Willem L. Mosterd

Gastrointestinal symptoms in long-distance runners, cyclists, and triathletes: prevalence, medication, and etiology.

ObjectiveThe aim of this study was to determine the prevalence of exercise-related gastrointestinal (GI) symptoms and the use of medication for these symptoms among long-distance runners, cyclists, and triathletes, and to determine the relationship of different variables to GI symptoms.MethodsA mail questionnaire covering the preceding 12 months was sent to 606 well-trained endurance type athletes: 199 runners (114 men and 85 women), 197 cyclists (98 men and 99 women), and 210 triathletes (110 men and 100 women) and sent back by 93%, 88%, and 71% of these groups, respectively. Symptoms were evaluated with respect to the upper (nausea, vomiting, belching, heartburn, chest pain) or lower part of the GI tract (bloating, GI cramps, side ache, urge to defecate, defecation, diarrhea). For statistical analysis, Mann-Whitney U test, Fisher exact test, or Student t test were used.ResultsRunners experienced more lower (prevalence 71%) than upper (36%) GI symptoms during exercise. Cyclists experienced both upper (67%) and lower (64%) symptoms. Triathletes experienced during cycling both upper (52%) and lower (45%) symptoms, and during running more lower (79%) than upper (54%) symptoms. Bloating, diarrhea, and flatulence occurred more at rest than during exercise among all subjects. In general, exercise-related GI symptoms were significantly related to the occurrence of GI symptoms during nonexercise periods, age, gender, diet, and years of training. The prevalence of medication for exercise-related GI symptoms was 5%, 6%, and 3% for runners, cyclists, and triathletes, respectively.ConclusionsLong-distance running is mainly associated with lower GI symptoms, whereas cycling is associated with both upper and lower symptoms. Triathletes confirm this pattern during cycling and running. The prevalence of medication for exercise-related GI symptoms is lower in the Netherlands in comparison with other countries, in which a prevalence of 10–18% was reported. More research on the possible predisposition of athletes for GI symptoms during exercise is needed.

Effect of exercise training on quality of life in patients with chronic heart failure

The effect of exercise training on quality of life and exercise capacity was studied in 67 patients with mild to moderate chronic heart failure (CHF; age: 65.6+/-8.3 years; left ventricular ejection fraction: 26.5+/-9.6%). Patients were randomly allocated to either a training group or to a control group. After intervention a significantly larger decrease in Feelings of Being Disabled (a subscale of the Heart Patients Psychological Questionnaire) and a significantly larger increase in the Self-Assessment of General Well-Being (SAGWB) were observed in the training group. Exercise time and anaerobic threshold were increased in the training group only. The increase in exercise time was related to both Feelings of Being Disabled and SAGWB. We conclude that supervised exercise training improves both quality of life and exercise capacity and can be safely performed by chronic heart failure patients.

Exercise training in elderly patients with chronic heart failure.

BackgroundPhysical training currently constitutes an important part of treatment of heart failure patients. So far, no data are available on the effects of regular exercise in elderly (aged > 65 years) heart failure patients. MethodsIn a prospective trial, patients with chronic heart failure (New York Heart Association class II and III) were randomly assigned to a training group and a control group. Patients in the training group performed additional exercises three times a week, while patients in the control group continued regular treatment. To analyse the influence of age, both groups were subdivided into subjects younger than and older than 65 years. The effect of training on exercise parameters was evaluated by means of a treadmill test. Quality of life aspects were evaluated with the help of the Heart Patients Psychological Questionnaire and a single-question Self Awareness of General Well-Being test. ResultsComparison of changes between groups revealed that training increased the duration of the exercise test and improved aspects of quality of life in the trained patients aged both younger than and older than 65 years. ConclusionExercise training is equally effective in patients aged younger than and older than 65 years.

The role of exercise training in chronic heart failure

Chronic heart failure is a major health problem with a gloomy prognosis. It is now the most common discharge diagnosis in patients over 65 years of age and its incidence may be expected to grow in coming years. Characteristic of the failing heart is its inability to maintain an adequate cardiac output, first during exercise and later also at rest. Patients with chronic heart failure have a large end diastolic volume and little contractile reserve. Cardiac failure is thus a syndrome of circulatory failure, secondary to ventricular dysfunction. This primarily ventricular dysfunction is followed by a variety of neurohumoral, peripheral circulatory, skeletal muscle, and respiratory adaptations which determine the syndrome’s clinical presentation and prognosis more than the primary ventricular dysfunction itself. Traditionally, avoidance of exercise was thus advocated in all forms and stages of heart failure.1 However, there is now evidence that inactivity leads to a further deterioration of remaining functional capacity. Several studies on physical conditioning in patients with ventricular dysfunction have shown that selected patients can safely undergo exercise training, resulting in an improvement in functional class.2 3 Poor left ventricular function is not necessarily synonymous with chronic heart failure, which is characterised by reduced tissue oxygen supply. The best method of evaluating the disease state of a patient with a compromised heart is cardiopulmonary exercise testing, that is, the measurement of oxygen consumption (V˙o 2 in ml/kg/min) during exercise. In recent years studies on chronic heart failure have therefore focused on the combination of left ventricular dysfunction and a low peak oxygen consumption (less than 20 ml/kg/min). Determination of aerobic capacity is necessary to allow proper selection of patients for heart failure studies.4In this review we shall focus on the training studies (table 1) performed with chronic heart failure patients in functional class …

A double-blind randomized multicenter dose-ranging trial of intravenous streptokinase in acute myocardial infarction☆

