Migraine and the risk of stroke in a middle-aged and elderly population: A prospective cohort study.

BACKGROUND: It has been suggested that patients with migraine have a higher risk of stroke. Despite considerable research on this topic in younger populations, a clear answer is still lacking for older individuals. We studied the association between migraine and the risk of stroke in a middle-aged and elderly population. METHODS: Within the ongoing prospective population-based Rotterdam Study, the presence of migraine was assessed using a validated questionnaire in a structured interview between 2006 and 2011, which formed the baseline. The association between migraine and the risk of stroke was analyzed using Cox proportional-hazards models with adjustments for age, sex, and cardiometabolic risk factors. RESULTS: A total of 6925 (mean age 65.7 ± 11.3 years, 57.8% females) stroke-free participants were included. At baseline, 1030 (14.9%) participants had lifetime history of migraine. During a median follow-up of 6.2 years, 195 participants developed a stroke (163 ischemic stroke). Analyzing the association between migraine and stroke, we found a hazard ratio of 1.44 with a 95% confidence interval of 0.96-2.15. The results were similar for the ischemic stroke (HR 1.50, CI: 0.97-2.32). CONCLUSION: Our data suggested an association between migraine and the risk of stroke in a middle-aged and elderly population, but this was not statistically significant.

Plasma ß-Amyloid, Total-Tau, and Neurofilament Light Chain Levels and the Risk of Stroke: A Prospective Population-Based Study.

BACKGROUND AND OBJECTIVES: To unravel whether Alzheimer disease-related pathology or neurodegeneration plays a role in stroke etiology, we determined the effect of plasma levels ß-amyloid (Aß), total-tau, and neurofilament light chain (NfL) on risk of stroke and its subtypes. METHODS: Between 2002 and 2005, we measured plasma Aß40, Aß42, total-tau, and NfL in 4,661 stroke-free participants from the population-based Rotterdam Study. We used Cox proportional-hazards models to determine the association between these markers with incident stroke for the entire cohort, per stroke subtype, and by median age, sex, APOE ε4 carriership, and education. RESULTS: After a mean follow-up of 10.8 ± 3.3 years, 379 participants had a first-ever stroke. Log2 total-tau at baseline showed a nonlinear association with risk of any stroke and ischemic stroke: compared to the first (lowest) quartile, the adjusted hazard ratio (HR) for the highest quartile total-tau was 1.68 (95% CI 1.18-2.40) for any stroke. Log2 NfL was associated with an increased risk of any stroke (HR per 1-SD increase 1.27, 95% CI 1.12-1.44), ischemic stroke, and hemorrhagic stroke (HR 1.56, 95% CI 1.14-2.12). Log2 Aß40, Aß42, and Aß42/40 ratio levels were not associated with stroke risk. DISCUSSION: Participants with higher total-tau and NfL at baseline had a higher risk of stroke and several stroke subtypes. These findings support the role of markers of neurodegeneration in the etiology of stroke. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that higher plasma levels of total-tau and NfL are associated with an increased risk of subsequent stroke.

Visit-to-visit blood pressure variability and the risk of stroke in the Netherlands: A population-based cohort study.

BACKGROUND: Apart from blood pressure level itself, variation in blood pressure has been implicated in the development of stroke in subgroups at high cardiovascular risk. We determined the association between visit-to-visit blood pressure variability and stroke risk in the general population, taking into account the size and direction of variation and several time intervals prior to stroke diagnosis. METHODS AND FINDINGS: From 1990 to 2016, we included 9,958 stroke-free participants of the population-based Rotterdam Study in the Netherlands. This is a prospective cohort study including participants aged 45 years and older. Systolic blood pressure (SBP) variability was calculated as absolute SBP difference divided by mean SBP over 2 sequential visits (median 4.6 years apart). Directional SBP variability was defined as SBP difference over 2 visits divided by mean SBP. Using time-varying Cox proportional hazards models adjusted for age, sex, mean SBP, and cardiovascular risk factors, hazard ratios (HRs) for stroke up to January 2016 were estimated per SD increase and in tertiles of variability. We also conducted analyses with 3-, 6-, and 9-year intervals between variability measurement and stroke assessment. These analyses were repeated for diastolic blood pressure (DBP). The mean age of the study population was 67.4 ± 8.2 years and 5,776 (58.0%) were women. During a median follow-up of 10.1 years, 971 (9.8%) participants had a stroke, including 641 ischemic, 89 hemorrhagic, and 241 unspecified strokes. SBP variability was associated with an increased risk of hemorrhagic stroke (HR per SD 1.27, 95% CI 1.05-1.54, p = 0.02) and unspecified stroke (HR per SD 1.21, 95% CI 1.09-1.34, p < 0.001). The associations were stronger for all stroke subtypes with longer time intervals; the HR for any stroke was 1.29 (95% CI 1.21-1.36, p < 0.001) at 3 years, 1.47 (95% CI 1.35-1.59, p < 0.001) at 6 years, and 1.38 (95%CI 1.24-1.51, p < 0.001) at 9 years. For DBP variability, we found an association with unspecified stroke risk. Both the rise and fall of SBP and the fall of DBP were associated with an increased risk for unspecified stroke. Limitations of the study include that, due to an average interval of 4 years between visits, our findings may not be generalizable to blood pressure variability over shorter periods. CONCLUSIONS: In this population-based study, we found that visit-to-visit blood pressure variation was associated with an increased risk of unspecified and hemorrhagic stroke, independent of direction of variation or mean blood pressure.

