample

OBJECTIVES

Older adults commonly take benzodiazepines (BZDs) that may have long-term adverse cognitive effects. We investigated whether BZD use was related to developing mild cognitive impairment (MCI) or dementia in cognitively normal older adults in the community.

SETTING/PARTICIPANTS

A population-based cohort (n = 1959) of adults aged 65 and over, recruited from communities of low socioeconomic status.

MEASUREMENTS

BZD use, Clinical Dementia Rating (CDR), anxiety symptoms, depression symptoms, sleep difficulties, and APOE genotype.

DESIGN

We examined time from study entry to MCI (CDR = 0.5) and time from study entry to dementia (CDR ≥ 1) in participants who were cognitively normal at baseline (CDR = 0). We used survival analysis (Cox model), adjusted for age, sex, education, sleep, anxiety, and depression. For all the models, we included an interaction term between BZD use and APOE*4.

RESULTS

Taking BZDs was significantly associated with higher risk of developing MCI, but not of developing dementia. The effect was not affected by APOE genotype.

CONCLUSIONS

In a population-based sample of cognitively normal older adults, BZD use is associated with developing MCI, but not dementia. BZD use may be a potentially modifiable risk factor for MCI.

Contributions of Vascular Burden and Amyloid Abnormality to Cognitive Decline in Memory Clinic Patients

Background

Alzheimer's disease pathology and vascular burden are highly prevalent and often co-occur in elderly. It remains unclear how both relate to cognitive decline.

Objective

To investigate whether amyloid abnormality and vascular burden synergistically contribute to cognitive decline in a memory clinic population.

Methods

We included 227 patients from Maastricht and Aachen memory clinics. Amyloid abnormality (A+) was defined by CSF Aβ42 using data-driven cut-offs. Vascular burden (V+) was defined as having moderate to severe white matter hyperintensities, or any microbleeds, macrohemorrhage or infarcts on MRI. Longitudinal change in global cognition, memory, processing speed, executive functioning, and verbal fluency was analysed across the A-V-, A-V+, A+V-, A+V+ groups by linear mixed models. Additionally, individual MRI measures, vascular risk and vascular disease were used as V definitions.

Results

At baseline, the A+V+ group scored worse on global cognition and verbal fluency compared to all other groups, and showed worse memory compared to A-V+ and A-V- groups. Over time (mean 2.7+ - 1.5 years), A+V+ and A+V- groups showed faster global cognition decline than A-V+ and A-V- groups. Only the A+V- group showed decline on memory and verbal fluency. The A-V+ group did not differ from the A-V- group. Individual MRI vascular measures only indicated an independent association of microbleeds with executive functioning decline. Findings were similar using other V definitions.

Conclusions

Our study demonstrates that amyloid abnormality predicts cognitive decline independent from vascular burden in a memory clinic population. Vascular burden shows a minor contribution to cognitive decline in these patients. This has important prognostic implications.

Cognitive decline monitoring through a web-based application

Cognitive decline usually begins after individuals reach maturity, which is more evident in late adulthood. Rapid and constant cognitive screenings allow early detection of cognitive decline and motivate individuals to participate in prevention interventions. Due to accelerated technological advances, cognitive screening and training are now available to the layperson using electronic devices connected to the internet. Large datasets generated by these platforms provide a unique opportunity to explore cognitive development throughout life and across multiple naturalistic environments. However, such data collection mechanisms must be validated. This study aimed to determine whether the data gathered by commercial visuospatial and phonological working memory tests (CogniFit Inc., San Francisco, USA) confirm the well-established argument that age predicts cognitive decline. Data from 3,212 participants (2,238 females) who were 45 years old or older were analyzed. A linear regression analysis explored the relationship between age and working memory while controlling for gender, sleep quality, and physical activity (variables that are known to affect working memory). We found that age negatively predicts working memory. Furthermore, there was an interaction between age and gender for visuospatial working memory, indicating that although male participants significantly outperformed females, the relationship between age and working memory differs for females and males. Our results suggest that the computerized assessment of visuospatial and phonological working memory is sensible enough to predict cognitive functions in aging. Suggestions for improving the sensitivity of self-reports are discussed. Further studies must explore the nature of gender effects on cognitive aging.

Citicoline May Prevent Cognitive Decline in Patients with Cerebrovascular Disease

Introduction

Neuroprotective drugs such as citicoline could improve cognitive performance and quality of life. We studied the effect of citicoline treatment and its association with Vascular Risk Factors (VRF) and APOE on cognition in patients with Subjective Cognitive Complaints (SCC) and Mild Cognitive Impairment (MCI).

Methods

This is an observational and prospective study with citicoline during 12 months follow-up. Eighty-one subjects who met criteria for SCC/MCI, aged 50-75 years with VRF were included and prescribed citicoline 1g/day. Subjects with previous cognitive impairment and any other central nervous system affection were excluded. Wilcoxon Signed Ranks test and paired samples t-test were used to analyze the change in neuropsychological performance.

