Asymptomatic Young Adults Research Articles

P1059 Fecal calprotectin response to Tasty&Healthy dietary intervention in asymptomatic children and young adults with biologically active Crohn’s disease: results of the “TASTI-E” randomized controlled trial

Abstract Background Tasty&HealthyTM (T&H) is a whole food diet aimed at alleviating inflammation in Crohn’s disease (CD). It excludes processed food, gluten, red meat, and dairy (except for plain yogurt), but does not include mandatory ingredients or partial enteral nutrition with formula as does the CD Exclusion Diet. In this RCT we evaluated T&H diet as an intervention for persistent subclinical inflammation compared with continuing habitual diet. (NCT#04239248; TASTI-E). Methods Patients with CD, aged 6-40 years, in clinical remission or with minimal symptoms (wPCDAI<20/CDAI<200), were randomized if their MINI-index was ≥8 (i.e. bowel inflammation), to receiving either T&H or continuing their habitual diet for 8 weeks. Patients in the latter group were also offered T&H after completing the initial 8 week randomization period. The primary outcome was calprotectin-defined response (i.e. reduction of >50%). Secondary outcomes included adherence, MINI-index, and CRP. Due to COVID-19-related slow enrolment, the study was terminated early, and thus analyses are exploratory on a per-protocol basis. Results 46 patients were randomized (mean age 18.2±7.6 years; median disease duration 9.01 months, IQR 2.9-17.1); 19 were assigned to T&H and 27 to the habitual group. The primary endpoint was achieved, with 7 patients (37%) in the T&H group achieving calprotectin response, vs 4 (15%) in the habitual group (RR 3.23 [95% CI 1.15-9.01]; p=0.028). A pre-post comparison of 15 patients who completed 8 weeks of habitual diet and crossed-over to T&H, showed higher rates of calprotectin<250 mcg/g at week 16 compared with their baseline at week 8 (47% vs. 17%, p=0.005) and MINI<8 (60% vs 20%, p=0.0013). Additionally, compared with the habitual diet, the improvement in CRP 0.48 (0.18-0.81) vs. 0.36 (0.1-0.36); p=0.0012) and MINI (10 (9-13) vs. 7 (5-10.5); p=0.047) was higher in the T&H arm, respectively. The absence of gluten levels in stool was used as a measure of adherence to the T&H diet. At week 8, only 2/13 patients (15%) in the T&H group tested positive for stool gluten, compared to 18/20 patients (90%) in the habitual diet group (p=0.002), demonstrating high adherence to T&H. Patients in the T&H arm met over 95% of Dietary Reference Intakes (DRI) for key macro- and micronutrients. No significant differences were found between the groups except for higher potassium and fiber in the T&H group (p=0.018 and p<0.001, respectively). Conclusion The T&H diet is effective in reducing inflammation in children and adults with CD who have subclinical inflammation. The flexibility of T&H without the need for formula feeds or mandatory ingredients is associated with high adherence.

Normative Extensor Hallucis Brevis Muscle Activity During Locomotion Following the Development of a Novel Ultrasound-Guided Fine-Wire Electromyography Protocol.

Fine-wire electromyography (EMG) is a traditional laboratory technique to estimate muscle activity of the small foot muscles, however, recordings have not been reported from extensor hallucis brevis (EHB). As an extensor of the great toe, EHB is an important muscle when studying physiological changes associated with foot pathologies such as hallux valgus. The purpose of this study was to develop an ultrasound-guided fine-wire EMG protocol to record EHB muscle activity and report normative EMG profiles of healthy young adults during locomotion. Sixteen asymptomatic young adults completed 20 walking trials at a self-selected velocity. Ensemble averages were calculated from the time normalized linear envelopes and represented from 0% to 100% of the single stance phase of gait. EHB muscle bursts were observed between 0% and 20% of the stance phase of gait in all participants. A second burst of EMG was observed between 80% and 100% of stance in 50% of the participants. This study introduces a novel ultrasound-guided EMG protocol and normative data from EHB recordings suggest a synergistic role to anterior compartment musculature at contact. These results provide preliminary insights into understanding the functional role of EHB and may help elucidate the biomechanical factors exacerbating the progression of hallux pathologies.

