Estudio mediante densitometría y ergoespirometría de los efectos de un programa de ejercicio físico en pacientes con cirrosis hepática y sobrepeso / Study by densitometry and ergospirometry of the effects of an exercise programme in overweight patients with liver cirrhosis

Objetivo: Estudiar los efectos del programa de ejercicio físico moderado sobre la composición corporal y la capacidad de esfuerzo evaluadas mediante densitometría y ergoespirometría, respectivamente, en pacientes con cirrosis y sobrepeso. Pacientes y metodología: Se incluyeron 14 pacientes con cirrosis y sobrepeso compensados que realizaron un programa de ejercicio físico moderado durante tres meses de una hora, tres días/semana. Se midió la variación antropométrica, la composición corporal mediante densitometría, la capacidad de esfuerzo mediante ergoespirometría y la calidad de vida (SF-36). Resultados: Al final del estudio, respecto al inicio, no hubo diferencias en el índice de masa corporal. Encontramos aumento de la masa muscular total y disminución de la masa grasa total. Aumentó el tiempo de esfuerzo total y el tiempo de esfuerzo aerobio. La presión arterial media y la creatinina sérica disminuyeron. La calidad de vida mejoró en todos los dominios del SF-36 aunque alcanzó significación estadística en la función física. Conclusiones: Un programa de ejercicio físico moderado disminuye la masa grasa y aumenta la masa muscular y la capacidad de esfuerzo en pacientes con cirrosis y sobrepeso (AU)

Objective: To study the effects of a moderate exercise programme on body composition and effort capacity evaluated by means of densitometry and ergospirometry, respectively, in overweight patients with cirrhosis. Patients and methods: Fourteen compensated overweight patients with cirrhosis underwent a moderate exercise programme during 3 months one hour 3 days/week. We analyzed the changes in anthropometric measures, body composition by densitometry, effort capacity by ergospirometry and quality of life by SF-36 questionnaire. Results: At the end of the study there were not differences in body mass index with respect to basal values, but we observed an increase in total body muscle mass evaluated by densitometry and a decrease in total fat body mass. Ergospirometry showed an increase in effort time and in aerobic effort time. Mean arterial pressure and serum creatinine decreased at the end of the study. With respect to quality of life, there was an improvement in all SF-36 domains that reached statistical significance in physical functioning. Conclusions: A moderate exercise programme decreases total body fat and increases total body muscle mass and effort capacity in overweight patients with cirrhosis (AU)

Long-term follow-up of bradycardia in elite athletes.

The aim of the study was to examine the hypothesis that when former high-level athletes retired from competition, bradycardia would vanish. ECG changes and factors possibly related to the persistence of bradycardia were investigated. We performed a longitudinal follow-up study in 157 former elite athletes who had records of bradycardia < 50 bpm when they were active in high-level competition. All had retired from competitive sport for a minimum of five years prior to participation in the follow-up examination. Data on sport modality, hours of weekly training during competition periods, years participating in high-level competition, and years since retirement from competition were abstracted from medical records at two sports medicine centers. ECGs from this time were studied. At the post-retirement follow-up examination, participants underwent a clinical examination that included blood pressure and ECG recordings, and answered a structured questionnaire about their physical exercise since retirement from their sporting career. In the post-retirement period, a total of 65 % of participants had persistent bradycardia, 18 % with bradycardia < 50 bpm. Multivariate analysis showed that persistence of resting bradycardia was associated with regular exercise and number of years in high-level competition, but not with symptoms such as palpitations, dizziness or syncope, or major ECG alterations.

Concordance between rest MIBG and exercise tetrofosmin defects: possible use of rest MIBG imaging as a marker of reversible ischaemia.