Thyroid Status and Brain Circulation: The Rotterdam Study.

CONTEXT: Whether thyroid dysfunction is related to altered brain circulation in the general population remains unknown. OBJECTIVE: We determined the association of thyroid hormones with different markers of brain circulation within community-dwelling elderly people. METHODS: This was a population-based study of 3 subcohorts of the Rotterdam Study, starting in 1989, 2000, and 2006. A total of 5142 participants (mean age, 63.8 years; 55.4% women), underwent venipuncture to measure serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4). Between 2005 and 2015, all participants underwent phase-contrast brain magnetic resonance imaging to assess global brain perfusion (mL of blood flow/100 mL of brain/minute). Arteriolar retinal calibers were assessed using digitized images of stereoscopic fundus color transparencies in 3105 participants as markers of microcirculation. We investigated associations of TSH, FT4 with brain circulation measures using (non)linear regression models. RESULTS: FT4 (in pmol/L) levels had an inverse U-shaped association with global brain perfusion, such that high and low levels of FT4 were associated with lower global brain perfusion than middle levels of FT4. The difference in global brain perfusion between high FT4 levels (25 pmol/L) and middle FT4 levels (FT4 = 15 pmol/L; P nonlinearity = .002) was up to -2.44 mL (95% CI -4.31; -0.56). Higher and lower levels of FT4, compared with middle FT4 levels, were associated with arteriolar retinal vessels (mean difference up to -2.46 µm, 95% CI -4.98; 0.05 for lower FT4). CONCLUSION: These results suggest that thyroid dysfunction could lead to brain diseases such as stroke or dementia through suboptimal brain circulation that is potentially modifiable.

Impaired fasting glucose, type 2 diabetes mellitus, and lifetime risk of cardiovascular disease among women and men: the Rotterdam Study.

INTRODUCTION: Data on sex-specific lifetime risk of cardiovascular disease (CVD) across the glycemic spectrum, in particular in impaired fasting glucose (IFG) state, are scarce. Whether overweight/obesity modifies the CVD burden also remains unclear. RESEARCH DESIGN AND METHODS: Using a prospective population-based Rotterdam Study, normoglycemia, IFG, and type 2 diabetes mellitus (T2D) were defined. First incident cases of coronary heart disease, heart failure, and stroke during a follow-up time until January 1, 2015 were identified and formed the composite CVD end point. The remaining lifetime risks of CVD were estimated in each glucose category at 55, 65, 75, and 85 years of age, using a modified version of survival analysis adjusted for the competing risk of death. RESULTS: Among 5698 women and 3803 men free of CVD at baseline, the mean age was 64.5 years (SD 9.6) and 60.0% of participants were women. At age 55 years, the remaining lifetime risk of any CVD event among women was 55.1% (95% CI 48.3 to 61.9) for IFG, compared with 52.7% (95% CI 49.5 to 55.9) for normoglycemia and 61.5% (95% CI 54.7 to 68.3) for T2D. For men, the remaining lifetime risk of any CVD event was 62.1% (95% CI 55.2 to 69.1) for IFG, compared with 59.1% (95% CI 55.5 to 62.7) for normoglycemia and 60.3% (95% CI 53.1 to 67.5) for T2D. At age 55 years, the lifetime risk for incident CVD was higher, although not statistically significant, among women and men with IFG who were overweight or had obesity compared with normal-weight women and men. CONCLUSION: IFG carried a large lifetime risk for incident CVD among both women and men compared with normoglycemia. In particular among men, the risk was comparable to that of T2D. Overweight/Obesity modifies the risk and conferred a larger burden of lifetime CVD risk among women and men with IFG.

