Joint Exposure to Multiple Air Pollutants, Genetic Susceptibility, and Incident Dementia: A Prospective Analysis in the UK Biobank Cohort.

Objectives: This study aimed to evaluate the joint effects of multiple air pollutants including PM2.5, PM10, NO2, and NOx with dementia and examined the modifying effects of genetic susceptibility. Methods: This study included 220,963 UK Biobank participants without dementia at baseline. Weighted air pollution score reflecting the joint exposure to multiple air pollutants were constructed by cross-validation analyses, and inverse-variance weighted meta-analyses were performed to create a pooled effect. The modifying effect of genetic susceptibility on air pollution score was assessed by genetic risk score and APOE ε4 genotype. Results: The HR (95% CI) of dementia for per interquartile range increase of air pollution score was 1.13 (1.07∼1.18). Compared with the lowest quartile (Q1) of air pollution score, the HR (95% CI) of Q4 was 1.26 (1.13∼1.40) (P trend = 2.17 × 10-5). Participants with high air pollution score and high genetic susceptibility had higher risk of dementia compared to those with low air pollution score and low genetic susceptibility. Conclusion: Our study provides evidence that joint exposure to multiple air pollutants substantially increases the risk of dementia, especially among individuals with high genetic susceptibility.

Point prevalence of epilepsy in dementia: A "real-world" estimate.

OBJECTIVE: Several studies have demonstrated a higher frequency of seizures and epilepsy in Alzheimer's disease and other forms of dementia as compared with healthy elderly individuals. However, incidence and prevalence of epilepsy in the general population of dementia are unknown since most previous studies were performed in secondary-tertiary referral centres. In addition, all prior studies but one provided "period" rather than "point" prevalence estimates. METHODS: We assessed point prevalence estimate of epileptic manifestations requiring antiepileptic medication in patients Alzheimer's disease, vascular dementia, and fronto-temporal dementia from a secondary clinical setting. RESULTS: Point prevalence estimates were 6.4% (95% CI: 1.5 to 11.3) in Alzheimer's disease, 8.9% (95% CI: 1.4 to 16.4), in vascular dementia, and 6% (95% CI: 1.3 to 10.7) in fronto-temporal dementia, rates that were greater than those observed in the healthy elderly population. Regardless of the etiology of dementia, epilepsy was characterized by unprovoked seizures that lacked distinguishing clinical features. SIGNIFICANCE: These findings support epilepsy as part of the spectrum of dementia. The similar point prevalence of definite epilepsy requiring AED treatment in Alzheimer's disease and non Alzheimer dementias raised the possibility of similar underlying mechanism of epileptogenesis. Although this was not a population-based study, accurate point prevalence data from clinic setting would be important to better define the burden of epilepsy in dementia and the demands on health services to manage the condition.

Investigating the nexus of metabolic syndrome, serum uric acid, and dementia risk: a prospective cohort study.

BACKGROUND: The global dementia prevalence is surging, necessitating research into contributing factors. We aimed to investigate the association between metabolic syndrome (MetS), its components, serum uric acid (SUA) levels, and dementia risk. METHODS: Our prospective study comprised 466,788 participants without pre-existing MetS from the UK Biobank. We confirmed dementia diagnoses based on the ICD-10 criteria (F00-03). To evaluate the dementia risk concerning MetS, its components, and SUA levels, we applied Cox proportional hazards models, while adjusting for demographic factors. RESULTS: Over a median follow-up of 12.7 years, we identified 6845 dementia cases. Individuals with MetS had a 25% higher risk of all-cause dementia (hazard ratio [HR] = 1.25, 95% confidence interval [CI] = 1.19-1.31). The risk increased with the number of MetS components including central obesity, dyslipidemia for high-density lipoprotein (HDL) cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides. Particularly for those with all five components (HR = 1.76, 95% CI = 1.51-2.04). Dyslipidemia for HDL cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides were independently associated with elevated dementia risk (p < 0.01). MetS was further linked to an increased risk of all-cause dementia (11%) and vascular dementia (VD, 50%) among individuals with SUA levels exceeding 400 µmol/L (all-cause dementia: HR = 1.11, 95% CI = 1.02-1.21; VD: HR = 1.50, 95% CI = 1.28-1.77). CONCLUSIONS: Our study provides robust evidence supporting the association between MetS, its components, and dementia risk. These findings emphasize the importance of considering MetS and SUA levels in assessing dementia risk, offering valuable insights for prevention and management strategies.