Perfusion imaging combined with pharmacological stress is the study of choice in patients with ischaemic heart disease who are incapable of exercising. Some medical conditions, however, can preclude the use of pharmacological stress. In these particular situations, availability of a diagnostic test which allows for the assessment of ischaemic territory at rest would be desirable. With the purpose of providing a marker of reversible ischaemia, we evaluated myocardial iodine-123 metaiodobenzylguanidine (MIBG) uptake in regions with fixed and reversible defects defined by exercise/rest perfusion study. Fifty-four male patients with ischaemic heart disease and previous myocardial infarction were studied by means of exercise/rest tetrofosmin and MIBG single-photon emission tomography (SPET). Regional tracer uptake was quantified and expressed as a percentage of maximum peak activity. Areas with denervated but perfused myocardium and areas with ischaemic myocardium were calculated. Regions with<75% of peak activity in the exercise perfusion study were divided into two groups according to whether the increase in peak activity in the respective rest study was >10% (reversible regional defect) or <10% (fixed regional defect). These percentages were compared with the percentages of the innervation study. The area of the innervation defect was significantly larger when the perfusion defect was reversible than when it was fixed. In regions with reversible perfusion defects, the size of the area of denervated but perfused myocardium was similar to the size of the area of ischaemic myocardium. In regions with reversible defects, the percentage of myocardial MIBG uptake was not significantly different from the percentage of tetrofosmin uptake at exercise, while it was significantly lower than the percentage of tetrofosmin uptake at rest. In regions with fixed defects, the percentage of myocardial MIBG uptake was significantly lower than the percentage of tetrofosmin uptake at exercise and at rest. In patients who developed angina during exercise test, the area of denervated but perfused myocardium was significantly larger than in patients without angina (4.1+/-2.4 vs 3.4+/-2.5, P=0.02). The same trend was observed with regard to the size of the innervation defect (8.6+/-2.4 vs 5.7+/-2.2, P=0.02). It is concluded that when the use of pharmacological stress is not possible in patients incapable of exercising, rest studies with MIBG combined with rest myocardial perfusion studies may be useful as a marker of reversible ischaemia.

Marked ventricular repolarization abnormalities in highly trained athletes' electrocardiograms: clinical and prognostic implications.

OBJECTIVE: We sought to study the functional, clinical and prognostic implications of marked repolarization abnormalities (MRA) sometimes seen in athletes' electrocardiograms (ECGs). BACKGROUND: The clinical meaning of ECG MRA in athletes is unknown. No relationship has been drawn between either training intensity or any particular type of sport and MRA. Athletes are usually symptom free and do not show any decrease in their physical performance. It is as yet unclear whether MRA may have a negative effect on the performance of such athletes in competitive sports. METHODS: We studied 26 athletes with MRA (negative T waves > or =2 mm in three or more ECG leads at rest). No athletes presented clinical symptoms of cardiac disease or decrease in their physical performance. Clinical and physical examinations, ECG at rest, exercise test and echocardiographic and antimyosin studies were performed in all athletes. Rest/exercise myocardial perfusion single-photon emission computed tomography studies were performed in 17 athletes. The follow-up ranged from 4 to 20 years (mean 6.7 years). RESULTS: Four athletes were excluded due to hypertrophic cardiomyopathy. Echocardiographic studies showed right and left normal ventricular dimensions for highly conditioned athletes. In the exercise test, heart rate was 166 +/- 12.4 beats/min, and exercise tolerance was 15.2 +/- 2.7 metabolic equivalents of the task. All athletes had ECG at rest simulating myocardial ischemia or "pseudoischemia" with a tendency to normalize during exercise. Myocardial perfusion studies were normal in the studied athletes. Antimyosin studies showed mild and diffuse myocardial radiotracer uptake in 15 athletes (68%). No adverse clinical events were observed in the follow-up. CONCLUSIONS: These results suggest that MRA have no clinical or pathological implications in athletes and should, therefore, not preclude physical training or participation in sporting events.

Myocardial sympathetic innervation in the athlete's sinus bradycardia: is there selective inferior myocardial wall denervation?