Long-term trajectories of decline in cognition and daily functioning before and after stroke.

OBJECTIVE: Although knowledge on poststroke cognitive and functional decline is increasing, little is known about the possible decline of these functions before stroke. We determined the long-term trajectories of cognition and daily functioning before and after stroke. METHODS: Between 1990 and 2016, we repeatedly assessed cognition (Mini-Mental State Examination (MMSE), 15-Word Learning, Letter-Digit Substitution, Stroop, Verbal Fluency, Purdue Pegboard) and basic and instrumental activities of daily living (BADL and IADL) in 14 712 participants within the population-based Rotterdam Study. Incident stroke was assessed through continuous monitoring of medical records until 2018. We matched participants with incident stroke to stroke-free participants (1:3) based on sex and birth year. Trajectories of cognition and daily functioning of patients who had a stroke 10 years before and 10 years after stroke and the corresponding trajectories of stroke-free individuals were constructed using adjusted linear mixed effects models. RESULTS: During a mean follow-up of 12.5±6.8 years, a total of 1662 participants suffered a first-ever stroke. Patients who had a stroke deviated from stroke-free controls up to 10 years before stroke diagnosis in cognition and daily functioning. Significant deviations before stroke were seen in scores of MMSE (6.4 years), Stroop (5.7 years), Purdue Pegboard (3.8 years) and BADL and IADL (2.2 and 3.0 years, respectively). CONCLUSION: Patients who had a stroke have steeper declines in cognition and daily functioning up to 10 years before their first-ever stroke compared with stroke-free individuals. Our findings suggest that accumulating intracerebral pathology already has a clinical impact before stroke.

Circulating biomarkers of immunity and inflammation, risk of Alzheimer's disease, and hippocampal volume: a Mendelian randomization study.

The aim of this study was to explore the association between genetically predicted circulating levels of immunity and inflammation, and the risk of Alzheimer's disease (AD) and hippocampal volume, by conducting a two-sample Mendelian Randomization Study. We identified 12 markers of immune cells and derived ratios (platelet count, eosinophil count, neutrophil count, basophil count, monocyte count, lymphocyte count, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, CD4 count, CD8 count, CD4-to-CD8 ratio, and CD56) and 5 signaling molecules (IL-6, fibrinogen, CRP, and Lp-PLA2 activity and mass) as primary exposures of interest. Other genetically available immune biomarkers with a weaker a priori link to AD were considered secondary exposures. Associations with AD were evaluated in The International Genomics of Alzheimer's Project (IGAP) GWAS dataset (21,982 cases; 41,944 controls of European ancestry). For hippocampal volume, we extracted data from a GWAS meta-analysis on 33,536 participants of European ancestry. None of the primary or secondary exposures showed statistically significant associations with AD or with hippocampal volume following P-value correction for multiple comparisons using false discovery rate < 5% (Q-value < 0.05). CD4 count showed the strongest suggestive association with AD (odds ratio 1.32, P < 0.01, Q > 0.05). There was evidence for heterogeneity in the MR inverse variance-weighted meta-analyses as measured by Cochran Q, and weighted median and weighted mode for multiple exposures. Further cluster analyses did not reveal clusters of variants that could influence the risk factor in distinct ways. This study suggests that genetically predicted circulating biomarkers of immunity and inflammation are not associated with AD risk or hippocampal volume. Future studies should assess competing risk, explore in more depth the role of adaptive immunity in AD, in particular T cells and the CD4 subtype, and confirm these findings in other ethnicities.

Herpes simplex virus 1 and the risk of dementia: a population-based study.

