Skeletal Muscle Texture Assessment Using Ultrasonography: Comparison with Magnetic Resonance Imaging in Chronic Kidney Disease.

Skeletal muscle dysfunction is common in chronic kidney disease (CKD). Of interest is the concept of "muscle quality," of which measures include ultrasound-derived echo intensity (EI). Alternative parameters of muscle texture, for example, gray level of co-occurrence matrix (GCLM), are available and may circumvent limitations in EI. The validity of EI is limited in humans, particularly in chronic diseases. This study aimed to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Images of the thigh were acquired using a 3 Tesla MRI scanner. Quantification of muscle (contractile), fat (non-contractile), and miscellaneous (connective tissue, fascia) components were estimated. Anatomical rectus femoris cross-sectional area was measured using B-mode 2D ultrasonography. To assess muscle texture, first (i.e., EI)- and second (i.e., GLCM)-order statistical analyses were performed. Fourteen participants with CKD were included (age: 58.0 ± 11.9 years, 50% male, eGFR: 27.0 ± 7.4 ml/min/1.73m2, 55% Stage 4). Higher EI was associated with lower muscle % (quadriceps: ß = -.568, p = .034; hamstrings: ß = -.644, p = .010). Higher EI was associated with a higher fat % in the hamstrings (ß = -.626, p = .017). A higher angular second moment from GLCM analysis was associated with greater muscle % (ß = .570, p = .033) and lower fat % (ß = -.534, p = .049). A higher inverse difference moment was associated with greater muscle % (ß = .610, p = .021 and lower fat % (ß = -.599, p = .024). This is the first study to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Our preliminary findings suggest ultrasound-derived texture analysis provides a novel indicator of reduced skeletal muscle % and thus increased intramuscular fat.

Characteristics of effective home-based resistance training in patients with noncommunicable chronic diseases: a systematic scoping review of randomised controlled trials.

Skeletal muscle atrophy, dysfunction, and weakness are consequences of noncommunicable diseases which result in exercise and functional limitations which contribute to poor quality of life and increased mortality. Home-based resistance training may promote skeletal muscle health. Electronic-based systematic searches were performed identifying randomised controlled trials utilising home-based resistance training in patients with noncommunicable diseases defined as cancer, cardiovascular disease, diabetes mellitus (type 1 and 2), chronic kidney disease (including dialysis), and chronic respiratory disease (asthma, chronic obstructive pulmonary disease, pulmonary hypertension). A comparator group was defined as one containing "non-exercise" or "usual care". Of the 239 studies identified (published between 1996 and 2020), 22 met the inclusion criteria. Sixteen studies contained an adjunct aerobic training component. Study designs and outcome measures showed large variation. Reporting of the principles of training applied within interventions was poor. Heterogeneity in study characteristics, and poor reporting of training characteristics, prevents formal recommendations for optimising home-based resistance training. However, home-based interventions are less resource-intensive than supervised programmes and appear to have the ability to improve or preserve pertinent outcomes such as strength, functional ability, and quality of life; potentially reducing the risk of mortality in patients with chronic disease.

The reliability and feasibility of non-contrast adenosine stress cardiovascular magnetic resonance T1 mapping in patients on haemodialysis.

BACKGROUND: Identifying coronary artery disease (CAD) in patients with end-stage renal disease (ESRD) is challenging. Adenosine stress native T1 mapping with cardiovascular magnetic resonance (CMR) may accurately detect obstructive CAD and microvascular dysfunction in the general population. This study assessed the feasibility and reliability of adenosine stress native T1 mapping in patients on haemodialysis. METHODS: The feasibility of undertaking rest and adenosine stress native T1 mapping using the single-shot Modified Look-Locker inversion recovery (MOLLI) sequence was assessed in 58 patients on maintenance haemodialysis using 3 T CMR. Ten patients underwent repeat stress CMR within 2 weeks for assessment of test-retest reliability of native T1, stress T1 and delta T1 (ΔT1). Interrater and intrarater agreement were assessed in 10 patients. Exploratory analyses were undertaken to assess associations between clinical variables and native T1 values in 51 patients on haemodialysis. RESULTS: Mean age of participants was 55 ± 15 years, 46 (79%) were male, and median dialysis vintage was 21 (8; 48) months. All patients completed the scan without complications. Mean native T1 rest, stress and ΔT1 were 1261 ± 57 ms, 1297 ± 50 ms and 2.9 ± 2.5%, respectively. Interrater and intrarater agreement of rest T1, stress T1 and ΔT1 were excellent, with intraclass correlation coefficients (ICC) > 0.9 for all. Test-retest reliability of rest and stress native T1 were excellent or good (CoV 1.2 and 1.5%; ICC, 0.79 and 0.69, respectively). Test-retest reliability of ΔT1 was moderate to poor (CoV 27.4%, ICC 0.55). On multivariate analysis, CAD, diabetes mellitus and resting native T1 time were independent determinants of ΔT1 (ß = - 0.275, p = 0.019; ß = - 0.297, p = 0.013; ß = - 0.455; p < 0.001, respectively). CONCLUSIONS: Rest and adenosine stress native T1 mapping is feasible and well-tolerated amongst patients with ESRD on haemodialysis. Although rater agreement of the technique is excellent, test-retest reliability of ΔT1 is moderate to poor. Prospective studies should evaluate the relationship between this technique and established methods of CAD assessment and association with outcomes.