BACKGROUND: Sinus bradycardia in trained athletes is predominantly a manifestation of increased vagal tone, but it is not known whether an alteration in the cardiac sympathetic system can contribute to blunted chronotropic response. This study assessed the integrity of the sympathetic system in trained athletes with sinus bradycardia by means of the iodine-123-metaiodobenzylguanidine (123I-MIBG) procedure. METHODS AND RESULTS: Fourteen athletes with sinus bradycardia and 8 athletes with a normal heart rate were explored by means of planar and single photon emission computed tomography MIBG studies. The heart/mediastinum ratio, regional myocardial distribution, and percent of regional myocardial MIBG uptake were evaluated. The heart/mediastinum ratio in athletes with sinus bradycardia was 1.87+/-0.10, and in athletes with a normal heart rate, the heart/mediastinum ratio was 1.86+/-0.16 (P = not significant). In athletes with sinus bradycardia, the regional distribution of MIBG showed an inferior and apical uptake defect in 8 athletes, an inferior, apical, and septal defect in 3 athletes, an inferior defect in 1 athlete, and normal distribution in 2 athletes (14%). In athletes with a normal heart rate, the regional distribution of MIBG showed an apical uptake defect in 3 athletes and normal distribution in 5 athletes (63%). The percent of regional MIBG uptake in the inferior region was significantly reduced in athletes with sinus bradycardia (44%+/-13% vs. 72%+/-11%, P<.01). CONCLUSION: These results show severely reduced myocardial MIBG distribution in the inferior region in athletes with sinus bradycardia, suggesting selective inferior myocardial wall sympathetic denervation, which may be related to increased vagal tone.

Influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation in ischaemic heart disease.

Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracers was quantified and expressed as a percentage of maximum peak activity. The percentage < or =55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%+/-1.4% vs 1.4%+/-1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial perfusion, but does not cause changes in sympathetic myocardial innervation.

Ascorbic acid inhibits the increase in low-density lipoprotein (LDL) susceptibility to oxidation and the proportion of electronegative LDL induced by intense aerobic exercise.

BACKGROUND: We have previously reported the finding of an acute increment in the susceptibility of low-density lipoprotein (LDL) to oxidation and in the proportion of electronegative LDL [LDL(-)] after intense exercise. We have now studied the effect of oral supplementation with 1 g ascorbic acid, immediately before a 4-h athletic race, on the susceptibility of LDL to oxidation, the proportion of LDL(-), and the alpha-tocopherol and lipid peroxides content in LDL, in order to inhibit such deleterious changes, and to confirm the oxidative nature of modifications of LDL induced by exercise. METHODS: We studied seven highly trained runners who received a supplement of 1 g ascorbic acid and a control group of seven who did not receive the supplement. The susceptibility of LDL to oxidation was assessed by measurement of conjugated dienes after CuSO4-induced oxidation, the proportion of LDL(-) was determined by anion exchange chromatography, alpha-tocopherol was quantified by reverse-phase high performance liquid chromatography, and lipid peroxides were measured by the thiobarbituric acid-reactive substances (TBARS) method. RESULTS: After exercise, in the control group there was an increase in both the susceptibility of LDL to oxidation (change in lag phase from 51.4 +/- 4.7 min to 47.0 +/- 4.6 min, P < 0.05) and the proportion of LDL(-) (from 11.1 +/- 1.4% to 13.0 +/- 2.2%, P < 0.05), but these did not occur in the ascorbic acid group (change in lag phase from 49.7 +/- 2.3 min to 50.4 +/- 4.2 min, and in LDL(-) from 9.7 +/- 1.7% to 10.1 +/- 1.7%). No significant changes in the absolute amount of LDL alpha-tocopherol were observed after exercise (ascorbic acid group: 6.65 +/- 0.94 mol/mol apoB before the race, 7.13 +/- 0.88 mol/mol apoB after the race; control group: 7.34 +/-0.69 mol/mol apoB before the race, 7.06 +/- 0.69 mol/mol apoB after the race), but significant differences were found when increments or decrements of alpha-tocopherol were tested (alpha-tocopherol increased 9.9 +/- 11.5% in the ascorbic acid group, and decreased 0.6 +/- 7.3% in the control group; P < 0.018). TBARS did not change after exercise. CONCLUSIONS: We conclude that 1 g ascorbic acid inhibits the increase in LDL susceptibility to oxidation after exercise, preventing this acute pro-atherogenic effect. In addition, the observation that LDL(-) enhancement is prevented by ascorbic acid supports the hypothesis that at least some of the circulating LDL(-) originates from oxidative processes.

