eLetters

70 e-Letters

published between 2019 and 2022

  • Low DHEA causes Covid-19 Infection and Subsequent Pathology. Exercise Increases DHEA

    I suggest the basis of the Ezzatvar, et al., report is increased dehydroepiandrosterone (DHEA). It is known exercise increases DHEA. It is my hypothesis of 2020 that low DHEA is linked to the severity of Covid-19 infection and subsequent pathology (© Copyright 2020, James Michael Howard, Fayetteville, Arkansas, U.S.A.) New research, 2022, regarding DHEA has been published that supports my hypothesis that severe Covid-19 illness is associated with low DHEA: “COVID-19 patients with altered steroid hormone levels are more likely to have higher disease severity,” ( 2022 Jul 30. doi: 10.1007/s12020-022-03140-6.) “DHEA was an independent indicator of the disease severity with COVID-19.”

  • RE: Device-measured physical activity, adiposity and mortality

    Tarp et al. evaluated the associations of total and intensity-specific physical activity and all-cause mortality (1). Compared with the obese-low total physical activity reference, the hazard ratios (HRs) (95% confidence intervals [CIs]) of subjects with normal weight-high total activity and obese-high total activity for mortality were 0.59 (0.44 to 0.79) 0.67 (0.48 to 0.94), respectively. In contrast, the HR (95% CI) of subjects with normal weight-low total physical activity for mortality was 1.28 (0.99 to 1.67). Physical activity has a preventive effect on mortality regardless of obesity, and I have some comments about the study with special reference to sedentary time and aging.

    Li et al. reported that the adjusted HRs (95% CIs) of daily sedentary time per 1 hour increase for all-cause mortality was 1.03 (1.01-1.05) and significant increase of the adjusted HR was observed in subjects with daily sedentary time of 8 or longer (2). This means that physically inactive lifestyle has an effect on increased risk in mortality, and physical activity and sedentary behaviour should be checked simultaneously. In addition, I suppose that the content of physical activity should be specified; such as leisure-time and work-related activity.

    Yang et al. conducted a meta-analysis to evaluate the effect of physical activity and sedentary behaviour over adulthood on all-cause and cause-specific mortality (3). They clarified that active subjects over adulthood was significantl...

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  • About data collection process, statistical analysis and interpretation of the reported findings

    I read with great interest the study by Atakan et al., (2022) where they summarize existing evidence regarding the effect of high intensity interval training (HIIT) and sprint interval training (SIT) over fat oxidation during sub-maximal intensity exercise. An impaired fat oxidation is a common feature of patients with obesity and type 2 diabetes. Thus, this meta-analysis provides novel information that could be used by physicians and personal trainers to improve the metabolic health of the above mentioned populations. In this rapid response, I discuss several issues regarding data collection process, statistical modelling and interpretation of the reported findings that raised up after a deep analysis of the studies included in this meta-analysis.

    The first meta-analysis of this study evaluated the effect of HIIT/SIT over exercise fat oxidation, summarizing the data from nine studies (Fig. 1). The findings of this meta-analysis are reported in g/min, nevertheless, Arad et al. (60) reported fat oxidation (Fox) relative to fat-free mass (mg∙kg FFM-1∙ min-1), Nybo et al. (30) reported Fox in kJ/min while Zapata-Lamana et al. (64) reported the relative contribution of lipids to energy expenditure. Of note, the authors do not report to request the fat oxidation in g/min from these studies (see data extraction section). Then, ¿How did the authors computed Fox in g∙min-1?

    Otherwise, Astorino et al. (44) and Schubert et al (33), evaluated the effect of both HIIT a...

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  • Re: Successful 10-second one-legged stance predicts survival in middle-aged and older individuals.

    Dear Editor,

    Dr Araujo and colleagues have demonstrated the utility for mortality risk assessment of the 10-second one leg standing (10s-OLS) test,1 colloquially known as the “flamingo test” (although every amateur ornithologist will know that the 10s-OLS test posture, illustrated in Figure 1 of Araujo et al., is different from that adopted by a flamingo, and that many other birds adopt a single-legged stance when roosting). The 10s-OLS test is easily administered, safe, and simply categorised (binary yes/no), so should be easy to apply in clinical practice. Failure to achieve 10s-OLS (“NO 10s-OLS”) was found to be associated with patient age, high waist-height ratio, and prevalence of diabetes mellitus.

