A mixed method, phase 2 clinical evaluation of a novel device to treat postpartum haemorrhage.

BACKGROUND: We evaluated the safety, efficacy, and acceptability of a new device designed to facilitate uterine compression in women with postpartum haemorrhage (PPH). METHODS: A prospective, phase two clinical device trial with concurrent qualitative study, conducted in a UK consultant obstetric unit. The device was used in addition to standard care in women unresponsive to initial oxytocin therapy. The primary effectiveness outcome was additional blood loss of over 1000mls, whilst safety was assessed through adverse events. Interviews assessed device feasibility and acceptability, and were analysed using framework analysis. RESULTS: We recruited 57 women with clinical PPH after vaginal birth; 67% were primiparous and 47% had undergone operative birth. All but two (96%) had atony as a cause of the haemorrhage; in addition, 30% also had bleeding from lacerations and 11% had retained tissue. After device use, only one woman had additional blood loss over 1000mls, although 3 women (7%) needed a Bakri balloon and 14% received a blood transfusion. All but one clinician felt that the device was easy to use. Clinicians stated that the device assisted management in 85% of cases. All 56 women who responded stated that if they bled in a future birth they would want the device to be used again. There were no serious adverse events related to the device. However, 3 events were judged as 'possibly' being caused by the device - 2 minor vaginal grazes and one postnatal episiotomy infection and breakdown. Lax vaginal tissue complicated the use of the device in three women. In 47 interviews, participants, birth partners, clinician users and attending midwives viewed the device positively. Clinicians found it useful as a way of stopping blood loss and as an aid to diagnose the source of bleeding. CONCLUSIONS: The PPH Butterfly may provide a rapid, acceptable and effective treatment for postpartum haemorrhage. Clinical Trial Registration prospective with ISRCTN15452399 11/09/2017 (www.isrctn.com/ISRCTN15452399).

Inflammatory and psychological consequences of chronic high exposure firefighting.

OBJECTIVES: This study aimed to examine the impact of extreme heat exposure frequency on inflammation and well-being in UK Fire Service personnel. METHODS: 136 Fire personnel and 14 controls (CON) were recruited [92 Firefighters (FF), 44 Breathing Apparatus Instructors (BAI)]. BAI were split into low (LBAI; ≤15 exposures per month) and high (HBAI; ≥20 exposures per month) categories. Measures of inflammation, mood and fatigue were collected at 0, 3 and 6 month times points. These variables were analysed for differences between groups and association with frequency of exposure. RESULTS: HBAI exhibited raised IL-1ß, IL-6, IL-10, IgE and lower IgM (p < 0.05). In addition, IL-1ß, IL-6, IL-10 and IgM were associated with monthly exposure number, with exposures accounting for 15.4% of the variance in IL-6, 11.8% of IL-1ß and 25.2% of IL-10. No differences in mood or fatigue were reported (p > 0.05). CONCLUSION: High exposure firefighting consistently causes systemic inflammation without perceptual recognition of potential health risks.

Pain Neuroscience Education and Motor Control Exercises versus Core Stability Exercises on Pain, Disability, and Balance in Women with Chronic Low Back Pain.

Background: Several interventions have been used to relieve chronic low back pain (CLBP). This study aimed to compare the effects of pain neuroscience education (PNE) followed by motor control exercises (MCEs) with core stability training (CST) on pain, disability, and balance in women with CLBP. Methods: Thirty-seven women with CLBP were randomly divided into two groups of PNE/MCE (n = 18, 55.2 ± 2.6 years) or CST (n = 19, 54.6 ± 2.4 years). Eight weeks of PNE/MCE or CST were prescribed for each group, independently. Pain intensity (VAS scale), disability (Roland Morris Disability Questionnaire), unipodal static balance, and dynamic balance (time up and go test) were measured at the beginning and 8 weeks after the intervention. Two-way mixed ANOVA was used to analyze the results with alpha of 5%. Results: After 8 weeks, there was a significant difference in VAS scale between groups (p = 0.024), with both PNE/MCE and CST showing 58% and 42% reductions, respectively. There were no differences for all other variables between groups. Regarding pre- to post-comparisons, both groups showed improvements in all dependent variables (p < 0.001). Conclusion: The treatment with PNE/MCE was more effective in improving pain disability and unipodal static and dynamic balance than treatment with CST. Even so, both treatments were shown to be valid and safe in improving all dependent variables analyzed in women with CLBP.