Herpes simplex virus 1 (HSV1) is a neuroinvasive virus capable of entering the brain which makes it a candidate pathogen for increasing risk of dementia. Previous studies are inconsistent in their findings regarding the link between HSV1 and dementia, therefore, we investigated how HSV1 relates to cognitive decline and dementia risk using data from a population-based study. We measured HSV1 immunoglobulin (IgG) antibodies in serum collected between 2002 and 2005 from participants of the Rotterdam Study. We used linear regression to determine HSV1 in relation to change in cognitive performance during 2 consecutive examination rounds on average 6.5 years apart. Next, we determined the association of HSV1 with risk of dementia (until 2016) using a Cox regression model. We repeated analyses for Alzheimer's disease. All models were adjusted for age, sex, cardiovascular risk factors, and apolipoprotein E genotype. Of 1915 non-demented participants (mean age 71.3 years, 56.7% women), with an average follow-up time of 9.1 years, 244 participants developed dementia (of whom 203 Alzheimer's disease). HSV1 seropositivity was associated with decline in global cognition (mean difference of HSV1 seropositive vs seronegative per standard deviation decrease in global cognition - 0.16; 95% confidence interval (95%CI), - 0.26; - 0.07), as well as separate cognitive domains, namely memory, information processing, and executive function, but not motor function. Finally, HSV1 seropositivity was not associated with risk of dementia (adjusted hazard ratio 1.18, 95% CI 0.83; 1.68), similar for Alzheimer's disease. HSV1 is associated with cognitive decline but not with incident dementia in the general population. These data suggest HSV1 to be associated only with subtle cognitive disturbances but not with greater cognitive disorders that result in dementia.

Circulatory markers of immunity and carotid atherosclerotic plaque.

BACKGROUND AND AIMS: We aimed to determine the association of circulatory markers of innate and adaptive immunity with carotid atherosclerotic plaque characteristics. METHODS: In 1602 participants from the population-based Rotterdam Study with subclinicalcarotid atherosclerosis, blood sampling was performed to determine granulocyte, platelet, monocyte (innate immunity) and lymphocyte (adaptive immunity) counts, from which the granulocyte-to-lymphocyte ratio [GLR], platelet-to-lymphocyte ratio [PLR], monocyte-to-lymphocyte ratio [MLR] and systemic immune-inflammation index [SII] were calculated. All participants underwent carotid MRI for evaluation of plaque characteristics. Plaque size (stenosis >30%, maximum plaque thickness) and plaque composition (presence of intraplaque hemorrhage [IPH], lipid-rich necrotic core [LRNC], and calcification) were assessed. Using linear and logistic regression models, the association of innate and adaptive immunity markers with plaque size and plaque components, adjusting for relevant confounders, was assessed. RESULTS: Higher levels of granulocytes were significantly associated with larger plaque thickness (mean difference [Ln (mm)] per Ln increase granulocyte count [95% CI]: 0.06 [0.02; 0.10]). Conversely, more lymphocytes related with smaller maximum plaque thickness (mean difference [Ln (mm)] per Ln increase lymphocyte count: 0.09 [-0.14;-0.04]) and a lower prevalence of IPH (odds ratio per Ln increase lymphocyte count: 0.60 [0.37; 0.97]). Moreover, all ratio measures were associated with larger plaque thickness, of which the MLR also associated with more frequent LRNC (odds ratio per Ln increase MLR: 1.26 [1.02; 1.56]). CONCLUSIONS: The innate immunity links to larger plaques, whilst the adaptive immunity seems to relate to smaller plaques and a lower frequency of IPH. These results suggest that an imbalance in innate and adaptive immunity may play a role in the vulnerability of carotid atherosclerotic plaques.

Circulatory MicroRNAs as Potential Biomarkers for Stroke Risk: The Rotterdam Study.

BACKGROUND AND PURPOSE: MicroRNAs (miRNAs) are post-transcriptionally regulators of gene expression that can be released extracellularly upon pathophysiological processes. By complementary binding of target transcripts, miRNAs can modulate the expression of an abundance of genes. Increasing evidence recognize miRNAs as promising biomarkers for complex traits, including cardiovascular disease and stroke. We conducted a longitudinal study to determine the association between circulatory miRNAs and incident stroke in a population-based setting. METHODS: Next-generation sequencing was used to measure expression levels of 2083 miRNAs in plasma samples, collected between 2002 and 2005, from 1914 stroke-free participants of the Rotterdam Study. Participants were assessed for incident stroke through continuous monitoring of medical records until January 1, 2016. Cox proportional hazards regression models adjusted for age, sex, and vascular risk factors were used to investigate the association between the levels of 591 miRNAs well-expressed in plasma and incident stroke. Furthermore, stroke subtype analysis was performed to assess the link between identified miRNAs and ischemic, hemorrhagic, and unspecified stroke. Subsequently, post hoc analyses were conducted to gain insight into the association between putative target genes of miRNAs and stroke. RESULTS: Of 1914 participants (mean age 71.5 years ±7.6; 57.7% women), 138 were diagnosed with incident stroke during a mean follow-up of 9.7±3.2 years. After adjusting for potential confounders, we found plasma levels of 3 miRNAs to be associated with incident stroke (false discovery rate-adjusted P<0.05). These include miR-6124 (hazard ratio, 1.66 [95% CI, 1.31-2.09]), miR-5196-5p (hazard ratio, 1.90 [95% CI, 1.39-2.61]), and miR-4292 (hazard ratio, 2.65 [95% CI, 1.62-4.34]). In silico analysis of the putative target genes of these miRNAs showed associations of variants in several target genes with stroke. CONCLUSIONS: This study indicates that plasma levels of 3 miRNAs are associated with the risk of stroke, proposing them as potential biomarkers for early detection of the disease.