Walking recovers cartilage compressive strain in vivo

BackgroundArticular cartilage is a fiber reinforced hydrated solid that serves a largely mechanical role of supporting load and enabling low friction joint articulation. Daily activities that load cartilage, lead to fluid exudation and compressive axial strain. To date, the only mechanism shown to recover this cartilage strain in vivo is unloading (e.g., lying supine). Based on recent work in cartilage explants, we hypothesized that loaded joint activity (walking) would also be capable of strain recovery in cartilage. MethodsEight asymptomatic young adults performed a fixed series of tasks, each of which was followed by magnetic resonance imaging to track changes in their knee cartilage thickness. The order of tasks was as follows: 1) stand for 30 ​min, 2) walk for 10 ​min, 3) stand for 30 ​min, and 4) lie supine for 50 ​min. The change in cartilage thickness was used to compute the axial cartilage strain. ResultsStanding produced an average axial strain of −5.1 ​% (compressive) in the tibiofemoral knee cartilage, while lying supine led to strain recovery. In agreement with our hypothesis, walking also led to cartilage strain recovery. Interestingly, the recovery rate during walking (0.19 ​% strain/min) was nearly 3-fold faster than lying supine (0.07 ​% strain/min). ConclusionsThis study represents the first in vivo demonstration that joint activity is capable of recovering compressive strain in cartilage. These findings indicate that joint activities such as walking may play a key role in maintaining and recovering cartilage strain, with implications for maintaining cartilage health and preventing or delaying cartilage degeneration.

Sex-Based Differences and Asymmetry in Hip Kinematics During Unilateral Extension From Deep Hip Flexion.

The purpose of this study was to identify side-to-side and sex-based differences in hip kinematics during a unilateral step-up from deep flexion. Twelve (eight men, four women) asymptomatic young adults performed a step ascent motion while synchronized biplane radiographs of the hip were collected at 50 images per second. Femur and pelvis position were determined using a validated volumetric model-based tracking technique that matched digitally reconstructed radiographs created from subject-specific computed tomography (CT) bone models to each pair of synchronized radiographs. Hip kinematics and side-to-side differences were calculated and a linear mixed effects model evaluated sex-based differences. Women were on average 10.2 deg more abducted and 0.2 mm more medially translated than men across the step up motion (p < 0.001). Asymmetry between hips was up to 14.1 ± 12.1 deg in internal rotation and 1.3 ± 1.4 mm in translation. This dataset demonstrates the inherent asymmetry during movements involving unilateral hip extension from deep flexion and may be used provide context for observed kinematics differences following surgery or rehabilitation. Previously reported kinematic differences between total hip arthroplasty and contralateral hips may be well within the natural side-to-side differences that exist in asymptomatic native hips.

Profile of oropharyngeal swallowing in healthy Brazilian adults and older adults

ObjectivesTo describe the findings of Fiberoptic Endoscopic Examination of Swallowing (FEES) in asymptomatic young and older adults, comparing results across different age groups. Additionally, this study aims to test the Eating Assessment Tool (EAT-10) as an instrument to identify dysphagia risk. MethodsA prospective cross-sectional observational analysis was conducted on a sample of individuals aged 20 and above, asymptomatic for dysphagia, stratified by age groups. The EAT-10 questionnaire was completed, and the FEES was employed to assess oropharyngeal swallowing function. Various parameters, including salivary stasis, swallowing reflex trigger, swallowing sequence, residue, penetration, and aspiration were blindly analyzed by two otolaryngologists. ResultsA total of 184 participants were included, with a mean age of 44.7 ± 18.5 years. There was good to excellent agreement between examiners for FEES parameters. The EAT-10 score ≥3 suggested dysphagia risk in 7.6% (n = 14) of the sample, with no association with age or any FEES parameter. Individuals aged ≥80 years presented more residue (50%; n = 5/10) compared to younger individuals (11.5%; n = 20/174; p = 0.039). Salivary stasis was found exclusively in individuals aged ≥60 years (n = 5/39; 12.8%; p = 0.027). Age did not influence on the swallowing reflex trigger, swallowing sequence, penetration, and aspiration. Penetration was observed in 4.9% (n = 9) of subjects and aspiration occurred in 0.5% (n = 1) of subjects, with no statistical significance in age groups. ConclusionAge does not have a linear influence on swallowing in healthy adults and elderly people. However, individuals aged ≥80 years showed a higher prevalence of residue, and individuals aged ≥60 years showed a higher prevalence of salivary stasis, suggesting an increased risk or presence of dysphagia. Other FEES parameters were not influenced by age. These findings provide valuable insights into the nuanced dynamics of swallowing across different age groups, emphasizing the importance of age-specific considerations in dysphagia assessment. Level of evidence4.

Fatigue-related changes in intermuscular electromyographic coherence across rotator cuff and deltoid muscles in individuals with and without subacromial pain.

