Cohort studies have reported that midlife high total serum cholesterol (TC) is associated with increased risk of Alzheimer's disease (AD) in late-life but findings have been based on few studies and ...previous reviews have been limited by a lack of compatible data.
We synthesized all high quality data from cohort studies reporting on the association between total serum cholesterol measured and late-life cognitive outcomes including Alzheimer's disease (AD), vascular dementia (VaD), any dementia, mild cognitive impairment (MCI), and cognitive decline.
The literature was searched up to October 2016 using a registered protocol. Thirty-four articles meeting study criteria were identified. Seventeen studies published from 1996 to 2014, including 23,338 participants were included in meta-analyses.
Relative risk of developing AD for adults with high TC in midlife was 2.14 (95% CI 1.33-3.44) compared with normal cholesterol. Individual studies that could not be pooled also reported high TC in midlife increased the risk of MCI and cognitive decline in late-life. High TC in late-life was not associated with MCI, AD, VaD, any dementia, or cognitive decline. Late-life measured HDL cholesterol and triglycerides were not associated with increased risk of VaD, and HDL was not associated with risk of MCI, AD, or any dementia. There were insufficient data to examine other cholesterol sub-fractions, sex differences, or APOE interactions.
Significant gaps in the literature regarding TC and late-life dementia remain. Evidence suggests that high midlife TC increases risk of late-life AD, and may correlate with the onset of AD pathology.
Both air pollution and dementia are current and growing global issues. There are plausible links between exposure to specific air pollutants and dementia.
To systematically review the evidence base ...with respect to the relationship between air pollution and later cognitive decline and dementia.
Medline, Embase, and PsychINFO® were searched from their inception to September 2018, for publications reporting on longitudinal studies of exposure to air pollution and incident dementia or cognitive decline in adults. Studies reporting on exposure to tobacco smoke including passive smoking or on occupational exposure to pollutants were excluded. Using standard Cochrane methodology, two readers identified relevant abstracts, read full text publications, and extracted data into structured tables from relevant papers, as defined by inclusion and exclusion criteria. Papers were also assessed for validity. CRD42018094299Results:From 3,720 records, 13 papers were found to be relevant, with studies from the USA, Canada, Taiwan, Sweden, and the UK. Study follow-up ranged from one to 15 years. Pollutants examined included particulate matter ≤2.5 μ (PM2.5), nitrogen dioxide (NO2), nitrous oxides (NOx), carbon monoxide (CO), and ozone. Studies varied in their methodology, population selection, assessment of exposure to pollution, and method of cognitive testing. Greater exposure to PM2.5, NO2/NOx, and CO were all associated with increased risk of dementia. The evidence for air pollutant exposure and cognitive decline was more equivocal.
Evidence is emerging that greater exposure to airborne pollutants is associated with increased risk of dementia.
Air pollution is associated with increased risk of respiratory, cardiovascular and cerebrovascular disease, but its association with cognitive functioning and impairment is unclear. The aim of this ...systematic review was to examine whether a relationship exists between these variables across the life course.
We searched Web of Knowledge, Pubmed, SciVerse Scopus, CINAHL, PsychInfo and Science Direct up to October 2015 to identify studies that investigated the association between air pollution and performance on neurocognitive tests.
Variations in exposure assessment and outcome measures make meta-analysis impossible. Thirty one studies published between 2006 and 2015, from the Americas (n=15), Asia (n=5) and Europe (n=11), met the criteria for inclusion. Many showed weak but quantified relationships between various air pollutants and cognitive function. Pollution exposure in utero has been associated with increased risk of neuro-developmental delay. Exposure in childhood has been inversely associated with neuro-developmental outcomes in younger children and with academic achievement and neurocognitive performance in older children. In older adults, air pollution has been associated with accelerated cognitive decline.
The evidence to date is coherent in that exposure to a range of largely traffic-related pollutants has been associated with quantifiable impairment of brain development in the young and cognitive decline in the elderly. There is insufficient evidence at present to comment on consistency, in view of the different indices of pollution and end-points measured, the limited number of studies, and the probability at this stage of publication bias. However, plausible toxicological mechanisms have been demonstrated and the evidence as a whole suggests that vehicular pollution, at least, contributes to cognitive impairment, adding to pressure on governments and individuals to continue to reduce air pollution.
