In Silico Models to Validate Novel Blood-Based Biomarkers.

Biological validation of preliminary findings is a key prerequisite in biomarker discovery. In recent years, the development of advanced large-scale sequencing technologies combined with high-throughput computational analysis methods led to the extraction of considerable amount of data from healthy and diseased tissues. Stored in large open-access repositories, these data can be accessed and interrogated by researchers aiming at understanding the biological rationale behind their results. These so called in silico analyses, in opposite to in vitro analyses, have gained increasing importance in recent years, becoming a major component of research projects and publications. However, making sense of the large amount of data available can be challenging and may lead to a misinterpretation of the data. To reduce the dimensionality of this data, recent years have seen the development of statistical m\ethods and advanced graph analytics which help researchers summarize the available data and draw appropriate conclusions. In this chapter we will describe three in silico methods to investigate the biological underpinnings of a panel of seven blood-based biomarkers of Alzheimer's disease.

Effects of vitamin D, omega-3 and a simple strength exercise programme in cardiovascular disease prevention: The DO-HEALTH randomized controlled trial.

BACKGROUND: The effects of non-pharmaceutical interventions in the prevention of cardiovascular diseases (CVD) in older adults remains unclear. Therefore, the aim was to investigate the effect of 2000 IU/day of vitamin D3, omega-3 fatty acids (1 g/day), and a simple home strength exercise program (SHEP) (3×/week) on lipid and CVD biomarkers plasma changes over 3 years, incident hypertension and major cardiovascular events (MACE). METHODS: The risk of MACE (coronary heart event or intervention, heart failure, stroke) was an exploratory endpoint of DO-HEALTH, incident hypertension and change in biomarkers were secondary endpoints. DO-HEALTH is a completed multicentre, randomised, placebo-controlled, 2 × 2 × 2 factorial design trial enrolling 2157 Europeans aged ≥70 years. RESULTS: Participants' median age was 74 [72, 77] years, 61.7% were women, 82.5% were at least moderately physically active, and 40.7% had 25(OH)D < 20 ng/mL at baseline. Compared to their controls, omega-3 increased HDL-cholesterol (difference in change over 3 years: 0.08 mmol/L, 95% CI 0.05-0.10), decreased triglycerides (-0.08 mmol/L, (95%CI -0.12 to -0.03), but increased total- (0.15 mmol/L, 95%CI 0.09; 0.2), LDL- (0.11 mmol/L, 0.06; 0.16), and non-HDL-cholesterol (0.07 mmol/L, 95%CI 0.02; 0.12). However, neither omega-3 (adjustedHR 1.00, 95%CI 0.64-1.56), nor vitamin D3 (aHR 1.37, 95%CI 0.88-2.14), nor SHEP (aHR 1.18, 95%CI 0.76-1.84) reduced risk of MACE or incident hypertension compared to control. CONCLUSION: Among generally healthy, active, and largely vitamin D replete, older adults, treatment with omega-3, vitamin D3, and/or SHEP had no benefit on MACE prevention. Only omega-3 supplementation changed lipid biomarkers, but with mixed effects. TRIAL REGISTRATION CLINICALTRIALS. GOV IDENTIFIER: NCT01745263.

Patients with geriatric syndromes and anti-amyloid therapies: lack of consideration? An exploratory analysis of the literature.

Introduction: Patients who should benefit from anti-amyloid therapies (AAT) are found across all geriatric settings. Yet, it remains unclear how the use of AAT in patients with geriatric syndromes, such as frailty and polypharmacy, has so far been discussed in the literature. Methods: Articles on aducanumab, gantenerumab, lecanemab, donanemab, crenezumab, solanezumab were retrieved in MEDLINE from inception to July 2023. For each article, identified geriatric relevant terms were assigned to five discussion contexts (eligibility of AAT study population, safety, prescription, patient clinical profile, alternative outcomes measurement). Article type and the involvement of geriatric healthcare professionals as an author were further extracted. Results: Out of 538 articles, 23 (4.27%) were published in journals from the geriatric category, 44 (8.18%) included an author affiliated with a geriatric institution. One hundred and sixteen (21.56%) articles included at least one geriatric relevant term, which were mostly discussed in the context of safety and eligibility. Articles mentioning geriatric syndromes were more frequently authored by a geriatric healthcare professional (p = 0.044). Discussion: The use of AAT in patients with geriatric syndromes has so far received poor attention in the literature raising concerns on their use in this patient group. The involvement of geriatric healthcare professionals in future studies may increase the relevance of AAT research in patients with geriatric syndromes.