Exercise hyperthermia induces greater changes in gastrointestinal permeability than equivalent passive hyperthermia.

Hyperthermia and exertional heat illness increase gastrointestinal (GI) permeability, although whether the latter is only via hyperthermia is unclear. The aim of this pilot study was to determine whether different changes in GI permeability, characterized by an increased plasma lactulose:rhamnose concentration ratio ([L:R]), occurred in exercise hyperthermia in comparison to equivalent passive hyperthermia. Six healthy adult male participants (age 25 ± 5 years, mass 77.0 ± 6.7 kg, height 181 ± 6 cm, peak oxygen uptake [ V·O2peak ] 48 ± 8 ml.kg-1 .min-1 ) underwent exercise under hot conditions (Ex-Heat) and passive heating during hot water immersion (HWI). Heart rate (HR), rectal temperature (TCORE ), rating of perceived exertion (RPE), and whole-body sweat loss (WBSL) were recorded throughout the trials. The L:R ratio, peak HR, change in HR, and change in RPE were higher in Ex-Heat than HWI, despite no differences in trial duration, peak core temperature or WBSL. L:R was strongly correlated (p < 0.05) with HR peak (r = 0.626) and change in HR (r = 0.615) but no other variable. The greater L:R in Ex-Heat, despite equal TCORE responses to HWI, indicates that increased cardiovascular strain occurred during exercise, and exacerbates hyperthermia-induced GI permeability at the same absolute temperature.

The BabySaver: Design of a New Device for Neonatal Resuscitation at Birth with Intact Placental Circulation.

The initial bedside care of premature babies with an intact cord has been shown to reduce mortality; there is evidence that resuscitation of term babies with an intact cord may also improve outcomes. This process has been facilitated by the development of bedside resuscitation surfaces. These new devices are unaffordable, however, in most of sub-Saharan Africa, where 42% of the world's 2.4 million annual newborn deaths occur. This paper describes the rationale and design of BabySaver, an innovative low-cost mobile resuscitation unit, which was developed iteratively over five years in a collaboration between the Sanyu Africa Research Institute (SAfRI) in Uganda and the University of Liverpool in the UK. The final BabySaver design comprises two compartments; a tray to provide a firm resuscitation surface, and a base to store resuscitation equipment. The design was formed while considering contextual factors, using the views of individual women from the community served by the local hospitals, medical staff, and skilled birth attendants in both Uganda and the UK.

Exercise heat acclimation and post-exercise hot water immersion improve resting and exercise responses to heat stress in the elderly.

OBJECTIVES: To investigate the efficacy of heat acclimation (HA) in the young (YEX) and elderly (EEX) following exercise-HA, and the elderly utilising post-exercise hot water immersion HA (EHWI). DESIGN: Cross-sectional study. METHOD: Twenty-six participants (YEX: n = 11 aged 22 ±â€¯2 years, EEX:n = 8 aged 68 ±â€¯3 years, EHWI: n = 7 aged 73 ±â€¯3 years) completed two pre-/post-tests, separated by five intervention days. YEX and EEX exercised in hot conditions to raise rectal temperature (Trec) ≥38.5 °C within 60 min, with this increase maintained for a further 60 min. EHWI completed 30 min of cycling in temperate conditions, then 30 min of HWI (40 °C), followed by 30 min seated blanket wrap. Pre- and post-testing comprised 30 min rest, followed by 30 min of cycling exercise (3.5 W·kg-1 Hprod), and a six-minute walk test (6MWT), all in 35 °C, 50% RH. RESULTS: The HA protocols did not elicit different mean heart rate (HR), Trec, and duration Trec ≥ 38.5 °C (p > 0.05) between YEX, EEX, and EHWI groups. Resting Trec, peak skin temperature, systolic and mean arterial pressure, perceived exertion and thermal sensation decreased, and 6MWT distance increased pre- to post-HA (p < 0.05), with no difference between groups. YEX also demonstrated a reduction in resting HR (p < 0.05). No change was observed in peak Trec or HR, vascular conductance, sweat rate, or thermal comfort in any group (p > 0.05). CONCLUSIONS: Irrespective of age or intervention, HA induced thermoregulatory, perceptual and exercise performance improvements. Both exercise-HA (EEX), and post-exercise HWI (EHWI) are considered viable interventions to prepare the elderly for heat stress.

