Gastrocnemius muscle architecture in distance runners with and without Achilles tendinopathy

Background

Achilles tendinopathy is a common condition amongst distance runners due to the cumulative repetitive overload of the tendon. Gastrocnemius weakness and inflexibility can predispose to this condition. These predisposing functional deficits could have architectural underpinnings, but the gastrocnemius architecture of distance runners with Achilles tendinopathy has not been previously described or compared to the architecture of healthy distance runners.

Objectives

We aimed to investigate the differences in gastrocnemius architecture between distance runners with Achilles tendinopathy and uninjured counterparts.

Methods

Twenty distance runners (10 with Achilles tendinopathy; 10 uninjured) were recruited to this study. Ultrasound measurement of the gastrocnemius muscle architecture (pennation angle; fascicle length; muscle thickness; muscle belly length; muscle volume; physiological cross-sectional area) was performed.

Results

Gastrocnemius Medial Head (GM) fascicle length was significantly greater (p = 0.02), whilst the physiological cross-sectional area (PCSA) was significantly less (p = 0.01) in the case group. Gastrocnemius Lateral Head (GL) pennation angle (p = 0.01) and PCSA (p = 0.01) were significantly lower, whilst fascicle length was significantly greater (p = 0.01) in the case group. There were no significant between-group differences in GM and GL muscle thickness, muscle belly length, or muscle volume.

Conclusion

Components of gastrocnemius architecture differ significantly between distance runners with Achilles tendinopathy and uninjured controls in our study sample. This study cannot infer whether these results are secondary or predisposing to the condition. Further longitudinal investigation is required to explore these relationships further.

The ecological validity of traditional standing and novel bicycle balance and agility tests for predicting performance in mountain bikers

Falls are a common mechanism of injury in mountain biking and may be related to a loss of control of the bicycle. Traditionally, the components of bicycle control (balance and agility) are measured in standing and running, which may not reflect the skills required in mountain biking. In this paper, we present the validity of both traditional standing and novel bicycle-specific balance tests in mountain bikers. Twenty-nine male and female participants completed indoor laboratory tests and an outdoor downhill trail. Participants completed single-leg stance balance, Y-balance test, one static and four dynamic bicycle-specific balance tests, a bicycle agility test, and an outdoor downhill trail. Single-leg stance balance and Y-balance tests with eyes open had poor validity when associated with bicycle control. The static (r ​= ​-0.57, p = 0.001) and four dynamic bicycle balance tests (r ​= ​-0.51 to -0.78, p = 0.005 to 0.0001), and the bicycle agility test (r ​= ​0.87, p < 0.0001) had moderate to strong relationships with the outdoor downhill run. Single-leg stance balance and Y-balance tests with eyes open are not valid measures of performance on a mountain bike, and should not be used to assess these populations. Our novel bicycle balance tests have adequate validity to be used as measures of performance in mountain bikers.

NNC6019–0001, a humanized monoclonal antibody, in patients with transthyretin amyloid cardiomyopathy (ATTR-CM): rationale and study design of a phase 2, randomized, placebo-controlled trial

Introduction

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a chronic condition associated with progressive heart failure, resulting from extracellular deposition of misfolded transthyretin (TTR) protein as amyloid fibrils in the myocardium. Currently, there are few disease-modifying treatments. NNC6019–0001 is a humanized monoclonal antibody designed to deplete amyloid via antibody-mediated phagocytosis by targeting a unique epitope that is exposed only on misfolded monomeric and aggregated forms of TTR. In a phase 1, open-label, 3-month dose escalation trial, NNC6019–0001 was well tolerated at all doses tested (up to and including 30 mg/kg).1 The maximum tolerated dose was not reached. Exploratory cardiac endpoints were stable or indicated a possible benefit.

Purpose

To evaluate the effect of NNC6019–0001 30 mg/kg and 100 mg/kg on cardiac functional endpoints and predictive biomarkers in patients with ATTR-CM, and to assess pharmacokinetics, safety and tolerability, to establish the optimal dose for a phase 3 trial.