What to do with foundation therapies for heart failure for patients with end-stage kidney disease on haemodialysis.

There is a significant burden of cardiovascular disease morbidity and mortality in the end-stage kidney disease population, driven by traditional and non-traditional risk factors. Despite its prevalence, heart failure is difficult to diagnose in the dialysis population due to overlapping clinical presentations, limitations of investigations, and the impact on the cardiorenal axis. 'Foundation therapies' are the key medications which improve patient outcomes in heart failure with reduced ejection fraction and include beta-blockers, renin-angiotensin-aldosterone system inhibitors and sodium-glucose cotransporter-2 inhibitors. They are underutilised in the dialysis population due to the exclusion of chronic kidney disease patients from major trials and legitimate clinical concerns e.g. hyperkalaemia, intradialytic hypotension and residual kidney function preservation. A coordinated cardiorenal multidisciplinary approach can guide appropriate diagnostic considerations (biomarkers interpretation, imaging, addressing unique complications of kidney disease), optimise dialysis management (prescription length, frequency and ultrafiltration targets) and when at euvolaemia facilitate the stepwise introduction of appropriate foundation therapies.

Impact of changing medical workforce demographics in renal medicine over 7 years: Analysis of GMC national trainee survey data.

Increasing numbers of doctors in training are taking career breaks, with burnout cited as a potential cause. This study analysed General Medical Council (GMC) national training survey data (renal medicine) to understand the impacts of changing workforce demographics on trainee outcomes and wellbeing. Increasing proportions of female, Black, Asian and minority ethnic (BAME), and international medical graduates are entering the workforce. Specialty exam pass rates have fallen and are lower for BAME and international medical graduates in renal medicine. Time to complete higher specialty training has increased for female trainees. Self-reported burnout rates for renal trainees were higher than other medical specialties and highest for male BAME trainees. Burnout was only partially mitigated by less-than-full-time working, but had no impact on progression, sick-leave or time out of training. It is important to recognise changes to the workforce and proactively plan to effectively support a more diverse group of trainees, to enable them to succeed and reduce differential attainment.

A pilot randomised controlled trial of a structured, home-based exercise programme on cardiovascular structure and function in kidney transplant recipients: the ECSERT study design and methods.

BACKGROUND: Cardiovascular disease (CVD) is a major cause of morbidity and mortality in kidney transplant recipients (KTRs). CVD risk scores underestimate risk in this population as CVD is driven by clustering of traditional and non-traditional risk factors, which lead to prognostic pathological changes in cardiovascular structure and function. While exercise may mitigate CVD in this population, evidence is limited, and physical activity levels and patient activation towards exercise and self-management are low. This pilot study will assess the feasibility of delivering a structured, home-based exercise intervention in a population of KTRs at increased cardiometabolic risk and evaluate the putative effects on cardiovascular structural and functional changes, cardiorespiratory fitness, quality of life, patient activation, healthcare utilisation and engagement with the prescribed exercise programme. METHODS AND ANALYSIS: Fifty KTRs will be randomised 1:1 to: (1) the intervention; a 12week, home-based combined resistance and aerobic exercise intervention; or (2) the control; usual care. Intervention participants will have one introductory session for instruction and practice of the recommended exercises prior to receiving an exercise diary, dumbbells, resistance bands and access to instructional videos. The study will evaluate the feasibility of recruitment, randomisation, retention, assessment procedures and the intervention implementation. Outcomes, to be assessed prior to randomisation and postintervention, include: cardiac structure and function with stress perfusion cardiac MRI, cardiorespiratory fitness, physical function, blood biomarkers of cardiometabolic health, quality of life and patient activation. These data will be used to inform the power calculations for future definitive trials. ETHICS AND DISSEMINATION: The protocol was reviewed and given favourable opinion by the East Midlands-Nottingham 2 Research Ethics Committee (reference: 19/EM/0209; 14 October 2019). Results will be published in peer-reviewed academic journals and will be disseminated to the patient and public community via social media, newsletter articles and presentations at conferences. TRIAL REGISTRATION NUMBER: NCT04123951.