Association of Chronic Pain with Biomarkers of Neurodegeneration, Microglial Activation, and Inflammation in Cerebrospinal Fluid and Impaired Cognitive Function.

OBJECTIVE: Debate surrounds the role of chronic pain as a risk factor for cognitive decline and dementia. This study aimed at examining the association of chronic pain with biomarkers of neurodegeneration using data from the Alzheimer's Disease Neuroimaging Initiative. METHODS: Participants were classified using the ATN (amyloid, tau, neurodegeneration) classification. Chronic pain was defined as persistent or recurrent pain reported at baseline. For each ATN group, analysis of covariance models identified differences in cerebrospinal fluid (CSF) levels of amyloid ß1-42 , phosphorylated tau 181 (ptau181 ), total tau (t-tau), soluble triggering receptor expressed on myeloid cells 2 (sTREM2), and cognitive function between chronic pain states. Differences in CSF levels of inflammatory markers between chronic pain states were further analyzed. Linear mixed effect models examined longitudinal changes. RESULTS: The study included 995 individuals, with 605 (60.81%) reporting chronic pain at baseline. At baseline, individuals with suspected non-Alzheimer pathophysiology and chronic pain showed increased CSF levels of t-tau and sTREM2. Chronic pain was associated with increased tumor necrosis factor α levels, irrespective of the ATN group. Longitudinally, an increase in ptau181 CSF levels was observed in chronic pain patients with negative amyloid and neurodegeneration markers. Amyloid-positive and neurodegeneration-negative chronic pain patients showed higher memory function cross-sectionally. No significant longitudinal decline in cognitive function was observed for any ATN group. INTERPRETATION: Our study suggests that chronic pain induces neuronal damage and microglial activation in particular subgroups of patients along the AD spectrum. Further studies are needed to confirm these findings. ANN NEUROL 2023.

Prospective Study of Ageing Trajectories in the European DO-HEALTH Study.

INTRODUCTION: Ageing trajectories range from delayed ageing with extended health to accelerated ageing, with an increased risk of frailty. We evaluated the prevalence and prospective change between health states among community-dwelling European older adults. METHODS: This prospective study is a secondary analysis of DO-HEALTH, a randomized trial that included adults aged 70 years and older across 5 European countries. Healthy agers (HA) fulfilled the Nurses' Health Study healthy ageing criteria and accelerated agers were non-HA being at least pre-frail according to the Fried frailty criteria. We assessed the proportion of participants changing between health states over 4 assessments and evaluated the odds of changing to a more favourable category. To increase reliability and avoid regression to the mean, we averaged the first 2 years and compared them to the average of the last 2 years. RESULTS: Of 2,157 participants, 12.4% were excluded for meeting both healthy ageing and pre-frailty criteria simultaneously. Among the remaining 1,889 participants (mean age 75.1 years, 60.9% female), 23.1% were initially HA, 44.4% were non-HA but not pre-frail, and 32.6% were pre-frail or frail. Subsequently, 65.3% remained in the same health state, 12.0% improved to a healthier state, and 22.8% progressed to a less advantageous state. After adjusting for sex, study centre, treatment, and body mass index, each year of age was associated with 6% lower odds of improving health states. Women had 35% higher odds than men of following a disadvantageous trajectory. CONCLUSION: We observed dynamic trajectories of ageing where transitioning to a healthier state became less likely with advancing age and among women.