Neuromuscular fatigue induces superior migration of the humeral head in individuals with subacromial pain. This has been attributed to weakness of rotator cuff muscles and overactive deltoid muscles. Investigation of common inputs to motoneuron pools of the rotator cuff and deltoid muscles offers valuable insight into the underlying mechanisms of neuromuscular control deficits associated with subacromial pain. This study aims to investigate intermuscular coherence across the rotator cuff and deltoid muscles during a sustained submaximal isometric fatiguing contraction in individuals with and without subacromial pain. Twenty symptomatic and 18 asymptomatic young adults participated in this study. Surface electromyogram (EMG) was recorded from the middle deltoid (MD) and infraspinatus (IS). Intramuscular EMG was recorded with fine-wire electrodes in the supraspinatus (SS). Participants performed an isometric fatiguing contraction of 30° scaption at 25% maximum voluntary contraction (MVC) until endurance limit. Pooled coherence of muscle pairs (SS-IS, SS-MD, IS-MD) in the 2-5 Hz (delta), 5-15 Hz (alpha), and 15-35 Hz (beta) frequency bands during the initial and final 30 s of the fatigue task were compared. SS-IS and SS-MD delta-band coherence increased with fatigue in the asymptomatic group but not the symptomatic group. In the alpha and beta bands, SS-IS and SS-MD coherence increased with fatigue in both groups. IS-MD beta-band coherence was greater in the symptomatic than the asymptomatic group. Individuals with subacromial pain failed to increase common drive across rotator cuff and deltoid muscles and have altered control strategies during neuromuscular fatigue. This may contribute to glenohumeral joint instability and subacromial pain experienced by these individuals.NEW & NOTEWORTHY Through the computation of shared neural drive across glenohumeral muscles, this study reveals that individuals with subacromial pain were unable to increase shared neural drive within the rotator cuff and across the supraspinatus and deltoid muscles during neuromuscular fatigue induced by sustained isometric contraction. These deficits in common drive across the shoulder muscles likely contribute to the joint instability and pain experienced by these individuals.

Lower Humoral and Cellular Immunity Following Asymptomatic SARS-CoV-2 Infection Compared to Symptomatic Infection in Education (The ACE Cohort)

PurposeAsymptomatic SARS-CoV-2 infections were widely reported during the COVID-19 pandemic, acting as a hidden source of infection. Many existing studies investigating asymptomatic immunity failed to recruit true asymptomatic individuals. Thus, we conducted a longitudinal cohort study to evaluate humoral- and cell-mediated responses to infection and vaccination in well-defined asymptomatic young adults (the Asymptomatic COVID-19 in Education [ACE] cohort).MethodsAsymptomatic testing services located at three UK universities identified asymptomatic young adults who were subsequently recruited with age- and sex-matched symptomatic and uninfected controls. Blood and saliva samples were collected after SARS-CoV-2 Wuhan infection, and again after vaccination. 51 participant’s anti-spike antibody titres, neutralizing antibodies, and spike-specific T-cell responses were measured, against both Wuhan and Omicron B.1.1.529.1.ResultsAsymptomatic participants exhibited reduced Wuhan-specific neutralization antibodies pre- and post-vaccination, as well as fewer Omicron-specific neutralization antibodies post-vaccination, compared to symptomatic participants. Lower Wuhan and Omicron-specific IgG titres in asymptomatic individuals were also observed pre- and post-vaccination, compared to symptomatic participants. There were no differences in salivary IgA levels. Conventional flow cytometry analysis and multi-dimensional clustering analysis indicated unvaccinated asymptomatic participants had significantly fewer Wuhan-specific IL-2 secreting CD4+ CD45RA+ T cells and activated CD8+ T cells than symptomatic participants, though these differences dissipated after vaccination.ConclusionsAsymptomatic infection results in decreased antibody and T cell responses to further exposure to SARS-CoV-2 variants, compared to symptomatic infection. Post-vaccination, antibody responses are still inferior, but T cell immunity increases to match symptomatic subjects, emphasising the importance of vaccination to help protect asymptomatic individuals against future variants.

Deep Learning Detection of Early Retinal Peripheral Degeneration From Ultra-Widefield Fundus Photographs of Asymptomatic Young Adult (17-19 Years) Candidates to Airforce Cadets.

