Muscle quantity and function measurements are acceptable to older adults during and post- hospitalisation: results of a questionnaire-based study

BACKGROUND

To evaluate the acceptability of handgrip strength, gait speed, quadriceps ultrasound, and Bioelectrical Impedance Analysis (BIA) to older adults conducted during and following hospitalisation.

METHODS

Questionnaire-based study conducted upon completion of prospective cohort study, with follow-up in either Queen Elizabeth Hospital Birmingham (QEHB), UK, or participant's own home following recent admission to QEHB. Outcome measures were acceptability as defined by total multi-domain score for each test (maximum score 35), and by frailty status.

RESULTS

Forty adults aged 70 years and older admitted for emergency abdominal surgery, elective colorectal surgery, or acute bacterial infections (general medicine) participated. Handgrip strength (median 33, IQR 30-35; p = 0.001), gait speed (median 32, IQR 30-35; p = 0.002), ultrasound quadriceps (median 33, IQR 31-35; p = 0.001), and BIA (median 33.5, IQR 31-35; p = 0.001) were considered highly acceptable. Participants responded positively that they enjoyed participating in these tests, and considered these tests of importance. There was no difference in scores between tests (p = 0.166). Individual total test scores did not differ between patients with and without frailty. Qualitative data are also presented on drivers for research participation.

CONCLUSIONS

Handgrip strength, gait speed, ultrasound quadriceps, and BIA are acceptable tests to older adults during and following hospitalisation. Our results may serve as standards when evaluating acceptability of other tests.

TRIAL REGISTRATION

Prospectively registered February 2019: https://clinicaltrials.gov/ct2/show/NCT03858192.

The interplay between spatial and heliconical orientational order in twist-bend nematic materials

The helical pitch formed by organic molecules, such as the α-helix of proteins, usually requires hydrogen bonding between chiral units and long-range positional order. It was recently found that certain liquid crystal oligomers can have a twist-bend nematic (NTB) phase with nanoscale heliconical structure without hydrogen bonding, molecular chirality or positional order. To understand the nature of this unique structure, here we present hard and resonant tender X-ray scattering studies of two novel sulfur containing dimer materials. We simultaneously measure the temperature dependences of the helical pitch and the correlation length of both the helical and positional order. In addition to an unexpected strong variation of the pitch with the length of the spacer connecting the monomer units, we find that at the transition to the NTB phase the positional correlation length drops. The helical structure was found not only in the NTB phase but observed even in the upper range of a smectic phase that forms just below the NTB state. The coexistence of smectic layering and the heliconical order indicates a layered (SmATB) phase wherein the rigid units of the dimers are tilted with respect to the smectic layer normal in order to accommodate the bent conformation of the dimers and the tilt direction rotates along the heliconical axis.

Probable delirium is a presenting symptom of COVID-19 in frail, older adults: a cohort study of 322 hospitalised and 535 community-based older adults

BACKGROUND

Frailty, increased vulnerability to physiological stressors, is associated with adverse outcomes. COVID-19 exhibits a more severe disease course in older, comorbid adults. Awareness of atypical presentations is critical to facilitate early identification.

OBJECTIVE

To assess how frailty affects presenting COVID-19 symptoms in older adults.

DESIGN

Observational cohort study of hospitalised older patients and self-report data for community-based older adults.

SETTING

Admissions to St Thomas' Hospital, London with laboratory-confirmed COVID-19. Community-based data for older adults using the COVID Symptom Study mobile application.

SUBJECTS

Hospital cohort: patients aged 65 and over (n = 322); unscheduled hospital admission between 1 March 2020 and 5 May 2020; COVID-19 confirmed by RT-PCR of nasopharyngeal swab. Community-based cohort: participants aged 65 and over enrolled in the COVID Symptom Study (n = 535); reported test-positive for COVID-19 from 24 March (application launch) to 8 May 2020.

METHODS

Multivariable logistic regression analysis performed on age-matched samples from hospital and community-based cohorts to ascertain association of frailty with symptoms of confirmed COVID-19.

RESULTS

Hospital cohort: significantly higher prevalence of probable delirium in the frail sample, with no difference in fever or cough. Community-based cohort: significantly higher prevalence of possible delirium in frailer, older adults and fatigue and shortness of breath.

CONCLUSIONS

This is the first study demonstrating higher prevalence of probable delirium as a COVID-19 symptom in older adults with frailty compared to other older adults. This emphasises need for systematic frailty assessment and screening for delirium in acutely ill older patients in hospital and community settings. Clinicians should suspect COVID-19 in frail adults with delirium.