Association of Combined Healthy Lifestyle Factors With Incident Dementia in Participants With and Without Multimorbidity: A Large Population-Based Prospective Cohort Study.

BACKGROUND: The effect of a healthy lifestyle on dementia associated with multimorbidity is not well understood. Our objective is to examine whether the adoption of a healthy lifestyle could potentially reduce the elevated risk of dementia in individuals with and without multimorbidity. METHODS: We utilized data from the UK Biobank cohort. A comprehensive healthy lifestyle score, ranging from 0 to 6, was generated. Cox proportional hazards models were used to examine the associations between multimorbidity, the healthy lifestyle score, and the incidence risk of dementia. RESULTS: Over a median follow-up period of 12.5 years, 5 852 all-cause dementia were recorded. Multimorbidity including cardiovascular, metabolic, neuropsychiatric, and inflammation-related diseases was associated with a higher risk of subsequent dementia. Each additional chronic disease was associated with a hazard ratio (HR) of 1.38 (95% CI: 1.33, 1.44). Compared to individuals without multimorbidity and a healthy lifestyle score of 5-6, patients with multimorbidity and a lifestyle score of 0-1 had a significantly higher risk of dementia (HR: 3.13; 95% CI: 2.64, 3.72), but the risk was markedly attenuated among those with multimorbidity and a lifestyle score of 5-6. Among patients with 3 or more diseases, the HR for dementia was 0.53 (95%CI: 0.42, 0.68) when comparing a lifestyle score of 5-6 to 0-1. And we observed more pronounced association between them among people younger than 60 years old. CONCLUSIONS: Adherence to a combination of healthy lifestyle factors, especially at a young age, was associated with a significantly lower risk of dementia among participants with multimorbidity.

[Dementia Prevention]. / Demenzprävention.

Dementia is common and will continue to grow in importance and numbers in the future. However, as causal treatment is not possible in most cases, prevention is particularly important. This is not only aimed at cognitively healthy people, but is also a central element in all phases of the disease.

Sarcopenic obesity is part of obesity paradox in dementia development: evidence from a population-based cohort study.

BACKGROUND: Sarcopenic obesity, a clinical and functional condition characterized by the coexistence of obesity and sarcopenia, has not been investigated in relation to dementia risk and its onset. METHODS: We included 208,867 participants from UK biobank, who aged 60 to 69 years at baseline. Dementia diagnoses were identified using hospital records and death register data. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models to evaluate the associations of obesity, sarcopenia, and sarcopenic obesity with dementia risk, stratified by sex. Stratified analyses were performed across dementia-related polygenic risk score (PRS). Restricted mean survival time models were established to estimate the difference and 95%CIs of dementia onset across different status. Additionally, linear regression models were employed to estimate associations of different status with brain imaging parameters. The mediation effects of chronic diseases were also examined. RESULTS: Obese women with high PRS had a decreased risk (HR = 0.855 [0.761-0.961]), but obese men with low PRS had an increased risk (HR = 1.223 [1.045-1.431]). Additionally, sarcopenia was associated with elevated dementia risk (HRwomen = 1.323 [1.064-1.644]; HRmen = 2.144 [1.753-2.621]) in those with low PRS. Among those with high PRS, however, the association was only significant in early-life (HRwomen = 1.679 [1.355-2.081]; HRmen = 2.069 [1.656-2.585]). Of note, sarcopenic obesity was associated with higher dementia risk (HRwomen = 1.424 [1.227-1.653]; HRmen = 1.989 [1.702-2.323]), and results remained similar stratified by PRS. Considering dementia onset, obesity was associated with dementia by 1.114 years delayed in women, however, 0.170 years advanced in men. Sarcopenia (women: 0.080 years; men: 0.192 years) and sarcopenic obesity (women: 0.109 years; men: 0.511 years) respectively advanced dementia onset. Obesity, sarcopenia, and sarcopenic obesity were respectively related to alterations in different brain regions. Association between sarcopenic obesity and dementia was mediated by chronic diseases. CONCLUSIONS: Sarcopenic obesity and sarcopenia were respectively associated with increased dementia risk and advanced dementia onset to vary degree. The role of obesity in dementia may differ by sex and genetic background.