Artificial intelligence (AI)-assisted ultra-widefield (UWF) fundus photographic interpretation is beneficial to improve the screening of fundus abnormalities. Therefore we constructed an AI machine-learning approach and performed preliminary training and validation. We proposed a two-stage deep learning-based framework to detect early retinal peripheral degeneration using UWF images from the Chinese Air Force cadets' medical selection between February 2016 and June 2022. We developed a detection model for the localization of optic disc and macula, which are used to find the peripheral areas. Then we developed six classification models for the screening of various retinal cases. We also compared our proposed framework with two baseline models reported in the literature. The performance of the screening models was evaluated by area under the receiver operating curve (AUC) with 95% confidence interval. A total of 3911 UWF fundus images were used to develop the deep learning model. The external validation included 760 UWF fundus images. The results of comparison study revealed that our proposed framework achieved competitive performance compared to existing baselines while also demonstrating significantly faster inference time. The developed classification models achieved an average AUC of 0.879 on six different retinal cases in the external validation dataset. Our two-stage deep learning-based framework improved the machine learning efficiency of the AI model for fundus images with high resolution and many interference factors by maximizing the retention of valid information and compressing the image file size. This machine learning model may become a new paradigm for developing UWF fundus photography AI-assisted diagnosis.

Few sex-specific effects of fatigue on muscle synergies in a repetitive pointing task

Previous studies have identified some sex differences in how individual muscles change their activation during repetitive multi-joint arm motion-induced fatigue. However, little is known about how indicators of multi-muscle coordination change with fatigue in males and females. Fifty-six (29 females) asymptomatic young adults performed a repetitive, forward-backward pointing task until scoring 8/10 on a Borg CR10 scale while surface electromyographic activity of upper trapezius, anterior deltoid, biceps brachii, and triceps brachii was recorded. Activation coefficient, synergy structure, and relative weight of each muscle within synergies were calculated using the non-negative matrix factorization method. Two muscle synergies were extracted from the fatiguing task. The synergy structures were mostly preserved after fatigue, while the activation coefficients were altered. A significant Sex × Fatigue interaction effect showed more use of the anterior deltoid in males especially before fatigue in synergy 1 during shoulder stabilization (p = 0.04). As for synergy 2, it was characterized by variations in the relative weight of biceps, which was higher by 16 % in females compared to males (p = 0.04), and increased with fatigue (p = 0.03) during the elbow flexion acceleration phase and the deceleration phase of the backward pointing movement. Findings suggest that both sexes adapted to fatigue similarly, using fixed synergy structures, with alterations in synergy activation patterns and relative weights of individual muscles. Results support previous findings of an important role for the biceps and anterior deltoid in explaining sex differences in patterns of repetitive motion-induced upper limb fatigue.

Frequency of Coexistent Spinal Segment Variants: Retrospective Analysis in Asymptomatic Young Adults.

Spinal segment variants are highly prevalent and can potentially lead to incorrect spinal enumeration and, consequently, interventions or surgeries at the wrong vertebral levels. Our aim was to assess the prevalence of spinal segment variants and to study the potential association among these variants in a population without histories of spine symptoms. Consecutive computed tomography exams of 450 young adults originally evaluated for non-spinal conditions and without a history of spinal diseases from a single institution. In addition to using descriptive statistics for reporting frequencies of spinal segment variants, the association between these variants was studied by calculating odds ratios and their 95% confidence interval. Consecutive CT exams were evaluated to determine the total number of presacral segments, presence of cervical rib, thoracolumbar transitional vertebra, iliolumbar ligament, and lumbosacral transitional vertebra. The spinal segment distribution variants (an atypical number of presacral segments or an atypical distribution of thoracolumbar vertebrae), cervical rib, thoracolumbar transitional vertebra, and lumbosacral transitional vertebra were reported in 23.8%, 4.2%, 15.3%, and 26.4% of cases in our study population. The presence of a cervical rib or a thoracolumbar transitional vertebra was associated with concurrent lumbosacral transitional vertebra (OR = 3.28; 95% CI, 1.29-8.47 and 1.87; 95% CI, 1.08-3.20, respectively). The inability to visualize the iliolumbar ligament was also associated with the presence of cervical ribs (OR = 3.06; 95% CI, 1.18-7.80). In a population of asymptomatic young adults, spinal segment variants are both highly prevalent with a high rate of coexistence. When a spinal segment variant (eg, transitional vertebra) is diagnosed, additional imaging might be considered for accurate spine enumeration before interventions or operations.