Effect of position and exercise on measurement of muscle quantity and quality: towards a standardised pragmatic protocol for clinical practice

BACKGROUND

Ultrasonography is an emerging non-invasive bedside tool for muscle quantity/quality assessment; Bioelectrical Impedance Analysis (BIA) is an alternative non-invasive bedside measure of body composition, recommended for evaluation of sarcopenia in clinical practice. We set out to assess impact of position and exercise upon measures towards protocol standardisation.

METHODS

Healthy volunteers aged 18-35 were recruited. Bilateral Anterior Thigh Thickness (BATT; rectus femoris and vastus intermedius), BATT: Subcutaneous Ratio (BATT:SCR), and rectus femoris echogenicity were measured using ultrasound and BIA was performed; 1) lying with upper body at 45° (Reclined), 2) lying fully supine at 180o (Supine), 3) sat in a chair with upper body at 90o (Sitting), and 4) after exercise Reclined. Variability of Skeletal Muscle Mass (SMM) by two different equations from BIA (SMM-Janssen, SMM-Sergi), phase angle, fat percentage, and total body (TBW), extracellular (ECW), and intracellular water (ICW) were assessed.

RESULTS

Forty-four participants (52% female; mean 25.7 years-old (SD 5.0)) were recruited. BATT increased from Reclined to Sitting (+ 1.45 cm, 1.27-1.63), and after exercise (+ 0.51, 0.29-0.73). Echogenicity reduced from Reclined to Sitting (- 2.1, - 3.9 - -0.26). SMM-Sergi declined from Reclined to Supine (- 0.65 kg, - 1.08 - - 0.23) and after exercise (- 0.70 kg, - 1.27 - -0.14). ECW increased from Reclined to Sitting (+ 1.19 L, 0.04-2.35). There were no other statistically significant changes.

CONCLUSION

Standardisation of protocols is especially important for assessment of muscle quantity by ultrasonography; BIA measurements may also vary dependent on the equations used. Where possible, participants should be rested prior to muscle ultrasonography and BIA, and flexion of the knees should be avoided.

The endocrinology of sarcopenia and frailty

Sarcopenia describes low muscle mass and strength associated with ageing, whilst reduced physical performance indicates the severity of the condition. It can happen independently of other medical conditions and can be a key feature of the frailty phenotype. Frailty is a syndrome of increased vulnerability to incomplete resolution of homeostasis, following a stressor event. Researchers have described the implications of hypothalamic pituitary dysregulation in the pathogenesis of both entities. This review summarizes the recent evidence in this area as well as other endocrine factors such as insulin resistance and vitamin D status and outlines current research priorities. We conducted searches to PubMed and Embase databases for articles, reviews and studies reporting new data on the interaction between hormones of the endocrine system and frailty and/ or sarcopenia in the last 5 years. Interventional studies, cohort studies, case-control studies and animal studies were included. Clinical trials register was also searched to identify ongoing relevant studies. Studies have given us insights into the complex relationships between factors such as anabolic hormones, glucocorticoids and vitamin D on muscle strength and performance and their involvement in ageing phenotypes. However, robust randomized controlled trials are needed to consolidate existing evidence in humans and inform clinical practice. Current evidence supports hormone replacement in patients with confirmed deficiencies, to optimize health and prevent complications. Hormone replacement has limited use for age-related conditions. Current interest is focused on muscle/bone/fat interactions and health outcomes in "sarcopenic obesity." A life-course approach to improving 'health-span' is advocated. Lifestyle factors such as nutrition and physical activity have important interactions with body composition, physical function and metabolic outcomes. Large-scale clinical trials will determine the efficacy and long-term safety of hormone supplementation in the management of sarcopenia and frailty.

The endocrinology of sarcopenia and frailty

INTRODUCTION

Sarcopenia describes low muscle mass and strength associated with ageing, whilst reduced physical performance indicates the severity of the condition. It can happen independently of other medical conditions and can be a key feature of the frailty phenotype. Frailty is a syndrome of increased vulnerability to incomplete resolution of homeostasis, following a stressor event. Researchers have described the implications of hypothalamic pituitary dysregulation in the pathogenesis of both entities. This review summarises the recent evidence in this area as well as other endocrine factors such as insulin resistance and vitamin D status and outlines current research priorities.

EVIDENCE ACQUISITION

We conducted searches to PubMed and Embase databases for articles, reviews and studies reporting new data on the interaction between hormones of the endocrine system and frailty and/ or sarcopenia in the last 5 years. Interventional studies, cohort studies, case-control studies and animal studies were included. Clinical trials register was also searched to identify ongoing relevant studies.