Association of Metabolic Dysfunction-Associated Fatty Liver Disease with Cognitive Impairment and All-Cause Dementia: A Comprehensive Review.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a significant public health concern, affecting one-third of the global population and posing a risk for progressive liver disease. MAFLD is characterized by hepatic steatosis and impaired metabolic status, which not only impact the liver but also other systems of the human body, making it a multisystemic disorder. Emerging evidence suggests that MAFLD and its associated pathological pathways may contribute to cognitive impairment, potentially through neuroinflammation and neurodegeneration. Studies have detected cognitive impairment in patients with MAFLD using magnetic resonance imaging, which revealed decreased brain volume and cerebral perfusion, in addition to self-reported cognitive tests. While numerous studies have demonstrated an association between MAFLD and cognitive impairment, the relationship between MAFLD and all-cause dementia remains controversial. However, the shared pathological pathways between MAFLD and dementia, such as systemic inflammation, insulin resistance, gut dysbiosis, hyperammonemia, and vascular dysfunction, indicate the possibility of a common prevention strategy for both diseases. In this review, we provide a summary of the current evidence regarding the association between cognitive impairment, all-cause dementia, and MAFLD.

Potentially modifiable risk factors for dementia in six low-income and middle-income countries: A multinational, population-based survey.

OBJECTIVES: We aimed to determine the proportion of dementia cases potentially preventable in six low-income and middle-income countries. STUDY DESIGN: We analyzed data from 19,278 adults aged 50 years or more from China, South Africa, Ghana, India, Russia, and Mexico included in the WHO's Study on global AGEing and adult health. MAIN OUTCOME MEASURES: We calculated the population attributable fraction for ten potentially modifiable risk factors: less education, hearing loss, hypertension, diabetes, depression, heavy drinking, obesity, smoking, physical inactivity, and social isolation. Weighted attributable fraction was calculated considering communality among risk factors. RESULTS: We estimated that 37.6 % of the burden of dementia might be attributable to these risk factors. The highest and lowest overall weighted attributable fractions were 38.3 % and 22.9 % in China and Ghana, respectively. Less education (8.3 %), smoking (6.3 %), and physical inactivity (5.7 %) showed the highest attributable fraction for dementia. The overall attributable fraction was higher in the poorest (38.1 %) than in the richest (30.9 %) income quintile. The burden of obesity, diabetes, and hypertension was 61 % higher in the wealthiest than in the poorest population. A total of 7.2 million cases of dementia in these six low- and middle-income countries are potentially caused by these ten potentially modifiable risk factors. CONCLUSIONS: Overall, 38 % of cases of dementia in China, South Africa, Ghana, India, Russia, and Mexico can be attributable to ten potentially modifiable risk factors. Cardiometabolic risk factors account for a more significant burden of dementia in the wealthiest population. Less education had the highest population attributable fraction independent of living area and income.

The usefulness of the retina for identifying people with type 2 diabetes with prodromal stages of dementia.

Type 2 diabetes (T2D) is associated with cognitive impairment and dementia. The detection of cognitive impairment is important because this population is at higher risk of experiencing difficulties in the self-management of diabetes. Mild cognitive impairment (MCI) often remains undiagnosed due to lack of simple tools for screening at large scale. This represents an important gap in the patients' management because subjects with diabetes and MCI are at high risk of progressing to dementia. Due to its developmental origin as a brain-derived tissue, the retina has been proposed as a potential means of non-invasive and readily accessible exploration of brain pathology. Recent evidence showed that retinal imaging and/or functional tests are correlated with the cognitive function and brain changes in T2D. Simple retinal functional tests (i.e. retinal microperimetry) have proven to be useful as reliable tool for the cognitive evaluation and monitoring in patients with T2D>65 years. This review gives an overall update on the usefulness of retinal imaging in identifying patients with T2D at risk of developing dementia.