Do key measurement parameters derived from specific cervical vertebral segments differ between lordotic and non-lordotic cervical spine alignments? A study of asymptomatic young adults

BackgroundMeasurement parameters derived from specific cervical vertebral segments (e.g., C2 slope) can provide clinicians with important information on cervical sagittal balance and guide pre- and post-surgical decision-making processes. It is unclear however, what constitutes typical values for these types of measurements in an asymptomatic population of young adults, whether values change depending upon the classification of the cervical spine's global alignment, and if any non-lordotic cervical subtypes display values that are comparable to those reported for pre-surgery patients. MethodsNeutral lateral cervical radiographs of 150 asymptomatic participants (18–30 years) were taken. Global cervical alignment was classified as lordotic or one of four non-lordotic subtypes using a multi-method subtyping protocol. Four key measurement parameters - the anterior translation of the head measure (ATHM), C0–C2 angle, C2 slope, and C7 slope – were derived from specific cervical segments. Independent samples t-tests were used to compare lordotic and non-lordotic groups. ResultsThere was considerable variation in the four key measurement parameters amongst this asymptomatic population of young adults. Thirty-four percent of the sample were classified as lordotic and 66% were classified as non-lordotic. There was a significant difference (p ≤ 0.0125) between lordotic and non-lordotic groups for the C0–C2 angle, C2 slope and C7 slope. There was no difference between groups for the ATHM (p ≥ 0.0125). Within the non-lordotic group, the global-kyphotic (GK) subtype had the largest mean C2 slope, largest mean C0–C2 angle, and smallest mean C7 slope. ConclusionsLong term prospective investigations are required to determine whether possible biomarkers (alignment parameters/radiological measurements) for spinal degenerative changes can be identified so that early interventions can be put in place to try and reduce the impact of neck pain on society.

The Abnormal Accumulation of Lipopolysaccharide Secreted by Enriched Gram-Negative Bacteria Increases the Risk of Rotavirus Colonization in Young Adults.

Human rotavirus (HRV) is an enteric virus that causes infantile diarrhea. However, the risk factors contributing to HRV colonization in young adults have not been thoroughly investigated. Here, we compared the differences in dietary habits and composition of gut microbiota between asymptomatic HRV-infected young adults and their healthy counterparts and investigated potential risk factors contributing to HRV colonization. Our results indicated that asymptomatic HRV-infected adults had an excessive intake of milk and dairy and high levels of veterinary antibiotics (VAs) and preferred veterinary antibiotic (PVAs) residues in urine samples. Their gut microbiota is characterized by abundant Gram-negative (G-) bacteria and high concentrations of lipopolysaccharide (LPS). Several opportunistic pathogens provide discriminatory power to asymptomatic, HRV-infected adults. Finally, we observed an association between HRV colonization and disrupted gut microbiota caused by the exposure to VAs and PVAs. Our study reveals the traits of disrupted gut microbiota in asymptomatic HRV-infected adults and provides a potential avenue for gut microbiota-based prevention strategies for HRV colonization.

Poster 217: Changes in Dynamic Hip Muscle Moment Arms During Activities of Daily Living

