Wouter R. de Vries

Effects of regular physical activity on defecation pattern in middle-aged patients complaining of chronic constipation

Objective . It is not well known whether physical activity (PA) is useful in the management of patients complaining of constipation. The aim of this study was to test the influence of regular PA on colonic transit time and defecation in middle-aged inactive patients suffering from chronic idiopathic constipation. Material and methods . Forty-three subjects (>45 years) were randomly divided into group A (n=18, 16 F, 2 M) and group B (n=25, 20 F, 5 M). Group A subjects maintained their normal lifestyle during 12 weeks, followed by a 12-week PA programme. Group B performed a 12-week PA programme after randomization. PA comprised 30 min of brisk walking and a daily 11-min home-based programme. Both groups received dietary advice. Colonic transit time was measured using a radiographic multiple marker single film technique. Results . Despite dietary advice, mean fibre and fluid intake did not change. In group B a significant reduction in 3 out of 4 of the Rome I criteria for constipation was observed, i.e. percentage of incomplete defecations, percentage of defecations requiring straining and percentage of hard stools (p<0.05). As a consequence, the number of fulfilled Rome criteria for constipation decreased (2.7 to 1.7; p<0.05). Furthermore, the rectosigmoid and total colonic transit time decreased (17.5 to 9.6 h and 79.2 to 58.4 h, respectively; p<0.05). After PA the number of fulfilled Rome criteria also decreased in group A (2.6 to 1.7; p<0.05). Conclusions . In middle-aged inactive subjects with symptoms of chronic constipation, it is advisable to promote regular physical activity since it improves both the defecation pattern and rectosigmoid or total colonic transit time.

Injury prevention target groups in soccer: Injury characteristics and incidence rates in male junior and senior players

To identify target groups for injury prevention in male amateur soccer players under 35 years of age. A computer-assisted telephone survey with a 12-month recall period for injuries in a representative sample of Dutch citizens from the Injuries and Physical Activity Netherlands (IPAN)-database. A comparison of the volume of soccer injuries, the incidence and the need for medical attention per level of exposure and age category. The incidence in seniors was twice that of juniors (17.5% versus 8.1%; odds ratio (OR=2.4). In juniors the overall incidence was lowest in the category with the least amount of soccer exposure time (0-3 h: 2.9%; 3-5 h: 13.0%; 5+ h: 12.3%). A comparable result was found in seniors: (0-3 h: 12.0%; 3-5 h: 21.6%; 5+ h: 21.5%). Within each level of soccer exposure, a different incidence was found in juniors and seniors (0-3 h: OR=4.6; 3-5 h: OR=1.8; 5+ h: OR=1.9). Ankle, knee and upper leg injuries were most common (59.9%). Contusions, strains and sprains dominated (78.1%). Body region and type of injuries were similar in both age categories. Medical treatment for injuries was equally necessary in both age groups. Senior male amateur soccer players and particularly the more skilled seniors (involved in soccer at least 3 h per week), should be primarily targeted for studies on injury risk factors and prevention programs.

Gastrointestinal problems as a function of carbohydrate supplements and mode of exercise.

The aim of the study was to examine prevalence and duration/seriousness of gastrointestinal (GI) problems as a function of carbohydrate-rich (CHO) supplements and mode of exercise. The relationship between GI problems and a variety of physiological and personal factors (age, exercise experience) was also examined. Thirty-two male tri-athletes performed three experimental trials at 1-wk intervals, each trial on a different supplement: a conventional, semisolid supplement (S; 1.2 g CHO, 0.1 g protein, and 0.02 g fat.kg BW-1 x h-1); an almost isocaloric fluid supplement (F; 1.3 g CHO.kg BW-1 x h-1, no fat, no protein); and a fluid placebo (P). The 3 h of exercise started at 75% VO2max and consisted of alternately cycling (bouts 1 and 3) and running (bouts 2 and 4). GI symptoms were monitored by a questionnaire. Analysis of variance revealed that nausea lasted longer with P as compared with S (P < 0.05). Bloating lasted longer during bout 3 with P as compared with F and S (P < 0.05). Accounting for confounding factors, most GI symptoms occurred more frequently and lasted longer during running than during cycling. Multiple regression analysis revealed significant relationships between nausea and urge to defecate, between an urge to defecate, GI cramps and flatulence, and between belching and side ache. From all other factors energy depletion, CHO malabsorption, exercise intensity, exercise experience, and age were significantly related to GI symptoms during the exercise.

Evaluation of two methods for continuous cardiac output assessment during exercise in chronic heart failure patients.

