Promoting physical activity and physical function in people with long-term conditions in primary care: the Function First realist synthesis with co-design

Background

As people age and accumulate long-term conditions, their physical activity and physical function declines, resulting in disability and loss of independence. Primary care is well placed to empower individuals and communities to reduce this decline; however, the best approach is uncertain.

Objectives

To develop a programme theory to explain the mechanisms through which interventions improve physical activity and physical function in people with long-term conditions in different primary care contexts, and to co-design a prototype intervention.

Data sources

Systematic literature searches of relevant databases with forwards and backwards citation tracking, grey literature searches and further purposive searches were conducted. Qualitative data were collected through workshops and interviews.

Design

Realist evidence synthesis and co-design for primary care service innovation.

Setting

Primary care in Wales and England.

Participants

Stakeholders included people with long-term conditions, primary care professionals, people working in relevant community roles and researchers.

Methods

The realist evidence synthesis combined evidence from varied sources of literature with the views, experiences and ideas of stakeholders. The resulting context, mechanism and outcome statements informed three co-design workshops and a knowledge mobilisation workshop for primary care service innovation.

Results

Five context, mechanism and outcome statements were developed. (1) Improving physical activity and function is not prioritised in primary care (context). If the practice team culture is aligned to the elements of physical literacy (mechanism), then physical activity promotion will become routine and embedded in usual care (outcome). (2) Physical activity promotion is inconsistent and unco-ordinated (context). If specific resources are allocated to physical activity promotion (in combination with a supportive practice culture) (mechanism), then this will improve opportunities to change behaviour (outcome). (3) People with long-term conditions have varying levels of physical function and physical activity, varying attitudes to physical activity and differing access to local resources that enable physical activity (context). If physical activity promotion is adapted to individual needs, preferences and local resources (mechanism), then this will facilitate a sustained improvement in physical activity (outcome). (4) Many primary care practice staff lack the knowledge and confidence to promote physical activity (context). If staff develop an improved sense of capability through education and training (mechanism), then they will increase their engagement with physical activity promotion (outcome). (5) If a programme is credible with patients and professionals (context), then trust and confidence in the programme will develop (mechanism) and more patients and professionals will engage with the programme (outcome). A prototype multicomponent intervention was developed. This consisted of resources to nurture a culture of physical literacy, materials to develop the role of a credible professional who can promote physical activity using a directory of local opportunities and resources to assist with individual behaviour change.

Limitations

Realist synthesis and co-design is about what works in which contexts, so these resources and practice implications will need to be modified for different primary care contexts.

Conclusions

We developed a programme theory to explain how physical activity could be promoted in primary care in people with long-term conditions, which informed a prototype intervention.

Future work

A future research programme could further develop the prototype multicomponent intervention and assess its acceptability in practice alongside existing schemes before it is tested in a feasibility study to inform a future randomised controlled trial.

Study registration

This study is registered as PROSPERO CRD42018103027.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 16. See the NIHR Journals Library website for further project information.

Muscle loss following a single high-dose intramuscular injection of corticosteroids to treat disease flare in patients with rheumatoid arthritis

OBJECTIVE

Adverse changes in body composition, specifically decreased muscle mass (MM) and increased fat mass, characterize rheumatoid arthritis (RA). These changes, termed rheumatoid cachexia (RC), are important contributors to the disability and elevated co-morbidity risk of RA. Recently, we observed substantial muscle loss (~2 kg) in a patient with RA following a single intramuscular (IM) corticosteroid (CS) injection to treat a disease flare. The aim of the current study is to determine whether this apparent iatrogenic effect of IM CS is typical, i.e., does this routine, recommended treatment contribute to RC?

METHODS

Body composition was assessed by dual-energy X-ray absorptiometry (DXA) in eight patients with established RA who received a 120 mg IM methylprednisolone injection to treat a disease flare. DXA scans estimated appendicular lean mass (ALM; a surrogate measure of MM), total lean mass (LM), and total and regional adiposity at baseline (injection day) and 4 weeks and 6-9 months post-injection. Statistical analysis was performed using one-way ANOVA.

RESULTS

There was significant loss of ALM (-0.93 kg, p=0.001, 95% CI [-0.49, -1.36]) and a trend toward reduced LM (-1.10 kg, p=0.165, 95% CI [0.58, -2.79]) at 4 weeks relative to baseline. At 6-9 months despite control of inflammation and disease activity, these losses remained.

CONCLUSION

Substantial muscle loss occurred in patients with RA following IM CS injection to treat a disease flare. Thus, this recommended treatment appears to exacerbate RC, thereby potentially increasing disability and co-morbidity risk. If this effect is confirmed by larger studies, the role of one-off high-dose CS in the treatment of RA should be reviewed.

The 8-foot up and go test is the best way to assess physical function in the rheumatoid arthritis clinic

Objectives

RA is characterized by poor physical function, which compromises patients’ quality of life and outcome. Clinical assessment of function is usually performed using self-reported questionnaires, such as the Multi-Dimensional HAQ (MDHAQ) and the Short Form-36 (physical component) (SF36-PC). However, such subjective measures may not accurately reflect real functional status. This study aimed to determine: (i) which clinically practicable objective test best represents overall physical function; and (ii) the extent to which self-reported subjective functional measures reflect objectively assessed function.