Results

Mean age of the sample was 68.2 (SD 6.8) years and 26 (32.09%) were females. Fifteen subjects (24.6%) were APOE-ε4 carriers, fifty-six (76.7%) had hypertension, fifty-eight (79.5%) had dyslipidemia, twenty-one (28.8%) had diabetes mellitus and twenty-six (35.6%) had cardiopathy. Thirty-two (43.8%) subjects were diagnosed as SCC and forty-one (56.16%) as MCI. During the follow-up, Tweny-six patients (81.25%) in the group of SCC remained stable, six subjects (18.8%) converted to MCI. Twelve patients (29.9%) with MCI reverted to SCC and twenty-nine patients (70.7%) remained stable. At follow-up, SCC subjects had an improvement in the global language domain (p=0.03), naming (p<0.001), attention (p=0.01) and visuospatial abilities (p<0.01). MCI group showed an improvement in the screening test (p=0.03), delayed memory (p<0.01), global cognition (p=0.04) and in cognitive flexibility (p=0.03). Presence of APOE-ε4 had no impact on the above findings.

Discussion

SCC subjects showed an improvement in language and attention domains, while those with MCI performed better after 12 months in total scores of MoCA and RBANS domains, some converting back to SCC. This supports the idea that citicoline may prevent cognitive decline in patients with cognitive deficits.

APOE differentially moderates cerebrospinal fluid and plasma phosphorylated tau181 associations with multi-domain cognition

Biofluid markers of phosphorylated tau181 (p-tau181) are increasingly popular for the detection of early Alzheimer's pathologic changes. However, the differential dynamics of cerebrospinal fluid (CSF) and plasma p-tau181 remain under investigation. We studied 727 participants from the Alzheimer's Disease Neuroimaging Initiative with plasma and CSF p-tau181 data, apolipoprotein (APOE) ε4 carrier status, amyloid positron emission tomography (PET) imaging, and neuropsychological data. Higher levels of plasma and CSF p-tau181 were observed among APOE ε4 carriers. CSF and plasma p-tau181 were significantly associated with memory, and this effect was greater in APOE ε4 carriers. However, whereas CSF p-tau181 was not significantly associated with language or attention/executive function among ε4 carriers or non-carriers, APOE ε4 status moderated the association of plasma p-tau181 with both language and attention/executive function. These findings lend support to the notion that p-tau181 biofluid markers are useful in measuring AD pathologic changes but also suggest that CSF and plasma p-tau181 have unique properties and dynamics that should be considered when using these markers in research and clinical practice.

Chronic cerebral hypoperfusion alters the CypA-EMMPRIN-gelatinase pathway: Implications for vascular dementia

Chronic cerebral hypoperfusion (CCH) is postulated to underlie multiple pathophysiological processes in vascular dementia (VaD), including extracellular matrix dysfunction. While several extracellular matrix proteins, namely cyclophilin A (CypA), extracellular matrix metalloproteinase inducer (EMMPRIN) and gelatinases (matrix metalloproteinases, MMP-2 and -9) have been investigated in acute stroke, their involvement in CCH and VaD remains unclear. In this study, CypA-EMMPRIN-gelatinase proteins were analysed in a clinical cohort of 36 aged, cognitively unimpaired subjects and 48 VaD patients, as well as in a bilateral carotid artery stenosis mouse model of CCH. Lower CypA and higher EMMPRIN levels were found in both VaD serum and CCH mouse brain. Furthermore, gelatinases were differentially altered in CCH mice and VaD patients, with significant MMP-2 increase in CCH brain and serum, whilst serum MMP-9 was elevated in VaD but reduced in CCH, suggesting complex CypA-EMMPRIN-gelatinase regulatory mechanisms. Interestingly, subjects with cortical infarcts had higher serum MMP-2, while white matter hyperintensities, cortical infarcts and lacunes were associated with higher serum MMP-9. Taken together, our data indicate that perturbations of CypA-EMMPRIN signalling may be associated with gelatinase-mediated vascular sequelae, highlighting the potential utility of the CypA-EMMPRIN-gelatinase pathway as clinical biomarkers and therapeutic targets in VaD.

Cognitive Impairment and the Associated Factors Among Older People in Rural Central Tanzania

AIM

This study examined the profile of cognitive impairment and associated factors among older people in rural central Tanzania.

METHODS

We conducted a cross-sectional study involving 462 community-dwelling older adults. We performed cognitive, psychosocial, and clinical assessments and face-to-face interviews with all older adults. Descriptive, bivariate and multivariate linear regression analyses were performed to determine the participant's cognitive performance and the associated factors.

RESULTS

The mean cognitive score on the Identification and Intervention for Dementia in Elderly Africans cognitive test was 11.04 (SD=2.89). Per the proposed cut-off scores to define probable and possible dementia, 13.2% of the population had probable dementia and another 13.9% had possible dementia. Increase in age was associated with poor cognitive performance (β=-0.076, 95% CI=-0.109 to -0.043, P<0.001); whereas male sex (β=0.989, 95% CI=0.333 to 1.645, P=0.003), higher educational attainment (β=2.575, 95% CI=0.557 to 4.594, P=0.013) and performance in instrumental activities of daily living (β=0.552, 95% CI=0.376 to 0.729, P<0.001) were associated with higher cognitive performance.

