Off- to in-season body composition adaptations in elite male and female endurance and power event athletics competitors: an observational study.

BACKGROUND: Monitoring elite athletes' body composition (BC) is vital for health and optimizing performance in sports emphasizing leanness, such as athletics. This study aims to investigate and compare sex- and event-specific off-to in-season BC changes in endurance and power event athletics competitors. METHODS: Elite male and female endurance athletes (> 800 m runners; n = 21) and power event athletes (sprinters, jumpers; n = 32) underwent dual-energy X-ray absorptiometry (DXA) scans for whole and regional lean mass (LM), fat mass (FM), bone mineral content (BMC), and density (BMD) during off-season (September-October) and in-season (April-May). Linear mixed models tested between-group off-season differences in BC, within-group off-season to in-season changes, and between-group differences in change. To assess meaningful or least significant changes (LSC) in BC, DXA precision errors were determined from two consecutive total body scans in a subsample of athletes (n = 30). RESULTS: Male athletes (n = 26) gained significantly (p < 0.05) more body mass (BM; mean difference 1.5 [95% confidence interval (CI):0.5-2.4] kg), LM (843 [95% CI:-253:1459] g), and trunk LM (756 [-502:1156] g) than female athletes (n = 27). The proportion of changes in athlete's BC exceeding the LSC threshold for LM and trunk LM were 70% and 65% in males, and 48% and 26% in females. Significant (p < 0.05) within-group off-season to in-season increases in LM were found for male endurance and power athletes, and female power athletes. All groups significantly increased BMD (p < 0.05). Only male and female power athletes had significant in- to-off-season increases in BMC. 80% of all athletes who had a meaningful increase in BMC belonged to the power event group. No significant within- or between group change in FM was observed. CONCLUSIONS: The present study found that male athletes gained more BM, LM and trunk LM than females. Within-group increases in regional and whole-body LM and BMC were predominantly found among power event competitors. Incorporating individual meaningful changes alongside traditional statistics provided additional insights into sex and event-group differences. Future research on elite athletic event groups should include DXA measurements closer to major outdoor-season competitions, coupled with site-specific measures (ultrasound, MRI) for better detection of subtle changes in LM and FM.

[Pre-duty medical assessment in fire-fighters requires modernization - relevance of exercise ECG is questioned]. / Oklar nytta av upprepade arbets-EKG hos brandmän.

Medical assessment of Swedish smoke diving firefighters includes cardiac evaluation by maximal exercise testing with ECG recording. The exercise ECG procedure for firefighters was introduced in 1986, and remains consistent in the recently updated guidelines from 2019.  Exercise ECG is a non-invasive and easily available method for detection of chronic coronary syndromes, but due to the declining population risk in high-income countries, its ability to accurately detect disease has decreased. Thus, the clinical relevance of exercise ECG in firefighters is questioned and the pre-duty medical assessment requires modernization.

Exercise-induced ST depression in an asymptomatic population without coronary artery disease.

Objectives. Exercise electrocardiogram (ExECG) in low risk populations frequently generates false positive ST depression. We aimed to characterize factors that are associated with exercise-induced ST depression in asymptomatic men without coronary artery disease. Design. Cycle ergometer exercise tests from 509 male firefighters without imaging proof of significant coronary artery disease were analysed. Analysed test data included heart rate at rest before exercise, and workload, blood pressure, heart rate, ST depression and ST segment slope at peak exercise. ST depression of >0.1 mV was considered significant (STdep). With a mean follow-up of 6.1 ± 1.7 years, medical records were reviewed for cardiovascular diagnoses, hyperlipidemia and diabetes. Logistic regression analysis was used for risk assessment. Results. In total, 22% had STdep in ≥1 lead. Subjects with STdep were older than those with normal ExECG (p < .001). Downsloping STdep was more common in extremity leads (9%) than in precordial leads (2%). STdep was categorized according to location (precordial/extremity) and slope direction into eight categories. Larger age-adjusted heart rate increase predicted STdep in seven categories (p < .05). Age-adjusted peak heart rate correlated with STdep in five categories, predominantly where the ST slope was positive. Peak blood pressure and exercise capacity were both associated with STdep in few categories. We found no association between STdep and hypertension, hyperlipidemia or diabetes (all p > .05). Conclusions. In asymptomatic men with a physically demanding occupation and no coronary artery disease, both age and heart rate response were associated with ST depression, whereas common cardiovascular risk factors, blood pressure response and exercise capacity were not.