Prevalence of polypharmacy in community-dwelling older adults from seven centres in five European countries: a cross-sectional study of DO-HEALTH.

OBJECTIVE: To investigate the prevalence of polypharmacy and characteristics associated with polypharmacy in older adults from seven European cities. DESIGN: Cross-sectional study of baseline data from DO-HEALTH. SETTING AND PARTICIPANTS: DO-HEALTH enrolled 2157 community-dwelling adults age 70 and older from seven centres in Europe. Participants were excluded if they had major health problems or Mini-Mental State Examination Score <24 at baseline. PRIMARY OUTCOME MEASURES: Extensive information on prescription and over-the-counter medications were recorded. Polypharmacy was defined as the concomitant use of five or more medications, excluding vitamins or dietary supplements. Bivariate and multivariable logistic regression was used to test the association of sociodemographic factors (age, sex, years of education, living situation and city) and health-related indicators (number of comorbidities, cognitive function, frailty status, body mass index (BMI), prior fall, self-rated health and smoking status) with polypharmacy. RESULTS: 27.2% of participants reported polypharmacy ranging from 16.4% in Geneva to 60.8% in Coimbra. In the multivariable logistic regression analyses, older age (OR 1.07; 95% CI 1.04 to 1.10), greater BMI (OR 1.09; 95% CI 1.06 to 1.12) and increased number of comorbidities (OR 2.13; 95% CI 1.92 to 2.36) were associated with polypharmacy. Women were less likely to report polypharmacy than men (OR 0.65; 95% CI 0.51 to 0.84). In comparison to participants from Zurich, participants from Coimbra were more likely to report polypharmacy (OR 2.36; 95% CI 1.56 to 3.55), while participants from Geneva or Toulouse were less likely to report polypharmacy ((OR 0.36; 95% CI 0.22 to 0.59 and OR 0.64; 95% CI 0.42 to 0.96), respectively). Living situation, smoking status, years of education, prior fall, cognitive function, self-rated health and frailty status were not significantly associated with polypharmacy. CONCLUSION: Polypharmacy is common among relatively healthy older adults, with moderate variability across seven European cities. Independent of several confounders, being a woman, older age, greater BMI and greater number of comorbidities were associated with increased odds for polypharmacy. TRIAL REGISTRATION NUMBER: NCT01745263.

Prevalence of healthy aging among community dwelling adults age 70 and older from five European countries.

BACKGROUND: To compare the prevalence of healthy aging among adults age 70 and older from 5 European countries recruited for the DO-HEALTH clinical trial. Participants were selected for absence of prior major health events. METHODS: Cross-sectional analysis of DO-HEALTH baseline data. All 2,157 participants (mean age 74.9, SD 4.4; 61.7% women) were included and 2,123 had data for all domains of the healthy aging status (HA) definition. HA was assessed based on the Nurses` Health Study (NHS) definition requiring four domains: no major chronic diseases, no disabilities, no cognitive impairment (Montreal Cognitive Assessment, MoCA ≥25), no mental health limitation (GDS-5 <2, and no diagnosis of depression). Association between HA and age, BMI, gender, and physical function (sit-to-stand, gait speed, grip strength) was assessed by multivariate logistic regression analyses adjusting for center. RESULTS: Overall, 41.8% of DO-HEALTH participants were healthy agers with significant variability by country: Austria (Innsbruck) 58.3%, Switzerland (Zurich, Basel, Geneva) 51.2%, Germany (Berlin) 37.6%, France (Toulouse) 36.7% and Portugal (Coimbra) 8.8% (p <0.0001). Differences in prevalence by country persisted after adjustment for age. In the multivariate model, younger age (OR = 0.95, 95% CI 0.93 to 0.98), female gender (OR = 1.36, 95% CI 1.03 to 1.81), lower BMI (OR = 0.94, 95% CI 0.91 to 0.96), faster gait speed (OR = 4.70, 95% CI 2.68 to 8.25) and faster performance in sit-to-stand test (OR = 0.90, 95% CI 0.87 to 0.93) were independently and significantly associated with HA. CONCLUSIONS: Despite the same inclusion and exclusion criteria preselecting relatively healthy adults age 70 years and older, HA prevalence in DO-HEALTH varied significantly between countries and was highest in participants from Austria and Switzerland, lowest in participants from Portugal. Independent of country, younger age, female gender, lower BMI and better physical function were associated with HA. TRIAL REGISTRATION: DO-HEALTH was registered under the protocol NCT01745263 at the International Trials Registry ( clinicaltrials.gov ), and under the protocol number 2012-001249-41 at the Registration at the European Community Clinical Trial System (EudraCT).