Extreme occupational heat exposure is associated with elevated haematological and inflammatory markers in Fire Service Instructors.

NEW FINDINGS: What is the central question of this study? Fire service instructors are frequently exposed to live fire scenarios, representing the most extreme chronic occupational heat exposure. These individuals report a series of unique health issues. We sought to identify whether the number of exposures completed was associated with inflammatory and immunological markers and symptoms of ill health. What is the main finding and its importance? Fire service instructors exhibit greater levels of inflammatory markers in comparison to firefighters. The number of exposures to fire is positively related to the prevalence of ill health and inflammation. Implementation of a proposed limit of nine exposures per month might be appropriate to minimize health issues. ABSTRACT: Fire Service Instructors (FSIs) experience ∼10 times more fire exposures than firefighters (FFs), and the increased physiological stress from this potentially puts them at risk of ill health and future cardiac events. The aim of the study was to establish whether FSIs exhibit elevated biomarkers associated with cardiac event risk, identify whether FSIs experience systemic inflammation linked to the frequency of fire exposure and evaluate a proposed exposure limit of nine exposures per month. Blood samples were collected from 110 Fire Service personnel (mean ± SD, age,44 ± 7 years; height, 178.1 ± 7.1 cm; and body mass, 84.3 ± 12.0 kg; FSIs n = 53 and FFs n = 57) for biomarker analysis. Work history details were collected from all participants. Participants with biomarker concentrations above healthy reference ranges were classified as being 'at risk'. The neutrophil-to-lymphocyte ratio, platelet count, cardiac troponin T, interleukin (IL)-6, IL-1ß, C-reactive protein and immunoglobulin G were greater in FSIs than in FFs (P < 0.05). Multiple regression analysis revealed that 18.8% of IL-6, 24.9% of IL-1ß, 29.2% of C-reactive protein and 10.9% of immunoglobulin G variance could be explained by the number of exposures to heat per month. Odds ratios revealed that those FSIs above the nine per month exposure limit were six to 12 times more likely to be classified as 'at risk' and were 16 times more likely to experience symptoms of ill health. Increased cytokine levels suggest that FSIs experience systemic inflammation, which is related to symptoms of ill health. We propose that an exposure limit could reduce the prevalence of these biomarker risk factors and ill health.

Differences in Achilles tendon stiffness in people with gout: a pilot study.

BACKGROUND: Gout has been associated with weaker foot/leg muscles and altered gait patterns. There is also evidence of on-going foot pain and an increased risk of tendinopathy, with the Achilles and patella tendons most frequently affected in gout. Additionally, the inflammation associated with gout may change tissue elasticity. Ultrasound imaging utilising shear wave elastography (SWE) offers a non-invasive method of quantifying changes in tendon stiffness. SWE findings have not previously been reported in individuals with gout. We sought to determine differences in Achilles tendon stiffness in people with gout compared to controls (non-gout). METHODS: A cross sectional study comparing 24 people with gout and 26 age/sex-matched controls. Clinical and demographic data were collated, and US imaging used to determine tendon thickness, presence of gouty tophi and/or aggregates and levels of angiogenesis. Ten shear wave elastography (SWE) measures were taken along the centre of a longitudinal section of the mid-portion of each Achilles tendon. Prior to data collection, intra-observer error was good (>0.69). Data were summarised using descriptive statistics and a repeated measures ANCOVA was used to compare SWE measures between the two groups for the left and right foot separately after accounting for Body Mass Index (BMI). RESULTS: A small proportion of those with gout presented with intra-tendon aggregates and/or intra-tendon tophi in one or both tendons. There was no statistically significant difference in tendon thickness between groups. Neo-vascularity was present in a third of gout participants. SWE findings demonstrated significantly reduced tendon stiffness in those with gout compared to controls: right Achilles mdiff =1.04 m/s (95% CI (0.38 to 1.7) p = 0.003 and left Achilles mdiff = 0.7 m/s (95% CI 0.09 to 1.32) p = 0.025. No relationship between the presence of tophi and SWE values were detected. CONCLUSION: Subjects with chronic gout show significantly reduced Achilles tendon stiffness compared to non-gout controls. From a clinical standpoint, our findings were similar to SWE measurements in subjects with Achilles tendinopathy and who did not have gout.