Methods

This is a randomized, double-blind, placebo-controlled trial recruiting 99 patients with hereditary or wild-type ATTR-CM (Figure). Inclusion criteria are New York Heart Association (NYHA) class II or III heart failure, left ventricle wall thickening (LVWT) ≥12 mm, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels ≥650 pg/mL in sinus rhythm and &gt;1000 pg/mL in atrial fibrillation, and a 6-minute walk test (6MWT) distance of 150–450 m. Patients will be randomly assigned to receive intravenous NNC6019–0001 30 mg/kg or 100 mg/kg or placebo, each in addition to standard of care, every 4 weeks for 52 weeks, followed by a 12-week follow-up. In a sentinel dosing phase, three patients per arm will receive the study drug or placebo, in combination with 24-hour inpatient cardiac monitoring and 7 days of continuous cardiac (tele-) monitoring. The primary endpoints are change from baseline to week 52 in 6MWT and in NT-proBNP levels. Secondary endpoints include cardiac measures: extracellular volume on cardiac magnetic resonance imaging, global longitudinal strain, troponin T levels, hospitalization due to cardiovascular events, and urgent visits due to heart failure. Quality of life will be assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ). All-cause mortality, pharmacokinetics and treatment-emergent adverse events will also be assessed.

Results

The trial will start mid-2022 with global recruitment.

Conclusion

Disease-modifying treatments are needed for patients with ATTR-CM, where treatment is often limited to managing symptoms and best supportive care; the first disease-modifying therapies recently became available. This phase 2 trial will be used to determine the appropriate dose for the phase 3 trial of NNC6019–0001, a novel antibody therapy designed to deplete amyloid in patients with ATTR-CM.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This trial was funded by Novo Nordisk A/S. Medical writing support was provided by Johanna Scheinost PhD, PharmaGenesis Oxford Central, Oxford, UK, with funding from Novo Nordisk A/S.

Safety and efficacy of combination therapy with semaglutide, cilofexor and firsocostat in patients with non-alcoholic steatohepatitis: A randomised, open-label phase II trial

BACKGROUND & AIMS

Non-alcoholic steatohepatitis (NASH) is associated with increased risk of liver-related and cardiovascular morbidity and mortality. Given the complex pathophysiology of NASH, combining therapies with complementary mechanisms may be beneficial. This trial evaluated the safety and efficacy of semaglutide, a glucagon-like peptide-1 receptor agonist, alone and in combination with the farnesoid X receptor agonist cilofexor and/or the acetyl-coenzyme A carboxylase inhibitor firsocostat in patients with NASH.

METHODS

This was a phase II, open-label, proof-of-concept trial in which patients with NASH (F2-F3 on biopsy, or MRI-proton density fat fraction [MRI-PDFF] ≥10% and liver stiffness by transient elastography ≥7 kPa) were randomised to 24 weeks' treatment with semaglutide 2.4 mg once weekly as monotherapy or combined with once-daily cilofexor (30 or 100 mg) and/or once-daily firsocostat 20 mg. The primary endpoint was safety. All efficacy endpoints were exploratory.

RESULTS

A total of 108 patients were randomised to semaglutide (n = 21), semaglutide plus cilofexor 30 mg (n = 22), semaglutide plus cilofexor 100 mg (n = 22), semaglutide plus firsocostat (n = 22) or semaglutide, cilofexor 30 mg and firsocostat (n = 21). Treatments were well tolerated - the incidence of adverse events was similar across groups (73-90%) and most events were gastrointestinal in nature. Despite similar weight loss (7-10%), compared with semaglutide monotherapy, combinations resulted in greater improvements in liver steatosis measured by MRI-PDFF (least-squares mean of absolute changes: -9.8 to -11.0% vs. -8.0%), liver biochemistry, and non-invasive tests of fibrosis.