Analyzing the effect of APOE on Alzheimer's disease progression using an event-based model for stratified populations.

Alzheimer's disease (AD) is the most common form of dementia and is phenotypically heterogeneous. APOE is a triallelic gene which correlates with phenotypic heterogeneity in AD. In this work, we determined the effect of APOE alleles on the disease progression timeline of AD using a discriminative event-based model (DEBM). Since DEBM is a data-driven model, stratification into smaller disease subgroups would lead to more inaccurate models as compared to fitting the model on the entire dataset. Hence our secondary aim is to propose and evaluate novel approaches in which we split the different steps of DEBM into group-aspecific and group-specific parts, where the entire dataset is used to train the group-aspecific parts and only the data from a specific group is used to train the group-specific parts of the DEBM. We performed simulation experiments to benchmark the accuracy of the proposed approaches and to select the optimal approach. Subsequently, the chosen approach was applied to the baseline data of 417 cognitively normal, 235 mild cognitively impaired who convert to AD within 3 years, and 342 AD patients from the Alzheimers Disease Neuroimaging Initiative (ADNI) dataset to gain new insights into the effect of APOE carriership on the disease progression timeline of AD. In the ε4 carrier group, the model predicted with high confidence that CSF Amyloidß42 and the cognitive score of Alzheimer's Disease Assessment Scale (ADAS) are early biomarkers. Hippocampus was the earliest volumetric biomarker to become abnormal, closely followed by the CSF Phosphorylated Tau181 (PTAU) biomarker. In the homozygous ε3 carrier group, the model predicted a similar ordering among CSF biomarkers. However, the volume of the fusiform gyrus was identified as one of the earliest volumetric biomarker. While the findings in the ε4 carrier and the homozygous ε3 carrier groups fit the current understanding of progression of AD, the finding in the ε2 carrier group did not. The model predicted, with relatively low confidence, CSF Neurogranin as one of the earliest biomarkers along with cognitive score of Mini-Mental State Examination (MMSE). Amyloid ß42 was found to become abnormal after PTAU. The presented models could aid understanding of the disease, and in selecting homogeneous group of presymptomatic subjects at-risk of developing symptoms for clinical trials.

Immunity and amyloid beta, total tau and neurofilament light chain: Findings from a community-based cohort study.

INTRODUCTION: We investigated how components of immunity relate to biomarkers of Alzheimer's disease (AD) in plasma and explored the influence of AD genetic risk factors in the population-based Rotterdam Study. METHODS: In 7397 persons, we calculated the granulocyte-to-lymphocyte ratio (GLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). In 3615 of these persons, plasma amyloid-beta (Aß)42 and Aß40 were measured. Next, we constructed an overall genetic risk score (GRS) based on genome-wide significant variants, both including and excluding APOE ε4. RESULTS: All innate immunity phenotypes were related to higher Aß, most strongly with a doubling in GLR leading to a 1.9% higher Aß42 (95% confidence interval [95% CI] 0.4 to 3.3%) and 3.2% higher Aß40 (95% CI 2.0 to 4.3%). Higher AD GRS including APOE ε4 was associated with higher immunity markers. DISCUSSION: Higher levels of immunity markers were associated with higher Aß in plasma. Participants with a higher genetic predisposition to AD had higher immunity markers, where these effects were mainly driven by APOE ε4.

Physical Exercise Interventions Targeting Cognitive Functioning and the Cognitive Domains in Nondementia Samples: A Systematic Review of Meta-Analyses.