Methods

Objective [isometric knee extensor strength, handgrip strength, sit-to-stands in 30 s, 8-foot up and go (8′UG), 50-foot walk (50′W) and estimated aerobic capacity (V̇O₂max)] and subjective (MDHAQ and SF36-PC) measures of function were correlated with one another to determine the best overall test of functional status in 82 well-controlled RA patients (DAS28 (s.d.) = 2.8 (1.0)).

Results

In rank order of size, averaged correlations (r) to the other outcome measures were as follows: 8′UG: 0.650; 50′W: 0.636; isometric knee extensor strength: 0.502; handgrip strength: 0.449; sit-to-stands in 30 s: 0.432; and estimated V̇O₂max: 0.358. The MDHAQ was weakly (0.361) and the SF36-PC moderately correlated (0.415) with objective measures.

Conclusion

Our results show that the most appropriate measure of objective physical function in RA patients is the 8′UG, followed by the 50′W. We found discordance between objectively and subjectively measured function. In clinical practice, an objective measure that is simple and quick to perform, such as the 8′UG, is advocated for assessing real functional status.

Can Creatine Supplementation Improve Body Composition and Objective Physical Function in Rheumatoid Arthritis Patients? A Randomized Controlled Trial

OBJECTIVE

Rheumatoid cachexia (muscle wasting) in rheumatoid arthritis (RA) patients contributes to substantial reductions in strength and impaired physical function. The objective of this randomized controlled trial was to investigate the effectiveness of oral creatine (Cr) supplementation in increasing lean mass and improving strength and physical function in RA patients.

METHODS

In a double-blind design, 40 RA patients were randomized to either 12 weeks' supplementation of Cr or placebo. Body composition (dual x-ray absorptiometry and bioelectrical impedance spectroscopy [BIS]), strength, and objectively assessed physical function were measured at baseline, day 6, week 12, and week 24. Data analysis was performed by analysis of covariance.

RESULTS

Cr supplementation increased appendicular lean mass (ALM; a surrogate measure of muscle mass) by mean ± SE 0.52 ± 0.13 kg (P = 0.004 versus placebo), and total LM by 0.60 ± 0.37 kg (P = 0.158). The change in LM concurred with the gain in intracellular water (0.64 ± 0.22 liters; P = 0.035) measured by BIS. Despite increasing ALM, Cr supplementation, relative to placebo, failed to improve isometric knee extensor strength (P = 0.408), handgrip strength (P = 0.833), or objectively assessed physical function (P = 0.335-0.764).

CONCLUSION

In patients with RA, Cr supplementation increased muscle mass, but not strength or objective physical function. No treatment-related adverse effects were reported, suggesting that Cr supplementation may offer a safe and acceptable adjunct treatment for attenuating muscle loss; this treatment may be beneficial for patients experiencing severe rheumatoid cachexia.

Tight control of disease activity fails to improve body composition or physical function in rheumatoid arthritis patients

OBJECTIVE

RA typically features rheumatoid cachexia [loss of muscle mass (MM) and excessive total fat mass (TFM), especially trunk FM], which contributes to physical disability. Since rheumatoid cachexia is driven by inflammation, it would be anticipated that the success of tight control of disease activity, such as treat-to-target (T2T), in attenuating inflammation would benefit body composition and physical function. This aim of this cross-sectional study was to assess the impact of T2T on body composition and objectively assessed function in RA patients.

METHODS

A total of 82 RA patients exclusively treated by T2T, were compared with 85 matched sedentary healthy controls (HCs). Body composition was estimated by DXA, with appendicular lean mass the surrogate measure of total MM. Physical function was assessed by knee extensor strength, handgrip strength, 30 s sit-to-stands, 8' up and go, and 50' walk (tests which reflect the ability to perform activities of daily living).

RESULTS

Although generally well treated (mean DAS28 = 2.8, with 49% in remission), RA patients had ∼10% proportionally less appendicular lean mass and were considerably fatter (by ∼27%), particularly in the trunk (∼32%), than HCs. All measures of function were 24-34% poorer in the RA patients relative to HC.

CONCLUSIONS

Despite marked improvements in disease control (most patients achieving or approaching remission), the relative loss of MM and increased adiposity in RA patients compared with matched HCs was similar to that observed pre-T2T. Additionally, performance of objective function tests was unchanged from that reported by our group for pre-T2T RA patients. Thus T2T, even in responsive RA patients, did not attenuate rheumatoid cachexia or improve objectively assessed function.