Iron deficiency and biomarkers of inflammation: a 3-year prospective analysis of the DO-HEALTH trial.

BACKGROUND: The longitudinal association between iron deficiency and inflammatory biomarkers levels has not been fully explored among relatively healthy older adults. AIMS: To assess whether iron deficiency at baseline and at any yearly follow-up time point, with or without anemia, was associated with changes from baseline in high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6) levels over 3 years. METHODS: This is a post-hoc observational analysis of DO-HEALTH, a double-blind, randomized controlled trial including 2157 European community-dwelling adults age 70+. The outcomes were changes from baseline in hs-CRP and IL-6 levels, measured at 12, 24, and 36 months of follow-up. Iron deficiency was defined by soluble transferrin receptor levels > 28.1 nmol/L and baseline anemia by hemoglobin levels < 130 g/L for men and < 120 g/L for women. RESULTS: In total, 2141 participants were included in the analyses (mean age: 74.9 years, 61.5% of women, 26.8% with iron deficiency). Baseline iron deficiency was associated with greater increase in IL-6 levels (mean difference in change: 0.52 ng/L, 95%CI 0.03-1.00, P = .04) over 3 years. Iron deficiency at any yearly time point was associated with higher increases in hs-CRP (mean difference in change: 1.62 mg/L, 95%CI 0.98-2.26, P < .001) and IL-6 levels (mean difference in change: 1.33 ng/L, 95%CI 0.87-1.79, P < .001) over 3 years. No significant interaction between iron deficiency and anemia was found, suggesting that the results are independent of the anemic status. CONCLUSIONS: These findings suggest that iron deficiency may play a role in low-grade chronic inflammation among relatively healthy older adults.

Are patients with cognitive impairment fit to fly? Current evidence and practical recommendations.

BACKGROUND: The worldwide prevalence of dementia is increasing and represents a major public health concern. In the last decades, air travel services have undergone an impressive expansion and one of ten passengers is aged 65 years and older. While air travel can be stressful at all ages and health conditions, older individuals with cognitive impairment carry a greater risk for air-travel-related complications. Consequently, demands to general practitioners for assessing their older patient's fitness to fly are increasing. METHODS: We conducted a search of the literature in PubMed on the impact of in-flight environmental changes on passengers with cognitive impairment and possible resulting complications. This set the base for a discussion on pharmacological and non-pharmacological interventions aimed at preventing in-flight complications in this vulnerable population. RESULTS: While our research strategy identified a total of 11 articles related to older age and air travel, only three focused on passengers with cognitive impairment. Our literature review showed that the airplane environment may lead to a large spectrum of symptoms in passengers of all age groups. However, passengers with cognitive impairment due to neurodegenerative diseases are at increased risk for experiencing the most extreme symptoms such as acute confusional state. Non-pharmacological and pharmacological interventions at different stages of the travel process (before, during and after) can help prevent complications in this vulnerable population. CONCLUSION: The decision to let a patient with cognitive impairment fly requires a solid understanding of the in-flight environmental changes and their impact on older patients with cognitive impairment. Moreover, a sound weighing of the risks and benefits while considering different aspects of the patient's history is demanded. In this regard, the role of the treating physicians and caregivers is essential along with the support of the medical department of the airline.

Soluble TREM2 and Inflammatory Proteins in Alzheimer's Disease Cerebrospinal Fluid.