DISCUSSION

Older people in rural settings of central Tanzania have poor cognitive functions and are at high risk of further cognitive decline. Preventive and therapeutic programs for the affected older people are warranted to prevent further decline and maintain quality of life.

Alzheimer's disease biomarkers in patients with obstructive sleep apnea hypopnea syndrome and effects of surgery: A prospective cohort study

Background

Obstructive sleep apnea hypopnea syndrome (OSAHS) may cause Alzheimer's disease (AD), t-tau, p-tau, Aβ42, and Aβ40 are important elements in the process of AD, and changes in the levels of these biomarkers may affect the cognitive functioning of patients. Our objective was to investigate whether uvulopalatopharyngoplasty could reduce the plasma levels of AD biomarkers in OSAHS patients and the potential correlations of AD biomarkers with cognitive impairment and sleepiness, and explore the independent influencing factors of cognitive function.

Methods

Alzheimer's disease biomarkers were measured in the plasma of 35 patients with severe OSAHS requiring surgical treatment and 16 healthy controls without OSAHS. The cognitive function and sleepiness of OSAHS patients was also evaluated. The case group was given uvulopalatopharyngoplasty and followed at the postoperative sixth month, the follow-up cases were 27, and plasma AD biomarker levels, cognitive function, and sleepiness were re-evaluated. The preoperative and postoperative AD biomarker levels OSAHS patients were compared with each other and those of the control group. Linear stepwise regression and lasso regression were used to explore the relationships of AD biomarkers with cognitive impairment and sleepiness.

Results

Significantly higher Aβ40, t-tau, p-tau in plasma were observed preoperatively in OSAHS patients comparing to controls (29.24 ± 32.52 vs. 13.18 ± 10.78, p = 0.049; 11.88 ± 7.05 vs. 7.64 ± 4.17, p = 0.037; 26.31 ± 14.41 vs. 17.34 ± 9.12, p = 0.027). The sixth month of postoperation, the plasma AD biomarkers (Aβ42, Aβ40, t-tau, p-tau) in plasma levels decreased significantly (0.23 ± 0.17 vs. 0.20 ± 0.16, p = 0.0001; 29.24 ± 32.52 vs. 23.52 ± 24.46, p = 0.0046; 11.88 ± 7.05 vs. 8.88 ± 6.21, p = 0.0001;26.31 ± 14.41 vs. 20.43 ± 10.50, p = 0.0001). A comparison of MMSE and ESS scores from before to after surgery revealed obvious differences (27.14 ± 1.65 vs. 29.07 ± 1.78, p = 0.0001; 11.91 ± 4.84 vs. 5.89 ± 2.83, p = 0.0001). Changes in cognitive function and sleepiness scores from before to after uvulopalatopharyngoplasty were significantly correlated with AD biomarkers. Body mass index and t-tau were potential influencing factors cognitive function.

Conclusion

Obstructive sleep apnea hypopnea syndrome can increase plasma AD biomarkers levels. Uvulopalatopharyngoplasty can improve patients' cognition and sleepiness, and the mechanism may be related to changes in plasma AD biomarkers. Higher AHI and higher t-tau level were identified as independent risk factors for cognitive decline.

Association of cardiometabolic health factors with age-related executive function and episodic memory

Although decline of cognitive abilities in late life is regarded as a common facet of aging, there is inter-individual variability in this decline. Possible contributors are cardiometabolic risk factors associated with cerebrovascular dysfunction, but a dearth in unifying health-cognition models confound exactly how these risk factors mediate age-related changes in executive function (EF) and episodic memory. This study investigated the indirect effect of age on these cognitive abilities via cardiometabolic risk factors using a structural equation modeling approach. Participants included 738 adults (64% female) ranging from 21 to 85 years of age (M = 47.47, SD = 18.28). An exploratory factor analysis was applied to an EF battery yielding a two-factor solution, consisting of inhibition and cognitive flexibility, that showed acceptable fit (χ2(48) = 101.84, p < .001, CFI = .980, RMSEA = .039, SRMR = .035). The EF latent factors were then included in a confirmatory factor analysis exploring the indirect role of age on episodic memory and EF via blood pressure, cholesterol, triglycerides and body mass index. The theoretical model demonstrated acceptable fit, χ2(108) = 204.071, p < .001, CFI = .972, RMSEA = .035, SRMR = .035. Blood pressure was associated with lower cognitive flexibility (β = -.20, p < .001) and there was a significant indirect effect of age on episodic memory through cognitive flexibility (β = .07, p = .021). Results support the "Executive Decline Hypothesis" of age-related episodic memory decline and specifically implicate lower blood pressure control and cognitive flexibility in these changes.

Association between blood pressure control status, visit-to-visit blood pressure variability, and cognitive function in elderly Chinese: A nationwide study

Background

Cognitive function is a concern among the elderly, which is related to the quality of life, life expectancy, and economic burdens. The relationship between blood pressure (BP) control status, visit-to-visit BP variability, and cognitive function remains controversial.

