| 1. |
- Sjöström, Rita, et al.
(author)
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Qualitative identification and characterisation of self-reported symptoms arising in humans during experimental exposure to cold air
- 2019
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In: International Journal of Circumpolar Health. - : Taylor & Francis. - 1239-9736 .- 2242-3982. ; 78:1
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Journal article (peer-reviewed)abstract
- Background: Exposure to cold air is associated with increased morbidity and mortality in the general population. It is difficult to study the effects of whole-body exposure to cold air under controlled conditions in real life. Objectives: The aim of this study was to (1) explore and describe the experience of symptoms in humans during experimental and controlled exposures to cold air, by using controlled environmental chamber exposures and qualitative methodology, and to (2) categorise the symptoms. Method: The study used a randomised, double blind design, in which 34 subjects undertook rest and moderate-intensity exercise in an environmental chamber set to two or three different temperatures (0, -10, and -17 degrees C) on separate occasions. During the chamber exposures, subjects were interviewed. Qualitative content analysis was selected as the method of analysis. Findings: Subjects reported 50 distinct symptoms during the exposures. The symptoms were grouped into ten sub-categories and two major categories; airway versus whole-body symptoms. Conclusion: We have identified a broad range of symptoms in humans undertaking rest and moderate-intensity exercise at sub-zero temperatures. The symptoms and their categories may well be used to more extensively and quantitatively map cold-induced morbidity.
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| 2. |
- Ahokas, E K, et al.
(author)
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Minimal effect of water immersion on markers of inflammation and muscle damage after intensive exercise
- 2019
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In: Proc Physiol Soc 44.
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Conference paper (peer-reviewed)abstract
- Water immersion methods, such as cold water immersion and contrast water therapy are popular recovery interventions after athletic training and competition. Nevertheless, post-exercise cold water immersion may actually inhibit hypertrophic signalling pathways and muscle adaptation to training (1). It is has been commonly assumed that the mechanism of impaired training adaptation is mediated by blunted inflammatory responses to muscle-damaging exercise, although this assumption has been questioned by recent data (2). A weakness of previous studies is omission of active recovery in water immersion interventions, which would arguably be utilised in addition to water immersion by athletic populations. The aim of this study was to compare the influence of three water immersion methods, performed after active recovery, on inflammatory responses to muscle-damaging exercise. Nine male participants (age 20-35 y) performed an intensive exercise protocol, consisting of maximal jumps and sprinting, on four occasions. After each trial, participants completed one of four recovery protocols in a randomised, crossover design (ACT, active recovery only, 10 min cycling; heart rate 120-140 b/min; CWI, active recovery followed by 10 min cold water immersion, 10°C; TWI, active recovery followed by 10 min temperate water immersion, 24°C and CWT, active recovery followed by contrast water therapy, 10 min alternating 10°C and 38°C in 1 min cycles). The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethical review board. Venous blood samples were collected pre-exercise and 5 min, 60 min, 24 h, 48 h and 96 h post-exercise, then analysed for myocyte chemoattractant protein 1 (MCP-1) and creatine kinase (CK) using ELISA and high-sensitivity C-reactive protein (hs-CRP) using a chemiluminescence assay. Two-way repeated measures ANOVA was used to compare biomarker concentrations between groups over time. There were no differences in biomarker concentrations during exercise and recovery between groups across the six time points, however main effects of time were present for all three markers (MCP-1: F(2.32, 18.56) = 23.1, p < 0.0001; CK: F(2.059, 16.47) = 8.74, p = 0.002; hs-CRP: F(1.07, 8.57 = 13.8, p = 0.005). Tukey’s post-hoc analysis of simple time effects revealed increases in MCP-1 at post-5 min versus pre in all groups except CWT. In TWI and CWI, MCP-1 was still elevated above pre at 60 min post-exercise. hs-CRP peaked at 24 h post-exercise in all groups. CK was elevated at post-60 versus pre in all groups and at post-24 except in CWT. Our findings suggest that use of cold or thermoneutral water immersion in combination with active recovery may slightly prolong the immediate post-exercise elevation in MCP-1 but have minimal overall effect on markers of inflammation and muscle damage.
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| 3. |
- Hanstock, Helen, 1989-, et al.
(author)
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Tear Lactoferrin and Lysozyme as Clinically Relevant Biomarkers of Mucosal Immune Competence
- 2019
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In: Frontiers in Immunology. - Lausanne : Frontiers Media S.A.. - 1664-3224. ; 10
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Journal article (peer-reviewed)abstract
- Tears have attracted interest as a minimally-invasive biological fluid from which to assess biomarkers. Lactoferrin (Lf) and lysozyme (Lys) are abundant in the tear fluid and have antimicrobial properties. Since the eye is a portal for infection transmission, assessment of immune status at the ocular surface may be clinically relevant. Therefore, the aim of this series of studies was to investigate the tear fluid antimicrobial proteins (AMPs) Lf and Lys as biomarkers of mucosal immune status. To be considered biomarkers of interest, we would expect tear AMPs to respond to stressors known to perturb immunity but be robust to confounding variables, and to be lower in participants with heightened risk or incidence of illness. We investigated the relationship between tear AMPs and upper respiratory tract infection (URTI; study 1) as well as the response of tear AMPs to prolonged treadmill exercise (study 2) and dehydration (study 3). Study 1 was a prospective cohort study conducted during the common cold season whereas studies 2 and 3 used repeated-measures crossover designs. In study 1, tear Lys concentration (C) as well as tear AMP secretion rates (SRs) were lower in individuals who reported pathogen-confirmed URTI (n = 9) throughout the observation period than in healthy, pathogen-free controls (n = 17; Lys-C, P = 0.002, d = 0.85; Lys-SR, P < 0.001, d = 1.00; Lf-SR, P = 0.018, d = 0.66). Tear AMP secretion rates were also lower in contact lens wearers. In study 2, tear AMP SRs were 42–49% lower at 30 min−1 h post-exercise vs. pre-exercise (P < 0.001, d = 0.80–0.93). Finally, in study 3, tear AMPs were not influenced by dehydration, although tear AMP concentrations (but not secretion rates) displayed diurnal variation. We conclude that Lf and Lys have potential as biomarkers of mucosal immune competence; in particular, whether these markers are lower in infection-prone individuals warrants further investigation.
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