[The effect of a race 4 hours in duration on the production of beta-endorphin and adrenocorticotropic hormone]. / Efecto de una carrera de cuatro horas de duración sobre la producción de betaendorfina y hormona adrenocorticotropa.

BACKGROUND: Physiological hormone adaptation to a prolonged and submaximum exercise is not well known. The present study was designed to evaluate changes in plasma levels of beta-endorphin and ACTH before and after a 4 hour pedestrian race. SUBJECTS AND METHOD: Fourteen amateur athletes enrolled in a 4-hour race were studied. Beta-endorphin and ACTH determinations were performed (double antibody IRMA) 10 minutes before and after the race. Simultaneously, heart rate and blood pressure were registered. RESULTS: After the race beta-endorphin level increased 2.8 times with respect to basal values (X [DE]) (42.2 [20,5] VS 14.9 [5.1] pM/I; p < 0.0001), and ACTH level increased 3.5 times (110.8 [72.9] vs 31.4 [14.2] pg/ml; p < 0.0001). There was a positive correlation between the increase of beta-endorphin and ACTH and the distance covered by each athlete (r = 0.617, p < 0.001 and r = 0.533, p < 0.05, respectively), and between the increase of basal and post-race values of both hormones (r = 0.935; p < 0.001). CONCLUSION: Prolonged and submaximum exercise provokes beta-endorphin and ACTH increase, and is related to the amount of performed exercise. There is a positive correlation between the increase of plasma levels of both hormones. Therefore, exercise amount could be one of the main modulator mechanism of beta-endorphin and ACTH release.

Influence of prolonged exercise on myocardial distribution of 123I-MIBG in long-distance runners.

BACKGROUND: A study was conducted to determine if prolonged exercise could provoke sympathetic neuronal alteration in an athlete's heart through assessment of myocardial distribution of 123I-metaiodobenzylguanidine (MIBG) in nine ultramarathon runners at baseline and after a 4-hour race. METHODS AND RESULTS: After injection of 370 MBq of 123I-MIBG, the athletes ran for 4 hours, covering 45 +/- 8 km. Planar and single-photon emission computed tomography (SPECT) images of the thorax were acquired at the end of the race. Two weeks later, studies at baseline were performed. A heart:mediastinum ratio (HMR) was calculated to quantify MIBG uptake. Basal MIBG studies showed normal myocardial tracer uptake, on both planar and SPECT images, and the HMR was 1.84 +/- 0.16. After the 4-hour race, MIBG studies showed decreased myocardial uptake in all athletes, and the HMR was 1.70 +/- 0.18 (p < 0.005). A positive correlation between the percentage of decrease of HMR after the race and the distance covered was observed (r = .910, p < 0.001). CONCLUSIONS: Myocardial MIBG activity is decreased by prolonged exercise in long-distance runners. The degree of reduction of myocardial MIBG activity is related to the distance covered. Prolonged exercise, as sustained sympathetic stimulus, may alter myocardial distribution of MIBG.

Marathon runners presented lower serum cholesteryl ester transfer activity than sedentary subjects.

Acute exercise promotes raised HDL cholesterol concentrations by lipolysis stimulation, but this effect is insufficient to explain the more permanent HDL increases seen during regular exercise. During training periods in a group of marathon runners, we measured lipid transfer protein I (LTP-I)-mediated cholesteryl ester transfer activity (CETA) and its relationship to their HDL concentrations. Runners of both sexes showed significantly lower CETA values than those of sedentary controls. Male runners also had significantly lower serum concentrations of triglyceride, VLDL cholesterol and apolipoprotein B, and significantly higher concentrations of HDL cholesterol and apolipoprotein A-I than male controls. Results indicate that regular practice of aerobic exercise promotes modifications of lipoprotein metabolism related not only to lipolysis, but also to lower CETA. Such modifications are associated with reduced risk of atherosclerosis.

[Biventricular functional adaptation during a prolonged race. An analysis of global and regional ventricular function]. / Adaptación funcional biventricular durante una carrera de larga duración. Análisis de la función ventricular global y regional.