Fracture in the Elderly Multidisciplinary Rehabilitation (FEMuR): study protocol for a phase II randomised feasibility study of a multidisciplinary rehabilitation package following hip fracture [ISRCTN22464643]

BACKGROUND

Proximal femoral fracture is a common, major health problem in old age resulting in loss of functional independence and a high-cost burden on society, with estimated health and social care costs of £2.3 billion per year in the UK. Rehabilitation has the potential to maximise functional recovery and maintain independent living, but evidence of effectiveness is lacking. Usual rehabilitation care is delivered by a multi-disciplinary team in the hospital and in the community. An 'enhanced rehabilitation' intervention has been developed consisting of a workbook, goal-setting diary and extra therapy sessions, designed to improve self-efficacy and increase the amount and quality of the practice of physical exercise and activities of daily living.

METHODS/DESIGN

This paper describes the design of a phase II study comprising an anonymous cohort of all proximal femoral fracture patients admitted to the three acute hospitals in Betsi Cadwaladr University Health Board over a 6-month period with a randomised feasibility study comparing the enhanced rehabilitation intervention with usual care. These will assess the feasibility of a future definitive randomised controlled trial and concurrent economic evaluation in terms of recruitment, retention, outcome measure completion, compliance with the intervention and fidelity of delivery, health service use data, willingness to be randomised and effect size for a future sample size calculation. Focus groups will provide qualitative data to contribute to the assessment of the acceptability of the intervention amongst patients, carers and rehabilitation professionals and the feasibility of delivering the planned intervention. The primary outcome measure is function assessed by the Barthel Index. Secondary outcomes measure the ability to perform activities of daily living, anxiety and depression, potential mediators of outcomes such as hip pain, self-efficacy and fear of falling, health utility, health service use, objectively assessed physical function and adverse events. Participants' preference for rehabilitation services will be assessed in a discrete choice experiment.

DISCUSSION

Phase II studies are an opportunity to not only assess the feasibility of trial methods but also to compare different methods of outcome measurement and novel methods of obtaining health service use data from routinely collected patient information.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN22464643, UKCRN16677.

Oral creatine supplementation: A potential adjunct therapy for rheumatoid arthritis patients

Creatine is one of the most popular forms of protein supplements and is known to improve performance in healthy athletic populations via enhanced muscle mass and adenosine triphosphate energy regeneration. Clinical use of creatine may similarly benefit patients with rheumatoid arthritis (RA), an inflammatory condition characterised by generalised muscle loss termed “rheumatoid cachexia”. The adverse consequences of rheumatoid cachexia include reduced strength, physical function and, as a consequence, quality of life. Whilst regular high-intensity exercise training has been shown to increase muscle mass and restore function in RA patients, this form of therapy has very low uptake amongst RA patients. Thus, acceptable alternatives are required. The aim of this review is to consider the potential efficacy of creatine as an anabolic and ergonomic therapy for RA patients. To date, only one study has supplemented RA patients with creatine, and the findings from this investigation were inconclusive. However, trials in populations with similar losses of muscle mass and function as RA, including older adults and those with other muscle wasting conditions, indicate that creatine is an efficacious way of improving muscle mass, strength and physical function, and may offer an easy, safe and cheap means of treating rheumatoid cachexia and its consequences.

Exercising in a hot environment with muscle damage: effects on acute kidney injury biomarkers and kidney function

Unaccustomed strenuous physical exertion in hot environments can result in heat stroke and acute kidney injury (AKI). Both exercise-induced muscle damage and AKI are associated with the release of interleukin-6, but whether muscle damage causes AKI in the heat is unknown. We hypothesized that muscle-damaging exercise, before exercise in the heat, would increase kidney stress. Ten healthy euhydrated men underwent a randomized, crossover trial involving both a 60-min downhill muscle-damaging run (exercise-induced muscle damage; EIMD), and an exercise intensity-matched non-muscle-damaging flat run (CON), in random order separated by 2 wk. Both treatments were followed by heat stress elicited by a 40-min run at 33°C. Urine and blood were sampled at baseline, after treatment, and after subjects ran in the heat. By design, EIMD induced higher plasma creatine kinase and interleukin-6 than CON. EIMD elevated kidney injury biomarkers (e.g., urinary neutrophil gelatinase-associated lipocalin (NGAL) after a run in the heat: EIMD-CON, mean difference [95% CI]: 12 [5, 19] ng/ml) and reduced kidney function (e.g., plasma creatinine after a run in the heat: EIMD-CON, mean difference [95% CI]: 0.2 [0.1, 0.3] mg/dl), where CI is the confidence interval. Plasma interleukin-6 was positively correlated with plasma NGAL ( r = 0.9, P = 0.001). Moreover, following EIMD, 5 of 10 participants met AKIN criteria for AKI. Thus for the first time we demonstrate that muscle-damaging exercise before running in the heat results in a greater inflammatory state and kidney stress compared with non-muscle-damaging exercise. Muscle damage should therefore be considered a risk factor for AKI when performing exercise in hot environments.

Are the benefits of a high-intensity progressive resistance training program sustained in rheumatoid arthritis patients? A 3-year followup study

OBJECTIVE

Rheumatoid arthritis (RA) patients were reassessed for body composition and physical function mean ± SD 39 ± 6 months after commencing a randomized controlled trial involving 24 weeks of either high-intensity progressive resistance training (PRT) or low-intensity range of movement exercise (control) to determine whether the benefits of PRT (i.e., reduced fat mass [FM], increased lean mass [LM], and improved function) were retained.