Objectives: Hip muscle function is affected by surgical intervention and is of particular concern when considering post-operative rehabilitation of the joint1. However, little is known about the dynamic, in vivo function of the hip muscles during activities of daily living. Marker-based motion capture studies have associated dysplastic hip anatomy with shorter abductor moment arm lengths during walking2, but these measurements are complicated by soft tissue artifact3. Biplane radiography is a highly accurate technique for measuring in vivo bone motion of the hip4 and has recently been utilized to estimate dynamic muscle moment arms, which are important factors influencing force and torque capabilities. Previous research studies utilizing biplane radiography have identified shorter muscle lengths and moment arms in the implanted hip compared to the contralateral hip of individuals with total hip arthroplasty during the double support phase of gait2, but normative in vivo moment arms of the hip musculature in asymptomatic individuals have yet to be established. Further, it remains unknown how moment arms change between activities of daily living, particularly during deep flexion activities that challenge hip stability. Developing a normative dataset of dynamic in vivo moment arm lengths would provide a valuable reference for clinicians and physical therapists developing rehabilitation protocols to strengthen the hip musculature and increase stability. The objective of this study was to determine in vivo moment arms of the hip abductors, adductors, and external rotators during gait and squatting in a cohort of asymptomatic adults. We hypothesized that the maximum moment arm length during squatting would be longer than during walking and static standing. Methods: Young adults with no history of hip surgery, chronic hip pathology, or severe lower extremity musculoskeletal injury were recruited to participate in this IRB-approved study. Participants performed bodyweight squats and treadmill walking within a biplane radiography system while ground reaction forces were collected at 1000 Hz from a dual-belt instrumented treadmill. The support phase of gait was defined by vertical ground reaction forces over 50 N. Synchronized biplane radiographs were collected at 50 images per second to image three trials of each hip for each activity. Subject-specific bone models of the pelvis and proximal femur were created from computed tomography (CT) scans (average 0.37x0.3 mm in-plane resolution, 0.625mm slice thickness). Coordinate systems5 and muscle origin and insertion points for the gluteus medius (hip abductor), gluteus minimus (hip abductor), pectineus (hip adductor), and grouped external rotators1 were identified based upon bony landmarks on the 3D bone models (Figure 1). In-vivo bone motion during each activity was determined by matching digitally reconstructed radiographs, created from the CT-based bone models, to the biplane radiographs using a registration process with a validated accuracy4 of 0.3mm. The line of action for each muscle segment was determined for each frame of the biplane radiographs as the vector from the muscle origin to the insertion. Moment arm length (MAL) was calculated for each frame of the dynamic biplane radiographs as the perpendicular distance between the hip joint center (acetabulum center) and the line of action of each muscle1 and interpolated to gait cycle for walking or percent maximum hip flexion during squatting. Differences between the maximum MAL during static standing, walking, and squatting were assessed within each muscle group using ANOVA with post-hoc pairwise comparisons performed as necessary. Results: Data from 186 trials of 43 hips from 22 individuals were included in the analysis (9M, 13F; mean age 22.0±2.2years; BMI 21.3±5.2kg/m2). Average walking velocity was 1.0±0.2m/s and the average maximum hip flexion during squatting was 101.6±16.1°. Average static standing MAL was greatest in the gluteus medius and smallest in the pectineus (Table 1). Maximum MAL was significantly different between all activities for all muscle groups (all p&lt;0.001) (Table 1, Figure 2). Contrary to our hypothesis, moment arms of the abductors were smaller during squatting compared to other motions. Conclusions: This study demonstrates the in vivo torque generating capabilities of muscles surrounding the hip (reflected by their moment arm) change considerably from the standing position to positions encountered during active functional motions. Muscles involved in hip abduction and stabilization have less mechanical advantage at greater hip flexion, highlighting the importance of strengthening these muscle groups during rehabilitation. Specifically, moment arms of the hip abductors and external rotators are shorter during walking and squatting compared to standing, while moment arms of the adductors are shorter during walking and greater during squatting and standing. Knowledge of these postural changes in mechanical advantage can be useful when designing targeted rehabilitation protocols to strengthen the hip musculature and improve stability. Further research into relationships between dynamic in vivo hip muscle moment arms and lengths will yield additional insight into force and torque generating capacity of muscles during activities of daily living. These results are limited to treadmill walking and bodyweight squatting in asymptomatic young adults.

Early vascular ageing phenotypes and urinary targeted metabolomics in children and young adults: the ExAMIN Youth SA and African-PREDICT studies

Some individuals are susceptible to accelerated biological ageing, resulting in premature alterations in arterial structure and function. Identifying early-onset vascular ageing characterised by arterial stiffening is vital for intervention and preventive strategies. We stratified and phenotyped healthy children (5–9 yrs) and young adults (20–30 yrs) into their vascular ageing extremes established by carotid-femoral pulse wave velocity (cfPWV) percentiles (i.e., healthy vascular ageing (HVA) and early vascular ageing (EVA)). We compared anthropometric, cardiovascular, and metabolomic profiles and explored associations between cfPWV and urinary metabolites. Children and adults in the EVA groups displayed higher levels of adiposity, cardiovascular, and lifestyle risk factors (adults only) (all p ≤ 0.018). In adults, several urinary metabolites were lower in the EVA group (all q ≤ 0.039) when compared to the HVA group, with no differences observed in children. In multiple regression analysis (adults only), we found inverse associations between cfPWV with histidine (adj. R2 = 0.038; β = –0.192; p = 0.013) and beta-alanine (adj. R2 = 0.034; β = –0.181; p = 0.019) in the EVA group, but with arginine (adj. R2 = 0.021; β = –0.160; p = 0.024) in the HVA group. The inverse associations of beta-alanine and histidine with cfPWV in the EVA group is suggestive that asymptomatic young adults who present with an altered metabolomic and less desired cardiovascular profile in combination with unfavourable lifestyle behaviours may be predisposed to early-onset vascular ageing. Taken together, screening on both a phenotypic and metabolic level may prove important in the early detection, prevention, and intervention of advanced biological ageing.

