Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study

Assessment of gastrointestinal health in racing Alaskan sled dogs using capsule endoscopy and inflammatory cytokines

OBJECTIVES

Exercise-induced gastrointestinal syndrome occurs in dogs and people and might compromise athlete performance by increasing intestinal permeability and causing gastrointestinal erosions. Racing sled dogs often receive acid suppressant prophylaxis which decreases the incidence of gastric erosions induced by exercise. The objectives were to quantify intestinal injury by measuring serum pro-inflammatory cytokine concentrations before and after exercise and to evaluate gastrointestinal mucosa using video capsule endoscopy after exercise.

MATERIALS AND METHODS

Prospective study of 12 racing Alaskan sled dogs receiving approximately 1 mg/kg omeprazole once daily from the day before the race until race completion. Blood was drawn before and 8 to 10 hours after an endurance race for the quantification of cytokines. Gastrointestinal tract mucosa was assessed with video capsule endoscopy immediately post-race.

RESULTS

Eight of nine dogs (89%; 95% confidence interval 52 to 100%) had gastric erosions; all dogs (100%, 95% confidence interval 63 to 100%) had small intestinal erosions. Most of the dogs (seven of nine) had straw or foreign material present. Cytokine levels were not different from before to after the race.

CLINICAL SIGNIFICANCE

Video capsule endoscopy identified gastrointestinal tract mucosal erosions after exercise in all dogs receiving once-daily omeprazole treatment, though other causes for the lesions besides exercise are possible.

Gastrointestinal bleeding in athletes

Gastrointestinal (GI) bleeding (GIB) in athletes has previously been reported in several studies, as an important factor of underperformance in competitive sports events. Yet it is still underreported, partly because it is usually occult and self-limited soon after the effort. It can originate in either the upper or the lower GI tract and can be proportionally related to the amount and duration of effort. Key pathophysiological factors seem to include splanchnic hypoperfusion, mechanical trauma of the GI wall, and the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Appropriate nutrition, hydration and regulation of exercise, along with substances such as arginine and citrulline can relieve upper and lower GI symptoms, including nausea, vomiting, cramping, diarrhea, and possibly hemorrhage. Cessation of NSAIDs, use of proton pump inhibitors and H2-receptor-antagonists, as well as "training" the gut, also seem to be effective in reducing the incidence of GIB in athletes. Maintenance of hemodynamic stability and identification of the source of bleeding are key elements in the management of this condition. Endoscopy might be necessary for both. GIB should not be immediately attributed to endurance exercise, and endoscopy should always be performed to rule out other existing pathology.

The Effects of Sex, Age and Performance Level on Pacing in Ultra-Marathon Runners in the ‘Spartathlon’

Background

Pacing has been investigated in different kinds of ultra-marathon races, but not in one of the toughest ultra-marathons in the world, the ‘Spartathlon’.

Objective

The aim of the present study was to analyse the pacing of female and male finishers competing in the ‘Spartathlon’ in regards to their age and performance groups.

Methods

A total of 2598 runners (2255 men and 343 women) finishing ‘Spartathlon’ between 2011 and 2019 were analysed. We selected 10 checkpoints with split times corresponding to important race sections. Average running speed was calculated for each participant and the average checkpoint running speed for each of the 10 race checkpoints. Furthermore, to assess the pacing strategy of each runner, the percentage of change in checkpoint speed (CCS) in relation to the average race speed was calculated (for each of 10 checkpoints). Finally, the average change in checkpoint speed (ACCS) was calculated for each participant as a mean of the 10 CCSs.

Results

Both women and men slowed down through the first 7 checkpoints but increased running speed towards the end of the race (reverse J-shaped pacing). Men showed a significantly greater CCS in the first and second checkpoint (p < 0.01 and p < 0.05, respectively), whereas women showed a more significant change in CCS in the last checkpoint (p < 0.05). Furthermore, age and sex showed no effect on ACCS, whereas ACCS differed between the performance groups. In particular, the slowest and the fastest runners showed a more minor change in ACCS than the two medium groups of both men and women (p < 0.01).