METHODS

Nine PRT and 9 control subjects were reassessed for body composition (dual x-ray absorptiometry) and function (knee extensor strength, chair test, arm curl test, 50-foot walk) approximately 3 years after resuming normal activity following the exercise intervention.

RESULTS

At followup, PRT subjects remained significantly leaner than control subjects (P = 0.03), who conversely had accumulated considerable FM during the study period (approximately -1.0 kg versus +2.4 kg, PRT versus controls). PRT subjects also retained most of the improvement in walking speed gained from training (P = 0.03 versus controls at followup). In contrast, the PRT-induced gains in LM and strength-related function were completely lost. Data from the controls suggest that established and stable RA patients have similar rates of LM loss but elevated rates of FM accretion relative to age-matched sedentary non-RA controls.

CONCLUSION

We found that long-term resumption of normal activity resulted in loss of PRT-induced improvements in LM and strength-related function, but substantial retention of the benefits in FM reduction and walking ability. The relatively long-term benefit of reduced adiposity, in particular, is likely to be clinically significant, as obesity is very prevalent among RA patients and is associated with their disability and exacerbated cardiovascular disease risk.

An appraisal of rehabilitation regimes used for improving functional outcome after total hip replacement surgery

This study aimed to systematically review the literature with regards to studies of rehabilitation programmes that have tried to improve function after total hip replacement (THR) surgery. 15 randomised controlled trials were identified of which 11 were centre-based, 2 were home based and 2 were trials comparing home and centre based interventions. The use of a progressive resistance training (PRT) programme led to significant improvement in muscle strength and function if the intervention was carried out early (< 1 month following surgery) in a centre (6/11 centre-based studies used PRT), or late (> 1 month following surgery) in a home based setting (2/2 home based studies used PRT). In direct comparison, there was no difference in functional measures between home and centre based programmes (2 studies), with PRT not included in the regimes prescribed. A limitation of the majority of these intervention studies was the short period of follow up. Centre based program delivery is expensive as high costs are associated with supervision, facility provision, and transport of patients. Early interventions are important to counteract the deficit in muscle strength in the affected limb, as well as persistent atrophy that exists around the affected hip at 2 years post-operatively. Studies of early home-based regimes featuring PRT with long term follow up are needed to address the problems currently associated with rehabilitation following THR.

Skeletal muscle properties in rheumatoid arthritis patients

PURPOSE

Disability in patients with rheumatoid arthritis (RA) is a multifactorial process involving various unaccounted factors. Loss of lean body mass plays an important role in impaired physical function, and exercise studies in RA have shown promising results in restoring muscle mass, strength, and function. However, no comprehensive assessment of the muscle characteristics has been undertaken to determine whether qualitative changes in muscle also contribute to RA disability. This study explores the physiological muscle properties of a community-based population with stable RA.

METHODS

Vastus lateralis (VL) force and physiological cross-sectional area (PCSA), voluntary muscle activation capacity, and contractile properties were assessed in 23 patients with stable RA (age = 60 ± 2 yr (mean ± SEM); 16 women) and age- and sex-matched healthy controls (age = 60 ± 3 yr). Measurements with EMG were obtained during maximal isometric knee extension contractions, with resting and superimposed electrical stimulations. Concentric knee extension contractions were also assessed. Pennation angle and VL volume were measured with ultrasound to determine fiber fascicle length and PCSA. Muscle-specific force was calculated (VL force/VL PCSA). Body composition using dual-energy x-ray absorptiometry and objective physical function were also measured.

RESULTS

The patients displayed typical features of RA with reduced physical function (P = 0.001-0.09), a trend toward lower appendicular lean mass (P = 0.09) and increased total body fat (P < 0.05) relative to controls. However, there were no differences in specific force, contractile properties, voluntary activation capacity, and contraction velocity (P = 0.41-0.99). VL PCSA was reduced (P < 0.05) with minor architectural changes in patients with RA.

CONCLUSIONS

Physiological properties of muscle that determine specific force are not compromised in patients with stable RA despite deficits in physical function.

Benefits of exercise in rheumatoid arthritis

This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, “rheumatoid cachexia”. These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training.

Effects of high-intensity resistance training in patients with rheumatoid arthritis: a randomized controlled trial

OBJECTIVE

To confirm, in a randomized controlled trial (RCT), the efficacy of high-intensity progressive resistance training (PRT) in restoring muscle mass and function in patients with rheumatoid arthritis (RA). Additionally, to investigate the role of the insulin-like growth factor (IGF) system in exercise-induced muscle hypertrophy in the context of RA.

METHODS

Twenty-eight patients with established, controlled RA were randomized to either 24 weeks of twice-weekly PRT (n = 13) or a range of movement home exercise control group (n = 15). Dual x-ray absorptiometry-assessed body composition (including lean body mass [LBM], appendicular lean mass [ALM], and fat mass); objective physical function; disease activity; and muscle IGFs were assessed at weeks 0 and 24.

