Biomedical subjects

T Kostka

Publications and source records attributed to T Kostka.

At least 19 recordsLinked to original sources

PubMed2002

[Relation between physical activity, muscle function and IGF-1, testosterone and DHEAS concentrations in the elderly].

OBJECTIVE: Lower amounts of circulating anabolic hormones are thought to accelerate the age related decline in muscle mass and function. Replacement therapies are promising interventions but there are problems with these therapies. Thus alternative strategies should be developed. The age related changes in hormonal status may be probably influenced by exercise. The purpose of this study was: a) to confirm with other methods, more adapted for elderly people, the results of a previous study that has shown relationship between physical activity (PA) and quadriceps muscle function with dehydroepiandrosterone sulphate (DHEAS), insulin like growth factor-1 (IGF-1). Quadriceps muscle power (Pmax) is measured in this new work with a recently developed leg extensor machine and, b) to complete the results of the first study examining simultaneously the relationship between PA, Pmax and cardiorespiratory fitness (VO2max) with DHEAS, IGF-1 and testosterone in a group of healthy elderly people. METHODS: Fifty independent, community dwelling elderly subjects (25 mens and 25 womens) aged from 66 to 84 volunteered to participate in the study. PA was evaluated by the questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). Pmax and optimal shortening velocity (vopt) were measured on a Ergopower dynamometer. The Pmax was expressed relative to body mass, Pmax/kg (W kg-1), and relative to the mass of the two quadriceps muscles, Pmax/Quadr (W.kgQuadr-1). VO2max has been measured during a maximal treadmill exercise. RESULTS: In women, IGF-1 correlated significantly with MHDEE (r = 0.54, P = 0.004), Pmax/kg (r = 0.54, P = 0.004) and Pmax/Quadr (r = 0.46, P = 0.02), whereas DHEAS with MHDEE (r = 0.54, P = 0.004), Sports Activity (r = 0.65, P < 0.001), VO2max (r = 0.46, P = 0.02), Pmax/kg (r = 0.46, P = 0.02) and Pmax/Quadr (r = 0.55, P = 0.004). No such correlation was found in men. CONCLUSION: These findings confirm that in healthy elderly women physical activity, cardiorespiratory fitness and quadriceps muscle function are similarly related to levels of circulating DHEAS and IGF-1 suggesting a favourable influence of exercise on anabolic hormonal production in the elderly.

Aged↗

PubMed2002

Decision support systems for chemical structure representation, reaction modeling, and spectra simulation.

The choice of an appropriate structure coding scheme is the secret to success in QSAR studies. Depending on the problem at hand, 2D or 3D descriptors have to be chosen; the consideration of electronic effects might be crucial, conformational flexibility has to be of special concern. Artificial neural networks, both with unsupervised and with supervised learning schemes, are powerful tools for establishing relationships between structure and physical, chemical, or biological properties. The EROS system for the simulation of chemical reactions is briefly presented and its application to the degradation of s-triazine herbicides is shown. It is further shown how the simulation of chemical reactions can be combined with the simulation of infrared spectra for the efficient identification of the structure of degradation products.

Decision Support Techniques↗

PubMed2001

A combined application of reaction prediction and infrared spectra simulation for the identification of degradation products of s-triazine herbicides.

Substance identification in analytical chemistry is usually performed by comparing an experimental spectrum with a reference spectrum. Especially in environmental chemistry, reference spectra from databases are only available for a limited number of compounds. The combination of the reaction prediction system EROS and of infrared spectra simulation is a powerful tool for computer-assisted substance identification. First, possible degradation products of a chemical are predicted and then the infrared spectra of all these compounds are simulated. Comparison of the simulated infrared spectra with experimental spectra allows one to identify the structure of compounds. The method is demonstrated with the example of s-triazine herbicides.

Computer Simulation↗

PubMed2001

Simultaneous validation of ten physical activity questionnaires in older men: a doubly labeled water study.

OBJECTIVE: The purpose of this study was to simultaneously validate 10 physical activity (PA) questionnaires in a homogenous population of healthy elderly men against the reference method: doubly labeled water (DLW). DESIGN: Cross-sectional study. SETTING: Community-based sample from Lyon, France. PARTICIPANTS: Nineteen healthy old men (age 73.4 +/- 4.1 years), recruited from various associations for elderly people in Lyon, agreed to participate in the study. MEASUREMENTS: The questionnaire-derived measures (scores) were compared with two validation measures: DLW and maximal oxygen uptake (VO2max). With the DLW method three parameters were calculated: (1) total energy expenditure (TEE), (2) physical activity level (PAL), i.e., the ratio of TEE to resting metabolic rate, (3) energy expenditure of PA. RESULTS: Relative validity. Correlation between the questionnaires and TEE ranged from 0.11 for the Yale Physical Activity Survey (YPAS) total index to 0.63 for the Stanford usual activity questionnaire. This questionnaire also gave the best correlation coefficients with PAL (0.75), and with VO2max (0.62). Significant results with TEE measured by the DLW method were also obtained for college alumni sports score, Seven Day Recall moderate activity, and Questionnaire d'Activité Physique Saint-Etienne sports activity (r = 0.54, r = 0.52, and r = 0.54, respectively). Absolute validity. No difference was found between PA measured by the Seven Day Recall or by the YPAS and DLW, on a group basis. The limits of agreement were wide for all the questionnaires. CONCLUSIONS: Only a few questionnaires demonstrated a reasonable degree of reliability and could be used to rank healthy older men according to PA. Correlation coefficients were best when the Stanford Usual Activity Questionnaire was compared with all the validation measures. The two questionnaires reporting recent PA, the Seven Day Recall, and YPAS accurately assessed energy expenditure for the group. The individual variability was high for all the questionnaires, suggesting that their use as a proxy measure of individual energy expenditure may be limited.