CONCLUSIONS

In patients with mild-to-moderate fibrosis due to NASH, semaglutide with firsocostat and/or cilofexor was generally well tolerated. In exploratory efficacy analyses, treatment resulted in additional improvements in liver steatosis and biochemistry vs. semaglutide alone. Given this was a small-scale open-label trial, double-blind placebo-controlled trials with adequate patient numbers are warranted to assess the efficacy and safety of these combinations in NASH.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03987074.

LAY SUMMARY

Non-alcoholic fatty liver disease and its more severe form, non-alcoholic steatohepatitis (NASH), are serious liver conditions that worsen over time if untreated. The reasons people develop NASH are complex and combining therapies that target different aspects of the disease may be more helpful than using single treatments. This trial showed that the use of 3 different types of drugs, namely semaglutide, cilofexor and firsocostat, in combination was safe and may offer additional benefits over treatment with semaglutide alone.

A Placebo-Controlled Trial of Subcutaneous Semaglutide in Nonalcoholic Steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a common disease that is associated with increased morbidity and mortality, but treatment options are limited. The efficacy and safety of the glucagon-like peptide-1 receptor agonist semaglutide in patients with NASH is not known.

METHODS

We conducted a 72-week, double-blind phase 2 trial involving patients with biopsy-confirmed NASH and liver fibrosis of stage F1, F2, or F3. Patients were randomly assigned, in a 3:3:3:1:1:1 ratio, to receive once-daily subcutaneous semaglutide at a dose of 0.1, 0.2, or 0.4 mg or corresponding placebo. The primary end point was resolution of NASH with no worsening of fibrosis. The confirmatory secondary end point was an improvement of at least one fibrosis stage with no worsening of NASH. The analyses of these end points were performed only in patients with stage F2 or F3 fibrosis; other analyses were performed in all the patients.

RESULTS

In total, 320 patients (of whom 230 had stage F2 or F3 fibrosis) were randomly assigned to receive semaglutide at a dose of 0.1 mg (80 patients), 0.2 mg (78 patients), or 0.4 mg (82 patients) or to receive placebo (80 patients). The percentage of patients in whom NASH resolution was achieved with no worsening of fibrosis was 40% in the 0.1-mg group, 36% in the 0.2-mg group, 59% in the 0.4-mg group, and 17% in the placebo group (P<0.001 for semaglutide 0.4 mg vs. placebo). An improvement in fibrosis stage occurred in 43% of the patients in the 0.4-mg group and in 33% of the patients in the placebo group (P = 0.48). The mean percent weight loss was 13% in the 0.4-mg group and 1% in the placebo group. The incidence of nausea, constipation, and vomiting was higher in the 0.4-mg group than in the placebo group (nausea, 42% vs. 11%; constipation, 22% vs. 12%; and vomiting, 15% vs. 2%). Malignant neoplasms were reported in 3 patients who received semaglutide (1%) and in no patients who received placebo. Overall, neoplasms (benign, malignant, or unspecified) were reported in 15% of the patients in the semaglutide groups and in 8% in the placebo group; no pattern of occurrence in specific organs was observed.

CONCLUSIONS

This phase 2 trial involving patients with NASH showed that treatment with semaglutide resulted in a significantly higher percentage of patients with NASH resolution than placebo. However, the trial did not show a significant between-group difference in the percentage of patients with an improvement in fibrosis stage. (Funded by Novo Nordisk; ClinicalTrials.gov number, NCT02970942.).

Systematic Literature Review and Critical Appraisal of Health Economic Models Used in Cost-Effectiveness Analyses in Non-Alcoholic Steatohepatitis: Potential for Improvements

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a severe, typically progressive form of non-alcoholic fatty liver disease (NAFLD). The global prevalence of NASH is increasing, driven partly by the global increase in obesity and type 2 diabetes mellitus (T2DM), such that NASH is now a leading cause of cirrhosis. There is currently an unmet clinical need for efficacious and cost-effective treatments for NASH; no pharmacologic agents have an approved indication for NASH.

OBJECTIVE

Our objective was to summarise and critically appraise published health economic models of NASH, to evaluate their quality and suitability for use in the assessment of novel treatments for NASH, and to identify knowledge gaps, challenges and opportunities for future modelling.