Risk factors analysis and modeling prediction of non-alcoholic fatty liver disease in asymptomatic young adults

Risk factors analysis and modeling prediction of non-alcoholic fatty liver disease in asymptomatic young adults

Assessing the effects of sway-back posture on global and regional spinal sagittal angles using inertial measurement units.

Sway-back posture in the sagittal profile is a commonly adopted poor standing posture. Although the terms, definitions, and adverse health problems of sway-back posture are widely used clinically, few studies have quantified sway-back posture. To investigate spinal sagittal alignment in sway-back posture while standing based on global and regional angles using inertial measurement units (IMUs). This cross-sectional study recruited 30 asymptomatic young adults. After measuring the sway angle while standing, the participants were divided into sway-back and non-sway-back groups (normal thoracic group). Each participant stood in a comfortable posture for 5 seconds with IMUs at the T1, T7, T12, L3, and S2 levels. Then, we measured the global and regional lumbar and thoracic angles and sacral inclination in the standing position. Although there was no difference in the global lumbar angle, there was a difference in regional lumbar angles between the two groups. The normal thoracic group had balanced lumbar lordosis between the upper and lower lordotic arcs, whereas the sway back group tended to have a flat upper lumbar angle and increased lower lumbar angle. It is useful to assess the global and regional angles in the spinal sagittal assessment of individuals with sway-back posture.

Validation of dried blood spot sampling for detecting SARS-CoV-2 antibodies and total immunoglobulins in a large cohort of asymptomatic young adults

BackgroundDetecting antibody responses following infection with SARS-CoV-2 is necessary for sero-epidemiological studies and assessing the role of specific antibodies in disease, but serum or plasma sampling is not always viable due to logistical challenges. Dried blood spot sampling (DBS) is a cheaper, simpler alternative and samples can be self-collected and returned by post, reducing risk for SARS-CoV-2 exposure from direct patient contact. The value of large-scale DBS sampling for the assessment of serological responses to SARS-CoV-2 has not been assessed in depth and provides a model for examining the logistics of using this approach to other infectious diseases. The ability to measure specific antigens is attractive for remote outbreak situations where testing may be limited or for patients who require sampling after remote consultation. MethodsWe compared the performance of SARS-CoV-2 anti-spike and anti-nucleocapsid antibody detection from DBS samples with matched serum collected by venepuncture in a large population of asymptomatic young adults (N = 1070) living and working in congregate settings (military recruits, N = 625); university students, N = 445). We also compared the effect of self-sampling (ssDBS) with investigator-collected samples (labDBS) on assay performance, and the quantitative measurement of total IgA, IgG and IgM between DBS eluates and serum. ResultsBaseline seropositivity for anti-spike IgGAM antibody was significantly higher among university students than military recruits. Strong correlations were observed between matched DBS and serum samples in both university students and recruits for the anti-spike IgGAM assay. Minimal differences were found in results by ssDBS and labDBS and serum by Bland Altman and Cohen kappa analyses. LabDBS achieved 82.0% sensitivity and 98.2% specificity and ssDBS samples 86.1% sensitivity and 96.7% specificity for detecting anti-spike IgGAM antibodies relative to serum samples. For anti-SARS-CoV-2 nucleocapsid IgG there was qualitatively 100% agreement between serum and DBS samples and weak correlation in ratio measurements. Strong correlations were observed between serum and DBS-derived total IgG, IgA, and IgM. ConclusionsThis is the largest validation of DBS against paired serum for SARS-CoV-2 specific antibody measurement and we have shown that DBS retains performance from prior smaller studies. There were no significant differences regarding DBS collection methods, suggesting that self-collected samples are a viable sampling collection method. These data offer confidence that DBS can be employed more widely as an alternative to classical serology.

Does Forward Head Posture Influence Somatosensory Evoked Potentials and Somatosensory Processing in Asymptomatic Young Adults?