OBJECTIVE: We investigated whether physical exercise interventions improve cognitive functioning in nondementia populations. METHODS: We conducted a systematic review of meta-analyses including only randomized controlled trials (RCTs). Two reviewers completed a systematic search of PubMed, Embase, PsychInfo, and Cochrane Controlled Register of Trials. Study characteristics, effect size data, and heterogeneity estimates were extracted and presented in tabular form. Methodological quality was assessed by 2 reviewers using the AMSTAR-2 checklist. The validity of results was considered based on AMSTAR-2 scores and study characteristics. RESULTS: We included 11 meta-analyses: 6 focused on disease-free older adults and 5 on mild cognitive impairment (MCI) excluding dementia. These meta-analyses summarized 97 unique RCTs. Methodological quality ranged from critically low to high. For overall cognitive functioning, which was the outcome of 6 meta-analyses, 1 showed improvement due to exercise interventions in disease-free older adults (g = 0.29, P < .01), while 2 reported nonsignificant effects. In patients with MCI, 3 meta-analyses reported significant benefits of exercise interventions on overall cognitive functioning (g = 0.25-0.57, P < .01). For cognitive domains such as attention and memory, there was limited evidence of beneficial effects of exercise demonstrated in either disease-free or MCI samples. CONCLUSIONS: Exercise may improve overall cognitive functioning in disease-free older adults, but there is too little high-quality evidence to conclude whether this is achieved through improvement in any of the specific cognitive domains assessed. There is clearer evidence that exercise may improve cognitive functioning in MCI, but again there is limited evidence across most cognitive domains.

Association of Circulating Monocyte Chemoattractant Protein-1 Levels With Cardiovascular Mortality: A Meta-analysis of Population-Based Studies.

Importance: Human genetics and studies in experimental models support a key role of monocyte-chemoattractant protein-1 (MCP-1) in atherosclerosis. Yet, the associations of circulating MCP-1 levels with risk of coronary heart disease and cardiovascular death in the general population remain largely unexplored. Objective: To explore whether circulating levels of MCP-1 are associated with risk of incident coronary heart disease, myocardial infarction, and cardiovascular mortality in the general population. Data Sources and Selection: Population-based cohort studies, identified through a systematic review, that have examined associations of circulating MCP-1 levels with cardiovascular end points. Data Extraction and Synthesis: Using a prespecified harmonized analysis plan, study-specific summary data were obtained from Cox regression models after excluding individuals with overt cardiovascular disease at baseline. Derived hazard ratios (HRs) were synthesized using random-effects meta-analyses. Main Outcomes and Measures: Incident coronary heart disease (myocardial infarction, coronary revascularization, and unstable angina), nonfatal myocardial infarction, and cardiovascular death (from cardiac or cerebrovascular causes). Results: The meta-analysis included 7 cohort studies involving 21 401 individuals (mean [SD] age, 53.7 [10.2] years; 10 012 men [46.8%]). Mean (SD) follow-up was 15.3 (4.5) years (326 392 person-years at risk). In models adjusting for age, sex, and race/ethnicity, higher MCP-1 levels at baseline were associated with increased risk of coronary heart disease (HR per 1-SD increment in MCP-1 levels: 1.06 [95% CI, 1.01-1.11]; P = .01), nonfatal myocardial infarction (HR, 1.07 [95% CI, 1.01-1.13]; P = .02), and cardiovascular death (HR, 1.12 [95% CI, 1.05-1.20]; P < .001). In analyses comparing MCP-1 quartiles, these associations followed dose-response patterns. After additionally adjusting for vascular risk factors, the risk estimates were attenuated, but the associations of MCP-1 levels with cardiovascular death remained statistically significant, as did the association of MCP-1 levels in the upper quartile with coronary heart disease. There was no significant heterogeneity; the results did not change in sensitivity analyses excluding events occurring in the first 5 years after MCP-1 measurement, and the risk estimates were stable after additional adjustments for circulating levels of interleukin-6 and high-sensitivity C-reactive protein. Conclusions and Relevance: Higher circulating MCP-1 levels are associated with higher long-term cardiovascular mortality in community-dwelling individuals free of overt cardiovascular disease. These findings provide further support for a key role of MCP-1-signaling in cardiovascular disease.

Higher Plasma Amyloid-ß Levels Are Associated with a Higher Risk of Cancer: A Population-Based Prospective Cohort Study.