Integrin-associated ILK and PINCH1 protein content are reduced in skeletal muscle of maintenance haemodialysis patients.

KEY POINTS: Patients with renal failure undergoing maintenance haemodialysis are associated with insulin resistance and protein metabolism dysfunction. Novel research suggests that disruption to the transmembrane protein linkage between the cytoskeleton and the extracellular matrix in skeletal muscle may contribute to reduced amino acid metabolism and insulin resistance in haemodialysis. ILK, PINCH1 and pFAKTyr397 were significantly decreased in haemodialysis compared to controls, whereas Rac1 and Akt2 showed no different between groups. Rac1 deletion in the Rac1 knockout model did not alter the expression of integrin-associated proteins. Phenylalanine kinetics were reduced in the haemodialysis group at 30 and 60 min post meal ingestion compared to controls; both groups showed similar levels of insulin sensitivity and ß-cell function. Key proteins in the integrin-cytoskeleton linkage are reduced in haemodialysis patients, suggesting for the first time that integrin-associated proteins dysfunction may contribute to reduced phenylalanine flux without affecting insulin resistance in haemodialysis patients. ABSTRACT: Muscle atrophy, insulin resistance and reduced muscle phosphoinositide 3-kinase-Akt signalling are common characteristics of patients undergoing maintenance haemodialysis (MHD). Disruption to the transmembrane protein linkage between the cytoskeleton and the extracellular matrix in skeletal muscle may contribute to reduced amino acid metabolism and insulin resistance in MHD patients. Eight MHD patients (age: 56 ± 5 years: body mass index: 32 ± 2 kg m-2 ) and non-diseased controls (age: 50 ± 2 years: body mass index: 31 ± 1 kg m-2 ) received primed continuous l-[ring-2 H5 ]phenylalanine before consuming a mixed meal. Phenylalanine metabolism was determined using two-compartment modelling. Muscle biopsies were collected prior to the meal and at 300 min postprandially. In a separate experiment, skeletal muscle tissue from muscle-specific Rac1 knockout (Rac1 mKO) was harvested to investigate whether Rac1 depletion disrupted the cytoskeleton-integrin linkage, allowing for cross-model examination of proteins of interest. ILK, PINCH1 and pFAKTyr397 were significantly lower in MHD (P < 0.01). Rac1 and Akt showed no difference between groups for the human trial. Rac1 deletion in the Rac1 mKO model did not alter the expression of integrin-associated proteins. Phenylalanine rates of appearance and disappearance, as well as metabolic clearance rates, were lower in the MHD group at 30 and 60 min post meal ingestion compared to controls (P < 0.05). Both groups showed similar levels of insulin sensitivity and ß-cell function. Key proteins in the integrin-cytoskeleton linkage are reduced in MHD patients, suggesting for the first time that integrin-associated proteins dysfunction may contribute to reduced phenylalanine flux without affecting insulin resistance in haemodialysis patients.

Ingestion of lean meat elevates muscle inositol hexakisphosphate kinase 1 protein content independent of a distinct post-prandial circulating proteome in young adults with obesity.

