Pulmonary Aspects of Exercise and Sports

Symptom Duration, Recurrence, and Long-Term Effects of Swimming-Induced Pulmonary Edema: A 30-Month Follow-Up Study

BACKGROUND

Swimming-induced pulmonary edema (SIPE) has been reported to subside within 24 to 48 h, but comprehensive follow-up studies on symptom duration and long-term effects are missing.

RESEARCH QUESTION

What are the symptom duration, recurrence, and long-term effects of SIPE?

STUDY DESIGN AND METHODS

A follow-up study was conducted, based on 165 cases of SIPE from Sweden's largest open-water swimming event with 26,125 individuals participating during 2017-2019. Data on patient characteristics, clinical findings, and symptoms were collected at admission. Telephone interviews at 10 days and 30 months were performed to explore symptom duration, recurrence of SIPE symptoms, need for medical evaluation, and long-term effects of self-assessed general health and physical activity level.

RESULTS

Follow-up at 10 days was performed for 132 cases and at 30 months for 152 cases. Most of the patients were women, and their mean age was 48 years. At the 10-day follow-up, symptom duration > 2 days after the swimming race was reported by 38%. The most common symptoms were dyspnea and cough. In patients at 30-month follow-up, recurrence of respiratory symptoms during open-water swimming was reported by 28%. In multivariable logistic regression, asthma was independently associated with both symptom duration > 2 days and recurrence of SIPE symptoms (P = .045 and P = .022, respectively). Most participants reported equal or improved general health (93%) and physical activity level (85%) after experiencing SIPE, but 58% had not swum in open water since the event.

INTERPRETATION

The present large cohort study challenges the established hallmark of SIPE symptom duration < 48 h, whereas SIPE recurrence was in the previously reported range. At 30 months, most patients reported unchanged self-assessed general health and physical activity level. These findings add to our understanding of the course of SIPE and can provide evidence-based information to swimmers and health care professionals.

Sex-Specific Physiological Responses to Ultramarathon

PURPOSE

Despite a growing body of literature on the physiological responses to ultramarathon, there is a paucity of data in females. This study assessed the female physiological response to ultramarathon and compared the frequency of perturbations to a group of race- and time-matched males.

METHODS

Data were collected from 53 contestants of an ultramarathon trail race at the Ultra-Trail du Mont-Blanc (UTMB®) in 2018/19. Before and within 2 h of the finish, participants underwent physiological assessments, including blood sampling for biomarkers (creatine kinase-MB isoenzyme [CK-MB], cardiac troponin I [cTnI], brain natriuretic peptide [BNP], and creatinine [Cr]), pulmonary function testing (spirometry, exhaled NO, diffusing capacities, and mouth pressures), and transthoracic ultrasound (lung comet tails, cardiac function). Data from eight female finishers (age = 36.6 ± 6.9 yr; finish time = 30:57 ± 11:36 h:min) were compared with a group of eight time-matched males (age = 40.3 ± 8.3 yr; finish time = 30:46 ± 10:32 h:min).

RESULTS

Females exhibited significant pre- to postrace increases in BNP (25.8 ± 14.6 vs 140.9 ± 102.7 pg·mL -1 ; P = 0.007) and CK-MB (3.3 ± 2.4 vs 74.6 ± 49.6 IU·L -1 ; P = 0.005), whereas males exhibited significant pre- to postrace increases in BNP (26.6 ± 17.5 vs 96.4 ± 51.9 pg·mL -1 ; P = 0.002), CK-MB (7.2 ± 3.9 vs 108.8 ± 37.4 IU·L -1 ; P = 0.002), and Cr (1.06 ± 0.19 vs 1.23 ± 0.24 mg·dL -1 ; P = 0.028). Lung function declined in both groups, but males exhibited additional reductions in lung diffusing capacities (DL CO = 34.4 ± 5.7 vs 29.2 ± 6.9 mL⋅min -1 ⋅mm Hg -1 , P = 0.004; DL NO = 179.1 ± 26.2 vs 152.8 ± 33.4 mL⋅min -1 ⋅mm Hg -1 , P = 0.002) and pulmonary capillary blood volumes (77.4 ± 16.7 vs 57.3 ± 16.1 mL; P = 0.002). Males, but not females, exhibited evidence of mild postrace pulmonary edema. Pooled effect sizes for within-group pre- to postrace changes, for all variables, were generally larger in males versus females ( d = 0.86 vs 0.63).

CONCLUSIONS

Ultramarathon negatively affects a range of physiological functions but generally evokes more frequent perturbations, with larger effect sizes, in males compared to females with similar race performances.

Incidence of Swimming-Induced Pulmonary Edema: A Cohort Study Based on 47,600 Open-Water Swimming Distances

Background

Despite increasing awareness of swimming-induced pulmonary edema (SIPE), large population-based studies are lacking and the incidence is unknown.

Research Question

What is the incidence of SIPE in a mixed group of competitive and recreational swimmers during a large open-water swimming event?

Methods

In four consecutive years (2016-2019), a prospective cohort study was conducted during Sweden’s largest open-water swimming event, Vansbrosimningen. All swimmers seeking medical care with acute respiratory symptoms were eligible for the study. SIPE diagnosis was based on clinical findings in 2016 and 2017 and pulmonary edema assessed by lung ultrasound in 2018 and 2019. Data on patient characteristics, clinical findings, and information about the race were collected.