METHODS

A systematic literature review was performed using the MEDLINE, Embase, Cochrane Library and EconLit databases to identify published health economic analyses in patients with NAFLD or NASH. Supplementary hand searches of grey literature were also performed. Articles published up to November 2019 were included in the review. Quality assessment of identified studies was also performed.

RESULTS

A total of 19 articles comprising 16 unique models including either NAFLD as a whole or NASH alone were included in the review. Structurally, most models had a state-transition component; in terms of health states, two different approaches to early disease states were used, modelling either progression through fibrosis stages or NAFLD/NASH-specific health states. Conditions that frequently co-exist with NASH, such as obesity, T2DM and cardiovascular disease were not captured in models identified here. Late-stage complications such as cirrhosis, decompensated cirrhosis and hepatocellular carcinoma were consistently included, but input data (e.g. costs, utilities and transition probabilities) for late-stage complications were frequently sourced from other liver disease areas. The quality of included studies was heterogenous, and only a small proportion of studies reported internal and external validation processes.

CONCLUSION

The health economic models identified in this review are associated with limitations primarily driven by a lack of NASH-specific data. Identified models also largely overlooked the intricate association between NASH and other conditions, including obesity and T2DM, and did not capture the increased risk of cardiovascular events associated with NASH. High-quality, transparent, validated health economic models of NASH will be required to evaluate the cost effectiveness of treatments currently in development, particularly compounds that may target other non-hepatic outcomes.

An evaluation of bicycle-specific agility and reaction times in mountain bikers and road cyclists

Background

Cycling is a popular recreational and competitive sport with many health benefits but also significant risks, with 85% of recreational cyclists reporting an injury each season. The most common mechanism of injury is through a loss of control of the bicycle, and collisions with other objects. Reaction time and agility in cyclists may contribute to the ability to control a bicycle.

Objectives

To evaluate bicycle-specific agility and reaction time in cyclists.

Methods

The study was a cross-sectional observational study. Thirty-five cyclists (27 males, eight females) participated in this study. Participants attended a single testing session where they completed a bicycle-specific agility test, and online simple and choice reaction time testing while cycling at three different exercise intensities.

Results

There was a significant difference in agility between males and females (p=0.01). There was also a significant difference in choice reaction time between cycling at 'light' and 'very hard' intensities (p=0.004), and a significant positive relationship between agility and simple reaction time at a 'hard' intensity.

Discussion

Choice reaction time improved at 'very hard' cycling intensity, supporting the theory that increased exercise intensity improves cognitive arousal. This reaction time may be essential as a means to avoid collisions and falls from bicycles. Bicycle-specific agility appears to be related to simple reaction time, but there are no existing validated bicycle-specific agility tests available. The value of the tests undertaken by the authors needs to be assessed further.

Conclusion

Choice reaction time was significantly decreased in high intensity cycling compared to cycling at low intensities. Further prospective studies are needed to establish links between reaction times and bicycle-specific agility.

Does a greater training load increase the risk of injury and illness in ultramarathon runners? : A prospective, descriptive, longitudinal design

Background

Ultramarathon running has become extremely popular over the years. Despite the numerous health benefits of running, there are also many negative effects of running, such as increased risk of musculoskeletal injury and illness. Monitoring of an athlete's training load has become extremely important in terms of injury prevention. Currently, the relationship between training loads and injury and illness incidence is uncertain.

Objectives

To determine if there are any associations between injury and illness incidences and training loads among ultramarathon runners in the 12 week period preceding an ultramarathon event and the four week period after the event.

Methods

This prospective, descriptive, longitudinal study design was conducted in 119 runners who were training for the 2019 Two Oceans ultramarathon event. Data were collected once a week via an online logbook over 16 weeks. Training parameters measured included weekly average running distance, average duration, average frequency and average sessional RPE. Injury data included injury counts, the structure injured, the main anatomical location and the time-loss as a result of injury. Illness data included illness counts, the main illness-related symptoms and the time-loss as a result of illness.