BACKGROUND: We have recently shown that a novel signalling kinase, inositol hexakisphosphate kinase 1 (IP6K1), is implicated in whole-body insulin resistance via its inhibitory action on Akt. Insulin and insulin like growth factor 1 (IGF-1) share many intracellular processes with both known to play a key role in glucose and protein metabolism in skeletal muscle. AIMS: We aimed to compare IGF/IP6K1/Akt signalling and the plasma proteomic signature in individuals with a range of BMIs after ingestion of lean meat. METHODS: Ten lean [Body mass index (BMI) (in kg/m2): 22.7 ±â€¯0.4; Homeostatic model assessment of insulin resistance (HOMAIR): 1.36 ±â€¯0.17], 10 overweight (BMI: 27.1 ±â€¯0.5; HOMAIR: 1.25 ±â€¯0.11), and 10 obese (BMI: 35.9 ±â€¯1.3; HOMAIR: 5.82 ±â€¯0.81) adults received primed continuous L-[ring-13C6]phenylalanine infusions. Blood and muscle biopsy samples were collected at 0 min (post-absorptive), 120 min and 300 min relative to the ingestion of 170 g pork loin (36 g protein and 5 g fat) to examine skeletal muscle protein signalling, plasma proteomic signatures, and whole-body phenylalanine disappearance rates (Rd). RESULTS: Phenylalanine Rd was not different in obese compared to lean individuals at all time points and was not responsive to a pork ingestion (basal, P = 0.056; 120 & 300 min, P > 0.05). IP6K1 was elevated in obese individuals at 120 min post-prandial vs basal (P < 0.05). There were no acute differences plasma proteomic profiles between groups in the post-prandial state (P > 0.05). CONCLUSIONS: These data demonstrate, for the first time that muscle IP6K1 protein content is elevated after lean meat ingestion in obese adults, suggesting that IP6K1 may be contributing to the dysregulation of nutrient uptake in skeletal muscle. In addition, proteomic analysis showed no differences in proteomic signatures between obese, overweight or lean individuals.

Heat tolerance of Fire Service Instructors.

OBJECTIVES: Fire Service Instructors (FSI) experience repeated fire exposures a median of 13 ±â€¯8 times a month; consequently they may develop an acclimatised state. However, the chronic immunological implications of heat acclimation are yet to be understood. This study aimed to establish whether FSI exhibit an increased heat tolerance and altered immunological response to heat exposures, compared to non-exposed individuals. The study also aimed to identify if heat tolerance is related to symptoms of ill health. METHODS: Twenty-two participants were recruited: 11 FSI (age: 41 ±â€¯7 yrs, body mass: 77.4 ±â€¯12.2 kg, height: 174.1 ±â€¯8.2 cm) and 11 non-exposed controls (CON) (age: 41 ±â€¯7 yrs, body mass: 75.9 ±â€¯12.2 kg, height: 177.0 ±â€¯8.1 cm). Participants completed a 40 min heat occupational tolerance test (HOTT) exercising at 6 W kg-1 (50.0 ±â€¯1.0 °C, 12.3 ±â€¯3.3% relative humidity) on two occasions, separated by 2 months. Physiological and perceptual measures were collected throughout and venous blood samples were collected prior to and post exposure. RESULTS: FSI displayed significantly reduced peak rectal temperature (Tre) (-0.42 °C), change in Tre (-0.33 °C), and thermal sensation (-1.0) and increased sweat rate (+0.25 L h-1) at the end of the HOTT compared to CON (p < 0.05). FSI exhibited similar responses to the HOTT as CON for all haematological variables. However, resting interleukin-6, interleukin-1ß, and immunoglobulin G were significantly greater in FSI than CON. There was no difference in responses following the 2 month working period. FSI peak Tre was negatively correlated with symptoms of ill health (rpb = -0.473, p = 0.026) and the number of fire exposures in the previous 2 weeks (rs = -0.589, p = 0.004). CONCLUSION: Despite increased heat tolerance compared to non-exposed individuals, FSI may develop a maladaptation to repeated fire exposures, with elevated resting cytokine levels and an increased prevalence of ill health symptoms.

Fire service instructors' working practices: A UK survey.

