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Biomedical subjects

I A Huisveld

Publications and source records attributed to I A Huisveld.

At least 19 recordsLinked to original sources
PubMed2004

Endothelial markers in chronic heart failure: training normalizes exercise-induced vWF release.

BACKGROUND: Chronic heart failure (CHF) is characterized by endothelial dysfunction. Vascular endothelium is important for control of haemostasis and vasoregulation. The aim of the present study was to investigate plasma levels of several endothelial markers and the exercise-induced changes on these plasma levels in CHF patients. Subsequently, the effect of a 6-month training programme on these markers is described. MATERIALS AND METHODS: Twenty-nine male CHF patients (NYHA II/III, age 60 +/- 8 year, body mass index 26.7 +/- 2.3 kg m(-2), left ventricular ejection fraction 26.3-7.2%; mean +/- SD) participated. Patients were randomly assigned to a training or control group. Training (26 weeks; combined strength and endurance exercises) was four sessions/week: two sessions supervised and two sessions at home. Before and after intervention, anthropometry, endothelial markers (haemostasis and vasoregulation), maximal workload and peak oxygen uptake were assessed. RESULTS: Physical training positively affected maximal workload. Plasma levels of endothelial markers were not affected by physical training and not related to exercise tolerance. After training, stimulated (maximal exercise) plasma von Willebrand Factor (vWF) release was present, whereas at baseline this release was absent. CONCLUSION: Physical training led to normalization of the stimulated plasma vWF release. Plasma levels of other endothelial markers were not affected by physical training either at rest or under stimulated (maximal exercise) conditions.

Aged↗
PubMed2003

Determinants of insulin sensitivity in chronic heart failure.

OBJECTIVE: To describe the determinants of insulin sensitivity (IS) in chronic heart failure (CHF), we created a model in which the influence of lifestyle factors and etiology of heart failure on IS were incorporated concomitantly with age, left ventricular ejection fraction (LVEF) and parameters of body composition. DESIGN: Observational cohort study. SETTING: Outpatient clinic for chronic heart failure. PATIENTS: Fifty-seven male CHF patients [NYHA class II-III, age 61+/-9 years, body mass index (BMI) 26.9+/-3.3 kg/m2 (mean+/-S.D.)]. INTERVENTIONS: Euglycemic hyperinsulinemic clamp, cycle ergometry, anthropometric measurements, LVEF and a physical activity questionnaire. MAIN OUTCOME MEASURES: A model explaining the variance of IS in CHF. RESULTS: IS was 18.2+/-8.6 microg.kg(-1).min(-1).mU(-1).l(-1), fasting insulin level was 15.9+/-11.0 mU/l and fasting glucose level was 5.5+/-0.6 mmol/l. Peak VO2 was 19.1+/-4.9 ml.kg(-1).min(-1) and LVEF 26.2+/-7.1%. IS was inversely associated with fasting insulin concentration (r=-0.50, P<0.001) and BMI (r=-0.54, P<0.001). After controlling for BMI, IS also revealed a correlation with age (r=-0.36, P<0.01). The model explained 60% of variance in IS: BMI contributed 20%, smoking 17%, age 17% and physical activity in daily life (DPA) 16% (all P<0.05) to the variance of IS, whereas LVEF (9%) and etiology of heart failure (8%) contributed moderately. CONCLUSIONS: In CHF patients, IS is for a major part predicted by BMI, smoking, age, daily physical activity, LVEF and etiology of heart failure.

Adult↗
PubMed2000

Aging, physical conditioning, and exercise-induced changes in hemostatic factors and reaction products.

The influence of age on training-induced changes in resting and stimulated hemostatic potential was studied in three age categories (Cat I-III; 20-30 yr, 35-45 yr, and 50-60 yr, respectively) of sedentary men before and after 12 wk of training. Coagulation, fibrinolytic activity, and activation markers (reflecting fibrin formation and degradation) were determined. Physical conditioning resulted in a more pronounced increase in von Willebrand factor (vWF) and factor VIII clotting activity (FVIII:c) in Cat I and II and a more pronounced shortening of the activated partial thromboplastin time in all categories at maximal exertion and during recovery. Enhanced increases in tissue-type plasminogen activator (t-PA) antigen and activity and single-chain (sc) urokinase-type plasminogen activator (u-PA) at maximal exercise and 5 min of recovery were observed in all age groups after training. The effects on FVIII:c, vWF, and scu-PA were most pronounced in the youngest age group (Cat I). Increases in the marker of thrombin generation were highest in Cat III; no effect was seen on thrombin-antithrombin complex, plasmin-antiplasmin complex, and D-dimer in any of the age groups. We concluded that training enhances both coagulation and fibrinolytic potential during strenuous exercise. The effect on FVIII/vWF and t-PA/u-PA is most pronounced in younger individuals, whereas thrombin formation is most pronounced in older individuals.