Methods

We aimed to explore the association between BP control status at baseline, visit-to-visit BP variability, and cognitive function. This study included 3,511 elderlies in the China Health and Retirement Longitudinal Study, covering four waves for 7-year follow-up (baseline 2011, 2013, 2015, and 2018). BP was measured in Wave 2011, 2013, and 2015. Cognitive function was measured by Mini-Mental State Exam in Wave 2018. Participants were divided into two groups: mid-old group for reflecting midlife BP and cognition (45–59 years at baseline but aged 60 or over in Wave 2018), and old-old group for reflecting late-life BP and cognition (aged 60 or over at baseline). We use univariate analysis and general linear model to analyze.

Results

Late-life BP showed stronger associations with cognitive function than midlife BP. As to late-life BP control status, controlled hypertension group get higher cognitive score than uncontrolled hypertension group in language (adjusted β = −0.34, 95%CI −0.68 to 0.00), and untreated hypertension group in orientation (adjusted β = −0.41, 95%CI −0.72 to −0.11), language (adjusted β = −0.35, 95%CI −0.67 to −0.04), and total (adjusted β = −0.99, 95%CI −1.85 to −0.12). Regarding visit-to-visit BP variability, midlife visit-to-visit systolic blood pressure (SBP) variability was associated with language (adjusted β = −3.70, 95% CI −5.83 to −1.57), while late-life visit-to-visit SBP variability was associated with orientation (adjusted β = −2.99, 95% CI −4.84 to −1.14), recall (adjusted β = −1.69, 95% CI −2.89 to −0.48), language (adjusted β = −2.26, 95% CI −4.13 to −0.38), and total (adjusted β = −9.50, 95% CI −14.71 to −4.28); Midlife diastolic blood pressure (DBP) variability and pulse pressure (PP) variability showed a significant relationship with language (adjusted β = 3.25, 95% CI −1.31 to −5.19) and calculation (adjusted β = −0.26, 95% CI −0.47 to −0.04), respectively. No significant correlation was found between midlife BP control status, late-life visit-to-visit DBP variability, late-life visit-to-visit PP variability, and cognitive score. There was no significant correlation between BP and memory.

Conclusions

BP control status and visit-to-visit BP variability were significantly related to cognitive function among the Chinese elderly. Receiving effective late-life antihypertensive treatment and keeping SBP stable might contribute to prevent the development of cognitive impairment and dementia, especially for orientation and language function.

The adverse effect of modifiable dementia risk factors on cognition amplifies across the adult lifespan

Background

Reversible lifestyle behaviors (modifiable risk factors) can reduce dementia risk by 40%, but their prevalence and association with cognition throughout the adult lifespan is less well understood.

Methods

The associations between the number of modifiable risk factors for dementia (low education, hypertension, hearing loss, traumatic brain injury, alcohol or substance abuse, diabetes, smoking, and depression) and cognition were examined in an online sample (N = 22,117, ages 18–89).

Findings

Older adults (ages 66–89) had more risk factors than middle‐aged (ages 45–65) and younger adults (ages 18–44). Polynomial regression revealed that each additional risk factor was associated with lower cognitive performance (equivalent to 3 years of aging), with a larger association as age increased. People with no risk factors in their forties to seventies showed similar cognitive performance to people 10 or 20 years younger with many risk factors.

Interpretation

Modifiable dementia risk factors amplify lifespan age differences in cognitive performance.

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.

The Role of Cilostazol and Inflammation in Cognitive Impairment After Ischemic Stroke

PURPOSE

The aim of this study is to examine the potential effect of cilostazol and inflammation on cognitive impairment after stroke in an Asian population.

METHODS

Forty-five patients with cognitive impairment after ischemic stroke using cilostazol were enrolled as the study group and 45 patients using aspirin or clopidogrel were enrolled as the control group. Neuropsychiatric assessments were administered at the start of the study and after 6 months. Multiple logistic regression analysis was used to estimate the association between the cognitive change and cilostazol use. Macrophage polarization were assessed using flow cytometry in 7 patients.

RESULTS

There were a significantly higher number of patients with peripheral arterial occlusive disease in the cilostazol group. No significant differences were observed in the cognitive change between the cilostazol and control groups. M1 macrophage subset increment were observed in the patient having a declined cognitive change.

CONCLUSION

Cilostazol did not make a significant difference in cognitive change after ischemic stroke. M1 macrophage subset increment may indicate post stroke cognitive decline. Due to limited number of subjects, these findings should be examined further in large-scale randomized clinical trials.

Predictors of Dementia in the Oldest Old: A Novel Machine Learning Approach

BACKGROUND

Incidence of dementia increases exponentially with age; little is known about its risk factors in the ninth and 10th decades of life. We identified predictors of dementia with onset after age 85 years in a longitudinal population-based cohort.

METHODS

On the basis of annual assessments, incident cases of dementia were defined as those newly receiving Clinical Dementia Rating (CDR) ≥1. We used a machine learning method, Markov modeling with hybrid density-based and partition-based clustering, to identify variables associated with subsequent incident dementia.

RESULTS

Of 1439 participants, 641 reached age 85 years during 10 years of follow-up and 45 of these became incident dementia cases. Using hybrid density-based and partition-based, among those aged 85+ years, probability of incident dementia was associated with worse self-rated health, more prescription drugs, subjective memory complaints, heart disease, cardiac arrhythmia, thyroid disease, arthritis, reported hypertension, higher systolic and diastolic blood pressure, and hearing impairment. In the subgroup aged 85 to 89 years, risk of dementia was also associated with depression symptoms, not currently smoking, and lacking confidantes.