Conclusions

In summary, successful finishers in ‘Spartathlon’ showed a reverse J-shaped pacing curve with a decrease in running speed from the start to the 7th checkpoint and an increase in running speed thereafter. This strategy was most probably due to the profile of the race course. Men showed a more significant change in checkpoint speed in the first two checkpoints, whereas women showed a more substantial change in the last checkpoint. Age and sex did not affect average checkpoint speed, whereas this speed was different between the different performance groups. The slowest and the fastest runners showed fewer changes in average checkpoint speed than the two medium groups in men and women.

Increased serum levels of fibroblast growth factor 23 after an ultradistance run

OBJECTIVES

Healthy bones need to be loaded on a regular basis. However, overstrenuous exercise causes uncoupling of bone metabolism. Thus, it is important to be aware of exercise-induced alterations in bone metabolism. The aim of this observational study was to determine whether participation in an ultradistance run has an impact on the phosphaturic hormone fibroblast growth factor 23 (FGF23), which is produced by osteocytes and suppresses osteoblast differentiation as well as matix mineralization.

DESIGN

Observational study.

METHODS

Nine participants of the Spartathlon (246km) had venous blood samples taken before and within 15min after finishing the race as well as during recovery. Serum levels of FGF23, phosphate, and blood urea nitrogen were determined.

RESULTS

FGF23 increased 6.5-fold from pre-race to post-race (2.2pmol/L [IQR: 0.4; 3.2pmol/L] to 14.4pmol/L [IQR: 4.7; 20.0pmol/L]; p=0.001). Thereafter, serum levels of FGF23 fell to 1.4pmol/L [IQR: 0.5; 1.7pmol/L] (p<0.0001). The differences in FGF23 levels between pre-race and recovery (3 days after the start) did not achieve statistical significance (p=0.614). Serum levels of phosphate and blood urea nitrogen also did not change significantly.

CONCLUSIONS

Since FGF23 plays a central role in mineral homeostasis, the transient overexpression of FGF23 may be an important contributor to the short-term uncoupling of bone metabolism induced by overstrenuous exercise.

Physiology and Pathophysiology in Ultra-Marathon Running

In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra-marathons, ~50–60% of the participants experience musculoskeletal problems. The most common injuries in ultra-marathoners involve the lower limb, such as the ankle and the knee. An ultra-marathon can lead to an increase in creatine-kinase to values of 100,000–200,000 U/l depending upon the fitness level of the athlete and the length of the race. Furthermore, an ultra-marathon can lead to changes in the heart as shown by changes in cardiac biomarkers, electro- and echocardiography. Ultra-marathoners often suffer from digestive problems and gastrointestinal bleeding after an ultra-marathon is not uncommon. Liver enzymes can also considerably increase during an ultra-marathon. An ultra-marathon often leads to a temporary reduction in renal function. Ultra-marathoners often suffer from upper respiratory infections after an ultra-marathon. Considering the increased number of participants in ultra-marathons, the findings of the present review would have practical applications for a large number of sports scientists and sports medicine practitioners working in this field.

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Zusammenfassung. Wir stellen die wichtigsten Erkenntnisse zu Organschädigungen durch einen Ultramarathon zusammen. Nach einem Ultramarathon können kardiale Biomarker wie CK, CK-MB, kardiales Troponin I (cTnI) und N-terminales pro-Brain Natriuretic Peptide (NT-pro BNP) erhöht sein. Bis 80 % und mehr der Finisher klagen über Verdauungsprobleme, die einer der Hauptgründe sind, einen Ultramarathon nicht zu finishen. Bis zu 90 % der Läufer, die einen Ultramarathon aufgeben, klagen über Übelkeit. Nach einem Ultramarathon steigen die Leberwerte oft an, schwerwiegende Konsequenzen bleiben meist aus. Risikofaktoren für eine Einschränkung der Nierenfunktion sind eine ausgeprägte Muskelschädigung mit Rhabdomyolyse, Dehydratation, Hypotonie, Hyperurikämie, Hyponatriämie, geringe Wettkampferfahrung sowie die Einnahme von NSARs. Ultraläufer leiden nach einem Ultramarathon oft an Infekten der oberen Atemwege.

