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Abstract Background The advent of Alzheimer’s disease-modifying drugs requires accurate biological diagnosis to identify candidates for these therapies. So far, the most promising single plasma biomarker is phosphorylated tau at threonine 217 (p-tau217). To understand its biological features, it is essential to know its longitudinal trajectory and factors influencing it in cognitively unimpaired subjects with no brain pathology. Methods We analyzed longitudinal plasma p-tau217 values (mean follow-up time = 768.3 days) in a cohort of 209 healthy volunteers. We have studied factors associated with plasma p-tau217 changes by using different linear mixed-effects models. Results In amyloid-negative cognitively healthy subjects (n = 151) carriers of ApoE ε4 allele had significantly higher p-tau217 values than non-carriers (0.85 pg/mL; p-value

Abstract Background The arrival of new disease-modifying treatments for Alzheimer’s disease (AD) requires the identification of subjects at risk in a simple, inexpensive, and non-invasive way. With tools allowing an adequate screening, it would be possible to optimize the use of these treatments. Plasma markers of AD are very promising, but it is necessary to prove that alterations in their levels are related to alterations in gold standard markers such as cerebrospinal fluid or PET imaging. With this research, we want to evaluate the performance of plasma Aβ40, Aβ42, and p-tau181 to detect the pathological changes in CSF using the automated Lumipulse platform. Methods Both plasma and CSF Aβ40, Aβ42, and p-tau181 have been evaluated in a group of 208 cognitively unimpaired subjects with a 30.3% of ApoE4 carriers. We have correlated plasma and CSF values of each biomarker. Then, we have also assessed the differences in plasma marker values according to amyloid status (A − / +), AD status (considering AD + subjects to those A + plus Tau +), and ATN group defined by CSF. Finally, ROC curves have been performed, and the area under the curve has been measured using amyloid status and AD status as an outcome and different combinations of plasma markers as predictors. Results Aβ42, amyloid ratio, p-tau181, and p-tau181/Aβ42 ratio correlated significantly between plasma and CSF. For these markers, the levels were significantly different in the A + / − , AD + / − , and ATN groups. Amyloid ratio predicts amyloid and AD pathology in CSF with an AUC of 0.89. Conclusions Plasma biomarkers of AD using the automated Lumipulse platform show good diagnostic performance in detecting Alzheimer’s pathology in cognitively unimpaired subjects.

Abstract Background To evaluate a wide range of optical coherence tomography (OCT) parameters for possible application as a screening tool for cognitively healthy individuals at risk of Alzheimer’s disease (AD), assessing the potential relationship with established cerebrospinal fluid (CSF) core AD biomarkers and magnetic resonance imaging (MRI). Methods We studied 99 participants from the Valdecilla Study for Memory and Brain Aging. This is a prospective cohort for multimodal biomarker discovery and validation that includes participants older than 55 years without dementia. Participants received a comprehensive neuropsychological battery and underwent structural 3-T brain MRI, lumbar puncture for CSF biomarkers (phosphorylated-181-Tau (pTau), total Tau (tTau), beta-amyloid 1–42 (Aβ 1–42), and beta-amyloid 1–40 (Aβ 1–40)). All individuals underwent OCT to measure the retinal ganglion cell layer (GCL), the retinal nerve fiber layer (RFNL), the Bruch’s membrane opening-minimum rim width (BMO-MRW), and choroidal thickness (CT). In the first stage, we performed a univariate analysis, using Student’s t-test. In the second stage, we performed a multivariate analysis including only those OCT parameters that discriminated at a nominal level, between positive/negative biomarkers in stage 1. Results We found significant differences between the OCT measurements of pTau- and tTau-positive individuals compared with those who were negative for these markers, most notably that the GCL and the RNFL were thinner in the former. In stage 2, our dependent variables were the quantitative values of CSF markers and the hippocampal volume. The Aβ 1–42/40 ratio did not show a significant correlation with OCT measurements while the associations between pTau and tTau with GCL were statistically significant, especially in the temporal region of the macula. Besides, the multivariate analysis showed a significant correlation between hippocampal volume with GCL and RNFL. However, after false discovery rate correction, only the associations with hippocampal volume remained significant. Conclusions We found a significant correlation between Tau (pTau) and neurodegeneration biomarkers (tTau and hippocampus volume) with GCL degeneration and, to a lesser degree, with damage in RFNL. OCT analysis constitutes a non-invasive and unexpensive biomarker that allows the detection of neurodegeneration in cognitively asymptomatic individuals.

Abstract Background There is increasing evidence of weight regain in patients after bariatric surgery (BS), generally occurring from 12 to 24 months postoperatively. Postoperative exercise has been suggested to ad long-term weight maintenance and to improve physical function in BS patients. However, there are a limited number of intervention studies investigating the possible benefits of exercise in this population. The aim of the current report is to provide a comprehensive CERT (Consensus on Exercise Reporting Template)-based description of the rationale and details of the exercise programme implemented in the EFIBAR Study (Ejercicio FÍsico tras cirugía BARiátrica), a randomised controlled trial investigating the effects of a 16-week supervised concurrent (aerobic and strength) exercise intervention program on weight loss (primary outcome), body composition, cardiometabolic risk, physical fitness, physical activity and quality of life (secondary outcomes) in patients with severe/morbid obesity following bariatric surgery. Methods A total of 80 BS patients [60–80% expected women, aged 18 to 60 years, body mass index (BMI) ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbid conditions)] will be enrolled in the EFIBAR Randomized Control Trial (RCT). Participants allocated in the exercise group (n = 40) will undertake a 16-week supervised concurrent (strength and aerobic) exercise programme (three sessions/week, 60 min/session), starting 7 to 14 days after surgery. The rationale of the exercise programme will be described following the CERT criteria detailing the 16 key items. The study has been reviewed and approved by the Ethics Committee of the Torrecárdenas University Hospital (Almería, Spain) (ref. N° 76/2016). Discussion The present study details the exercise programme of the EFIBAR RCT, which may serve: 1) exercise professionals who would like to implement an evidence-based exercise programme for BS patients, and 2) as an example of the application of the CERT criteria. Trial registration The trial was prospectively registered at Clinicaltrials.gov NCT03497546 on April 13, 2018.