CONCLUSIONS

An atheoretical machine learning method revealed several factors associated with increased probability of dementia after age 85 years in a population-based cohort. If independently validated in other cohorts, these findings could help identify the oldest-old at the highest risk of dementia.

Blood pressure and cognitive performances in middle-aged adults: the Aging, Health and Work longitudinal study

BACKGROUND

Our objective was to investigate the impact of both prevalent and incident hypertension on cognition in middle-aged individuals followed up for 10 years and to explore the extent to which blood pressure control by antihypertensive drugs could modify this relationship.

METHOD

Three thousand, two hundred and one participants from the Vieillissement Santé Travail (Aging, Health and Work) (VISAT) cohort study, aged 32, 42, 52 and 62 years at baseline were followed up 5 and 10 years later. Blood pressure, antihypertensive medication use as well as memory and speed cognitive performances were assessed at baseline and follow-up. Linear mixed models were used for analyses.

RESULTS

At 10-year follow-up, compared with nonhypertensive participants, prevalent hypertensive individuals showed poorer global cognitive performances (β = -2.99 ± 0.96, P = 0.002 for participants aged 32 or 42 years at baseline and β = -5.94 ± 1.00, P < 0.001 for those aged 52 or 62). Patients with incident hypertension had poorer global cognitive performances over time compared with patients without hypertension. When considering prevalent hypertension and blood pressure control status by antihypertensive therapy, untreated and uncontrolled hypertension were associated with poorer cognitive performances than controlled and no hypertension (untreated hypertension compared with no hypertension: β = -5.51 ± 0.75, P < 0.001; uncontrolled hypertension compared with no hypertension: β = -6.13 ± 1.40, P < 0.001).

CONCLUSION

Our findings showed that both prevalent and incident hypertension are associated with poorer global cognitive function in middle-aged individuals and suggested a potential preventive effect of antihypertensive therapy on cognition. Thus, for brain functioning, heightened efforts to detect hypertension and adequately treat it are of critical importance.

Cardiovascular risk factors and memory decline in middle-aged and older adults: the English Longitudinal Study of Ageing

BACKGROUND

We investigated the association between trajectories of verbal episodic memory and burden of cardiovascular risk factors in middle-aged and older community-dwellers.

METHODS

We analysed data from 4372 participants aged 50-64 and 3005 persons aged 65-79 years old from the English Longitudinal Study of Ageing who were repeatedly evaluated every 2 years and had six interviews of a 10-year follow-up. We measured the following baseline risk factors: diabetes, hypertension, smoking, physical inactivity and obesity to derive a cardiovascular risk factor score (CVRFs). Adjusted linear mixed effect regression models were estimated to determine the association between number of CVFRs and six repeated measurements of verbal memory scores, separately for middle-aged and older adults.

RESULTS

CVRFs was not significantly associated with memory at baseline. CVFRs was significantly associated with memory decline in middle-aged (50-64y), but not in older (65-79y) participants. This association followed a dose-response pattern with increasing number of CVFRs being associated with greater cognitive decline. Comparisons between none versus some CVRFs yielded significant differences (p < 0.05).

CONCLUSIONS

Our findings confirm that the effect of cumulative CVRFs on subsequent cognitive deterioration is age-dependent. CVRFs are associated with cognitive decline in people aged 50-64 years, but not in those aged ≥65 years. Although modest, the memory decline associated with accumulation of cardiovascular risk factors in midlife may increase the risk of late-life dementia.

Associations of Blood Pressure with Functional and Cognitive Changes in Patients with Alzheimer's Disease

BACKGROUND

Midlife hypertension followed by late life hypotension resulting from neurodegeneration increases amyloidogenesis and tauopathy.

METHODS

Consecutive outpatients with late-onset Alzheimer's disease (AD) at various stages and their respective caregivers were assessed for score variations in 1 year of tests assessing caregiver burden, functionality and cognition according to blood pressure (BP) variations and APOE haplotypes, while also taking into account differential effects of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, calcium channel blockers, diuretics, or no antihypertensive medication on score changes. The diagnosis and treatment of arterial hypertension followed the JNC 7 report.

RESULTS

Variations in systolic BP (-11.76 ± 17.1 mm Hg), diastolic BP (-4.92 ± 10.3 mm Hg) and pulse pressure (-6.84 ± 12.6 mm Hg) were significant after 1 year (n = 191; x03C1; < 0.01). For APOE4+ carriers, rises in systolic or diastolic BP improved Clinical Dementia Rating Scale Sum of Boxes scores (x03C1; < 0.04), with marginally significant improvements in Mini-Mental State Examination scores resulting from risen systolic (x03C1; = 0.069) or diastolic BP (x03C1; = 0.079), and in basic independence only regarding risen diastolic BP (x03C1; = 0.055). APOE4- carriers resisted any functional or cognitive effects of BP variations. No differences were found regarding any antihypertensive class for variations in BP or any test scores, regardless of APOE haplotypes.

CONCLUSIONS

Targeting mild BP elevations brings better functional and cognitive results for APOE4+ carriers with AD.