Physical Exercise and Health, 6: Sedentary Time, Independent of Health-Related Physical Activity, as a Risk Factor for Dementia in Older Adults.

Sedentary behaviors are leisurely behaviors that occur during waking hours performed while lying down or seated; examples are relaxing, conversing, using a smartphone, watching television, traveling in private or public transport, and thinking or working at a desk. Sedentary behaviors are common in everyday life; the average person spends 9-10 h/d sedentary. Findings from meta-analyses show that higher levels of physical activity are associated with a reduced risk of dementia and that near-absence of moderate to vigorous physical activity is associated with an increased risk of dementia. Sedentariness is a clearly defined construct that is more than just low levels of physical activity. Sedentariness, therefore, merits independent study. In this context, a recent cohort study, conducted in elderly subjects (mean age, 67 years) who were followed for a mean of 6.7 years, found that sedentariness, independent of current levels of moderate to vigorous physical activity, was associated in a dose-dependent fashion with the risk of incident dementia; the finding held true when reverse causation was addressed through the exclusion of subjects who developed dementia within 4 years of follow-up. The adjusted 10-year risk of dementia rose from about 8% with sedentariness at 10 h/d to about 23% with sedentariness at 15 h/d; the difference is clinically meaningful. Limitations of studies in the field are that residual confounding cannot be excluded, and that no randomized controlled trials exist upon which guidance may be based. Nevertheless, it could be prudent to decrease sedentary behaviors if only because these have also been associated with other adverse physical and mental health outcomes. Additional subjects explained in this article include reverse causation and how it may be dealt with during research design and data analysis, individual participant data meta-analysis, and making sense of results that are reported in terms of "per 1,000 person-years."

Clinical Reasoning: A 30-Year-Old Woman Presenting With Rapidly Progressive Dementia and Extreme Hypoglycorrhachia.

A 30-year-old woman presented with rapidly progressive dementia 1 month after the coronavirus disease 2019 infection. Repeated CSF analysis showed extreme hypoglycorrhachia, while cultures, metagenomic next-generation sequencing, and cytopathology testing of CSF were negative. Laboratory investigations for possible etiologies revealed elevated blood ammonia and cancer antigen 125. Brain MRI demonstrated bilateral symmetric diffuse cortical lesions with mild hyperintensity on T1-weighted image and postcontrast enhancement. A more thorough history and specific examinations subsequently indicated an underlying etiology. This case provides an approach for evaluating young patients with rapidly progressive dementia, extreme hypoglycorrhachia, and diffuse CNS lesions, highlighting the importance of considering a broad differential diagnosis.

Association between disease-modifying antirheumatic drugs for rheumatoid arthritis and risk of incident dementia: a systematic review with meta-analysis.

BACKGROUND: Dysregulation of several inflammatory cytokines including tumour necrosis factor (TNF) in dementia patients has also been identified as a key factor in the pathogenesis of rheumatoid arthritis (RA). We aimed to investigate the association of disease-modifying antirheumatic drugs (DMARDs) therapy for RA with risk of incident dementia. METHODS: Electronic database searches of PubMed, EMBASE and Cochrane Library were performed. Observational studies that assessed the association of dementia with DMARDs in RA were included. Pooled risk ratios (RRs) with 95% CIs were used as summary statistic. The certainty of evidence was judged by using the Grading of Recommendations Assessment, Development and Evaluation system. RESULTS: Overall, 14 studies involving 940 442 patients with RA were included. Pooled RR for developing dementia was 0.76 (95% CI 0.72 to 0.80) in patients taking biological DMARDs overall versus those taking conventional synthetic DMARDs, with 24% for TNF inhibitors (RR 0.76, 95% CI 0.71 to 0.82), 24% for non-TNF biologics (RR 0.76, 95% CI 0.70 to 0.83), separately. There was a significant subgroup effect among different types of TNF inhibitors (RR 0.58 [95%CI 0.53 to 0.65], 0.65 [95% CI 0.59 to 0.72], 0.80 [95% CI 0.72 to 0.88] for etanercept, adalimumab, infliximab, respectively; p value between groups=0.002). However, compared with non-users of DMARDs or investigative treatment, no significant effect on dementia incidence was observed in those receiving conventional synthetic DMARDs overall (RR 0.84, 95% CI 0.59 to 1.20), methotrexate (RR 0.78, 95% CI 0.54 to 1.12), hydroxychloroquine (RR 0.95, 95% CI 0.63 to 1.44), except for sulfasalazine (RR 1.27, 95% CI 1.06 to 1.50). CONCLUSIONS: Biological DMARDs for RA are associated with decreased dementia risk, while protective effect is not observed in conventional synthetic DMARDs. Controlled clinical trials on TNF inhibitors are necessary to test their neuroprotective potentials.