RESULTS

Analyses of variance revealed that PRT increased LBM and ALM (P < 0.01); reduced trunk fat mass by 2.5 kg (not significant); and improved training-specific strength by 119%, chair stands by 30%, knee extensor strength by 25%, arm curls by 23%, and walk time by 17% (for objective function tests, P values ranged from 0.027 to 0.001 versus controls). In contrast, body composition and physical function remained unchanged in control patients. Changes in LBM and regional lean mass were associated with changes in objective function (P values ranged from 0.126 to <0.0001). Coinciding with muscle hypertrophy, previously diminished muscle levels of IGF-1 and IGF binding protein 3 both increased following PRT (P < 0.05).

CONCLUSION

In an RCT, 24 weeks of PRT proved safe and effective in restoring lean mass and function in patients with RA. Muscle hypertrophy coincided with significant elevations of attenuated muscle IGF levels, revealing a possible contributory mechanism for rheumatoid cachexia. PRT should feature in disease management.

Nandrolone Decanoate as Anabolic Therapy in Chronic Kidney Disease: A Randomized Phase II Dose-Finding Study

BACKGROUND/AIMS

In patients with chronic kidney disease (CKD) receiving adequate erythropoietin therapy, the ideal dose of nandrolone decanoate (ND) to enhance muscle mass is not known.

METHODS

In this phase II dose-finding study, 54 patients with CKD stage 5 were randomized to either low, medium or high doses of ND (50, 100 or 200 mg/week for 24 weeks, respectively, in males; doses halved in females), while 7 patients acted as non-randomized controls. The primary outcome measure was appendicular lean mass (ALM) by dual-energy X-ray absorptiometry. Fluid overload (hydration of the fat-free mass) and indicators of physical functioning were secondary measures. Harms were also recorded. Data were analysed using Quade's (1967) non-parametric analysis of covariance.

RESULTS

ND increased ALM in a dose-responsive manner (change scores = 0.3 +/- 0.3 vs. 0.8 +/- 0.3 vs. 1.5 +/- 0.5 vs. 2.1 +/- 0.4 kg, control vs. low vs. medium vs. high dose groups, respectively, p < 0.001) with no increases in fluid overload but no consistent effect on physical functioning. The highest dose of ND (100 mg/week) was intolerable in females because of virilizing effects.

CONCLUSION

If goals of future studies are to improve body composition, dosing of ND up to 200 mg/week in males and 50 mg/week in females should be investigated. However, to realize improvements in physical functioning, future phase III trials of ND may require additional interventions such as exercise training.

Randomized phase 2 trial of anti-tumor necrosis factor therapy for cachexia in patients with early rheumatoid arthritis

BACKGROUND

Tumor necrosis factor (TNF) is an important mediator of cachexia, and its blockade prevents catabolism in animal models. However, little evidence shows that anti-TNF therapy is effective in treating cachexia in humans.

OBJECTIVE

The main aim of this study was to investigate the effect of etanercept, a synthetic soluble TNF receptor, on body composition in patients with early rheumatoid arthritis (RA).

DESIGN

Twenty-six patients were randomly assigned to 24 wk of treatment with etanercept or methotrexate; the latter is the first-line therapy for RA. Body composition, physical function, disease activity, systemic inflammation, and the circulating insulin-like growth factor (IGF) system were measured at baseline (week 0) and at follow-up (weeks 12 and 24). Twelve patients in each treatment group (9 F, 3 M) completed the study.

RESULTS

Overall, no important changes in body composition were observed, despite a transient increase in IGF-I at week 12 (P < 0.01). However, the secondary analysis of those patients (6/treatment group) who gained weight during follow-up showed a significant effect of etanercept on the composition of the weight gained: 44% of weight gained in the etanercept group was fat-free mass, as compared with only 14% in the methotrexate group (P = 0.04). Etanercept and methotrexate were equally effective in controlling the disease and improving physical function.

CONCLUSIONS

Anti-TNF therapy with etanercept is not superior to that with methotrexate for the treatment of rheumatoid cachexia over a period of 6 mo. However, TNF blockade seems to normalize the anabolic response to overfeeding and, if these findings are confirmed, may be useful in conditions characterized by anorexia and weight loss.

Muscle insulin-like growth factor status, body composition, and functional capacity in hemodialysis patients

BACKGROUND

Hemodialysis (HD) patients typically have reduced muscle mass and diminished functional capacity. The role of the muscle insulin-like growth factors (IGFs), a principal anabolic system that is involved in protein synthesis and that has downregulation that is implicated in muscle loss in animal models of uremia, has previously not been assessed in vivo in HD patients.

METHODS

Seventeen HD patients were compared cross-sectionally with 17 age-, sex-, and body mass index-matched healthy controls. Body composition was assessed by dual energy x-ray absorptiometry and bioelectrical impedance spectrometry; functional capacity by hand grip strength, quadriceps strength, and 30-second sit-to-stand test; systemic inflammation by tumor necrosis factor-alpha (TNF-alpha) and TNF receptor 1 (TNFR1); serum and muscle IGF-I and IGFBP-3 by radioimmunoassay; and fragmentation of serum IGFBP-3 by Western immunoblotting.