BACKGROUND: Various studies show an inverse relation between Alzheimer disease and cancer, but findings are likely to be biased by surveillance and survival bias. Plasma amyloid-ß (Aß) is defined as a preclinical feature of Alzheimer disease, with lower levels of Aß42 being associated with a higher risk of Alzheimer disease. To get more insight into the biological link between Alzheimer disease and cancer, we investigated plasma Aß levels in relation to the risk of cancer. METHODS: Between 2002 and 2005, we measured plasma Aß40 and Aß42 levels in 3,949 participants from the population-based Rotterdam Study. These participants were followed until the onset of cancer, all-cause dementia, death, loss to follow-up, or January 1, 2014, whichever came first. We used Cox proportional hazards models to investigate the association between plasma Aß40 and Aß42 levels, and the risk of cancer. Analyses were stratified by cancer site. RESULTS: During a median (interquartile range) follow-up of 9.0 years (6.9-10.1), 560 participants were diagnosed with cancer. Higher levels of log2 plasma Aß40 and Aß42 were associated with a higher risk of cancer [hazard ratio per standard deviation increase for Aß40 = 1.12 (95% confidence interval, CI = 1.02-1.23) and Aß42 = 1.12 (95% CI = 1.03-1.23)]. These effect estimates were most pronounced for hematologic cancers, urinary tract cancers, and cancers of unknown primary origin. CONCLUSIONS: We found that higher levels of both plasma Aß40 and Aß42 were associated with a higher risk of cancer. IMPACT: Our study suggests a potential biological link between Alzheimer disease and cancer. The pathophysiologic role of Aß in cancer and its causality warrant further investigation.

The association of innate and adaptive immunity, subclinical atherosclerosis, and cardiovascular disease in the Rotterdam Study: A prospective cohort study.

BACKGROUND: Atherosclerotic cardiovascular disease (ASCVD) is driven by multifaceted contributions of the immune system. However, the dysregulation of immune cells that leads to ASCVD is poorly understood. We determined the association of components of innate and adaptive immunity longitudinally with ASCVD, and assessed whether arterial calcifications play a role in this association. METHODS AND FINDINGS: Granulocyte (innate immunity) and lymphocyte (adaptive immunity) counts were determined 3 times (2002-2008, mean age 65.2 years; 2009-2013, mean age 69.0 years; and 2014-2015, mean age 78.5 years) in participants of the population-based Rotterdam Study without ASCVD at baseline. Participants were followed-up for ASCVD or death until 1 January 2015. A random sample of 2,366 underwent computed tomography at baseline to quantify arterial calcification volume in 4 vessel beds. We studied the association between immunity components with risk of ASCVD and assessed whether immunity components were related to arterial calcifications at baseline. Of 7,730 participants (59.4% women), 801 developed ASCVD during a median follow-up of 8.1 years. Having an increased granulocyte count increased ASCVD risk (adjusted hazard ratio for doubled granulocyte count [95% CI] = 1.78 [1.34-2.37], P < 0.001). Higher granulocyte counts were related to larger calcification volumes in all vessels, most prominently in the coronary arteries (mean difference in calcium volume [mm3] per SD increase in granulocyte count [95% CI] = 32.3 [9.9-54.7], P < 0.001). Respectively, the association between granulocyte count and incident coronary heart disease and stroke was partly mediated by coronary artery calcification (overall proportion mediated [95% CI] = 19.0% [-10% to 32.3%], P = 0.08) and intracranial artery calcification (14.9% [-10.9% to 19.1%], P = 0.05). A limitation of our study is that studying the etiology of ASCVD remains difficult within an epidemiological setting due to the limited availability of surrogates for innate and especially adaptive immunity. CONCLUSIONS: In this study, we found that an increased granulocyte count was associated with a higher risk of ASCVD in the general population. Moreover, higher levels of granulocytes were associated with larger volumes of arterial calcification. Arterial calcifications may explain a proportion of the link between granulocytes and ASCVD.

Telomere Length and the Risk of Alzheimer's Disease: The Rotterdam Study.