EVIDENCE SYNTHESIS

Studies have given us insights into the complex relationships between factors such as anabolic hormones, glucocorticoids and vitamin D on muscle strength and performance and their involvement in ageing phenotypes. However, robust randomised controlled trials are needed to consolidate existing evidence in humans and inform clinical practice. Current evidence supports hormone replacement in patients with confirmed deficiencies, to optimise health and prevent complications. Hormone replacement has limited use for age-related conditions. Current interest is focused on muscle/bone/fat interactions and health outcomes in 'sarcopenic obesity'.

CONCLUSIONS

A life-course approach to improving 'health-span' is advocated. Lifestyle factors such as nutrition and physical activity have important interactions with body composition, physical function and metabolic outcomes. Large-scale clinical trials will determine the efficacy and long-term safety of hormone supplementation in the management of sarcopenia and frailty.

Exposure to bisphenol A differentially impacts neurodevelopment and behavior in Drosophila melanogaster from distinct genetic backgrounds

Bisphenol A (BPA) is a ubiquitous environmental chemical that has been linked to behavioral differences in children and shown to impact critical neurodevelopmental processes in animal models. Though data is emerging, we still have an incomplete picture of how BPA disrupts neurodevelopment; in particular, how its impacts may vary across different genetic backgrounds. Given the genetic tractability of Drosophila melanogaster, they present a valuable model to address this question. Fruit flies are increasingly being used for assessment of neurotoxicants because of their relatively simple brain structure and variety of measurable behaviors. Here we investigated the neurodevelopmental impacts of BPA across two genetic strains of Drosophila-w¹¹¹⁸ (control) and the Fragile X Syndrome (FXS) model-by examining both behavioral and neuronal phenotypes. We show that BPA induces hyperactivity in larvae, increases repetitive grooming behavior in adults, reduces courtship behavior, impairs axon guidance in the mushroom body, and disrupts neural stem cell development in the w¹¹¹⁸ genetic strain. Remarkably, for every behavioral and neuronal phenotype examined, the impact of BPA in FXS flies was either insignificant or contrasted with the phenotypes observed in the w¹¹¹⁸ strain. This data indicates that the neurodevelopmental impacts of BPA can vary widely depending on genetic background and suggests BPA may elicit a gene-environment interaction with Drosophila fragile X mental retardation 1 (dFmr1)-the ortholog of human FMR1, which causes Fragile X Syndrome and is associated with autism spectrum disorder.

COVID-19 and Acute Sarcopenia

The COVID-19 pandemic has had a devastating global impact, with older adults being most at risk of death from the disease. However, acute sarcopenia occurs in survivors of COVID-19; older adults and the most critically unwell patients are the most at risk. Acute sarcopenia is an under-recognised condition of acute muscle insufficiency, defined by declines in muscle function and/or quantity within six months, usually following a stressor event. This commentary reviews definition and mechanisms of acute sarcopenia in COVID-19 and suggests recommendations for research and clinical practice. Research should now focus on the longer-term consequences of acute sarcopenia in patients who have suffered from COVID-19. At the same time, clinicians need to be increasingly aware of the condition, and measurements of muscle strength, quantity, and physical performance should be embedded into clinical practice. Clinicians should consider the risks of acute sarcopenia when weighing up the risks and benefits of treatment (e.g. dexamethasone), and instigate multidisciplinary treatment including dietetics input.

Decision-making for older patients undergoing emergency laparotomy: defining patient and clinician values and priorities

AIM

There remains limited knowledge on what patients value and prioritize in their decision to undergo emergency laparotomy (ELap) and during their subsequent recovery. The aim of this study was to explore factors in decision-making and to reach a consensus amongst patients on the 10 most important priorities in decision-making in ELap.

METHODS

Patients aged over 65 years who had required an ELap decision within the preceding 12 months (regardless of management) were identified and invited to attend a modified Delphi process focus group.

RESULTS

A total of 20 participants attended: eight patients, four relatives and eight perioperative specialists. The perioperative specialists group defined 12 important factors for perioperative decision-making. The patient group agreed that only six (50%) of these factors were important: independence, postoperative complications, readmission to hospital, requirement for stoma formation, delirium (including long-term cognition) and presence of an advocate (such as a friend or family member). Open discussion refined multiple themes. Agreement was reached by patients and relatives about 10 factors that they valued as most important in their ELap patient journey: return to independence, realistic expectations, postoperative complications, what to expect postoperatively, readmission to hospital, nutrition, postoperative communication, stoma, follow-up and delirium.