Results

Based on 47,573 consecutive swimming distances, 322 patients with acute respiratory symptoms (0.68%; CI, 0.61%-0.75%) were treated at the mobile medical unit. Of these, 211 patients (0.44%; CI, 0.39%-0.51%) received a diagnosis of SIPE. The annual incidence of SIPE was 0.34%, 0.47%, 0.41%, and 0.57%, respectively, from 2016 through 2019. Most patients diagnosed with SIPE were women (90%), despite about equal percentages of men and women participating (47% men and 53% women). The incidence of SIPE overall was 0.75% in women and 0.09% in men. The incidence increased with age, from 0.08% in the youngest age group (18-30 years) to 1.1% in the oldest age group (≥ 61 years). Based on multiple logistic regression analysis, the adjusted odds for SIPE occurring was 8.59 times higher for women compared with men and 12.74 times higher for the oldest age group compared with the youngest age group.

Interpretation

The incidence of SIPE over 4 years during a large open-water swimming event in Sweden was 0.44%. The incidence was higher in women than in men and increased with age.

The "Angiogenic Switch" and Functional Resources in Cyclic Sports Athletes

Regular physical activity in cyclic sports can influence the so-called “angiogenic switch”, which is considered as an imbalance between proangiogenic and anti-angiogenic molecules. Disruption of the synthesis of angiogenic molecules can be caused by local changes in tissues under the influence of excessive physical exertion and its consequences, such as chronic oxidative stress and associated hypoxia, metabolic acidosis, sports injuries, etc. A review of publications on signaling pathways that activate and inhibit angiogenesis in skeletal muscles, myocardium, lung, and nervous tissue under the influence of intense physical activity in cyclic sports. Materials: We searched PubMed, SCOPUS, Web of Science, Google Scholar, Clinical keys, and e-LIBRARY databases for full-text articles published from 2000 to 2020, using keywords and their combinations. Results: An important aspect of adaptation to training loads in cyclic sports is an increase in the number of capillaries in muscle fibers, which improves the metabolism of skeletal muscles and myocardium, as well as nervous and lung tissue. Recent studies have shown that myocardial endothelial cells not only respond to hemodynamic forces and paracrine signals from neighboring cells, but also take an active part in heart remodeling processes, stimulating the growth and contractility of cardiomyocytes or the production of extracellular matrix proteins in myofibroblasts. As myocardial vascularization plays a central role in the transition from adaptive heart hypertrophy to heart failure, further study of the signaling mechanisms involved in the regulation of angiogenesis in the myocardium is important in sports practice. The study of the “angiogenic switch” problem in the cerebrovascular and cardiovascular systems allows us to claim that the formation of new vessels is mediated by a complex interaction of all growth factors. Although the lungs are one of the limiting systems of the body in cyclic sports, their response to high-intensity loads and other environmental stresses is often overlooked. Airway epithelial cells are the predominant source of several growth factors throughout lung organogenesis and appear to be critical for normal alveolarization, rapid alveolar proliferation, and normal vascular development. There are many controversial questions about the role of growth factors in the physiology and pathology of the lungs. The presented review has demonstrated that when doing sports, it is necessary to give a careful consideration to the possible positive and negative effects of growth factors on muscles, myocardium, lung tissue, and brain. Primarily, the “angiogenic switch” is important in aerobic sports (long distance running). Conclusions: Angiogenesis is a physiological process of the formation of new blood capillaries, which play an important role in the functioning of skeletal muscles, myocardium, lung, and nervous tissue in athletes. Violation of the “angiogenic switch” as a balance between proangiogenic and anti-angiogenic molecules can lead to a decrease in the functional resources of the nervous, musculoskeletal, cardiovascular, and respiratory systems in athletes and, as a consequence, to a decrease in sports performance.

Immersion pulmonary oedema in a healthy diver not exposed to cold or strenuous exercise

In healthy divers, the occurrence of immersion pulmonary oedema (IPE) is commonly caused by contributory factors including strenuous exercise, cold water and negative-pressure breathing. Contrary to this established paradigm, this case reports on a 26-year-old, well-trained combat swimmer who succumbed to acute IPE during static immersion in temperate (21°C) water, while using a front-mounted counterlung rebreather. The incident occurred during repeated depth-controlled ascent practice at the French military diving school. It was discovered that the diver had attempted to stop any gas leakage into the system by over-tightening the automatic diluent valve (ADV) (25th notch of 27) during the dive, thus causing a high resistance to inspiratory flow. The ventilatory constraints imposed by this ADV setting were assessed as a 3.2 Joules·L⁻¹ inspiratory work of breathing and -5 kPa (-50 mbar) transpulmonary pressure. This report confirms the key role of negative pressure breathing in the development of interstitial pulmonary oedema. Such a breathing pattern can cause a lowering of thoracic, airway and interstitial lung pressure, leading to high capillary pressure during each inspiration. Repetition of the diving drills resulted in an accumulation of interstitial lung water extravasation, causing pathological decompensation and proven symptoms.