Effects of rhythm-control and rate-control strategies on cognitive function and dementia in atrial fibrillation: a systematic review and meta-analysis.

BACKGROUND: Growing evidence suggests that atrial fibrillation (AF) is an independent risk factor for cognitive impairment and dementia, even in the absence of thromboembolic events and stroke. Whether rhythm-control therapy can protect cognitive function remains unclear. We aimed to evaluate the efficacy of rhythm-control strategies in patients with AF regarding cognitive function and dementia risk. METHODS: We systematically searched the PubMed, Embase and Cochrane Library databases for randomised clinical trials, cohort and case-control studies evaluating the associations between rhythm-control strategies and cognitive function outcomes up to May 2023. We assessed the risk of bias using the ROBINS-I and the Cochrane risk-of-bias tool. Both fixed- and random-effects models were used to create summary estimates of risk. RESULTS: We included a total of 14 studies involving 193,830 AF patients. In the pooled analysis, compared with rate-control, rhythm-control therapy was significantly associated with a lower risk of future dementia (hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.62-0.89; I2 = 62%). Among the rhythm-control strategies, AF ablation is a promising treatment that was related to significantly lower risks of overall dementia (HR 0.62; 95% CI 0.56-0.68; I2 = 42%), Alzheimer's disease (HR 0.78; 95% CI 0.66-0.92; I2 = 0%) and vascular dementia (HR 0.58; 95% CI 0.42-0.80; I2 = 31%). Pooled results also showed that compared with patients without ablation, those who underwent AF ablation had significantly greater improvement in cognitive score (standardized mean difference (SMD) 0.85; 95% CI 0.30-1.40; P = 0.005; I2 = 76%). CONCLUSIONS: Rhythm-control strategies, especially ablation, are effective in protecting cognitive function, reducing dementia risk and thus improving quality of life in AF patients.

Infection, delirium, and risk of dementia in patients with and without white matter disease on previous brain imaging: a population-based study.