Adult↗
PubMed2000

Evaluation of a strategy to limit blood donor exposure in high risk premature newborns based on clinical estimation of transfusion need.

OBJECTIVES: Reservation of dedicated series of pedipacks, consisting of 3 to 4 units of 70 ml filtered red cell concentrate in additive solution SAGM from 1 donor, may reduce donor exposure. In this prospective efficacy study the benefits, release and expiration of pedipacks (PP) assigned to preterm infants requiring neonatal intensive care are analyzed. METHODS: On the basis of clinical assessment of the need for multiple transfusions, 96 preterm neonates (gestational age < 32 wks and/or birth weight < 1500 g) were assigned to either the high risk group (HRG), who were to receive dedicated donor blood units, or the low risk group (LRG). Inclusion criteria for HRG were 1) estimated time of admission > 21 days and 2) expected need for multiple transfusions due to clinical cardiorespiratory instability, prolonged parental feeding or frequent blood sampling. To reduce wastage of donor blood, dedication of donor blood units was limited to 21 days. RESULTS: 50 series (192 PP) were assigned to 42 HRG infants. Two HRG infants received 3 series, 4 received 2 series and 36 received 1 series of PP. Mean transfusion rate was 3.1 PP in the HRG and 0.4 in the LRG. In the LRG 35 of 54 were not transfused, 19 received 1 to 2 PP. In both groups transfused newborns were exposed to 1.1 donors in average. In the HRG of 192 PP, 137 PP (71%) were used within 21 days, and another 30 (16%) before the expiration date < 35 days. Twenty five PP (13%) expired, mainly because of logistical problems in the introduction phase. CONCLUSION: Assignment of dedicated PP on the basis of clinical parameters at entry considerably reduces donor exposure in HRG. Wastage of dedicated blood transfusions was reduced by limitation of the dedicated period (21 days). In terms of efficacy, reservation and use of PP can be optimized by standardized administrative measures.

Anemia↗
PubMed1999

von Willebrand factor propeptide in vascular disorders: A tool to distinguish between acute and chronic endothelial cell perturbation.

Before de novo synthesized von Willebrand factor (vWF) leaves the endothelial cell, it undergoes endoproteolytic cleavage of its propeptide (vW antigen II). The processed vWF and propeptide are either released constitutively or, following activation of the endothelium, released through the regulated pathway. In a recent study (Borchiellini et al, Blood 88:2951, 1996), we showed that the half-life of mature vWF and of its propeptide differ fourfold to fivefold. We postulated that the molar ratio of the propeptide to mature vWF could serve as a tool to assess the extent of endothelial cell activation under physiologic and clinical conditions. To test this hypothesis, we measured mature vWF and propeptide in patients with documented acute and chronic vascular disease, including patients with thrombotic thrombocytopenic purpura (TTP), acute septicemia, and diabetes mellitus. These data were compared with experimental conditions in healthy subjects in which perturbation of the endothelium was simulated by physical exercise or by administration of 1-deamino-8-D-arginine vasopressin (DDAVP) or endotoxin. In all individuals of the latter study group, both vWF and propeptide levels were elevated during the acute phase of the experimentally induced vascular perturbation; at later time points after stimulation, only vWF levels remained elevated. In patients with sepsis and TTP, both vWF and propeptide were elevated several-fold. Thus, this pattern can readily be explained in terms of acute perturbation of the endothelium. In contrast, in patients with diabetes mellitus propeptide levels were only slightly elevated, whereas vWF levels were elevated twofold to threefold. This pattern is a typical feature of chronic, low-grade activation of the endothelium. These observations support our hypothesis that measurement of both propeptide and vWF levels allows to discriminate between chronic and acute phases of endothelial cell activation in vivo. Measurement of only vWF is less indicative in this respect.