Analysis of Fire Service Instructors (FSI) working practices and health is needed to minimise health risks related to heat illness, cardiovascular events and immunological stress. Online surveys were distributed to UK FSI and Firefighters (FF). One hundred and thirty FSI (age: 43 ± 7yrs) and 232 FF (age: 41 ± 8yrs) responded. FSI experienced 2-10 live fires per week, with 45% of FSI reporting management does not set a limit on the number of exposures. Few FSI followed hydration guidelines, or cooling methods. New symptoms of ill health were reported by 41% of FSI and 21% of FF. FSI with ≥11 Breathing Apparatus exposures per month were 4.5 times (95% CI 1.33-15.09) more likely to experience new symptoms. A large proportion of FSI are experiencing new symptoms of illness after starting their career, and guidelines on exposure and hydration are not universally in place to reduce the risk of future health problems.

The acute effect of training fire exercises on fire service instructors.

Fire service instructors (FSI) regularly experience different types of fire exercises, however the strain experienced from these scenarios is not well understood. This study aims to identify the physiological and perceptual strain of Fire Service Instructors (FSI) to three training exercises: DEMO, ATTACK, COMPARTMENT, and the different roles performed: SETTER, INSTRUCTOR. The study also aims to assess the effect that different exercise patterns over a day (BOX, MULTI, COMBINATION) have on immunological responses. Sixteen FSI (age: 41 ± 8 years, body mass: 83.7 ± 6.7 kg, height: 177.0 ± 6.7 cm) were recruited, with 10 FSI completing the three exercises. Physiological and perceptual measures were collected prior to and immediately post each exercise. Venous blood samples were collected at the beginning and end of each day. One-way analysis of variance (ANOVA) were conducted to assess differences in physiological variables between exercise types, independent samples t-tests were conducted between roles. Day changes in hematological variables were assessed by paired sample t-tests and analyzed by one-way ANOVAs to identify differences between exercise patterns. The COMPARTMENT exercise resulted in a greater change in rectal temperature (ΔTre) (0.49 ± 0.28 °C) than both the DEMO (0.23 ± 0.19 °C, p = 0.045) and ATTACK (0.27 ± 0.22 °C, p = 0.016). Within the COMPARTMENT exercise, the SETTER resulted in a greater ΔTre and rating of perceived exertion than the INSTRUCTOR (0.67 ± 0.29 °C vs. 0.43 ± 0.18 °C, p = 0.027 and 14 ± 2 vs. 11 ± 2, p = 0.001, respectively). Following a day of fire exercises white blood cells (WBC), neutrophils, lymphocytes (LYMPH), monocytes (MONO), platelets (PLT), mean platelet volume (MPV), Interleukin (IL)-6, and cardiac troponin T (cTnT) all increased (p < 0.05). Exercise patterns containing a COMPARTMENT exercise resulted in greater PLT, MPV, and IL-6. Total daily variation in ΔTre was correlated with post-exercise WBC, MONO, and LYMPH. COMPARTMENT exercises produce the greatest physiological strain, with the SETTER role within this exercise causing the greatest ΔTre. Although predominately physiological responses remain within safe limits. Exercise patterns that include a COMPARTMENT exercise also generate a greater inflammatory response.

A new occupational heat tolerance test: A feasibility study.