CONCLUSION

Patients and clinicians have different values and priorities when discussing the risks and implications of undergoing ELap. Patients value quality of life outcomes, in particular, the formation of a stoma, returning to their own home and remaining independent. This work is the first to combine both perspectives to guide future ELap research outcomes.

Growing research in geriatric medicine: a trainee perspective

Growing research in geriatric medicine is a priority area. Currently, involvement of geriatricians in research lags behind other specialties. The reasons for this are multifactorial, but a lack of training infrastructure within geriatric medicine higher specialist training is contributory. This is widespread across European countries and internationally. The Geriatric Medicine Research Collaborative (GeMRC) offers an opportunity to engage trainees in research, regardless of their previous individual research experiences. Utilising national trainee networks, GeMRC is able to conduct large-scale projects within short periods of time that can have real impact upon patient care. We consider that embedding GeMRC within higher specialist training with formal college support will assist to upskill trainee geriatricians in research methodology. Collaboratives are internationally recognised across disciplines. Expansion across European and international countries offers the opportunity for international collaboration in geriatric medicine. International trainee-led networks will enable the conduct of large-scale global projects in geriatric medicine.

Protocol for understanding acute sarcopenia: a cohort study to characterise changes in muscle quantity and physical function in older adults following hospitalisation

BACKGROUND

Older adults are vulnerable to the effects of acute sarcopenia (acute muscle insufficiency) following hospitalisation. However, this condition remains poorly characterised to date. It is hypothesised that acute sarcopenia arises due to a combination of bed rest and inflammatory surge. This study aims to characterise changes in muscle quantity and function, determining which factors (clinical and biological) are most predictive, and how these relate to change in physical function at 13 weeks.

METHODS

This study will include three groups of patients aged 70 years and older; patients undergoing elective colorectal surgery, patients admitted for emergency abdominal surgery, and patients admitted under general medicine with acute bacterial infections. Changes in muscle quantity (Bilateral Anterior Thigh Thickness with ultrasound and bioelectrical impedance analysis) and muscle function (muscle strength, physical performance) within 1 week of hospitalisation or surgery will be characterised, with follow-up of patients at 13 weeks. Physical function will be measured using the Patient Reported Outcome Measures Information System, and the Short Physical Performance Battery (or gait speed alone within 1 week of surgery).

DISCUSSION

This study will fully characterise changes in muscle quantity and function in hospitalised older adults and enable risk stratification towards targeted interventions in clinical practice. The results of this study will inform further research involving interventions to ameliorate changes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03858192 ; Prospectively registered 28th February 2019.

Stochastic Methods for Inferring States of Cell Migration

Cell migration refers to the ability of cells to translocate across a substrate or through a matrix. To achieve net movement requires spatiotemporal regulation of the actin cytoskeleton. Computational approaches are necessary to identify and quantify the regulatory mechanisms that generate directed cell movement. To address this need, we developed computational tools, based on stochastic modeling, to analyze time series data for the position of randomly migrating cells. Our approach allows parameters that characterize cell movement to be efficiently estimated from cell track data. We applied our methods to analyze the random migration of Mouse Embryonic Fibroblasts (MEFS) and HeLa cells. Our analysis revealed that MEFs exist in two distinct states of migration characterized by differences in cell speed and persistence, whereas HeLa cells only exhibit a single state. Further analysis revealed that the Rho-family GTPase RhoG plays a role in determining the properties of the two migratory states of MEFs. An important feature of our computational approach is that it provides a method for predicting the current migration state of an individual cell from time series data. Finally, we applied our computational methods to HeLa cells expressing a Rac1 biosensor. The Rac1 biosensor is known to perturb movement when expressed at overly high concentrations; at these expression levels the HeLa cells showed two migratory states, which correlated with differences in the spatial distribution of active Rac1.

Dielectric response of electric-field distortions of the twist-bend nematic phase for LC dimers

Wide band dielectric spectroscopy of bent-shaped achiral liquid-crystal dimers 1″-n″-bis(4-cyanobiphenyl-4'-yl) n-alkanes (CBnCB n = 7, 9, 11) has been investigated in a frequency range 0.1 Hz-100 MHz using planar-aligned cells of sample thicknesses ranging from 2 to 10 (μm) over a temperature range that covers both nematic and twist bend nematic phases. Two peaks in the dielectric spectrum in the higher frequency range are assigned to the molecular relaxation processes. The peak at the highest frequency, ∼40 to 80 MHz, is assigned to an internal precessional rotation of a single unit of the dimer around the director. The mode in the next lower frequency range of 2-10 MHz is assigned to the spinning rotation of the dimer around its long axis. This involves fluctuations of the dipole moment of the bent-shaped conformation that is directed along its arrow direction of the bow shape formed by the dimer. The peak in the frequency range 100 kHz-1 MHz can be assigned to the collective fluctuations of the local director with reference to the helical axis of the N_TB structure. The dependence of its frequency on temperature is reminiscent of the soft mode observed at the SmA^* to SmC^* phase transition. This result clearly corresponds to the electro-clinic effect-the response of the director to the applied electric field in an electro-optic experiment. The lowest frequency mode, observed in the frequency range of 0.1 Hz-100 Hz, is identified with the Goldstone mode. This mode is concerned with the long range azimuthal angle fluctuations of the local director. This leads to an alternating compression and expansion of the periodic structure of the N_TB phase.