Acute Disease↗
PubMed1999

Safety and effects of physical training in chronic heart failure. Results of the Chronic Heart Failure and Graded Exercise study (CHANGE)

AIMS: Physical training is considered to be safe and beneficial as part of the treatment in heart failure patients. Prospective, sufficiently large studies are still needed to confirm this hypothesis. METHODS: In a prospective study, 80 patients with chronic heart failure class II and III (age, 56.6+/-8.3 years; left ventricular ejection fraction, 26.5+/-9.6%) were randomized to an endurance training group or to a control group with continuation of optimal pharmacological treatment. RESULTS: No training-related adverse event was reported, implying that the training programme was safe for these groups of chronic heart failure patients. Between-group comparison of changes revealed that training increased exercise time (from 608+/-35 to 738+/-40 s, P<0.0001), anaerobic threshold (from 10.5+/-0.4 to 11.8+/-0.3 ml x kg-1 min-1, P<0.05), and decreased the ventilatory equivalent for carbon dioxide at submaximal exercise level (from 2.8+/-0.1 to 2.7+/-0.1, P<0.05). Training did not increase peak oxygen consumption (15.2+/-0.5 to 16. 6+/-0.5 ml x kg-1 min-1, ns). An improvement in patients' assessment of quality of life was observed. There was a significant correlation between physiological and psychological improvements. Training was not effective in patients whose exercise test at entry had a duration of less than 7 min. None of the other baseline data could predict an effective training response. CONCLUSION: Physical training in chronic heart failure patients class II and III is safe and results in significant improvements in exercise time, anaerobic threshold, ventilatory equivalent for carbon dioxide at submaximal exercise level and quality of life.

Adult↗
PubMed1998

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.

Aged↗
PubMed1998

Exercise training in elderly patients with chronic heart failure.

BACKGROUND: Physical 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. METHODS: In 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. RESULTS: Comparison 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. CONCLUSION: Exercise training is equally effective in patients aged younger than and older than 65 years.

Adult↗
PubMed1997

Effect of endurance training and seasonal fluctuation on coagulation and fibrinolysis in young sedentary men.

The effect of 12 wk of submaximal training on hemostatic variables was studied in 20 young sedentary men (Tr) and 19 nontraining matched controls (Con). After training, a more pronounced increase in factor VIII coagulant activity (P < 0.01), reflected in a decrease in activated partial thromboplastin time (P < 0.01) during maximal exercise, was seen. Both basal plasminogen activator inhibitor 1 antigen (PAI-1 Ag) and activity (PAI-1 Act; P < 0.05), as well as basal and exercise-induced tissue-type plasminogen activator antigen (t-PA Ag; P < 0.05), were decreased after training. The overall effect on fibrinolysis was reflected in an increase in the t-PA Act/t-PA Ag ratio in the Tr group. In contrast, during the same period (February-June), the Con group demonstrated an increase in basal PAI-1 Ag and PAI-1 Act (P < 0.05), together with an increase in basal and exercise-induced t-PA Ag (P < 0.05). Both basal and exercise-induced t-PA Act were unchanged, but t-PA Act/t-PA Ag was decreased (P < 0.05) in the Con group. We conclude that physical training promotes both coagulation and fibrinolytic potential during exercise and may reverse unfavorable seasonal effects on fibrinolysis.

Adult↗
PubMed1995

Unbalanced haemostatic changes following strenuous physical exercise. A study in young sedentary males.

During acute exercise both coagulant and fibrinolytic potential increase. Since strenuous exertion is associated with an enhanced risk for cardiac events, especially in untrained individuals, it is important to determine whether the initial haemostatic balance is maintained during exercise. Twenty-nine sedentary males (20-30 years) were subjected to a standardized cycle ergometer test. Blood samples were obtained at two exercise levels, 70% VO2max (submaximal), 100% VO2max (maximal) and during 25 min recovery. Both during submaximal and maximal performance, tissue type plasminogen activator antigen, urokinase plasminogen activator antigen and tissue type plasminogen activator activity were increased. A concomitant enhancement of clotting activity of factors VII, VIII, IX, XII and fibrinogen resulted in a shortening of clotting times. Following correction for changes in plasma volume, the results for factor VII:c were reversed, and factor XII:c and fibrinogen no longer demonstrated exercise-related changes. Increases in coagulant (activated partial thromboplastin time) and fibrinolytic (tissue type plasminogen activator activity) potential proceeded in parallel during exercise. However, during recovery while there was a sustained increase in coagulant potential, fibrinolytic potential demonstrated a sharp fall. We conclude that during physical activity, while parallel changes in coagulant and fibrinolytic activity occur, this haemostatic balance is not maintained during recovery. This phenomenon could constitute an enhanced risk for coronary artery thrombosis which may contribute to exercise-related cardiovascular events.