Activities of Daily Living↗

PubMed2001

Response of Blood Lipids to Physical Exercise in Elderly Subjects.

Regular physical activity plays an important role in nonpharmacologic management of hyperlipidemia, in both the primary and secondary prevention of coronary heart disease. Training intensity and duration, health status (especially the presence of cardiovascular disease), and concomitant changes in body mass and dietary habits are the most important factors that can modify the physical activity-blood lipid profile relationship in the elderly. The benefit of regular exercise goes beyond direct influence on blood lipids; it aids in reducing weight, decreasing fat mass, increasing lean body mass, reducing elevated blood pressure, and increasing insulin sensitivity. Regular physical activity has become widely recommended as an important element of healthy and successful aging and should be encouraged in individuals without contraindications. (c)2001 CHF, Inc.

Journal Article↗

PubMed2001

Lack of correlation between 6-month fluctuations in habitual physical activity and testosterone. Concentrations in elderly subjects.

BACKGROUND: To examine the influence of long-term modifications in habitual physical activity (PA) on resting total testosterone (TT) concentrations in a group of healthy elderly subjects. METHODS EXPERIMENTAL DESIGN: 6-month prospective study. SETTING: University research departments of exercise physiology and geriatric medicine. PARTICIPANTS: thirty-one independent, community dwelling elderly subjects (16 men and 15 women) aged > 65 who volunteered to participate. INTERVENTIONS: correlational study. MEASURES: PA was evaluated by a questionnaire QAPSE (Questionnaire d Activité Physique Saint-Etienne) and expressed by two activity indices: mean habitual daily energy expenditure (MHDEE) and daily energy expenditure corresponding to leisure time sports activities (Sports activity index). RESULTS: Changes in resting TT concentrations were not related to changes in MHDEE (r = -0.28; p = 0.30 and r = -0.001; p=0.99) and Sports activity (r = -0.30; p = 0.26 and r = -0.05; p = 0.85) in men and women, respectively. Similarly, relative (%) changes in TT were not related to relative changes in MHDEE (r = -0.16; p=0.55 and r = 0.17; p=0.55) and Sports activity (r = -0.11; p=0.68 and r = 0.02; p = 0.92). CONCLUSIONS: The levels of habitual PA undertaken by an average senior do not appear to affect TT levels in healthy active elderly men and women.

Aged↗

PubMed2001

[Aging and so called "youth hormones". Potential influence of exercise training].

Plasma levels of dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor-I (IGF-I), and testosterone decline with ageing. These hormones share some biological activities which counteract the aging processes: increase in fat-free mass, decrease of adipose tissue and globally increased fitness and well being. It seems that lower levels of these hormones may reflect partially lower physical activity and fitness of older subjects. If further longitudinal studies confirm this, regular participation in exercise training would become a useful alternative to hormone replacement therapy.

Adult↗

PubMed2000

Leg extensor power and dehydroepiandrosterone sulfate, insulin-like growth factor-I and testosterone in healthy active elderly people.

We examined the association between quadriceps muscle function and serum levels of dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor I (IGF-I) and testosterone in a group of healthy elderly people. Fifty-three independent, community-dwelling elderly subjects (26 men and 27 women) aged from 66 to 84 years volunteered to participate in the study. Physical activity (PA) was evaluated by a questionnaire. Quadriceps maximal muscle power (Wmax) and optimal shortening velocity (v(opt)) were measured on a friction-loaded non-isokinetic cycle ergometer. The Wmax is expressed in relation to body mass (W(max/kg), W x kg(-1)), and in relation to the mass of the two quadriceps muscles (W(max/Quadr), W x kg(Quadr(-1))). In women, when adjusted for age, anthropometric measurements and PA indices, IGF-I correlated significantly with W(max/kg) (partial correlation: r = 0.59; P = 0.001), W(max/Quadr) (r = 0.58; P = 0.002) and v(opt) (r = 0.53; P = 0.004), whereas DHEAS was correlated significantly with W(max/kg) (r = 0.54; P = 0.003) and W(max/Quadr) (r = 0.58; P = 0.002). No such correlation was found in men. These findings indicate that in healthy elderly women lower values for quadriceps muscle Wmax and v(opt) are related, independently of age, anthropometric measurements and PA indices, to lower circulating levels of DHEAS and IGF-I.

Aged↗

PubMed2000

Physical activity, aerobic capacity and selected markers of oxidative stress and the anti-oxidant defence system in healthy active elderly men.