The purpose of this study was to evaluate the accuracy of two techniques for the continuous assessment of cardiac output in patients with chronic heart failure (CHF): a radial artery pulse contour analysis method that uses an indicator dilution method for calibration (LiDCO) and an impedance cardiography technique (Physioflow), using the Fick method as a reference. Ten male CHF patients (New York Heart Association class II-III) were included. At rest, cardiac output values obtained by LiDCO and Physioflow were compared with those of the direct Fick method. During exercise, the continuous Fick method was used as a reference. Exercise, performed on a cycle ergometer in upright position, consisted of two constant-load tests at 30% and 80% of the ventilatory threshold and a symptom-limited maximal test. Both at rest and during exercise LiDCO showed good agreement with reference values [bias +/- limits of agreement (LOA), -1% +/- 28% and 2% +/- 28%, respectively]. In contrast, Physioflow overestimated reference values both at rest and during exercise (bias +/- LOA, 48% +/- 60% and 48% +/- 52%, respectively). Exercise-related within-patient changes of cardiac output, expressed as a percent change, showed for both techniques clinically acceptable agreement with reference values (bias +/- LOA: 2% +/- 26% for LiDCO, and -2% +/- 36% for Physioflow, respectively). In conclusion, although the limits of agreement with the Fick method are pretty broad, LiDCO provides accurate measurements of cardiac output during rest and exercise in CHF patients. Although Physioflow overestimates cardiac output, this method may still be useful to estimate relative changes during exercise.

Relationship Between Circulating Levels of Sex Hormones and Insulin-Like Growth Factor-1 and Fluid Intelligence in Older Men

The relationship was investigated between baseline serum levels of total testosterone (T), free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), estradiol (E 2 ), sex hormone–binding globulin (SHBG), insulin-like growth factor-1 (IGF-1) and cognitive functioning in 25 healthy older men (mean age 69.1 years). Cognitive tests concerned measures not sensitive to aging (crystallized intelligence), and measures sensitive to aging (fluid intelligence and verbal long-term memory). Partial correlation coefficients (controlled for level of education) revealed significant associations of total T (r =- .52, p = .009), SHBG (r =- .59, p = .002) and IGF-1 (r = .54, p = .007) with the composite measure of fluid intelligence test performance, but not with crystallized intelligence, nor verbal long-term memory. Stepwise hierarchical regression analysis with the composite measure of fluid intelligence as the dependent variable showed that the contributions of SHBG, total T, and IGF-1 were not additive.The relationship was investigated between baseline serum levels of total testosterone (T), free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), ESTRADIOL (E2), sex hormone-binding globulin (SHBG), insulin-like growth factor-1 (IGF-1) and cognitive functioning in 25 healthy older men (mean age 69.1 years). Cognitive tests concerned measures not sensitive to ageing (crystallized intelligence), and measures sensitive to ageing (fluid intelligence and verbal long-term memory). Partial correlation coefficients (controlled for level of education) revealed significant associations of total T (r = -.52, p = -.009), SHBG (r - .59, p = .002) and IGF-1 (r = .54, p = .007) with the composite measure of fluid intelligence test performance, but not with crystallized intelligence, nor verbal long-term memory. Stepwise hierarchical regression analysis with the composite measure of fluid intelligence as the dependent variable showed that the contributions of SHBG, total T, and IGF-1 were not additive.

Sports-related flow limitations in the iliac arteries in endurance athletes: aetiology, diagnosis, treatment and future developments.

Approximately one in five top-level cyclists will develop sports-related flow limitations in the iliac arteries. These flow limitations may be caused by a vascular lumen narrowing due to endofibrotic thickening of the intima and/or by kinking of the vessels. In some athletes, extreme vessel length contributes to this kinking. Endofibrotic thickening is a result of a repetitive vessel damage due to haemodynamic and mechanical stress. Atherosclerotic intimal thickening is seldom encountered in these young athletes. This type of sports-related flow limitation shows no relationship with the classical risk factors for atherosclerosis like smoking, hypercholesterolaemia or family predisposition for arterial diseases.The patient’s history is paramount for diagnosis. If an athlete reports typical claudication-like complaints in a leg at maximal effort, which disappear quickly at rest, approximately two out of three will have a flow limitation in the iliac artery. In current (sports) medical practice, this diagnosis is often missed, since a vascular cause is not expected in this healthy athletic population. Even if suspected, the routinely available diagnostic tests often appear insufficient. Definite diagnosis can be made by a combination of the patient’s history and special designed tests consisting of a maximal cycle ergometer test with ankle blood pressure measurements and/or an echo-Doppler examination with provocative manoeuvres like hip flexion and exercise.Conservative treatment consists of diminishing or even completely stopping the provocative sports activity. If conservative treatment is insufficient or deemed unacceptable, surgical treatment might be considered. As surgery needs to be tailored to the underlying lesions, a detailed analysis before surgery is necessary. Standard clinical tests, used for visualising atherosclerotic diseases, are inadequate to identify and quantify the causes of flow limitations. Echo-Doppler examination and magnetic resonance angiography with both flexed and extended hips have been proven to be adequate tools. In particular, overprojection and eccentric location of the lesions seriously limit the usefulness of a two-dimensional technique like digital subtraction angiography.In the early stages, when kinking has not yet led to intimal thickening or excessive lengthening, simple surgical release of the iliac artery is effective. However, for patients with excessive vessel lengths or extensive endofibrotic thickening, a vascular reconstruction may be necessary. A major drawback of these interventions is that long-term effects and complications are unknown.As both the diagnostic methods and the treatments for this type of flow limitation differ substantially from routine vascular procedures, these patients should be examined in specialised research centres with appropriate diagnostic tools and medical experience.