Results

The overall injury incidence was five per 1000 training hours and the overall illness incidence was 16 per 1000 training days. There was a significant relationship between external training load and injury and illness incidence for those who ran less than 30 km per week. There was also a significant relationship between the ACWR (Acute Chronic Workload Ratio) and injury incidence when the ACWR was >1.5 and for illness incidence when the ACWR was <0.5.

Conclusion

The use of both absolute and relative workloads in the monitoring of an athlete's training load with the aim of minimising injury and illness risk and maximising performance in ultramarathon runners is recommended.

Efficacy and Safety of Fast-Acting Insulin Aspart in People with Type 1 Diabetes Using Carbohydrate Counting: A Post Hoc Analysis of Two Randomised Controlled Trials

INTRODUCTION

Insulin dosing based on carbohydrate counting is the gold standard for improving glycaemic control in type 1 diabetes (T1D). This post hoc analysis aimed to explore the efficacy and safety of fast-acting insulin aspart (faster aspart) according to bolus dose adjustment method in people with T1D.

METHODS

Post hoc analysis of two 26-week, treat-to-target, randomised trials investigating treatment with double-blind mealtime faster aspart, insulin aspart (IAsp), or open-label post-meal faster aspart (onset 1, n = 1143; onset 8, n = 1025). Participants with previous experience continued carbohydrate counting (onset 1, n = 669 [58.5%]; onset 8, n = 428 [41.8%]), while remaining participants used a bolus algorithm.

RESULTS

In onset 1, HbA1c reduction was statistically significantly in favour of mealtime faster aspart versus IAsp with carbohydrate counting (estimated treatment difference [ETD 95% CI] - 0.19% [- 0.30; - 0.09]; - 2.08 mmol/mol [- 3.23; - 0.93]). In onset 8, there was no statistically significant difference in HbA1c reduction with either dose adjustment method, although a trend towards improved HbA1c was observed for mealtime faster aspart with carbohydrate counting (ETD - 0.14% [- 0.28; 0.003]; - 1.53 mmol/mol [- 3.10; 0.04]). In both trials, bolus insulin doses and overall rates of severe or blood glucose-confirmed hypoglycaemia were similar between treatments across dose adjustment methods.

CONCLUSION

For people with T1D using carbohydrate counting, mealtime faster aspart may offer improved glycaemic control versus IAsp, with similar insulin dose and weight gain and no increased risk of hypoglycaemia.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01831765 (onset 1) and NCT02500706 (onset 8).

FUNDING

Novo Nordisk.

The effect of contract-relax-agonist-contract (CRAC) stretch of hamstrings on range of motion, sprint and agility performance in moderately active males: A randomised control trial

Background: Although stretching is done routinely to prevent injury during explosive sport activities, there is some concern that effective stretching might negatively impact on performance. Objectives: This study’s main objective was to investigate the impact of a specific stretch (CRAC), in which the muscle to be stretched, hamstrings, is actively contracted then relaxed. This is then followed by the antagonist muscle (quadriceps) contracting. Secondly, the impact of the stretch on performance was examined. Methods: A randomised control trial was used. Forty healthy active males between 21 and 35 years of age were assigned to either receive three repetitions of CRAC or rest. Hamstring flexibility and the Illinois Agility Test were the primary outcome measures. Results: The intervention was effective in improving hamstring flexibility by 37% immediately post-application and this was maintained for eight minutes thereafter. It had no significant effect on agility or sprint times. Conclusions: CRAC applied to stretch the hamstring muscles of active males resulted in a large increase of active knee extension range of motion, without decreasing performance. CRAC appears to be a safe and effective method of increasing the length of the hamstrings pre-sport activity and should be utilised by sports physiotherapists if deemed necessary and beneficial following initial assessment.

The effect of the contract-relax-agonist-contract (CRAC) stretch of hamstrings on range of motion, sprint and agility performance in moderately active males: A randomised control trial

Background

Although stretching is done routinely to prevent injury during explosive sport activities, there is some concern that effective stretching might negatively impact on performance.