Geriatric medicine and old age psychiatry joint training pre-feasibility pilot study: an innovative approach to collaborative postgraduate training

BACKGROUND

Physical and psychological health problems are prevalent in older adults and rarely exist in isolation. Treating these problems in isolation is resourceful and can be potentially harmful to patients due to delays in diagnosis and treatment and incomplete holistic care plans. Historically, trainees in geriatric medicine and old age psychiatry within the United Kingdom have completed very different training programmes.

METHODS

We undertook a pre-feasibility pilot study of collaborative postgraduate training between trainees in geriatric medicine and old age psychiatry within the West Midlands training region, United Kingdom. Trainees in each specialty were paired with each other and advised to arrange appropriate training opportunities for their counterpart; these included shadowing each other in their workplace and arranging opportunities to attend training opportunities with their consultants. Pre- and post-pilot surveys were completed by all trainees and reflections from trainees were collated.

RESULTS

Five trainee pairs were formed and arranged shadowing and training opportunities between October 2017 and May 2018. This included a combination of inpatient, outpatient, and community work. For both specialties, trainees' confidence in topics relating to their counterparts' specialty increased between the pre- and post-pilot surveys. Recurrent themes included within reflections included the benefits of collaborative training.

CONCLUSIONS

Our pilot has demonstrated that it is feasible to implement a programme of joint training into postgraduate medical training, and that this can have a positive impact upon the confidence of both specialties. An extended pilot is planned for the training year 2018-2019.

A pilot observational study measuring acute sarcopenia in older colorectal surgery patients

OBJECTIVE

To explore variability in acute changes in muscle mass and function in older patients undergoing elective colorectal surgery, as well as feasibility of measures, in order to refine study processes to inform the protocol for a larger study.

RESULTS

Results are presented for seven participants recruited to this pilot study. It is possible to perform serial measurements of bilateral anterior thigh thickness (BATT) and handgrip strength prior to, within 24 h of surgery, and 1 week postoperatively. Gait speed can be reliably measured preoperatively and at 1 week postoperatively. In this pilot study, BATT and gait speed declined at 1 week postoperatively (median BATT 4.17 cm, 3.47 cm, p = 0.028; median gait speed 0.89 m/s, 0.83 m/s, p = 0.043). Baseline hsCRP correlated with change in BATT (τb = 0.73, p = 0.04) and baseline DHEA-S correlated with change in gait speed (τb = 0.87, p = 0.02). This pilot study has assisted to refine the protocol for our larger study, which will further characterise these changes.

Soft modes of the dielectric response in the twist–bend nematic phase and identification of the transition to a nematic splay bend phase in the CBC7CB dimer

Two collective processes resulting from distortion of the heliconical structure of the twist–bend nematic phase of an achiral dimer: one tilt mode due to distortions of the conical angle and second related to long range fluctuation of the cone phase.

Can delirium research activity impact on routine delirium recognition? A prospective cohort study

OBJECTIVE

To assess if ongoing delirium research activity within an acute admissions unit impacts on prevalent delirium recognition.

DESIGN

Prospective cohort study.

SETTING

Single-site tertiary university teaching hospital.

PARTICIPANTS

125 patients with delirium, as diagnosed by an expert using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition reference criteria, were recruited to a prospective cohort study investigating use of informant tools to detect unrecognised dementia. This study evaluated recognition of delirium and documentation of delirium by medical staff.

INTERVENTIONS

The main study followed an observational design; the intervention discussed was the implementation of this study itself.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was recognition of delirium by the admitting medical team prior to study diagnosis. Secondary outcomes included recording of or description of delirium in discharge summaries, and factors which may be associated with unrecognised delirium.

RESULTS

Delirium recognition improved between the first half (48%) and second half (71%) of recruitment (p=0.01). There was no difference in recording of delirium or description of delirium in the text of discharge summaries.

CONCLUSION

Delirium research activity can improve recognition of delirium. This has the potential to improve patient outcomes.