ST/HR variables in firefighter exercise ECG - relation to ischemic heart disease.

Exercise electrocardiography (ExECG) is regularly performed by Swedish firefighters by law. Heart rate-corrected analysis of ST segment variables (ST/HR) has shown improved prediction of ischemic heart disease (IHD) compared to ST depression alone. This has not previously been extensively studied in asymptomatic persons with a low probability of IHD. We therefore evaluated the predictive performance of ST/HR analysis in firefighter ExECG. ExECG was studied in 521 male firefighters. During 8.4 ± 2.1 years, 2.3% (n = 12) were verified with IHD by catheterization or myocardial scintigraphy (age 51.5 ± 5.5 years) and were compared with firefighters without imaging proof of IHD (44.2 ± 10.1 years). The predictive value of ST depression, ST/HR index, ST/HR slope, and area and rotation of the ST/HR loop was calculated as age-adjusted odds ratios (OR), in 10 ECG leads. Predictive accuracy was analyzed with receiver operating characteristics (ROC) analysis. ST/HR index ≤-1.6 µV/bpm and ST/HR slope ≤-2.4 µV/bpm were associated with increased IHD risk in three individual leads (all OR > 1.0, P < 0.05). ST/HR loop area lower than the fifth percentile of non-IHD subjects indicated IHD risk in V4, V5, aVF, II, and -aVR (P < 0.05). ST depression ≤-0.1 mV was associated with IHD only in V4 (OR, 9.6, CI, 2.3-40.0). ROC analysis of each of these variables yielded areas under the curve of 0.72 or lower for all variables and leads. Clockwise-rotated ST/HR loops was associated with increased risk in most leads compared to counterclockwise rotation. The limited clinical value of ExECG in low-risk populations was emphasized, but if performed, ST/HR analysis should probably be given more importance.

Loaded treadmill walking and cycle ergometry to assess work capacity: a retrospective comparison in 424 firefighters.

The fitness of firefighters is regularly evaluated using exercise tests. We aimed to compare, with respect to age and body composition, two test modalities for the assessment work capacity. A total of 424 Swedish firefighters with cycle ergometer (CE) and treadmill (TM) tests available from Jan 2004 to Dec 2010 were included. We compared results from CE (6 min at 200 W, 250 W or incremental ramp exercise) with TM (6 min at 8° inclination, 4·5 km h-1 or faster, wearing 24-kg protective equipment). Oxygen requirements were estimated by prediction equations. It was more common to pass the TM test and fail the supposedly equivalent CE test (20%), than vice versa (0·5%), P<0·001. Low age and tall stature were significant predictors of passing both CE and TM tests (P<0·05), while low body mass predicted accomplishment of TM test only (P = 0·006). Firefighters who passed the TM but failed the supposedly equivalent CE test within 12 months had significantly lower body mass, lower BMI, lower BSA and shorter stature than did those who passed both tests. Calculated oxygen uptake was higher in TM tests compared with corresponding CE tests (P<0·001). Body constitution affected approval differently depending on the test modality. A higher approval rate in TM testing suggests lower cardiorespiratory requirements compared with CE testing, even though estimated oxygen uptake was higher during TM testing. The relevance of our findings in relation to the occupational demands needs reconsidering.

Guided Internet-delivered cognitive behavioural therapy in patients with non-cardiac chest pain - a pilot randomized controlled study.

BACKGROUND: Patients with recurrent episodes of non-cardiac chest pain may experience cardiac anxiety and avoidance behavior, leading to increased healthcare utilization. These patients might benefit from help and support to evaluate the perception and management of their chest pain. The purpose of this study was to test the feasibility of a short guided Internet-delivered cognitive behavioural therapy (CBT) program and explore the effects on cardiac anxiety, fear of body sensations, depressive symptoms, and chest pain in patients with non-cardiac chest pain, compared with usual care. METHODS: A pilot randomized controlled study was conducted. Fifteen patients with non-cardiac chest pain with cardiac anxiety or fear of body sensations, aged 22-76 years, were randomized to intervention (n = 7) or control (n = 8) groups. The four-session CBT program contained psychoeducation, physical activity, and relaxation. The control group received usual care. Data were collected before and after intervention. RESULTS: Five of seven patients in the intervention group completed the program, which was perceived as user-friendly with comprehensible language, adequate and varied content, and manageable homework assignments. Being guided and supported, patients were empowered and motivated to be active and complete the program. Patients in both intervention and control groups improved with regard to cardiac anxiety, fear of body sensations, and depressive symptoms, but no significant differences were found between the groups. CONCLUSIONS: The Internet-delivered CBT program seems feasible for patients with non-cardiac chest pain, but needs to be evaluated in larger groups and with a longer follow-up period. TRIAL REGISTRATION: Clinicaltrials.gov NCT02336880 . Registered on 8 January 2015.