Attention deficit/hyperactivity disorder (ADHD) is the most prevalent childhood psychiatric condition. It frequently persists into adulthood and can have serious health and other adverse ...consequences. The majority of previous adult ADHD studies have focused on young adults so that relatively little is known about ADHD symptoms and their effects in mid and late life. In addition, effects of subclinical levels of attention deficit and hyperactivity have not been studied in detail. In this study we investigated ADHD symptoms and related impairment in a large population-based sample of middle-aged Australian adults (n = 2091; 47% male). Applying the WHO adult ADHD Self Report Screener (ASRS) we observed that 6.2% of participants had scores that were previously associated with ADHD diagnosis. No significant gender difference in the distribution of ASRS scores was observed. Multiple regression analyses indicated strong positive correlations between symptoms of ADHD and depression/anxiety and significant negative associations (p<0.01) with employment, financial stress, relationship quality, health and well-being measures in this age group. Importantly, associations were highly significant even when few ADHD symptoms were reported. Compared to the hyperactivity component, the inattention trait was particularly strongly associated and remained significant after controlling for depression/anxiety symptoms. Our study confirms previous findings and significantly adds to existing literature especially for an age-group that has not been well-studied. Our results suggest that ADHD symptoms continue to be associated with ill-health and functional impairment in mid-life and are, therefore, likely to be a major, previously unrecognized source of late-life morbidity with associated social and economic costs. Thus, there is a compelling need for better understanding and development of age-appropriate approaches to the diagnosis and treatment of ADHD in mid- to late-life.
•Symptoms of depression and anxiety differ by menopausal status in midlife women.•Perimenopause is associated with increased risk of greater symptoms of depression.•Postmenopause is associated with ...increased risk of greater symptoms of anxiety.•Women without a history of symptoms may be at risk during perimenopause and postmenopause.
To examine the association between menopausal status and the risk of symptoms of depression and anxiety in a community-based sample of Australian midlife women.
Female participants (mean age 50.6±1.5) who were premenopausal (n=237), perimenopausal (n=249) or naturally postmenopausal (n=225) were drawn from the Personality and Total Health (PATH) Through Life Project, a longitudinal study.
Symptoms of depression and anxiety were measured using the Goldberg Depression Scale and Goldberg Anxiety Scale. Generalised linear regression models with a negative binomial log link were used.
Relative to premenopause and after adjusting for all relevant covariates, being perimenopausal was associated with increased risk of greater symptoms of depression (incidence rate ratio IRR=1.29, p=0.001), while being postmenopausal was associated with increased risk of greater symptoms of anxiety (IRR=1.15, p=0.041). Being perimenopausal or postmenopausal was associated with an increased risk of greater symptoms of depression (IRR=1.35, p=0.008; IRR=1.31, p=0.029) and anxiety (IRR=1.22, p=0.030; IRR=1.32, p=0.006) in women without a history of probable major depressive disorder or generalised anxiety disorder. Risk of symptoms did not differ with menopausal status in women with this history.
Menopausal status is associated with the risk of symptoms of depression and anxiety. There is a greater likelihood of increased symptoms of depression during perimenopause and symptoms of anxiety during postmenopause. In women without a history of depression or anxiety, the perimenopause and postmenopausal stages are associated with increased risk of greater symptoms of anxiety and depression relative to premenopause.
ObjectivesTo perform a systematic review of reported HRs of all cause dementia, Alzheimer's disease (AD) and vascular dementia (VaD) for late-life depression and depressive symptomatology on specific ...screening instruments at specific thresholds.DesignMeta-analysis with meta-regression.Setting and participantsPubMed, PsycInfo, and Cochrane databases were searched through 28 February 2014. Articles reporting HRs for incident all-cause dementia, AD and VaD based on published clinical criteria using validated measures of clinical depression or symptomatology from prospective studies of general population of adults were selected by consensus among multiple reviewers. Studies that did not use clinical dementia diagnoses or validated instruments for the assessment of depression were excluded. Data were extracted by two reviewers and reviewed by two other independent reviewers. The most specific analyses possible using continuous symptomatology ratings and categorical measures of clinical depression focusing on single instruments with defined reported cut-offs were conducted.Primary outcome measuresHRs for all-cause dementia, AD, and VaD were computed where possible for continuous depression scores, or for major depression assessed with single or comparable validated instruments.ResultsSearches yielded 121 301 articles, of which 36 (0.03%) were eligible. Included studies provided a combined sample size of 66 532 individuals including 6593 cases of dementia, 2797 cases of AD and 585 cases of VaD. The increased risk associated with depression did not significantly differ by type of dementia and ranged from 83% to 104% for diagnostic thresholds consistent with major depression. Risk associated with continuous depression symptomatology measures were consistent with those for clinical thresholds.ConclusionsLate-life depression is consistently and similarly associated with a twofold increased risk of dementia. The precise risk estimates produced in this study for specific instruments at specified thresholds will assist evidence-based medicine and inform policy on this important population health issue.
Associations between the Mediterranean-DASH diet Intervention for Neurological Delay (MIND) diet and incidence of cognitive impairment have not been evaluated outside the United States.
We ...investigated MIND and Mediterranean diet relations with 12-year incidence of Alzheimer's disease/Vascular dementia (National Institute of Neurological Disorders criteria) and mild cognitive impairment (Winbald criteria) in the Personality and Total Health (PATH) Through Life cohort (n = 1220) set in Canberra, Australia: wave-1 2001-2002; wave-2 2005-2006; wave-3 2009-2010; and wave-4 2013-2014.