The present study explores the associations of soluble TREM2, an important regulator of microglial activity linked to Alzheimer's disease (AD), with other known inflammatory proteins in cerebrospinal fluid (CSF). We studied 303 participants, including 89 controls, 135 mild cognitive impairment, and 79 AD dementia patients. Using established CSF biomarkers, subjects were classified according to the National Institute on Aging-Alzheimer's Association research framework, which groups markers into those of amyloid-ß deposition (A), tau pathology (T), and neurodegeneration (N). TNFR1, TNFR2, TGF-ß1, TGFß2, IL-9, TNF-α, ICAM1, and VCAM1 showed significant concentration differences between the ATN groups, with higher concentrations in more advanced disease categories. sTREM2 was positively associated with the pro-inflammatory proteins TNF-α, TNFR1, TNFR2, ICAM1, VCAM1, and IP-10 and negatively with IL-21; also, positive associations with the anti-inflammatory proteins TGFß1, IL-10, and IL-9 were found. Pathway enrichment analysis highlighted the involvement of sTREM2 in key functional clusters including immunoglobulin and cytokine production and cellular response to lipopolysaccharides, cytokines, and steroid hormones. Our work provides further evidence in support of TREM2 as amarker of neuroinflammatory response in AD.

Differential expression of microRNAs in Alzheimer's disease brain, blood, and cerebrospinal fluid.

INTRODUCTION: Several microRNAs (miRNAs) have been implicated in Alzheimer's disease pathogenesis, but the evidence from individual case-control studies remains inconclusive. METHODS: A systematic literature review was performed, followed by standardized multistage data extraction, quality control, and meta-analyses on eligible data for brain, blood, and cerebrospinal fluid specimens. Results were compared with miRNAs reported in the abstracts of eligible studies or recent qualitative reviews to assess novelty. RESULTS: Data from 147 independent data sets across 107 publications were quantitatively assessed in 461 meta-analyses. Twenty-five, five, and 32 miRNAs showed studywide significant differential expression (α < 1·08 × 10-4) in brain, cerebrospinal fluid, and blood-derived specimens, respectively, with 5 miRNAs showing differential expression in both brain and blood. Of these 57 miRNAs, 13 had not been reported in the abstracts of previous original or review articles. DISCUSSION: Our systematic assessment of differential miRNA expression is the first of its kind in Alzheimer's disease and highlights several miRNAs of potential relevance.

miRNAs Identify Shared Pathways in Alzheimer's and Parkinson's Diseases.

Despite the identification of several dozens of common genetic variants associated with Alzheimer's disease (AD) and Parkinson's disease (PD), most of the genetic risk remains uncharacterised. Therefore, it is important to understand the role of regulatory elements, such as miRNAs. Dysregulated miRNAs are implicated in AD and PD, with potential value in dissecting the shared pathophysiology between the two disorders. miRNAs relevant to both neurodegenerative diseases are related to axonal guidance, apoptosis, and inflammation, therefore, AD and PD likely arise from similar underlying biological pathway defects. Furthermore, pathways regulated by APP, L1CAM, and genes of the caspase family may represent promising therapeutic miRNA targets in AD and PD since they are targeted by dysregulated miRNAs in both disorders.