Temporal Cognitive Decline Associated With Exposure to Infectious Agents in a Population-based, Aging Cohort

BACKGROUND

Numerous cross-sectional studies have related exposure to neurotropic infectious agents with cognitive dysfunction in older adults, however, the temporal sequence is uncertain.

METHODS

In a representative, well-characterized, population-based aging cohort, we determined whether the temporal trajectories of multiple cognitive domains are associated with exposure to cytomegalovirus (CMV), Herpes Simplex virus, type 1 (HSV-1), Herpes Simplex virus, type 2 (HSV-2), or Toxoplasma gondii (TOX). Complex attention, executive functions, memory, language, and visuospatial function were assessed annually for 5 years among consenting individuals. Study entry IgG antibody titers indexing exposure to each infectious agent were examined in relation to slopes of subsequent temporal cognitive decline using multiple linear regressions adjusted for potential confounders.

RESULTS

The IgG levels for HSV-2 were significantly associated with baseline cognitive domain scores (N=1022 participants). Further, the IgG levels for HSV-2, TOX, and CMV, but not HSV-1 were significantly associated with greater temporal cognitive decline that varied by type of infection.

CONCLUSIONS

Exposure to CMV, HSV-2, or TOX is associated with cognitive deterioration in older individuals, independent of general age-related variables. An increased understanding of the role of infectious agents in cognitive decline may lead to new methods for its prevention and treatment.

Latent class analysis of multimorbidity patterns and associated outcomes in Spanish older adults: a prospective cohort study

Background

This study sought to identify multimorbidity patterns and determine the association between these latent classes with several outcomes, including health, functioning, disability, quality of life and use of services, at baseline and after 3 years of follow-up.

Methods

We analyzed data from a representative Spanish cohort of 3541 non-institutionalized people aged 50 years old and over. Measures were taken at baseline and after 3 years of follow-up. Latent Class Analysis (LCA) was conducted using eleven common chronic conditions. Generalized linear models were conducted to determine the adjusted association of multimorbidity latent classes with several outcomes.

Results

63.8% of participants were assigned to the “healthy” class, with minimum disease, 30% were classified under the “metabolic/stroke” class and 6% were assigned to the “cardiorespiratory/mental/arthritis” class. Significant cross-sectional associations were found between membership of both multimorbidity classes and poorer memory, quality of life, greater burden and more use of services. After 3 years of follow-up, the “metabolic/stroke” class was a significant predictor of lower levels of verbal fluency while the two multimorbidity classes predicted poor quality of life, problems in independent living, higher risk of hospitalization and greater use of health services.

Conclusions

Common chronic conditions in older people cluster together in broad categories. These broad clusters are qualitatively distinct and are important predictors of several health and functioning outcomes. Future studies are needed to understand underlying mechanisms and common risk factors for patterns of multimorbidity and to propose more effective treatments.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0586-1) contains supplementary material, which is available to authorized users.

Midlife Risk Factors for Impaired Physical and Cognitive Functioning at Older Ages: A Cohort Study

BACKGROUND

Previous studies examined midlife risk factors separately for old-age impaired physical and cognitive functioning. We determined the overlap of risk factors for both domains of functioning within the same setting.

METHODS

Biological and behavioral risk factors at age 50 years and cognitive and physical functioning were assessed 18 (SD = 5) years later in the Whitehall II study (N = 6,316). Impaired physical functioning was defined as ≥1 limitation on the activities of daily living scale. Impaired cognitive functioning was defined as Mini-Mental State Examination score <27. Two statistical analyses were employed: minimally adjusted analysis (for age, sex, and ethnicity) and mutually adjusted analysis (including all risk factors). Missing data on risk factors were imputed.

RESULTS

After confounder adjustment, impaired physical and cognitive functioning at older ages were predicted by hypertension (odds ratios [ORs] 1.80 95% confidence interval [CI] 1.39-2.33 and 1.57 95% CI 1.07-2.31, respectively), poor lung function (1.51 95% CI 1.28-1.78 and 1.31 95% CI 1.08-1.59), and physical inactivity, marginally in the case of cognitive function (1.50 95% CI 1.19-1.90 and 1.27 95% CI 0.99-1.62) at age 50 years. Impaired physical functioning but not cognitive functioning was additionally predicted by depression and higher body mass index (1.72 95% CI 1.46-2.03 and 1.29 95% CI 1.16-1.44, respectively).

CONCLUSIONS

Several midlife risk factors are associated with impaired physical and cognitive functioning in old age, supporting a unified prevention policy. Analysis of 12 risk factors at age 50 suggests that strategies targeting physical inactivity, hypertension, and poor lung function will reduce impairments in both cognitive and physical functioning in old age.

Homocysteine and cognition: A systematic review of 111 studies

BACKGROUND

Elevated plasma homocysteine ​​(Hcy) levels have been associated with cognitive dysfunction in a wide range of conditions. The aim of this review is to establish which cognitive domains and populations are the most affected.

METHODS

We systematically review the literature and consider all articles that showed any relationship between plasma Hcy levels and scores achieved on cognitive performance tests in both, the general population and patients suffering from central nervous system disorders and other diseases. When effect sizes were available and combinable, several meta-analyses were performed.