MIND diet and two alternate Mediterranean diet scores were calculated from the baseline food frequency questionnaire responses. Higher dietary scores signified greater adherence.
In adjusted logistic regression models, MIND diet (OR = 0.47, 95% CI 0.24, 0.91), but not Mediterranean diet, was associated with reduced odds of 12-year cognitive impairment.
Preliminary evidence suggests that protective effects of the MIND diet are geographically generalizable. Additional prospective studies are needed in diverse samples to determine the relative effects of the MIND and the Mediterranean diets against cognitive decline.
The translation of evidence on dementia risk factors into clinical advice requires careful evaluation of the methodology and scope of data from which risk estimates are obtained.
To evaluate the ...quantity, quality, and representativeness of evidence, we conducted a review of reviews of risk factors for Alzheimer's disease (AD), Vascular dementia (VaD), and Any Dementia.
PubMed, Cochrane library, and the Global Index Medicus were searched to identify meta-analyses of observational studies of risk factors for AD, VaD, and Any Dementia. PROSPERO CRD42017053920.
Meta-analysis data were available for 34 risk factors for AD, 26 risk factors for Any Dementia and eight for VaD. Quality of evidence varied greatly in terms of the number of contributing studies, whether data on midlife exposure was available, and consistency of measures. The most evidence was available for cardiovascular risk factors. The most geographically representative evidence (five of six global regions) was available for alcohol, physical activity, diabetes, high midlife BMI, antihypertensives, and motor function. Evidence from Australia/Oceana or Africa was limited. With the exception of diabetes, meta-analysis data were unavailable from Latin America/Caribbean. Midlife specific data were only available for cholesterol and arthritis.
There is a lack of midlife specific data, limited data on VaD, and a lack of geographical representation for many risk factors for dementia. The quality, quantity, and representativeness of evidence needs to be considered before recommendations are made about the relevance of risk factors in mid- or late-life or for dementia subtypes.
The Australian National University AD Risk Index (ANU-ADRI, http://anuadri.anu.edu.au) is a self-report risk index developed using an evidence-based medicine approach to measure risk of Alzheimer's ...disease (AD). We aimed to evaluate the extent to which the ANU-ADRI can predict the risk of AD in older adults and to compare the ANU-ADRI to the dementia risk index developed from the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study for middle-aged cohorts.
This study included three validation cohorts, i.e., the Rush Memory and Aging Study (MAP) (n = 903, age ≥53 years), the Kungsholmen Project (KP) (n = 905, age ≥75 years), and the Cardiovascular Health Cognition Study (CVHS) (n = 2496, age ≥65 years) that were each followed for dementia. Baseline data were collected on exposure to the 15 risk factors included in the ANU-ADRI of which MAP had 10, KP had 8 and CVHS had 9. Risk scores and C-statistics were computed for individual participants for the ANU-ADRI and the CAIDE index.
For the ANU-ADRI using available data, the MAP study c-statistic was 0·637 (95% CI 0·596-0·678), for the KP study it was 0·740 (0·712-0·768) and for the CVHS it was 0·733 (0·691-0·776) for predicting AD. When a common set of risk and protective factors were used c-statistics were 0.689 (95% CI 0.650-0.727), 0.666 (0.628-0.704) and 0.734 (0.707-0.761) for MAP, KP and CVHS respectively. Results for CAIDE ranged from c-statistics of 0.488 (0.427-0.554) to 0.595 (0.565-0.625).
A composite risk score derived from the ANU-ADRI weights including 8-10 risk or protective factors is a valid, self-report tool to identify those at risk of AD and dementia. The accuracy can be further improved in studies including more risk factors and younger cohorts with long-term follow-up.
To determine whether the Mediterranean diet and other dietary variables are predictors of transition from healthy cognitive aging to mild cognitive impairment and cognitive decline.
Longitudinal.
We ...assessed 1528 individuals, aged 60-64 years, who were participating in a prospective epidemiological study of mental health and aging. We tested participants at two time points, 4 years apart, for mild cognitive impairment using either the International Consensus Criteria, impairment on the Clinical Dementia Rating scale (Clinical Dementia Rating: 0.5), or any of a suite of criteria sets (any mild cognitive disorder). We used logistic regression to assess the dietary predictors of conversion to clinical diagnoses and multiple regression to identify the predictors of cognitive decline (change in global cognition) in healthy participants.
Of the 1528 participants with no cognitive impairment in the first wave of assessment and complete data, 10 participants were diagnosed with mild cognitive impairment, 19 with Clinical Dementia Rating 0.5, and 37 participants presented with any mild cognitive disorder at follow-up. Adherence to Mediterranean diet was not found to be protective against cognitive decline but excessive caloric intake, and high intake of monounsaturated fats was predictive of mild cognitive impairment.
In this large longitudinal investigation of generally healthy individuals Mediterranean diet was not found to be protective of cognitive decline.
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