Increased brain age in adults with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is the most common genetic obesity syndrome, with associated learning difficulties, neuroendocrine deficits, and behavioural and psychiatric problems. As the life expectancy of individuals with PWS increases, there is concern that alterations in brain structure associated with the syndrome, as a direct result of absent expression of PWS genes, and its metabolic complications and hormonal deficits, might cause early onset of physiological and brain aging. In this study, a machine learning approach was used to predict brain age based on grey matter (GM) and white matter (WM) maps derived from structural neuroimaging data using T1-weighted magnetic resonance imaging (MRI) scans. Brain-predicted age difference (brain-PAD) scores, calculated as the difference between chronological age and brain-predicted age, are designed to reflect deviations from healthy brain aging, with higher brain-PAD scores indicating premature aging. Two separate adult cohorts underwent brain-predicted age calculation. The main cohort consisted of adults with PWS (n = 20; age mean 23.1 years, range 19.8-27.7; 70.0% male; body mass index (BMI) mean 30.1 kg/m2, 21.5-47.7; n = 19 paternal chromosome 15q11-13 deletion) and age- and sex-matched controls (n = 40; age 22.9 years, 19.6-29.0; 65.0% male; BMI 24.1 kg/m2, 19.2-34.2) adults (BMI PWS vs. control P = .002). Brain-PAD was significantly greater in PWS than controls (effect size mean ±â€¯SEM +7.24 ±â€¯2.20 years [95% CI 2.83, 11.63], P = .002). Brain-PAD remained significantly greater in PWS than controls when restricting analysis to a sub-cohort matched for BMI consisting of n = 15 with PWS with BMI range 21.5-33.7 kg/m2, and n = 29 controls with BMI 21.7-34.2 kg/m2 (effect size +5.51 ±â€¯2.56 years [95% CI 3.44, 10.38], P = .037). In the PWS group, brain-PAD scores were not associated with intelligence quotient (IQ), use of hormonal and psychotropic medications, nor severity of repetitive or disruptive behaviours. A 24.5 year old man (BMI 36.9 kg/m2) with PWS from a SNORD116 microdeletion also had increased brain PAD of 12.87 years, compared to 0.84 ±â€¯6.52 years in a second control adult cohort (n = 95; age mean 34.0 years, range 19.9-55.5; 38.9% male; BMI 28.7 kg/m2, 19.1-43.1). This increase in brain-PAD in adults with PWS indicates abnormal brain structure that may reflect premature brain aging or abnormal brain development. The similar finding in a rare patient with a SNORD116 microdeletion implicates a potential causative role for this PWS region gene cluster in the structural brain abnormalities associated primarily with the syndrome and/or its complications. Further longitudinal neuroimaging studies are needed to clarify the natural history of this increase in brain age in PWS, its relationship with obesity, and whether similar findings are seen in those with PWS from maternal uniparental disomy.

Direct oral anticoagulants in the elderly: systematic review and meta-analysis of evidence, current and future directions.

BACKGROUND: Concerns regarding the use of direct oral anticoagulants (DOACs: apixaban, dabigatran, edoxaban, rivaroxaban) in the elderly persist owing to the lack of randomised controlled trials targeting this age group. OBJECTIVES: The aim of this study was to assess the efficacy and safety of DOACs in elderly patients (aged 75 years or more) with atrial fibrillation or venous thromboembolism (VTE), based on already published large randomised trials. METHODS: EMBASE, MEDLINE and the Cochrane Library were searched from inception to June 2015 for phase III trials. Pooled odds ratios with 95% confidence intervals were calculated for the target population using the fixed effect model. Heterogeneity between trials was assessed using the I2 Higgins test. RESULTS: A total of 30 655 participants aged 75 or older from eight studies (two apixaban, one dabigatran, two edoxaban, three rivaroxaban) were included in the statistical evaluation. Pooled analysis revealed that treatment with a DOAC was associated with a statistically significant odds reduction for stroke and embolism in elderly patients with atrial fibrillation. Also, DOACs significantly reduced the number of recurrent VTE events or VTE-related deaths in the participants aged 75 years or more with VTE. There was no statistically significant difference in safety outcome for both indications with DOAC compared with vitamin K antagonists although some differences in safety profiles between the DOACs were apparent. CONCLUSION: DOACs show the same or greater efficacy than vitamin K antagonists in elderly patients with atrial fibrillation and VTE. Individual differences between DOACs in terms of safety profile cannot be excluded on the basis of current evidence. Direct head-to-head comparisons are needed to investigate possible divergence in pharmacological profiles between DOACs. Additionally, further studies conducted in real-word settings and in the frail elderly are ongoing and it would be interesting to target this particular patient group.