Imaging Congestion With a Pocket Ultrasound Device: Prognostic Implications in Patients With Chronic Heart Failure.

BACKGROUND: Venous congestion is common in patients with chronic heart failure (HF). We used a pocket-sized ultrasound imaging device (PID) to assess the patients' congestive status and related our findings to prognosis. METHODS AND RESULTS: One hundred four consecutive outpatients from an HF outpatient clinic were studied. Interstitial lung water (ILW), pleural effusion (PE), and the diameter of the inferior vena cava (VCI) were assessed with the use of a PID. ILW was assessed by demonstration of B-lines (comet tail artifact (CTA). Out of the 104 patients, 28 had CTA and 8 had PE. Median VCI diameter was 18 mm (interquartile range 14-22 mm). Each of these parameters correlated weakly (r = 0.26-0.37; P < .05) with the HF biomarker N-terminal pro-B-type natriuretic peptide (NT-proBNP). During the median follow-up time of 530 days, 18 hospitalizations and 14 deaths were registered. Findings of CTA, PE, or both increased the risk of death or hospitalization (hazard ratio 3-4; P < .05). After adjustment for age, cardiac systolic function, and NT-proBNP, this difference remained significant for CTA alone and CTA + PE combined, but not for PE alone. CONCLUSIONS: With the use of a handheld ultrasound device, signs of pulmonary congestion could be demonstrated. When found, these had a significant prognostic impact in clinically stable HF.

Pocket-sized ultrasound examination of fluid imbalance in patients with heart failure: a pilot and feasibility study of heart failure nurses without prior experience of ultrasonography.

BACKGROUND: Detecting fluid imbalance in patients with chronic heart failure can be challenging. Use of a pocket-sized ultrasound device (PSUD) in addition to physical examination can be helpful to assess this important information. AIM: To evaluate the feasibility for nurses without prior experience of ultrasonography to examine fluid imbalance by the use of a PSUD on heart failure patients. METHOD: Four heart failure nurses and an expert cardiologist participated. The nurses underwent a four-hour PSUD training programme. One hundred and four heart failure outpatients were included. The examinations obtained information of pulmonary congestion, pleural effusion and the diameter of the vena cava inferior. RESULTS: Examinations took nine minutes on average. In 28% and 14% of the patients, pulmonary congestion and pleural effusion respectively were found by the nurses. The sensitivities and specificities for nurses' findings were 79% and 91%, and, 88% and 93% respectively. The inter-operator agreement between the nurses and the cardiologist reached a substantial level (kappa values: 0.71 and 0.66). The inter-operator agreement for vena cava inferior reached a fair level (kappa value=0.39). Bland-Altman plots of the level of agreement revealed a mean difference of vena cava inferior diameter of 0.11 cm, while the 95% lower and upper limits ranged from -0.78 cm to 1.00 cm. CONCLUSION: After brief training, heart failure nurses can reliably identify pulmonary congestion and pleural effusion with a PSUD. Assessment of vena cava inferior was less valid. PSUD readings, when added to the history and a physical examination, can improve nurse assessment of fluid status in patients with heart failure.

Neutrophil leukocyte motility requires directed water influx.

The ability of neutrophils to sense and move to sites of infection is essential for our defense against pathogens. For motility, lamellipodium extension and stabilization are prerequisites, but how cells form such membrane protrusions is still obscure. Using contrast-enhanced video microscopy and Transwell assays, we show that water-selective aquaporin channels regulate lamellipodium formation and neutrophil motility. Addition of anti-aquaporin-9 antibodies, HgCl(2), or tetraethyl ammonium inhibited the function(s) of the channels and blocked motility-related shape changes. On human neutrophils, aquaporin-9 preferentially localized to the cell edges, where N-formyl peptide receptors also accumulated, as assessed with fluorescence microscopy. To directly visualize water fluxes at cell edges, cells were loaded with high dilution-sensitive, self-quenching concentrations of fluorophore. In these cells, motile regions always displayed increased fluorescence compared with perinuclear regions. Our observations provide the first experimental support for motility models where water fluxes play a pivotal role in cell-volume increases accompanying membrane extensions.