RESULTS

Appendicular lean mass was significantly decreased in HD patients compared with controls (17.6 +/- 0.9 versus 21.5 +/- 1.5 kg, P < .05), as were all measures of functional capacity (P < .01 to .001), and highly significant positive correlations between appendicular lean mass and functional capacity were evident (appendicular lean mass and hand-grip strength, quadriceps strength, 30-second sit-to-stand test, all P < .001). TNF-alpha and TNFR1 were elevated in patients (P < .001). Although serum IGF-I and IGFBP-3 levels did not differ between the groups (P = .295 and .379 respectively), fragmented IGFBP-3 levels were increased (53.1 +/- 16.0 versus 29.81 +/- 15.3%, P < .005). In contrast, muscle IGF-I was substantially diminished in the patient group (n = 7) relative to control (n = 5) levels (0.84 +/- 0.06 versus 2.78 +/- 1.80 pg/microg, P < .05).

CONCLUSIONS

We provide evidence of reduced IGF-I in HD patients' skeletal muscle that may be a causal factor in the muscle wasting characteristic of this population. Future research should determine the exact consequences and causes of alterations to the muscle IGF system in HD patients.

Can progressive resistance training reverse cachexia in patients with rheumatoid arthritis? Results of a pilot study

OBJECTIVE

. A Phase II trial was performed as a preliminary test of the efficacy and safety of progressive resistance training (PRT) as adjunct treatment for rheumatoid cachexia.

METHODS

Ten mildly disabled patients with well-controlled rheumatoid arthritis (RA) trained, on average, 2.5 times per week for 12 weeks. Ten age and sex matched RA patients with similar disease characteristics were non-randomly assigned to a control group. Body composition, physical function, and disease activity were assessed pre and post intervention period.

RESULTS

Between group comparisons at followup by ANCOVA using baseline scores as covariate showed significant increases in fat-free mass (+1253 g, p = 0.004), total body protein (+1063 g, p = 0.044), and arm (+280 g, p = 0.005) and leg (+839 g, p = 0.001) lean mass (a proxy measure of total body skeletal muscle mass) in response to PRT with no exacerbation of disease activity. There was also a trend for loss of fat mass in the trunk (-752 g, p = 0.084) and a significant reduction in percent body fat (-1.1%, p = 0.047). Changes in body composition were associated with improvements in various measures of physical function.

CONCLUSION

Intense PRT with adequate volume seems to be an effective and safe intervention for stimulating muscle growth in patients with RA. Pending confirmation of these results in a larger randomized controlled trial that includes patients with more active and severe disease, a similar PRT program should be included in the management of RA as adjunct treatment for cachexia.

Can progressive resistance training reverse cachexia in patients with rheumatoid arthritis? Results of a pilot study

OBJECTIVE

. A Phase II trial was performed as a preliminary test of the efficacy and safety of progressive resistance training (PRT) as adjunct treatment for rheumatoid cachexia.

METHODS

Ten mildly disabled patients with well-controlled rheumatoid arthritis (RA) trained, on average, 2.5 times per week for 12 weeks. Ten age and sex matched RA patients with similar disease characteristics were non-randomly assigned to a control group. Body composition, physical function, and disease activity were assessed pre and post intervention period.

RESULTS

Between group comparisons at followup by ANCOVA using baseline scores as covariate showed significant increases in fat-free mass (+1253 g, p = 0.004), total body protein (+1063 g, p = 0.044), and arm (+280 g, p = 0.005) and leg (+839 g, p = 0.001) lean mass (a proxy measure of total body skeletal muscle mass) in response to PRT with no exacerbation of disease activity. There was also a trend for loss of fat mass in the trunk (-752 g, p = 0.084) and a significant reduction in percent body fat (-1.1%, p = 0.047). Changes in body composition were associated with improvements in various measures of physical function.

CONCLUSION

Intense PRT with adequate volume seems to be an effective and safe intervention for stimulating muscle growth in patients with RA. Pending confirmation of these results in a larger randomized controlled trial that includes patients with more active and severe disease, a similar PRT program should be included in the management of RA as adjunct treatment for cachexia.

Intradialytic exercise as anabolic therapy in haemodialysis patients - a pilot study

Haemodialysis (HD) patients are characterized by muscle wasting and consequently decreased physical functioning and poor outcome. This pilot study investigated if a novel intradialytic exercise programme could increase lean mass via up-regulation of the insulin-like growth factor (IGF) system. Nine HD patients were assessed before (w-12) and after a 3-month control phase (w0), after a three-month intradialytic interval training programme using high intensity cycle exercise (w12), and after a withdrawal of treatment phase (w24). Body composition was determined by dual energy X-ray absorptiometry (DEXA) and bioelectrical impedance spectroscopy (BIS); physical functioning by knee extensor strength (KES) and 30-s sit stand test (SST); and IGF-I and IGFBP-3 in serum and muscle by radioimmunoassay. Despite significant increases in training load (+274%, P<0.001), peak power output (+71%, P<0.001) and physical function (KES: +19%, P<0.05; SST: +20%, P<0.05) following the intervention phase, lean masses by DEXA, intra cellular water by BIS (a surrogate measure of body cell mass) and serum and muscle IGFs remained unchanged following training. Although this novel exercise programme, utilizing high intensity interval training, was safe, clinically feasible and beneficial in terms of physical functioning, the 12 weeks of intradialytic cycle exercise failed to reverse the muscle atrophy characteristic of this population. Future studies, using primary outcome measures similar to those employed in the present study, should investigate other anabolic interventions to determine potential treatments for the muscle wasting associated with end stage renal disease.