Skeletal muscle metabolic recovery following submaximal exercise in chronic heart failure is limited more by O2 delivery than O2 utilization

CHF (chronic heart failure) is associated with a prolonged recovery of skeletal muscle energy stores following submaximal exercise, limiting the ability to perform repetitive daily activities.However, the pathophysiological background of this impairment is not well established. The aim of the present study was to investigate whether muscle metabolic recovery following submaximal exercise in patients with CHF is limited by O2 delivery or O2 utilization. A total of 13 stable CHF patients (New York Heart Association classes II-III) and eight healthy subjects, matched for age and BMI (body mass index), were included. All subjects performed repetitive submaximal dynamic single leg extensions in the supine position. Post-exercise PCr (phosphocreatine) resynthesis was assessed by 31P-MRS (magnetic resonance spectroscopy). NIRS (near-IR spectroscopy) was applied simultaneously, using the rate of decrease in HHb (deoxygenated haemoglobin) as an index of post-exercise muscle re-oxygenation. As expected, PCr recovery was slower in CHF patients than in control subjects (time constant, 47+/-10 compared with 35+/-12 s respectively; P=0.04). HHb recovery kinetics were also prolonged in CHF patients (mean response time, 74+/-41 compared with 44+/-17 s respectively; P=0.04). In the patient group, HHb recovery kinetics were slower than PCr recovery kinetics (P=0.02), whereas no difference existed in the control group(P=0.32). In conclusion, prolonged metabolic recovery in CHF patients is associated with an even slower muscle tissue re-oxygenation, indicating a lower O(2) delivery relative to metabolic demands. Therefore we postulate that the impaired ability to perform repetitive daily activities in these patients depends more on a reduced muscle blood flow than on limitations in O(2) utilization.

Are oxygen uptake kinetics in chronic heart failure limited by oxygen delivery or oxygen utilization

BACKGROUND The delay in O(2) uptake kinetics during and after submaximal physical activity (O(2) onset and recovery kinetics, respectively) correlates well with the functional capacity of patients with chronic heart failure (CHF). This study examined the physiological background of this delay in moderately impaired CHF patients by comparing kinetics of cardiac output (Q) and O(2) uptake (V(O(2))). METHODS Fourteen stable CHF patients (New York Heart Association class II-III) and 8 healthy subjects, matched for age and body mass index, were included. All subjects performed a submaximal constant-load exercise test to assess O(2) uptake kinetics. Furthermore, in 10 CHF patients Q was measured by a radial artery pulse contour analysis method, which enabled the simultaneous modelling of exercise-related kinetics of Q and V(O(2)). RESULTS Both O(2) onset and recovery kinetics were delayed in the patient group. There were no significant differences between the time constants of Q and V(O(2)) during exercise-onset (62+/-25 s versus 59+/-28 s, p=0.51) or recovery (61+/-25 s versus 57+/-20 s, p=0.38) in the patient group, indicating that O(2) delivery was not in excess of the metabolic demands in these patients. CONCLUSION The delay in O(2) onset and recovery kinetics in moderately impaired CHF patients is suggested to be due to limitations in O(2) delivery. Therefore, strategies aimed at improving exercise performance of these patients should focus more on improvements of O(2) delivery than on O(2) utilization.

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.

Predicting Effects of Exercise Training in Patients With Heart Failure Secondary to Ischemic or Idiopathic Dilated Cardiomyopathy

The purpose of this study was to investigate which patient characteristics may predict training effects on maximal and submaximal exercise performance in patients with heart failure. Together with commonly used clinical and performance-related variables, oxygen uptake kinetics during exercise recovery were included as possible predictors. Fifty patients with heart failure (New York Heart Association class II or III) performed a 12-week training program (cycle interval and resistance training). Training effects were expressed as changes in peak oxygen uptake (Vo(2)), Vo(2) at ventilatory threshold (VT), and the time constant of Vo(2) recovery after submaximal exercise (tau-rec). After training, peak Vo(2), Vo(2) at VT, and tau-rec improved significantly, with a wide variety in training responses. Changes in peak Vo(2) were related to changes in VT (r = 0.79, p <0.001), but both changes were not related to changes in tau-rec. Using multivariate regression analyses, post-training changes in peak Vo(2) could be predicted by recovery halftime of peak Vo(2) (T1/2), peak Vo(2) (percentage of predicted), and peak respiratory exchange ratio (R(2) = 36%). Post-training changes in VT could be predicted by T1/2 and VT (predicted) (R(2) = 29%), whereas changes in tau-rec could be predicted only by tau-rec at baseline (R(2) = 34%). In conclusion, oxygen recovery kinetics after maximal and submaximal exercise substantially add to the prediction of training effects in patients with heart failure, presumably because of their relations with, respectively, central and peripheral impairments of exercise capacity. However, the explained variance in training effects is not sufficient to make a definite distinction between training responders and nonresponders.