Objective

This study's main objective was to investigate the impact of a specific stretch, the contract-relax-agonist-contract (CRAC) stretch, in which the muscle to be stretched, namely, the hamstrings, is actively contracted and then relaxed. This is followed by the antagonist muscle (the quadriceps) contracting. Secondly, the impact of the stretch on performance was examined.

Methods

A randomised control trial was used. Forty healthy active males between 21 and 35 years old were assigned to either receive three repetitions of CRAC or rest. Hamstring flexibility and the Illinois Agility Test were the primary outcome measures.

Results

The intervention was effective in improving hamstring flexibility by 37% immediately post-application and was maintained for eight minutes thereafter. It had no significant effect on agility or sprint times.

Conclusion

CRAC, when applied to stretch the hamstring muscles of active males, resulted in a large increase of active knee extension range of motion, without decreasing performance. Therefore, CRAC appears to be a safe and effective method of increasing the length of the hamstrings pre-sport activity and should be utilised by sports physiotherapists if deemed necessary. It was also shown to be beneficial following the initial assessment.

Fast-acting insulin aspart versus insulin aspart in the setting of insulin degludec-treated type 1 diabetes: Efficacy and safety from a randomized double-blind trial

AIM

To evaluate the efficacy and safety of mealtime or post-meal fast-acting insulin aspart (faster aspart) vs mealtime insulin aspart (IAsp), both in combination with insulin degludec, in participants with type 1 diabetes (T1D).

METHODS

This multicentre, treat-to-target trial (Clinical trial registry: NCT02500706, ClinicalTrials.gov) randomized participants to double-blind mealtime faster aspart (n = 342) or IAsp (n = 342) or open-label post-meal faster aspart (n = 341). The primary endpoint was change from baseline in HbA1c 26 weeks post randomization. All available information, regardless of treatment discontinuation, was used for evaluation of the effect.

RESULTS

Non-inferiority for the change from baseline in HbA1c was confirmed for mealtime and post-meal faster aspart vs IAsp (estimated treatment difference [ETD]: 95%CI, -0.02% [-0.11; 0.07] and 0.10% [0.004; 0.19], respectively). Mealtime faster aspart was superior to IAsp for 1-hour PPG increment using a meal test (ETD, -0.90 mmol/L [-1.36; -0.45]; P < 0.001). Self-monitored 1-hour PPG increment favoured faster aspart at breakfast (ETD, -0.58 mmol/L [-0.99; -0.17]; P = 0.006) and across all meals (-0.48 mmol/L [-0.74; -0.21]; P < 0.001). Safety profiles and overall rate of severe or blood glucose-confirmed hypoglycaemia were similar between treatments, but significantly less hypoglycaemia was seen 3 to 4 hours after meals with mealtime faster aspart.

CONCLUSION

Mealtime and post-meal faster aspart in conjunction with insulin degludec provided effective glycaemic control compared with IAsp, with no increased safety risk. Mealtime faster aspart provided PPG control superior to that of IAsp.

The effect of basal-bolus therapy varies with baseline 1,5-anhydroglucitol level in people with Type 2 diabetes: a post hoc analysis

AIMS

To investigate the impact of baseline 1,5-anhydroglucitol on the treatment effect of basal-bolus therapy in people with Type 2 diabetes.

METHODS

Post hoc analysis of onset 3, an 18-week, randomized, phase 3 trial evaluating the efficacy and safety of fast-acting insulin aspart in basal-bolus therapy (n = 116) vs. basal insulin-only therapy (n = 120) in people with Type 2 diabetes. The estimated treatment difference in change from baseline in HbA1c was investigated for different cut-off values of baseline 1,5-anhydroglucitol (2, 3, 4, 5 and 6 μg/ml).