Blood Coagulation Factors↗
PubMed1995

Changes in haemostatic factors and activation products after exercise in healthy subjects with different ages.

We studied exercise-induced changes in coagulation and fibrinolytic factors and activation products in different age categories. Thirty-eight sedentary males, divided in three age categories (cats I-III; 20-30, 35-45 and 50-60 y) were subjected to a standardized exercise test. Pre-exercise levels (cats I-III resp) of FVII:c (105 +/- 5, 121 +/- 6 and 123 +/- 7% NP), fibrinogen (2.35 +/- 0.12, 2.55 +/- 0.10 and 2.66 +/- 0.09 mg/ml), prothrombin activation fragment F1 + 2 (0.80 +/- 0.10, 0.80 +/- 0.11 and 1.22 +/- 0.16 nM), t-PA (5.2 +/- 0.6, 9.2 +/- 1.0, 8.6 +/- 1.2 ng/ml) and PAI-I (42.8 +/- 7.5, 67.6 +/- 7.6, 62.2 +/- 10.9 ng/ml) showed differences that seemed related to age. Regression analysis revealed associations with anthropometry (FVII:c, fibrinogen, F1+2, t-PA, PAI-1) rather than with age. Exercise-induced changes in coagulation (increase in von Willebrand factor and FVIII:c and a shortening of APTT) and fibrinolytic potential (increase in t-PA and u-PA) were of comparable magnitude for the three age categories. Hardly any change in F1 + 2 (6%) was observed, while thrombin-antithrombin complexes (93%), plasmin-antiplasmin complexes (79%) and D-dimer (77%) almost doubled during maximal exercise. We conclude that anthropometric differences play a more significant role than age on constitutive levels of haemostatic factors in participants up to 60 years of age. The magnitude of exercise-induced changes is comparable in the age categories under study, and simply super-imposed on constitutive (pre-exercise) levels. Clear evidence for prothrombin activation is lacking, but plasmin formation is enhanced during exercise.

Adult↗
PubMed1994

Differences in u-PA and t-PA increase during acute exercise: relation with exercise parameters.

Plasma levels of urokinase-type (u-PA Ag) and tissue-type (t-PA Ag) plasminogen activator are both enhanced during physical exercise. Whether, the extent of the increase and the post-exercise clearance rate of the two activators are comparable is not known. We studied the changes in u-PA Ag, t-PA Ag and t-PA activity during a standardized exercise test comprising submaximal and maximal exercise intensity. During submaximal (recreational) exercise, increases in u-PA are mainly due to changes in plasma volume, submaximal exercise demonstrates a continuous rise in level of t-PA Ag. During maximal performance peak levels of u-PA and t-PA Ag do not coincide in time and magnitude, moreover, u-PA Ag rather than t-PA Ag is related to t-PA Act. From these results we conclude that independent mechanisms regulate the exercise-induced plasma levels of u-PA and t-PA.

Adult↗
PubMed1990

Body fat mass, body fat distribution, and plasma hormones in early puberty in females.

We examined whether there is a relationship between body fat mass or body fat distribution and hormonal profiles in the plasma of early pubertal girls. Thirty-five apparently healthy caucasian schoolgirls were selected for Tanner's breast development stage M2; they had all been classified as being stage M1 6 months earlier. Body fat mass had no relationship with the total plasma sex steroid concentration or gonadotropins. However, body fat mass was correlated with the fraction of testosterone that was not bound to sex hormone-binding globulin and considered the fraction available for biological activity. Body fat distribution, rather than body fat mass, was different in relation to the total concentrations of estrone, estradiol (E2), and testosterone as well as the percentage of available E2 or testosterone. Girls with fat localized predominantly on the hips had the highest levels of sex steroids and gonadotropins. It seems likely that this type of fat distribution is a result of ovarian activity. Girls with predominantly abdominal fat were also more obese and showed increased plasma levels of total E2 and a lower androgen/estrogen ratio in plasma, possibly due to increased aromatization, especially in abdominal adipose tissue. The findings suggest a reciprocal relationship among body fat distribution, plasma sex hormone levels, and availability of sex steroids in early female puberty.