Intravenous streptokinase administration is now a widely applied therapy for patients in the early hours of acute myocardial infarction (AMI). The dosages used do not appear to be based on comparative clinical investigations. Therefore a double-blind randomized trial was carried out to establish the optimal dose of streptokinase. A total of 189 patients who had symptoms of AMI for less than 4 hours were treated with 200,000, 750,000, 1,500,000 or 3,000,000 IU streptokinase intravenously. At coronary angiography 2.8 +/- 2.7 hours (mean +/- standard deviation) after the start of streptokinase infusion, patency of the infarct-related coronary artery was observed in 38, 75, 60 and 82% of the patients, respectively, in the 4 groups. The result of the dosage of 200,000 IU was significantly poorer than that of the other dosages (p less than 0.01). The result of a dosage of 3,000,000 IU was significantly better than that of 1,500,000 IU (p less than 0.05), but the differences with 750,000 IU were not significant. Blood transfusion was required in 4 patients (2%), distributed over the 4 groups in 0, 2, 1 and 1 of the patients. One patient had major bleeding; this patient had been treated with 750,000 IU. The 3-month mortality-rate in the whole study population was 5%. Thus, of the 4 doses of streptokinase tested, 750,000 IU is the minimal therapeutic dosage, and the arguments for 1,500,000 IU as standard therapy for comparison with other fibrinolytic drugs are poor. The best results in this study were achieved with 3,000,000 IU, but further research will be needed to establish the efficacy and safety of this new regimen.

Cardiopulmonary exercise parameters in relation to all-cause mortality in patients with chronic heart failure

In this study we analysed the all-cause mortality over a period of maximal 6 years in 60 male patients (age: 63.4+/-8.3 years, mean+/-S.D.), suffering from chronic heart failure with resting left ventricular ejection fraction and E/O2 slope as independent factors. We assessed functional NYHA class (II: n=36, III: n=24), radionuclide left ventricular ejection fraction (29.2+/-10.4%) and peak values of heart rate, O2, CO2, E, anaerobic threshold and exercise duration with an incremental work load test on the treadmill. O2 relative to E was based on the individual slopes of the regression of O2 on E during the first 6 min of exercise. These slopes with other exercise-related variables and factors such as etiology, medication, and NYHA class were analysed with a Coxs Regression Method. A survival time analysis (Kaplan-Meier survival curve) was done to establish the influence of E/O2 slope and left ventricular ejection fraction (both split into above and below median values), as well as their interaction, on survival. From all investigated exercise-related variables. E/O2 slope is the most powerful variable regarding prediction of all-cause mortality in our group of chronic heart failure patients. Concerning risk stratification, the subgroup (n=18) with a relatively high left ventricular ejection fraction (>28%) and flat E/O2 slope (<27.6) had most survivors (77.8%) after about 3 years, while the subgroup (n=12) with a relatively high left ventricular ejection fraction (>28%), but a steep E/O2 slope (>27.6) had least survivors (33.3%). This difference in percentage is highly significant (P=0.0025). The fact that E/O2 slope and left ventricular ejection fraction show comparable main and interaction effects between measures of exercise tolerance (e.g., anaerobic threshold, peak O2, exercise duration) on the one hand, and all-cause mortality on the other, suggests the existence of common sources of variance. Based on our analysis, it is unlikely that effects on all-cause mortality are mediated through phenomena related to exercise tolerance. Therefore, we hypothesize that the effects on exercise tolerance and all-cause mortality both depend on common factors, which cause both cardiac and peripheral organ (c.q. muscular) dysfunctions. Moreover, this study clearly shows that E/O2 slope during incremental exercise is an important prognostic marker for risk stratification in chronic heart failure patients, NYHA class II and III.

Duodenal motility during a run-bike-run protocol: the effect of a sports drink.

Objective To examine the effect of a sports drink during strenuous exercise on duodenal motility and gastrointestinal symptoms. Methods In a cross-over design, seven male triathletes performed two 170-min run–bike–run tests at about 70% peak oxygen uptake (O2peak), with either a 7% carbohydrate (CHO) sports drink or tap water. Antroduodenal motility (phase III of the migrating motor complex; MMC) was measured with an ambulant manometry system. The effect of the two exercise trials on the first appearance of the MMC was assessed in the postprandial period. Results Exercise heart rate, percentage O2peak and loss of body mass did not differ significantly between the two trials. After the start of the exercise, the expected time before the first phase III occurrence, based on the actual energy intake of the last meal in the morning before exercise (1048 ± 294 kcal), a fixed gastric emptying rate and a lag phase for solid food, was 183 ± 113 min (mean ± standard deviation [SD]). The real time period between the start of the exercise with CHO and the first phase III was 63 ± 61 min, which was significantly shorter than that observed with tap water (152 ± 59 min). Both real time periods were shorter than the expected time period of 183 ± 113 min (P < 0.05). During exercise, the number of subjects with a phase III was higher with CHO than with tap water (n = 6 v. n = 1;P < 0.05). Also, the median number of phases III per hour with CHO was higher than with tap water (0.4 v. 0.0;P < 0.05). During cycling, significantly more phases III per hour (0.9) were measured than during running (0.2). All subjects reported one or more gastrointestinal symptoms during exercise, however, without a clear association with the mode of exercise or supplementation. Conclusions Prolonged exercise results in gastrointestinal symptoms and a significant interruption of postprandial motility. Only the latter phenomenon depends on the mode of exercise and supplementation.

Determinants of maximal exercise performance in chronic heart failure.

Background Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function. Aim To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance. Design In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan. Results Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r = −0.22), gender (r = 0.45), fat free mass (FFM) (r = 0.51), quadriceps muscle area (r = 0.73), hamstrings muscle area (r = 0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r = 0.71) and isometric strength (r = 0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax. Conclusion Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.