RESULTS

We found 111 pertinent articles. There were 24 cohort studies, 18 randomized trials, 21 case-control studies, and 48 cross-sectional studies. This review reveals a positive trend between cognitive decline and increased plasma Hcy concentrations in general population and in patients with cognitive impairments. Results from the meta-analyses also confirm this trend. Treatment with vitamin supplementation fails to show a reduction in cognitive decline.

DISCUSSION

Further investigations are warranted to clarify this relationship. Earlier detection of the elevated Hcy levels may be an effective intervention to prevent cognitive impairment and dementia.

Ankle-Brachial Index but Neither Intima Media Thickness Nor Coronary Artery Calcification is Associated With Mild Cognitive Impairment

BACKGROUND

Several studies have reported an association of atherosclerosis with mild cognitive impairment (MCI) and dementia independent of cardiovascular risk factors.

OBJECTIVE

To compare the cross-sectional association of the ankle-brachial index (ABI), intima media thickness (IMT), and coronary artery calcification (CAC) with MCI and its subtypes, amnestic MCI (aMCI) and non-amnestic MCI (naMCI) in the population-based Heinz Nixdorf Recall cohort study.

METHODS

4,086 participants performed a validated brief cognitive assessment at the first follow-up examination (2006-2008). MCI was diagnosed according to previously published criteria. Prevalence ratio (PR) regression models adjusted for age, gender, education, cardiovascular risk factors, and APOE genotype were used to compare the association of the ABI, the CAC-Agatston score and the IMT with MCI and its subtypes.

RESULTS

We identified 490 participants with MCI (mean age 66.1 ± 7.8, 46.9 % male, aMCI n = 249, naMCI n = 241) and 1,242 cognitively normal participants. A decreasing ABI (per 0.1) was significantly associated with a higher MCI prevalence in fully adjusted models (PR 1.06; 95% confidence interval (CI) 1.01-1.11), whereas an increasing CAC (log(CAC+1)) or IMT (per 0.1 mm) were not associated after adjustment. A decreasing ABI was also significantly associated with naMCI in fully adjusted models (PR 1.12; CI 1.03-1.21) but not with aMCI.

CONCLUSIONS

Our data show that the degree of generalized atherosclerosis as measured by the ABI is associated with MCI and with naMCI in a population-based cohort.

Dual Trajectories of Depression and Cognition: A Longitudinal Population-Based Study

OBJECTIVE

To examine the relationships over time between dual trajectories of depressive symptoms and several cognitive domains.

METHODS

In a 5-year longitudinal study, 1,978 randomly selected individuals aged 65+ years at recruitment were assessed annually. Repeated measures were of depressive symptoms on the modified Center for Epidemiologic Studies Depression Scale and composite scores in the cognitive domains of attention, executive function, memory, language, and visuospatial function. Latent class trajectories were identified for depression and for each cognitive domain and their associations investigated using dual trajectory modeling. Cognitive trajectories with z scores below -1 were designated as persistently low.

RESULTS

Five depressive symptom trajectories were observed: rarely depressed (60.5%); low-grade, decreasing symptoms (18.5%); low-grade, increasing symptoms (9.6%); moderate-grade symptoms (7.4%); and consistent higher-grade symptoms (4.0%). For each cognitive domain six trajectories were observed. The rarely depressed and low-grade decreasing symptom groups were the least likely to have persistently low cognition. The symptom trajectory most strongly associated with persistently low functioning in each domain was not the higher-grade group but rather the low-grade increasing group in the case of attention and the moderate-grade trajectory in the other four domains.

CONCLUSION

Consistently higher-grade depressive symptoms are less strongly associated with poor cognitive functioning than with either moderate- or low-grade increasing depressive symptom trajectories, over time and across different domains. Examining both depression and cognition longitudinally allows heterogeneity of both to be addressed, revealing latent groups with potential diagnostic and prognostic implications.

Decision-making quality of younger and older adults in familiar and unfamiliar domains

Age-related differences in purchasing decisions were examined as a function of age and familiarity. On each trial, participants received purchasing options which varied in quality but ultimately cost the same amount of money. On half the trials, participants made decisions about items familiar to younger adults and on the other half of the trials, participants made decisions about products familiar to older adults. The participants' task was to choose the option that provided the best value for the money. We were particularly interested in participants' performance when inferencing was required to select the optimal option from the two choices. Younger adults outperformed older adults in unfamiliar but not familiar domains. It appeared that both younger and older adults used inferencing and elaborative processing to make the best decision in familiar domains but that only younger adults used inferencing and elaborative processing in unfamiliar domains.

Factors associated with cognitive function in older adults in Mexico

Background

As populations age, cognitive decline and dementia pose significant burdens for societies and health care systems, including low- and middle-income countries such as Mexico. Minor age-related declines in cognitive function appear to represent a stable but heterogeneous phase in the continuum between normal cognitive ageing and dementia. Loss of cognitive function has impacts at societal and individual levels and understanding the risk factors can help provide a framework for health policies and interventions to target at-risk groups.