    Contrary to the view expressed by Dr Araujo and colleagues that "balance assessment is not routinely incorporated in the clinical examination",1 we suggest that most neurologists would include such an assessment in the neurological examination, particularly in older patients,2 and invariably if there is a complaint of imbalance or falling. Hence for neurologists, the findings of the study beg questions about underlying neurobiological mechanisms. Aside from speculating that "subclinical central or autonomic nervous system dysfunction" might contribute, the authors do not specifically address these issues, other than to indicate the exclusion from the study of patients with unstable gait or with signs of acute vestibular or otoneuro...

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  • Reply to: ‘Comment on: Isometric exercise versus high-intensity interval training for the management of blood pressure: a systematic review and meta-analysis by Edwards et al.’ by Wewege et al.

    Reply to: ‘Comment on: Isometric exercise versus high-intensity interval training for the management of blood pressure: a systematic review and meta-analysis by Edwards et al.’ by Wewege et al.

    Edwards, J.J., Wiles, J.D., & O’Driscoll, J.M.

    School of Psychology and Life Sciences, Canterbury Christ Church University, Kent, CT1 1QU

    Correspondence to Dr Jamie O’Driscoll, School of Psychology and Life Sciences, Canterbury Christ Church University, North Holmes Road, Canterbury, Kent, CT1 1 QU. Email: jamie.odriscoll@canterbury.ac.uk; Telephone: 01227922711.

    We thank Wewege et al. (1) for their assessment and comments on our recent work (2), highlighting their concerns over the employed statistical analysis approach, which they suggest may “invalidate the results”.

    We take these comments seriously and have therefore re-performed the analysis as suggested by Wewege et al. (1) and individually addressed the points raised within this rapid response.

    Wegewe et al. (1) state that the marked differences found in our study “contrast previous findings”, with reference to a previous large-scale network meta-analysis by Naci et al. (3). As detailed, Naci et al. (3) did not include high intensity interval training (HIIT), and the lower blood pressure (BP) changes observed can be attributed to a combination of differences to the present study, including a smaller pool of lower quality iso...

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  • Small steps, but based on the right conclusions?

    Dear Editor,

    As a general practitioner and specialist in the musculoskeletal system, I have read the article
    “Small Steps, strong shield: directly measured moderate physical activity in 65361 adults is associated with significant protective affects from severe COVID-19 outcomes” from Steenkamp et al with great interest. The covid epidemic has put a huge burden of disease on the entire world and is weighing heavily on the capacity of healthcare. More and more is known about risk and protective factors for individuals to become severely ill from COVID-19 and this study contributes to this. In addition, prevention of disease is becoming an increasingly important task of health care, partly in order to curb rising healthcare costs.(1) Good physical condition can help prevent certain diseases as mentioned in the article.

    The authors have collected a large dataset from a very large group of people in South Africa. What is missing in the analysis, however, is data on BMI. Studies show that BMI is an important risk factor for severe course of COVID-19. A high BMI, or adiposity, is one of the strongest reported risk factors for severe COVID-19. (2). In this study, the BMI was available in only 50% of the study population. Authors claim that when adding BMI to the model it did not alter the outcome for severe COVID-19 disease for the different physical activity groups. The authors attribute this to associated diseases such as hypertension and DM2, however researc...

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  • Exercise prehabilitation during neoadjuvant chemotherapy may enhance tumour regression in oesophageal cancer?

    Dear editor,
    I read with great appreciation the study “Exercise prehabilitation during neoadjuvant chemotherapy may enhance tumour regression in oesophageal cancer: results from a prospective non-randomised trial” [1]. The authors aimed to evaluate the clinical impact of a structured exercise intervention in patients with operable oesophageal cancer during Neoadjuvant chemotherapy compared with those on a standard treatment pathway (p. 1); and for that, they carried out a prospective non-randomised trial. The paper has an elegant rationale and I am sure that will generate new research, however, exist some methodological fragile that may compromise the results.