There is a wide interest in biomarkers that capture the burden of detrimental factors as these accumulate with the passage of time, i.e., increasing age. Telomere length has received considerable attention as such a marker, because it is easily quantified and it may aid in disentangling the etiology of dementia or serve as predictive marker. We determined the association of telomere length with risk of Alzheimer's disease and all-cause dementia in a population-based setting. Within the Rotterdam Study, we performed quantitative PCR to measure mean leukocyte telomere length in blood. We determined the association of telomere length with risk of Alzheimer's disease until 2016, using Cox regression models. Of 1,961 participants (mean age 71.4±9.3 years, 57.1% women) with a median follow-up of 8.3 years, 237 individuals were diagnosed with Alzheimer's disease. We found a U-shaped association between telomere length and risk of Alzheimer's disease: compared to the middle tertile the adjusted hazard ratio was 1.59 (95% confidence interval (CI), 1.13-2.23) for the lowest tertile and 1.47 (1.03-2.10) for the highest tertile. Results were similarly U-shaped but slightly attenuated for all-cause dementia. In conclusion, shorter and longer telomere length are both associated with an increased risk of Alzheimer's disease in the general population.

Vitamin D Status and Risk of Stroke: The Rotterdam Study.

Background and Purpose- Recent findings suggest that vitamin D, a neuroprotective prohormone, is involved in the pathogenesis of cardiovascular disease. However, previous studies investigating the association between vitamin D and stroke have shown inconsistent findings. In view of these discrepancies, we determined the association of vitamin D status with stroke using data from a population-based study. Methods- Within the RS (Rotterdam Study), an ongoing prospective population-based study, we measured serum 25-hydroxyvitamin D concentrations between 1997 and 2008 in 9680 participants (56.8% women) aged ≥45 years. We assessed a history of stroke at baseline and subsequently followed for incident stroke until January 1, 2016. Regression models were used to investigate the association of serum 25-hydroxyvitamin D with prevalent and incident stroke separately, adjusted for age, sex, study cohort, season of blood sampling, and other cardiovascular risk factors. Results- Of 9680 participants, 339 had a history of stroke at baseline. Serum 25-hydroxyvitamin D concentration was associated with prevalent stroke, adjusted odds ratio per SD decrease, 1.31; 95% CI, 1.14-1.51. After excluding participants with prevalent stroke, we followed 9338 participants for a total of 98 529 person-years. During follow-up, 735 participants developed a stroke. Lower serum 25-hydroxyvitamin D concentration was not associated with a higher stroke risk, adjusted hazard ratio per SD decrease, 1.06; 95% CI, 0.97-1.16. However, severe vitamin D deficiency did show a significant association: hazard ratio, 1.25; 95% CI, 1.05-1.50. Conclusions- In this population-based cohort, we found an association between vitamin D and prevalent stroke. Only severe vitamin D deficiency was associated with incident stroke. This suggests that lower vitamin D levels do not lead to a higher stroke risk but are instead a consequence of stroke.

Balance between innate versus adaptive immune system and the risk of dementia: a population-based cohort study.

BACKGROUND: Immunity has been suggested to be important in the pathogenesis of dementia. However, the contribution of innate versus adaptive immunity in the development of dementia is not clear. In this study, we aimed to investigate (1) the association between components of innate immunity (granulocytes and platelets) and adaptive immunity (lymphocytes) with risk of dementia and (2) the association between their derived ratios (granulocyte-to-lymphocyte ratio [GLR], platelet-to-lymphocyte ratio [PLR], and systemic immune-inflammation index [SII]), reflecting the balance between innate and adaptive immunity, with risk of dementia. METHODS: Blood cell counts were measured repeatedly between 2002 and 2015 in dementia-free participants of the prospective population-based Rotterdam Study. Participants were followed-up for dementia until 1 January 2016. Joint models were used to determine the association between granulocyte, platelets, and lymphocyte counts, and their derived ratios with risk of dementia. RESULTS: Of the 8313 participants (mean [standard deviation] age 61.1 [7.4] years, 56.9% women), 664 (8.0%) developed dementia during a median follow-up of 8.6 years. Doubling of granulocyte and platelet counts tended to be associated with an increased risk of dementia (HR [95%CI] 1.22 [0.89-1.67] and 1.45 [1.07-1.95], respectively). Doubling of the derived ratios GLR, PLR, and SII were all associated with an increased dementia risk (HR [95%CI] 1.26 [1.03-1.53], 1.27 [1.05-1.53], and 1.15 [0.98-1.34], respectively). CONCLUSIONS: GLR, PLR, and SII are associated with an increased risk of dementia in the general population. This supports the role of an imbalance in the immune system towards innate immunity in the pathogenesis of dementia.