RESULTS

The estimated treatment difference in change from baseline in HbA1c between basal-bolus therapy and basal insulin-only therapy was statistically significantly greater in participants with baseline 1,5-anhydroglucitol ≤3 μg/ml (n = 34) vs. >3 μg/ml (n = 198) [estimated treatment difference (95% CI): -1.53% (-2.12; -0.94) vs. -0.82% (-1.07; -0.57); P-value for interaction = 0.03]. The estimated treatment difference became more pronounced when comparing participants with 1,5-anhydroglucitol ≤2 μg/ml (n = 15) vs. >2 μg/ml (n = 217) [estimated treatment difference (95% CI): -2.26% (-3.15; -1.36) vs. -0.85% (-1.08; -0.62); P-value for interaction = 0.003]. For cut-off values ≥4 μg/ml, estimated treatment differences were numerically greater below the cut-off compared with above, although the interaction terms were not statistically significant.

CONCLUSION

This analysis indicates that people with Type 2 diabetes with low 1,5-anhydroglucitol have an added treatment benefit with basal-bolus therapy compared with people with higher 1,5-anhydroglucitol. Further research is needed to clarify any clinical utility of these findings. Clinical Trials Registry No: NCT01850615.

Preventing the seemingly unpreventable – challenging the return-to-play criteria for recurrent hamstring strain prevention

   Background: Hamstring strains are one of the most common injuries in sport. Previous injury has been found to be one of the greatest risk factors associated with recurrent hamstring strains. Although rehabilitation programmes have been developed and implemented to aid safe and efficient return-to-play, the incidence of hamstring injuries has not decreased.  Discussion: As hamstring strains most commonly occur during the eccentric phase of muscle action, rehabilitation should focus on eccentric muscle strengthening. The L-protocol and the Nordic Hamstring Exercise protocol strengthen the hamstring muscles eccentrically. They have been found to be effective in decreasing the incidence of new hamstring strains as well as the rate of recurrence. This commentary therefore aims to suggest changes to the return-to-play criteria following hamstring strains to prevent the seemingly unpreventable.

Once versus twice daily gentamicin dosing for infective endocarditis: a randomized clinical trial

OBJECTIVES

The aim of this randomized study was to investigate the effects of once versus twice daily gentamicin dosing on renal function and measures of infectious disease in a population with infective endocarditis (IE).

METHODS

Seventy-one IE patients needing gentamicin treatment according to guidelines were randomized to either once (n = 37) or twice daily (n = 34) doses of gentamicin. Kidney function (glomerular filtration rate, GFR) was measured with an isotope method ((51)Cr-EDTA) at the beginning of treatment and at discharge. Treatment efficacy was assessed by C-reactive protein (CRP) time to half-life, mean CRP and leukocytes.

RESULTS

Baseline GFR was similar in the two groups. Both groups displayed a significant fall in GFR from admission to discharge. The mean decrease in GFR was as follows: with once daily gentamicin, 17.0% (95% confidence interval 7.5-26.5), and with twice daily gentamicin, 20.4% (95% confidence interval 12.0-28.8). However, there was no significant difference in the GFR decrease between the once and twice daily regimens (p = 0.573). No difference in infection parameters was demonstrated between the two dosing regimens.

CONCLUSIONS

A twice daily gentamicin dosing regimen is neither less nephrotoxic nor more efficient than a once daily regimen in the treatment of IE patients. When indicated, gentamicin may therefore also be administered as a single-dose regimen in the treatment of IE patients.

In infectious endocarditis patients mortality is highly related to kidney function at time of diagnosis: a prospective observational cohort study of 231 cases

BACKGROUND

Infective endocarditis is a serious disease with a high mortality even with optimal treatment and care. A number of complicating conditions are known to be of importance for the outcome. But only few data are available in IE patients on the independent prognostic value of kidney function at the time of admittance.

METHODS

In a prospective observational cohort study data from 235 consecutive IE patients were collected at 2 tertiary heart centres in Copenhagen. Kidney function was evaluated as Estimated Endogenous Creatinine Clearance (EECC) calculated at the time of admission. Patients were divided into 4 groups according to their EECC: 1) >90 ml/min, 2) 60-90 ml/min, 3) 30-60 ml/min and 4) <30 ml/min. Mortality statistical analysis was then applied.