Heat tolerance tests identify those susceptible to heat illnesses and monitor heat adaptations. Currently, tolerance tests do not replicate the uncompensable heat strain environments experienced in some occupations. In addition, tests can take up to 2 h to complete, and cannot offer intra and inter individual comparisons, due to the use of a fixed exercise intensity. This study aimed to assess the validity and reliability of a new heat occupational tolerance test (HOTT: 40 min at 6 W kg-1 metabolic heat production, 50 °C 10% RH, in protective clothing) to the standard heat tolerance test (HTT: 2 h walk at 5 km h-1 1% gradient, 40 °C 40% RH, in shorts and t-shirt). Eighteen participants (age: 21 ±â€¯3 yrs, body mass: 81.3 ±â€¯5.9 kg) completed trials to assess the validity and/or reliability of the HOTT. Peak rectal temperature (Tre) displayed strong agreement and low measurement error (0.19 °C) between HTT (38.7 ±â€¯0.4 °C) and HOTT (38.6 ±â€¯0.4 °C). Strong agreement was also displayed for physiological and perceptual measures between the two HOTT trials, including peak Tre (38.5 ±â€¯0.4 °C vs. 38.5 ±â€¯0.4 °C) and peak heart rate (182 ±â€¯20 b min-1 vs. 182 ±â€¯21 b min-1). The HOTT is the first tolerance test that assesses individuals' responses whilst wearing protective clothing in high temperatures. It can consistently identify individuals' levels of heat tolerance within a reduced time frame. In addition, it allows for participant monitoring over time and comparisons between individuals to be made. A continuum based approach is recommended when assessing individuals' responses to the HOTT.

Practical pre-cooling methods for occupational heat exposure.

This study aimed to identify a pre-cooling method to reduce the physiological and perceptual strain, and the inflammatory response, experienced by individuals who wear personal protective equipment. Eleven males (age 20 ±â€¯2 years, weight 75.8 ±â€¯9.3 kg, height 177.1 ±â€¯5.0 cm) completed 15min pre-cooling (phase change vest [PCV], forearm cooling [ARM], ice slurry consumption [ICE], or a no cooling control [CON]) and 45min intermittent walk (4  km h-1, 1% gradient) in 49.5 ±â€¯0.6 °C and 15.4 ±â€¯1.0% RH, whilst wearing firefighter ensemble. ICE reduced rectal temperature (Tre) before heat exposure compared to CON (ΔTre: 0.24 ±â€¯0.09 °C, p < 0.001, d = 0.38) and during exercise compared to CON, ARM, and PCV (p = 0.026, ηp2 = 0.145). Thermal sensation was reduced in ICE and ARM vs. CON (p = 0.018, ηp2 = 0.150). Interleukin-6 was not affected by pre-cooling (p = 0.648, ηp2 = 0.032). It is recommended that those wearing protective equipment consume 500 ml of ice slurry 15min prior to work to reduce physiological and perceptual strain.

High-Intensity Exercise Decreases IP6K1 Muscle Content and Improves Insulin Sensitivity (SI2*) in Glucose-Intolerant Individuals.

Context: Insulin resistance (IR) in skeletal muscle contributes to whole body hyperglycemia and the secondary complications associated with type 2 diabetes. Inositol hexakisphosphate kinase-1 (IP6K1) may inhibit insulin-stimulated glucose transport in this tissue type. Objective: Muscle and plasma IP6K1 were correlated with two-compartment models of glucose control in insulin-resistant hyperinsulinemic individuals. Muscle IP6K1 was also compared after two different exercise trials. Design: Nine prediabetic [hemoglobin A1c; 6.1% (0.2%)] patients were recruited to take part in a resting control, a continuous exercise (90% of lactate threshold), and a high-intensity exercise trial (6 30-second sprints). Muscle biopsies were drawn before and after each 60-minute trial. A labeled ([6,62H2]glucose) intravenous glucose tolerance test was performed immediately after the second muscle sample. Results: Fasting muscle IP6K1 content did not correlate with insulin sensitivity (SI2*) (P = 0.961). High-intensity exercise reduced IP6K1 muscle protein and messenger RNA expression (P = 0.001). There was no effect on protein IP6K1 content after continuous exercise. Akt308 phosphorylation of was significantly greater after high-intensity exercise. Intermittent exercise reduced hepatic glucose production after the same trial. The same intervention also increased SI2*, and this effect was significantly greater compared with the effect of continuous exercise improvements. Our in vitro experiment demonstrated that the chemical inhibition of IP6K1 increased insulin signaling in C2C12 myotubes. Conclusions: The in vivo and in vitro approaches used in the current study suggest that a decrease in muscle IP6K1 may be linked to whole body increases in SI2*. In addition, high-intensity exercise reduces hepatic glucose production in insulin-resistant individuals.