BACKGROUND: The increased risk of dementia after delirium and infection might be influenced by cerebral white matter disease (WMD). In patients with transient ischaemic attack (TIA) and minor stroke, we assessed associations between hospital admissions with delirium and 5-year dementia risk and between admissions with infection and dementia risk, stratified by WMD severity (moderate or severe vs absent or mild) on baseline brain imaging. METHODS: We included patients with TIA and minor stroke (National Institutes of Health Stroke Score <3) from the Oxford Vascular Study (OXVASC), a longitudinal population-based study of the incidence and outcomes of acute vascular events in a population of 94 567 individuals, with no age restrictions, attending eight general practices in Oxfordshire, UK. Hospitalisation data were obtained through linkage to the Oxford Cognitive Comorbidity, Frailty, and Ageing Research Database-Electronic Patient Records (ORCHARD-EPR). Brain imaging was done using CT and MRI, and WMD was prospectively graded according to the age-related white matter changes (ARWMC) scale and categorised into absent, mild, moderate, or severe WMD. Delirium and infection were defined by ICD-10 coding supplemented by hand-searching of hospital records. Dementia was diagnosed using clinical or cognitive assessment, medical records, and death certificates. Associations between hospitalisation with delirium and hospitalisation with infection, and post-event dementia were assessed using time-varying Cox analysis with multivariable adjustment, and all models were stratified by WMD severity. FINDINGS: From April 1, 2002, to March 31, 2012, 1369 individuals were prospectively recruited into the study. Of 1369 patients (655 with TIA and 714 with minor stroke, mean age 72 [SD 13] years, 674 female and 695 male, and 364 with moderate or severe WMD), 209 (15%) developed dementia. Hospitalisation during follow-up occurred in 891 (65%) patients of whom 103 (12%) had at least one delirium episode and 236 (26%) had at least one infection episode. Hospitalisation without delirium or infection did not predict subsequent dementia (HR 1·01, 95% CI 0·86-1·20). In contrast, hospitalisation with delirium predicted subsequent dementia independently of infection in patients with and without WMD (2·64, 1·47-4·74; p=0·0013 vs 3·41, 1·91-6·09; p<0·0001) especially in those with unimpaired baseline cognition (cognitive test score above cutoff; 4·01, 2·23-7·19 vs 3·94, 1·95-7·93; both p≤0·0001). However, hospitalisation with infection only predicted dementia in those with moderate or severe WMD (1·75, 1·04-2·94 vs 0·68, 0·39-1·20; pdiff=0·023). INTERPRETATION: The increased risk of dementia after delirium is unrelated to the presence of WMD, whereas infection increases risk only in patients with WMD, suggesting differences in underlying mechanisms and in potential preventive strategies. FUNDING: National Institute for Health and Care Research and Wellcome Trust.

Long-Term Longitudinal Course of Cognitive and Motor Symptoms in Patients With Cerebral Small Vessel Disease.

BACKGROUND AND OBJECTIVES: Patients with cerebral small vessel disease (SVD) show a heterogenous clinical course. The aim of the current study was to investigate the longitudinal course of cognitive and motor function in patients who developed parkinsonism, dementia, both, or none. METHODS: Participants were from the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort study, a prospective cohort of patients with SVD. Parkinsonism and dementia were, respectively, diagnosed according to the UK Parkinson's Disease Society brain bank criteria and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria for major neurocognitive disorder. Linear and generalized linear mixed-effect analyses were used to study the longitudinal course of motor and cognitive tasks. RESULTS: After a median follow-up of 12.8 years (interquartile range 10.2-15.3), 132 of 501 (26.3%) participants developed parkinsonism, dementia, or both. Years before diagnosis of these disorders, participants showed distinct clinical trajectories from those who developed none: Participant who developed parkinsonism had an annual percentage of 22% (95% CI 18%-27%) increase in motor part of the Unified Parkinson's Disease Rating Scale score. This was significantly higher than the 16% (95% CI 14%-18%) of controls, mainly because of a steep increase in bradykinesia and posture and gait disturbances. When they developed dementia as well, the increase in Timed Up and Go Test time of 0.73 seconds per year (95% CI 0.58-0.87) was significantly higher than the 0.20 seconds per year increase (95% CI 0.16-0.23) of controls. All groups, including the participants who developed parkinsonism without dementia, showed a faster decline in executive function compared with controls: Annual decline in Z-score was -0.07 (95% CI -0.10 to -0.05), -0.09 (95% CI -0.11 to -0.08), and -0.11 (95% CI -0.14 to -0.08) for participants who developed, respectively, parkinsonism, dementia, and both parkinsonism and dementia. These declines were all significantly faster than the annual decline in Z-score of 0.07 (95% CI -0.10 to -0.05) of controls. DISCUSSION: A distinct pattern in deterioration of clinical markers is visible in patients with SVD, years before the diagnosis of parkinsonism and dementia. This knowledge aids early identification of patients with a high risk of developing these disorders.

Fish oil supplementation and risk of dementia among diabetic patients: a prospective study of 16,061 older patients.