RESULTS

>Gender: 70.2% male, mean age: 61.3+/-SD 15.0. The most common pathogens were streptococcus species (32.9%) and Staphylococcus aureus (21.8%). Mean follow-up time was 453 days (SD 350). A total number of 76 patients died (32%), with an in-hospital mortality of 14%, and a post discharge mortality of 18%. In 64.9% EECC was decreased at time of admission, and a highly significant relationship between EECC and mortality was demonstrated, P<0.001. For every decrease of 10 ml/min in EECC we found an increase in Hazard Ratio for mortality of 23.1% (CI 13.2-33.8), P<0.001.

CONCLUSION

Decreased kidney function is prevalent in patients with endocarditis. Calculated EECC at the time of admission is easily obtained in all IE patients and has a high and independent predictive prognostic value for mortality.

Severity of gentamicin's nephrotoxic effect on patients with infective endocarditis: a prospective observational cohort study of 373 patients

BACKGROUND

Gentamicin is often used to treat infective endocarditis (IE). Gentamicin is highly effective, but its applicability is reduced by its nephrotoxic effect. The aim of this study was to quantify the nephrotoxic effect of gentamicin and the association between the nephrotoxic effect and mortality in patients with IE.

METHODS

A prospective observational cohort study was performed at 2 tertiary university hospitals in Copenhagen from October 2002 through October 2007; 373 consecutive patients with IE were included. A total of 287 (77%) of the patients received gentamicin treatment (median duration, 14 days); dosage was adjusted according to daily serum creatinine and trough serum gentamicin levels. Kidney function was determined by estimated endogenous creatinine clearance (EECC). Statistical correlation between gentamicin and EECC change was analyzed, and the association between mortality and nephrotoxicity was investigated.

RESULTS

The primary bacteriological etiologies were as follows: Streptococcus species (37.1%), Staphylococcus aureus (18.2%), and Enterococcus species (16.1%). In the gentamicin group, the mean EECC change was an 8.6% decrease, but in the no-gentamicin group, the mean change was an increase of 2.3% (P = .05). The decrease in EECC was significantly correlated with the duration of gentamicin treatment: a 0.5% EECC decrease per day of gentamicin treatment (P = .002). The decrease in EECC during hospitalization was not related to postdischarge mortality. The mean duration of follow-up was 562 days.

CONCLUSIONS

The nephrotoxic effect of gentamicin is directly related to treatment duration, with a decrease in EECC of 0.5% per day of gentamicin treatment. In patients treated with gentamicin, the in-hospital decrease in EECC was not related to postdischarge mortality. Consequently, this study does not support abolishment of gentamicin in treatment of IE.

Heat susceptibility of aquatic mycobacteria

An investigation was carried out to measure the heat susceptibility of opportunistic mycobacteria frequently isolated from domestic water supply systems. The study was conducted under standardized conditions designed to resemble those found in oligotrophic aquatic habitats. Strains of the following species were tested: Mycobacterium avium, M. chelonae, M. fortuitum, M. intracellulare, M. kansasii (two strains), M. marinum, M. phlei, M. scrofulaceum, and M. xenopi. Suspensions of the test strains were exposed to temperatures of 50, 55, 60, and 70 degrees C; samples were taken at defined intervals to determine the concentration of survivors. From these data, the decimal reduction times were calculated for each test strain and test temperature. The results indicate that M. kansasii is more susceptible to heat than Legionella pneumophila, whereas the heat susceptibilities of M. fortuitum, M. intracellulare, and M. marinum lie in the same order of magnitude as that of L. pneumophila. The strains of M. avium, M. chelonae, M. phlei, M. scrofulaceum, and M. xenopi were found to be more thermoresistant than L. pneumophila, with the highest resistance being found in M. xenopi. Thermal measures to control L. pneumophila may therefore not be sufficient to control the last five mycobacterial species in contaminated water systems.