Effect of stride length on symptoms of exercise-induced muscle damage during a repeated bout of downhill running

The purpose of this study was to assess the effects of changes in stride length on the symptoms of exercise-induced muscle damage (EIMD) during a repeated bout of downhill running in a group of 18 men and women. Muscle tenderness, plasma creatine kinase activity (CK) and maximal voluntary isometric force were measured before and after two downhill runs, with each run separated by 5 weeks. The first downhill run was at the preferred stride frequency (PSF). Participants were then randomly allocated to one of three sex-balanced groups with equal numbers of men and women: overstride (-8% PSF), understride (+8% PSF) and normal stride frequency for the second downhill run. Stride length had no effect (P>0.05) on muscle tenderness, CK or isometric peak force. Increases in muscle tenderness (P<0.001) and CK were lower (P<0.05) following the second downhill run, although there was no difference in the pattern and extent of the strength decrement between the two runs. There were also no differences (P>0.05) in muscle tenderness, CK or the relative strength loss between the men and the women. Results suggest that the symptoms of EIMD are unaffected by gender and small alterations to the normal stride pattern during constant velocity downhill running. The observation that muscle tenderness and CK were reduced following a repeated bout of similar eccentric exercise is consistent with the phenomenon known as the 'repeated bout effect' of muscle damage.

Differential regulation of tissue insulin-like growth factor-binding protein (IGFBP)-3, IGF-I and IGF type 1 receptor mRNA levels, and serum IGF-I and IGFBP concentrations by growth hormone and IGF-I

The aims of this investigation were (1) to examine IGF-binding protein-3 (IGFBP-3) mRNA levels in candidate tissues which might be important sources for blood IGFBP-3 (liver and skin) and in a target tissue for IGF-I action (skeletal muscle), and (2) to examine the effects of a single dose (500 micrograms) of GH or IGF-I on IGFBP-3 message levels in these tissues since temporal responses (4, 8 and 24 h after the single subcutaneous dose of peptide to GH-deficient dwarf rats) would indicate which peptide is the primary modulator of IGFBP-3 synthesis. Circulating IGF-I and IGFBP-3 concentrations were significantly increased (P < 0.05) by IGF-I and GH. GH treatment increased liver IGFBP-3 mRNA levels by 4 h (P < 0.001 over the 24 h) whereas IGF-I had no effect. Similarly, GH, but not IGF-I, increased muscle IGFBP-3 mRNA levels (P < 0.001 for the 24 h study period). However, both IGF-I and GH induced increases in skin IGFBP-3 mRNA abundance throughout the 24 h period (P < 0.001 and P < 0.01 respectively) and skin IGFBP-3 message abundance was greater that in the liver. Liver IGF-I mRNA levels were, as expected, increased after GH and tended to decrease after IGF-I treatment; muscle IGF-I mRNA was increased by GH (P < 0.001) and, interestingly, progressively increased by IGF-I (P < 0.05 for the 24 h period); skin IGF-I mRNA levels were unchanged by both peptides. The IGF-I induced increase in serum IGFBP-3 concentrations in the absence of an increase in hepatic IGFBP-3 mRNA levels and a paucity of liver IGF-I type 1 receptor mRNA imply that other sources of IGFBP-3 protein or synthesis must exist. The response of skin IGFBP-3 mRNA levels to both GH and IGF-I suggests that other cell types, such as fibroblast-derived cells, could be more important than the liver in the regulation of circulating reservoir IGFBP-3 in certain circumstances. In contrast to some current suggestions, the rapid and consistent GH-induced increase in IGFBP-3 message levels in all tissues studied implies that GH might have a direct function in the regulation of IGFBP-3 synthesis.

Superior potency of infused IGF-I analogues which bind poorly to IGF-binding proteins is maintained when administered by injection