Current concepts: recognition and management of common activity-related gastrointestinal disorders

Sports medicine clinicians may encounter a wide variety of activity-related gastrointestinal (GI) disorders. The advancing ages and burgeoning obesity rates of the US population have generally increased the prevalence of GI conditions among adults. However, conditioned younger athletes with normal body mass indices also may experience disquieting activity-related GI disorders. While often mild and transient, some of these GI conditions may disrupt exercise routines or pose significant health risks to affected individuals. Gastroesophageal reflux occurs frequently during physical activity and should be empirically treated with activity reduction and dietary modifications in conjunction with antisecretory agents. Persistent or worrisome symptoms merit upper endoscopy, a thorough evaluation for non-GI causes and, rarely, surgery. Altered GI motility commonly occurs during vigorous activities that use dynamic or fluctuating body positions. Dietary and exercise modifications are usually enough to resolve these symptoms. Physical activity may also precipitate GI bleeding from upper and/or lower sources. Although mild or occult bleeding is most common, significant bleeding merits a thorough diagnostic evaluation after stabilization and treatment. Adequate hydration and gradual exercise progression may be particularly helpful to prevent the recurrence of bleeding. The judicious use of medications in conjunction with nonsteroidal anti-inflammatory drug avoidance may also be necessary. Fortunately, most activity-related GI disorders are self-limited and can be managed conservatively. After a brief period of modified activity, clinically stable individuals may progress their activity levels as symptoms allow.

Running, esophageal acid reflux, and atrial fibrillation: a chain of events linked by evidence from separate medical literatures

Using a previously described approach to generating novel medical hypotheses, this paper shows how two separate medical literatures taken together can suggest new information not apparent in either literature alone. Many studies have demonstrated that aerobic exercise in healthy people can induce esophageal acidic reflux that increases with the duration and intensity of exercise. Separately, independently of exercise, it has been shown that, in patients with gastroesophageal reflux, esophageal acid exposure can lead to atrial fibrillation (AF) and to other heart dysrhythmias. The two arguments together suggest that a regimen of excessive exercise may be conducive to AF mediated by acid reflux, an implicit, but unpublished, hypothesis. Proton pump inhibitors are widely used to treat gastroesophageal reflux. Remarkably, several small clinical trials of these drugs have been shown also to reduce symptoms and frequency of AF episodes in patients with comorbid acid reflux. Plausible mechanisms have been suggested. These small-scale tests in a highly restricted population may be of particular interest in the light of a possible exercise-reflux-AF causal chain of events in a broader population of athletes. Because the minimum degree of esophageal acidity exposure required to induce AF is unknown, further tests of proton pump inhibitors for that purpose are therefore merited without regard to any known prior reflux in a population of runners with lone AF. The prospect of reducing AF burden with a relatively benign agent is attractive in view of the limited options for effective treatment otherwise available. The study of arrhythmia and esophageal reflux in athletes may offer insights on the origin and natural history of lone atrial fibrillation.

Future expectations in the prophylaxis of intestinal bleeding

Prophylaxis of gastrointestinal bleeding is attempted in widely varying situations. In NSAID-induced peptic ulcer, the advantage of selective cyclooxygenase 2 inhibitors with regard to gastrointestinal damage has yet to be translated into an advantage in overall morbidity. Strategies for primary and secondary prevention of variceal bleeding have been established. Therapy tailored to hepatic venous pressure gradient has the potential to achieve clinical relevance. Several methods have been developed to prevent postpolypectomy bleeding, but their optimal risk-tailored application has yet to be demonstrated. Although octreotide treatment seems to be beneficial in reducing the blood loss from angiodysplasias, controlled studies to determine its optimal use are awaited. Stress-ulcer prophylaxis is commonly applied in critically ill patients. Although data indicate that H2-receptor antagonists and omeprazole are effective in preventing clinically significant bleeding, evidence for an advantage with respect to length of hospital or intensive-care-unit stay, as well as mortality, is still lacking. Since there is misuse of acid-suppressing drugs on regular wards, in-house guidelines may offer the potential for saving costs and reducing inappropriate prescription.