The current investigation used somatosensory evoked potentials (SEPs) to assess differences in sensorimotor integration and somatosensory processing variables between asymptomatic individuals with and without forward head posture (FHP). We assessed different neural regions of the somatosensory pathway, including the amplitudes of the peripheral N9, spinal N13, brainstem P14, peak-to-peak amplitudes of parietal N20 and P27, and frontal N30 potentials. Central conduction time (N13-N20) was measured as the difference in peak latencies of N13 and N20. We measured these variables in 60 participants with FHP defined as a craniovertebral angle (CVA) < 50° and 60 control participants matched for age, gender, and body mass index (BMI) with normal FHP defined as CVA > 55°. Differences in variable measures were examined using the parametric t-test. Pearson's correlation was used to evaluate the relationship between the CVA and sensorimotor integration and SEP measurements. A generalized linear model (GLM) was used to compare the SEP measures between groups, with adjustment for educational level, marital status, BMI, and working hours per week. There were statistically significant differences between the FHP group and control group for all sensorimotor integration and SEP processing variables, including the amplitudes of spinal N13 (p < 0.005), brainstem P14 (p < 0.005), peak-to-peak amplitudes of parietal N20 and P27 (p < 0.005), frontal N30 potentials (p < 0.005), and the conduction time N13-N20 (p = 0.004). The CVA significantly correlated with all measured neurophysiological variables indicating that as FHP increased, sensorimotor integration and SEP processing became less efficient. FHP group correlations were: N9 (r = -0.44, p < 0.001); N13 (r = -0.67, p < 0.001); P14 (r = -0.58, p < 0.001); N20 (r = -0.49, p = 0.001); P27 (r = -0.58, p < 0.001); N30 potentials (r = -0.64, p < 0.001); and N13-N20 (r = -0.61, p < 0.001). GLM identified that increased working hours adversely affected the SEP measures (p < 0.005), while each 1° increase in the CVA was associated with improved SEP amplitudes and more efficient central conduction time (N13-N20; p < 0.005). Less efficient sensorimotor integration and SEP processing may be related to previous scientific reports of altered sensorimotor control and athletic skill measures in populations with FHP. Future investigations should seek to replicate our findings in different spine disorders and symptomatic populations in an effort to understand how improving forward head posture might benefit functional outcomes of patient care.

Males and females have similar neuromuscular coordination strategies of the quadriceps during fatiguing repeated all-out cycling.

An imbalance of vastus medialis (VM) and vastus lateralis (VL) muscle activation and patterns of dyscoordination may contribute to the sex discrepancy in the incidence of patellofemoral pain syndrome (PFPS). While some studies have examined sex-specific VM/VL coordination strategies in some tasks, no previous studies have examined sex-specific VM/VL coordination strategies during repeated sprint exercise (RSE). In this study, asymptomatic young adults (N = 39, 19 females) completed a RSE protocol consisting of 10 × 10 s all-out cycling interspersed by 30 s of passive rest. Electromyographic (EMG) signals from the VM and VL muscles were recorded throughout exercise. VM:VL ratio did not change with fatigue and was not different between the sexes. From sprint 1 to 10, VM-VL onset delay increased from 9.62 to 16.95 ms and from 19.28 to 45.09 ms in males and females, respectively (p < 0.001); however, no sex difference was found (p = 0.524). Muscle activation amplitude plateaued at different sprint repetitions in males and females while mechanical work plateaued at similar repetitions. These findings suggest that sex differences in the incidence of PFPS may not be influenced by VM/VL muscle coordination as assessed by EMG.

Correlation Between the Simple Reaction Time and Cervical Proprioception in Asymptomatic Young Adults with Forward Head Posture (FHP): A Cross Sectional Study

Background: This study was designed to find the Correlation between the Simple Reaction Time and CervicalProprioception in asymptomatic young adults with Forward Head Posture (FHP).Purpose: To find the correlation between the Simple Reaction Time and Cervical Proprioception in asymptomaticyoung adults with Forward Head Posture (FHP).Materials and Methods: Materials required for this study were Body markers, Tripod stand, Laptop, ON Protractormobile application, Headband with laser beam device, Target with concentric circles, Deary-Liewald reaction timesoftware. It was a cross-sectional observational study design. The sampling method used was Purposive sampling.One Sixty subjects with Forward head posture (CVA= &lt;490) were included in this study. The written informedconsent was taken. Informed consent document was signed, retained by the principal investigator and a copywas given to the participant. Deary-Liewald Time task and Cervicocephalic Relocation test was used to study theSimple Reaction Time and Cervical Proprioception respectively. All the data obtained was statistically analysedusing proper tests.Results: The results showed no significant (p value &gt; 0.05) correlation of SRT with Cervical Rotation Proprioception,as the participants in our study were asymptomatic young adults with mean of 22.24±1.783years, had mild FHPand their scores on both the Simple Reaction Time and Cervical Proprioception tests were slightly above thenormal range.Conclusion: Our study concluded that there is no significant correlation of Cervical Proprioception with SimpleReaction Time in Asymptomatic Young Adults with Forward Head Posture.