Design

A cohort of older Mexican adults (50+) from the World Health Organization's Study on global AGEing and adult health (WHO SAGE) was used to examine cognitive function, including a total of 2315 respondents, with 325 respondents aged 80 years and older. Cognition was objectively evaluated using verbal recall, verbal fluency, forward digit span and backward digit span, with differences in an overall cognitive score assessed against sociodemographic variables, and associated factors using linear regression.

Results

The most significant predictors of poorer cognitive function were found to be older age (β=−13.88), rural living (β=−2.25), low income (β=−8.28), self-reported severe or extreme memory difficulties (β=−6.62), and difficulty with two or more activities of daily living (β=−2.02).

Conclusions

These findings can inform public health initiatives to address cognitive impairment in ageing populations in Mexico and other middle-income countries.

Thyroid-Stimulating Hormone and Mild Cognitive Impairment: Results of the Heinz Nixdorf Recall Study

BACKGROUND

Although some studies reported on the association of serum thyroid-stimulating hormone (TSH) concentration and cognition, only one population-based study investigated the association of TSH concentration and mild cognitive impairment (MCI).

OBJECTIVE

To investigate the gender-specific association of low- and high-normal TSH concentrations with MCI in euthyroid participants.

METHODS

Analysis sample 1 included 2,563 euthyroid participants (aged 50-80 years) from the second examination of the population-based Heinz Nixdorf Recall study. Gender-specific TSH quintiles (Q1 low, Q2-Q4 middle, Q5 high TSH concentration) were determined and group comparisons of age- and education-adjusted mean scores were performed for all cognitive subtests. Analysis sample 2 included 378 participants with MCI and 931 cognitively normal participants. MCI was diagnosed according to previously published MCI criteria. Multivariate logistic regression models were performed using TSH quintiles (Q2-Q4 as reference) to assess the association of low- and high-normal TSH concentration with MCI. Models were performed unadjusted and adjusted for sociodemographic and cardiovascular risk factors.

RESULTS

Group comparisons showed significant differences only in the immediate recall of the verbal memory task in women. Only women showed a strong association of high-normal TSH concentration with MCI (unadjusted: odds ratio 2.09, 95% confidence interval 1.29-3.37, full adjusted: 1.86, 1.06-3.27). There was no association with low-normal TSH concentration in women and no association of either low- or high-normal TSH concentration with MCI in men.

CONCLUSIONS

These results suggest that women with high-normal TSH concentration might be at higher risk of cognitive decline. This needs to be confirmed in the longitudinal analysis.

Rates and risk factors for progression to incident dementia vary by age in a population cohort

OBJECTIVE

To estimate rate of progression from normal cognition or mild impairment to dementia, and to identify potential risk and protective factors for incident dementia, based on age at dementia onset in a prospective study of a population-based cohort (n = 1,982) aged 65 years and older.

METHODS

Following the cohort annually for up to 5 years, we estimated incidence of dementia (Clinical Dementia Rating ≥1) among individuals previously normal or mildly impaired (Clinical Dementia Rating 0 or 0.5). In the whole cohort, and also stratified by median onset age, we examined several vascular, metabolic, and inflammatory variables as potential risk factors for developing dementia, using interval-censored survival models.

RESULTS

Based on 67 incident cases of dementia, incidence rate (per 1,000 person-years) was 10.0 overall, 5.8 in those with median onset age of 87 years or younger, and 31.5 in those with onset age after 87 years. Adjusting for demographics, the risk of incident dementia with onset age of 87 years or younger (n = 33) was significantly increased by baseline smoking, stroke, low systolic blood pressure, and APOE*4 genotype, and reduced by current alcohol use. Among those with dementia with onset after 87 years (n = 34), no risk or protective factor was significant.

CONCLUSION

Risk and protective factors were only found for incident dementia with onset before the median onset age of 87 years, and not for those with later onset. Either unexplored risk factors explain the continued increase in incidence with age, or unknown protective factors are allowing some individuals to delay onset into very old age.

The role of epigenetics in cognitive ageing

OBJECTIVE

As the population is ageing, a better understanding of the underlying causes of age-related cognitive decline (cognitive ageing) is required. Epigenetic dysregulation is proposed as one of the underlying mechanisms for cognitive ageing. We review the current knowledge on epigenetics and cognitive ageing and appraise the potential of epigenetic preventative and therapeutic interventions.

DESIGN

Articles on cognitive ageing and epigenetics in English were identified.

RESULTS

Epigenetic dysregulation occurs with cognitive ageing, with changes in histone post-translational modifications, DNA methylation and non-coding RNA reported. However, human studies are lacking, with most being cross-sectional using peripheral blood samples. Pharmacological and lifestyle factors have the potential to change aberrant epigenetic profiles; but few studies have examined this in relation to cognitive ageing.

CONCLUSIONS

The relationship between epigenetic modifications and cognitive ageing is only beginning to be investigated. Epigenetic dysregulation appears to be an important feature in cognitive ageing, but whether it is an epiphenomenon or a causal factor remains to be elucidated. Clarification of the relationship between epigenetic profiles of different cell types is essential and would determine whether epigenetic marks of peripheral tissues can be used as a proxy for changes occurring in the brain. The use of lifestyle and pharmacological interventions to improve cognitive performance and quality of life of older adults needs more investigation.