The relative potency of IGF-I and the analogue LR3IGF-I to either promote growth or reverse catabolism in rats when administered by injection rather than by continuous infusion has been examined. LR3IGF-I has very low affinity for the IGF-binding proteins in the rat and hence is cleared from the circulation more quickly than is IGF-I. Experiments were performed in normal growing rats (150 g body weight) and in rats made catabolic by dexamethasone infusion (20 micrograms/day). IGFs or vehicle were delivered subcutaneously for 7 days either by continuous infusion via osmotic pumps or by injection once or twice daily at 320 and 400 micrograms/day in normal and catabolic rats respectively. As expected, continuous infusion of IGFs showed greater efficacy than either of the injection modes especially in its anti-catabolic actions. When infused continuously LR3IGF-I was generally 1.5- to 2-fold more potent than IGF-I for changes in body weight gain, visceral organ weights and feed use efficiency. Notably, LR3IGF-I remained more potent than IGF-I in several of these effects even when the peptides were given by once-daily injection. In addition, N tau-methylhistidine excretion by dexamethasone-treated rats was reduced to a threefold greater extent by injected LR3IGF-I than by injected IGF-I. Notwithstanding these effects, LR3IGF-I was barely equipotent with IGF-I for reversal of carcass muscle loss in dexamethasone-treated rats. Despite its more rapid clearance from the circulation, injected LR3IGF-I retains superior potency to injected IGF-I for several actions, albeit the potency is much reduced compared with continuous infusion. Thus our data indicate that use of IGF analogues which have low affinity for binding proteins may have advantages in potency and/or tissue specificity where IGFs are necessarily administered by injection.

Treatment with IGF-I peptides improves function of the remnant gut following small bowel resection in rats

The effects of 7 days' s.c. infusion of 111-700 micrograms/day IGF-I on gut growth and absorptive function were examined in growing rats following removal of 70 or 80% of the jejuno-ileum, and compared with the responses to the analogues, LR3IGF-I and des(1-3)IGF-I, which bind poorly to IGF binding proteins. Administration of 278 micrograms/day IGF-I, LR3IGF-I or des(1-3)IGF-I following 70% jejuno-ileal resection significantly attenuated malabsorption of fat and nitrogen. Responses in rats with 80% resection were less substantial, but a dose-responsive reduction in malabsorption was apparent with LR3IGF-I. Both IGF-I and LR3IGF-I were shown to increase body weight gain and food conversion efficiency in a dose-dependent manner following 80% jejuno-ileal resection. Total gut weight was increased by up to 21%, due predominantly to increased weight of the stomach and proximal small bowel, with the latter effect attributable at least in part to an increased bowel length. LR3IGF-I was more potent than IGF-I at stimulating body weight gain and food conversion efficiency, but its potency advantage on gut absorptive function and small intestinal re-growth was less marked. We conclude that administration of IGF-I peptides improves gastro-intestinal absorptive function following partial gut resection, most likely reflecting, at least in part, an increase in gut absorptive surface area.

IGF-I and the truncated analogue des-(1-3)IGF-I enhance growth in rats after gut resection

Effects of insulin-like growth factor I (IGF-I) administration and that of the truncated analogue des-(1-3)IGF-I have been examined in 170-g rats over a 7-day period after surgery to remove 80% of the jejunum plus ileum. The doses administered via osmotic infusion pumps were 0.96 and 2.4 mg.kg-1.day-1 IGF-I and 0.96 mg.kg-1.day-1 des-(1-3)IGF-I. All groups lost weight on the day after surgery, but over the next 3 days the des-(1-3)IGF-I and high-dose IGF-I groups stabilized better and subsequently gained significantly (P less than 0.05) more weight than the vehicle or low-dose IGF-I groups over the last 3 days. The weight gains (mean +/- SE) for the groups over this last 3-day period were 14.0 +/- 1.7, 14.4 +/- 2.9, 21.9 +/- 1.7, and 20.8 +/- 1.0 g for the vehicle, low-dose IGF-I, high-dose IGF-I, and des-(1-3)IGF-I groups, respectively. The nitrogen balances over the last 3 days for the high-dose IGF-I and des-(1-3)IGF-I groups, at 242 +/- 14 and 217 +/- 13 mg/d, respectively, were significantly (P less than 0.05) more positive than the control group at 153 +/- 21 mg/d. These differences could at least partially be explained by changes in muscle protein breakdown, as assessed by 3-methyl-L-histidine excretion. The kidneys were heavier in all treatment groups and the thymus after administration of des-(1-3)IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung volume and spirometric standards for healthy female lifetime nonsmokers

The FRC, RV, VC, TLC, RV/TLC (%), FVC, FEV1.0, FEF25-75%, and FEV1.0/FVC (%) were measured in 161 South Australian females aged 18.4-81.2 yr using a Stead-Wells spirometer and helium analyzer. Multiple regression equations were generated to predict these lung volume and spirometric parameters from the best weighted combination of age, mass, standing height, and various other anthropometric variables (FRC: R = 0.715, SEE = 387 ml; RV: R = 0.684, SEE = 256 ml; VC: R = 0.815, SEE = 383 ml; TLC: R = 0.754, SEE = 468 ml; RV/TLC: R = 0.780, SEE = 4.2%; FVC: R = 0.839, SEE = 375 ml; FEV1.0: R = 0.869, SEE = 326 ml; FEV1.0/FVC: R = 0.644, SEE = 5.7%; FEF25-75%: R = 0.753, SEE = 802 ml/s). The range of normality for the lung volumes was defined as the predicted value plus or minus the 95% confidence interval (two-tailed test), and the lower limit of normality for the spirometric variables was designated as the predicted value minus the 95% confidence interval (one-tailed test). Cross-validation of other equations in the literature indicates that they are of limited use for the sample and instrumentation used in this study.