To determine the effects of a six-hour competitive race on left and right ventricular performance, 99mTc gated blood pool scans were performed to 6 long distance runners before the race (rest), each hour during the race and one hour after concluding the exercise (recovery). Heart rate increased during the race, peaking at 4th hour of competition (55 +/- 3 to 110 +/- 9 lpm; p = 0.001). Evolution of right ventricular ejection fraction showed a similar behavior with the evolution of left ventricular ejection fraction during the competition (r = 0.39; p = 0.006). Blood volume in the lungs increased at the end of the race (index 1.13 +/- 0.14) normalizing at recovery (index 1.03 +/- 0.03). Left and right ventricular peak filling rate had an inverse correlation with pulmonary blood volume (r = -0.31; p = 0.041 and r = -0.47; p = 0.001 respectively). Both left and right ventricular ejection fraction had an inverse correlation with pulmonary blood volume (r = -0.38; p = 0.006 and r = -0.34; p = 0.01 respectively). The anteroseptal regional ejection fraction showed an inverse correlation with end-systolic and end-diastolic volume (r = -0.32; p = 0.03 and r = -0.4; p less than 0.01 respectively). The posterolateral region showed a parallel evolution with the global ejection fraction for both left and right ventricles (r = 0.57; p less than 0.0001 and r = 0.38; p = 0.009 respectively). In conclusion, a transient biventricular functional adaptation during a prolonged race is related to pulmonary blood volume redistribution and to a higher preload for both ventricles and a greater afterload for the right ventricle. The posterolateral and inferoapical regions show a similar behavior as both left and right ventricular ejection fraction, response that does not occur with the anteroseptal regional ejection fraction.

Transient alterations in cardiac performance after a six-hour race.

Ten long distance runners were enrolled in a 6-hour competitive race. Immediately after the race technetium-99m-albumin gated blood pool scans were performed and indium-111 antimyosin was injected. Forty-eight hours later antimyosin scans were obtained and control gated blood pool scans were performed. Left ventricular ejection fraction was higher after the race (65 +/- 5 vs 60 +/- 7%, p less than 0.01) due to a decrease in end-systolic counts. Right ventricular ejection fraction was lower after the race (42 +/- 7 vs 54 +/- 12%, p = 0.03) due to an increase in both end-diastolic and end-systolic counts. A longer systolic period was observed after the race (53 +/- 5% of the RR interval vs 39 +/- 3%, p = 0.005). No significant differences were observed in peak filling or peak emptying rates after the race. An increase in pulmonary blood volume (116% of control) was observed after the race. Antimyosin scans were normal in 7 athletes and minimal antimyosin myocardial uptake was seen in 3. Transient alterations in biventricular performance present after the race correspond to function adaptation to strenuous exercise and are not due to irreversible myocyte damage.

[Circumferential profiles versus visual analysis in studies of myocardial perfusion during exertion using thallium-201]. / Perfiles circunferenciales versus análisis visual en los estudios de perfusión miocárdica de esfuerzo con talio-201.

Two methods of analysis for perfusion myocardial studies with thallium are compared: the conventional visual analysis, and a quantitative method which shows results as circumferential profiles. Three hundred and ninety myocardial segments in 65 patients were studied. Visual analysis showed abnormalities in 44/65 (68%) patients, the quantitative method did it in 53/65 (81%). When localization and/or extension discrepancy between the two methods was found, angiography was always concordant with circumferential profiles findings. Total agreement between the two methods was present in 20/65 (31%) patients. The quantitative method is more sensitive than the visual analysis. It is also more precise in defining localization and extension of thallium defects.

Gastric emptying in marathon runners.

Radionuclide gastric emptying studies using 99m-Tc human serum albumin egg omelette have been carried out in 10 long distance runners at rest and during a 90 minute run at sustained speed. Resting values are compared with controls comprising 10 sedentary subjects. Runners show a significantly accelerated basal gastric emptying (runners t 1/2 = 67.7 (5.9) min; sedentaries t 1/2 = 85.3 (4.5) min, p less than 0.001). The exercise had no significant effect on gastric emptying in these trained subjects (exercise t 1/2 = 66.8 (5.9) min, p = NS), suggesting adaptation to exercise.