BACKGROUND: Although n-3 Polyunsaturated fatty acids (PUFAs) may benefit cognitive performance, the association of n-3 PUFA intake with dementia risk under dysglycemia has not been examined. We aimed to evaluate the relationship between fish oil supplement use or fish consumption and dementia risk among older patients with diabetes. METHOD: A total of 16,061 diabetic patients aged over 60 years were followed up in the UK Biobank. Fish oil supplements use (yes or no) was collected by the touch screen questionnaire. The diagnosis of dementia was ascertained by the UK Biobank Outcome Adjudication Group. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models. RESULTS: A total of 337 cases of dementia were confirmed after a mean duration of 7.7 years (123,486 person-years) of follow-up. Habitual use of fish oil supplements showed a 24% lower dementia risk among older diabetic patients [HRs (95% CIs): 0.76 (0.60-0.98) (P = 0.031)] compared with non-users. Such inverse association was not modified by the APOE ε4 genotype. However, the consumption of both oily fish (≥2 times/week) and non-oily fish (≥2 times/week) had no significant association with dementia risk (p-trend = 0.271 and p-trend = 0.065) compared with non-consumers. CONCLUSION: In summary, fish oil supplementation may play a protective role in cognitive function across all APOE genotypes, while non-oily fish and oily fish consumption have no protective association among older diabetic patients.

Associations of body habitus and its changes with incident dementia in older adults.

BACKGROUND: This study examined the associations of body mass index (BMI) and waist circumference (WC), as well as their short- and long-term changes over time, with incident dementia in older individuals. METHODS: Data came from 18,837 community-dwelling individuals aged 65+ years from Australia and the United States, who were relatively healthy without major cognitive impairment at enrolment. Anthropometric measures were prospectively assessed at baseline, as well as change and variability from baseline to year two (three time-points). In a subgroup (n = 11,176), self-reported weight at age 18 and 70+ years was investigated. Dementia cases satisfied DSM-IV criteria. Cox regression was used to examine the associations between anthropometric measures and incident risk of dementia. RESULTS: Compared to normal weight, an overweight (HR: 0.67, 95%CI: 0.57-0.79, p < 0.001) or obese BMI (HR: 0.73, 95%CI: 0.60-0.89, p = 0.002), or a larger WC (elevated, HR: 0.71, 95%CI: 0.58-0.86, p < 0.001; highly elevated, HR: 0.65, 95%CI: 0.55-0.78, p < 0.001; relative to low) at baseline was associated with lower dementia risk. In contrast, substantial increases in BMI (>5%) over 2 years after baseline were associated with higher dementia risk (HR: 1.49, 95% CI: 1.17-1.91, p = 0.001). Increased dementia risk was also seen with an underweight BMI at baseline and a 2-year BMI decrease (>5%), but these associations appeared only in the first 4 years of follow-up. Compared to normal weight at both age 18 and 70+ years, being obese at both times was associated with increased dementia risk (HR: 2.27, 95%CI: 1.22-4.24, p = 0.01), while obesity only at age 70+ years was associated with decreased risk (HR: 0.70, 95%CI: 0.51-0.95, p = 0.02). CONCLUSIONS: Our findings suggest that long-term obesity and weight gain in later life may be risk factors for dementia. Being underweight or having substantial weight loss in old age may be early markers of pre-clinical dementia.

Weight change in people with depression and the risk of dementia: a nationwide cohort study.

BACKGROUND: Depression is a risk factor for dementia and weight change can appear as a symptom of depression. However, the association between weight change after the diagnosis of depression and the risk of dementia is poorly established. This study aimed to investigate the association between weight change before and after a diagnosis of depression with the subsequent risk of dementia. METHODS: The National Health Insurance Sharing Service database was used. 1 308 730 patients aged ⩾40 years diagnosed with depression were identified to be eligible. Weight changes after their depression diagnosis were categorized and subsequent incidence of dementia was followed up. RESULTS: During an average follow-up period of 5.2 years (s.d., 2.0 years), 69 373 subjects were newly diagnosed with all-cause dementia (56 351 were Alzheimer's disease and 6877 were vascular dementia). Regarding all outcomes, compared to those with a minimal weight change (-5 to 5%), all groups with weight gain or loss showed increased risks of dementia after adjusting potential risk factors for dementia, in all analysis models with a dose-response relationship, showing a U-shaped association. CONCLUSIONS: Weight change as a symptom of depression could be a predictor for the future development of dementia.