    1st, as this study specifically assessed the impact of exercise on measures of chemotherapy response (p. 1), the exercise program should be clearly described (e.g., exercise volume, time under tension, duration, cadence and range of motion, heart and respiratory rate). 2nd, the authors established moderate intensity for exercise, based on WHO recommendations for physical activity level (p. 2), however, physical activity is different of physical exercise; besides, they did not use the repetition-maximum [2] test to assess the strength of the patients and plan the intensity individually.

    3rd, the authors added aerobic exercise (p. 2) to the structured program, but it was unclear how patients were assessed for this intervention (what velocity? Incline? Heart rate? Vo2?). 4th, the strategy for sample...

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  • Reply to dr. Arts et al. on Reply on “Cost-effectiveness of full endoscopic versus open discectomy for sciatica” P. Gadjari et al., Br J Sports Med 2022”

    Dear editor,
    On behalf of the PTED study group, we would like to thank the authors for the rapid response on our recently published paper “Cost-effectiveness of Full Endoscopic versus Open Discectomy for Sciatica [1]. The authors mention that they don’t agree with the conclusion of this study and have several comments. Below we will respond to these comments.

    Firstly, the authors suggest that “another study design is needed to investigate cost-effectiveness of PTED above conventional microdiscectomy.” We strongly disagree. The study design was an economic evaluation alongside a pragmatic randomized controlled trial examining the cost-effectiveness of full-endoscopic versus open discectomy for sciatica. An economic evaluation alongside a pragmatic randomised controlled trial is considered an adequate design, because it provides timely information on an intervention’s cost-effectiveness with high internal and sufficient external validity [2]. Furthermore, the study design was peer reviewed by the grant agency (ZONMW in the Netherlands) and we have pre-published our study protocol in an open access, peer reviewed journal [3], supported in a covenant agreement including the Dutch Neurosurgical Society (NVvN), Dutch Orthopedical Society (NOV), Dutch Spine Society and the Dutch Association for patients with low back pain (NVVR).

    Secondly, the authors comment that “costs associated with endoscope equipment and disposables were not included in their cost measur...

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  • Is time loss a good indicator of hamstring injury severity in professional male football (soccer) players?

    Dear Editor,

    We read with great interest the article by Gronwald et al. that investigated the injury inciting events of moderate and severe acute hamstring injuries in professional male football (soccer) players with systematic video analysis.1 Despite the pain-taking reviewing of videos and motion analyses by the authors, there are still some practical concerns over injury severity and subject recruitment.

    Taking into account the importance of injury severity assessment that served as the basis for study subject enrollment in that study, the use of time loss to represent the severity of injury may not be optimal when considering other factors that may contribute to a prolonged rest after injury. For instance, pre-existing hamstring conditions including hamstring strings, proximal hamstring tendinopathy, or referred posterior thigh pain are not uncommon among soccer players.2 Following this argument, the recruitment of study subjects based on club or physician registration without meeting more objective criteria and without excluding those with previous hamstring injuries through a medical record review may introduce bias regarding the determination of injury severity. In this aspect, magnetic resonance imaging (MRI), which was available in 87% (45 out of 52 cases for pattern hamstring injury categorisation), may be a more reliable tool for evaluation because of its ability to show the extent of injury and the reported correlation between the size of injury a...

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  • Data Capture

    I would like to commend the authors on highlighting the risk factors for concussion in Rugby Football Union. This type of research is essential for current and future guidance and therefore to be referenced it must be of the highest academic standard.
    Don Gatherer and David Hamilton have published several papers on cervical assessment in rugby and have huge experience in the biomechanical function, action, rehabilitation, and measurement of the cervical spine especially at International Rugby Football Union level.
    It is with regret that we are writing to express our great concerns regarding the recent study published in BJSM in particular the prudence of the Testing Protocols and how the findings may be misleading and the results mis-interpreted.
    There are a number of methodological issues with this study which will have contributed to the misinterpretation of their results and subsequent conclusions.
    The scientific methodology construct of isometric testing of the Head, Neck, and Upper Shoulder Girdle (HNS) must be based upon the correct application of the principles defined in Newton’s Laws of Motion.

    The Aim of this study is to produce and measure a validated ISOMETRIC FORCE MAXIMA
    To clarity, the test action can be precisely stated as ‘the measurement of a one isometric voluntary muscle contraction repetition maxima’ - 1IVMCmax

    Principles and Forces related to this study.

    INTRINSIC FORCE
    • Head, Neck, and Upper S...

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