Adipose Tissue↗
PubMed1990

Plasma lipids and apoproteins, body fat distribution and body fatness in early pubertal children.

Besides body fatness, the body fat distribution is associated with coronary risk in adults, but little has been reported on this aspect in children. This study describes body fatness, body fat distribution (waist-to-hip ratio, WHR) and the plasma lipid and apoprotein profile (TC, HDL-C, LDL-C, TG, apo A-I and apo B) in 60 boys (age 10.8 +/- 0.1 year; mean +/- s.e.m.) and 64 girls (age 10.2 +/- 0.1 year), all caucasian. To avoid interference by the large changes in plasma sex hormone levels during puberty, only pre- and early pubertal children (Tanner stages of genital c.q. breast development 1 or 2) participated. Physical and sports activity was scored in hours per week using a questionnaire. The boys were taller than the girls (146.2 +/- 0.7 vs 143.2 +/- 0.9 cm; ANOVA, P less than or equal to 0.05) and their WHR was larger (0.88 +/- 0.01 vs 0.83 +/- 0.01; ANOVA, P less than or equal to 0.05). The boys spent 8.0 +/- 0.4 hours weekly on physical and sports activities, the girls 5.5 +/- 0.3 (ANOVA, P less than or equal to 0.05). The plasma lipid and apoprotein profiles were similar in both groups. Body fatness was significantly associated with the lipid and apoprotein profile, although in different ways in boys and girls. In boys there was a relationship with TG (r = 0.49), with apo B (r = 0.33) and with the apo A-I to apo B ratio (r = -0.24); in girls with TG (r = 0.25), HDL-C (r = -0.39), apo A-I (r = -0.28) and with the HDL-C to TC ratio (r = -0.31); P less than 0.05 for all correlations. A regional component of the subcutaneous fatmass, assessed by the partial correlations of the individual skinfold thicknesses with the plasma lipid and apoprotein profile after controlling for body fatness, was lacking in these early and prepubertal children. The WHR was associated with TC (r = 0.35), LDL-C (r = 0.32), apo B (r = 0.36) and with apo A-I/apo B (r = -0.34) in the girls after controlling for body fatness. Although closer investigation into the validity of the WHR as a measure of fat distribution in children is needed, the tentative conclusion is that in pre- and early pubertal girls the WHR has an impact on the plasma lipid and apoprotein profile similar to that seen in adults. It is suggested that in boys these relationships develop later in puberty.

Adipose Tissue↗
PubMed1985

Socio-economic factors in relation to lipid profiles in young girl athletes.

The influence of socio-economic factors on blood lipid values was studied in 4 groups of young female athletes. Based on type of sport (gymnastics and swimming) and of training intensity, the participants were subdivided into 25 talented, high achievement gymnasts (age 12.3 +/- 1.6 (SD) year), 42 non-talented, low achievement gymnasts (age 12.0 +/- 1.2 (SD) year), 12 high achievement swimmers (age 10.3 +/- 1.6 (SD) year), and 24 low achievement swimmers (age 10.8 +/- 1.6 (SD) year). With respect to socio-economic factors, no significant differences were observed between the two gymnastic groups nor between the two swimming groups. The blood lipid values revealed a significantly higher low density lipoprotein-cholesterol level and significantly lower high density lipoprotein-cholesterol/total cholesterol and high density lipoprotein-cholesterol/low density lipoprotein cholesterol ratios in the talented gymnasts as compared to the non-talented gymnasts. In the high achievement swimmers, low density lipoprotein-cholesterol and triglyceride levels were significantly lower and high density lipoprotein-cholesterol/total cholesterol was significantly higher as compared to the other swimmers. The Spearman rank order correlation coefficients for the relationships between socio-economic factors and blood lipid values were mostly weak or inconsistent. Therefore, no major influence of socio-economic factors on blood lipid values could be demonstrated in the groups investigated.

Adolescent↗