The relationship of oxidative stress and the anti-oxidant defence system to maximal oxygen consumption (VO2max) and habitual physical activity was assessed in 26 elderly men (71.0 +/- 4.2 years) and compared to that of 12 young men (22.1 +/- 5.1 years). Physical activity was assessed by a questionnaire. Malondialdehyde (MDA), plasma total anti-oxidant status (TAS), the levels of red blood cell (RBC) superoxide dismutase (SOD) and glutathione peroxidase (GPX), as well as serum GPX activities were determined under resting conditions. The older and young men had similar TAS and RBC SOD, while MDA, RBC GPX and plasma GPX were higher, and RBC SOD/GPX ratio was significantly lower in the older men. Neither MDA nor anti-oxidants were associated with any of the physical activity/aerobic capacity measures in the elderly men. We conclude that in healthy elderly men with a good nutritional status, indicators of the anti-oxidant defence system are not lower in comparison with young men. Increased RBC and plasma GPX coupled with a high level of lipid peroxidation marker may indicate an adaptation of anti-oxidant defences to sustained oxidative stress. Furthermore, the results of the present study suggest that the level of habitual physical activity and aerobic capacity have no major influence on the resting balance between radical generation and blood anti-oxidant potential in healthy older men.

Adolescent↗

PubMed2000

Long-term effects of different physical activity levels on coronary heart disease risk factors in middle-aged men.

In order to define the amount of physical activity appropriate in primary prevention of coronary heart disease (CHD), we have compared the effects during 5 years of physical activity in four groups of middle-aged men with different but stable approximate metabolic costs of leisure time sports activities (AMCSA): sedentary (n = 40; 0 kcal per week), low activity (n = 31; 1-999 kcal per week), moderate activity (n = 56; 1,000-1,999 kcal per week), and high activity (n = 71; > or = 2,000 kcal per week). Time related increase of body mass and BMI was more pronounced in lower activity groups. Changes in HDL cholesterol were more favourable in the high activity group as compared to sedentary and low activity groups. The increase of diastolic blood pressure (DBP) in the sedentary group was statistically significantly different from the decrease of DBP observed in both moderate and high activity groups. We conclude that favourable long-term stabilization of most coronary risk factors is achievable with physical activity energy expenditure above 1,000 kcal per week. Physical activity-related energy expenditure > or = 2,000 kcal per week is associated with some additional benefits, especially with a favourable modification of HDL cholesterol level.

Adipose Tissue↗

PubMed2000

Quadriceps muscle function in relation to habitual physical activity and VO2max in men and women aged more than 65 years.

The relationship of quadriceps maximal muscle power (Pmax), corresponding optimal shortening velocity (v(opt)), and relative fatigability (Pmax%D) to maximal oxygen uptake (VO2max) and habitual physical activity (PA) was examined in healthy community-dwelling subjects (29 women and 25 men) aged more than 65 years old. PA was evaluated by a questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). In women, Pmax correlated positively with VO2max (r = .56) and with Sports Activity (rho = .41). Both Sports Activity and Pmax were significant independent predictors of VO2max and accounted for 62% of variance in VO2max. In men, v(opt) was significantly negatively related to MHDEE (r = -.59) and to Sports Activity (rho = -.40). Neither in women nor in men was Pmax%D correlated with VO2max or PA indices. The different relationship of Pmax and v(opt) with VO2max and PA indices suggests that habitual PA may be sufficient in active older women, but not in men, to positively influence quadriceps muscle function. These gender differences may suggest different approaches in exercise programming for elderly women and men.

Aged↗

PubMed2000

The symptomatology of upper respiratory tract infections and exercise in elderly people.

PURPOSE: To analyze, both by a retrospective and prospective study design, the relationship of maximal oxygen consumption (VO2max) and physical activity (PA) to upper respiratory tract infections (URTI) symptomatology in elderly subjects. METHODS: 61 (33 men and 28 women) healthy and weight-stable active elderly volunteers aged 66-84 yr participated in the study. PA was evaluated by a questionnaire QAPSE (Questionnaire d'Activite Physique Saint-Etienne) and expressed by two QAPSE activity indices: MHDEE (mean habitual daily energy expenditure) and sports activity (daily energy expenditure corresponding to leisure time sports activities). Log books for daily recording of URTI symptomatology were used in prospective design. RESULTS: In a 1-yr retrospective study a significant correlation was found between number of weeks with URTI per year and Sports activity index (r = -0.27, P = 0.037). In a prospective 12-month follow-up, the number of episodes per year and number of days with URTI per year were significantly negatively associated with sports activity index (r = -0.29, P = 0.022 and r = -0.26, P = 0.041, respectively). CONCLUSIONS: In healthy active elderly subjects the symptomatology of URTI over long periods of time is inversly related to energy expenditure utilized during moderately intensive physical exercise.

Aged↗

PubMed2000

[Red wine in medicine: panacea, fashion or ... risk factor?].

Red wine has been a subject of much interest of professionals representing different fields of medicine. However, most of scientific studies have been searching for the reason of so called French paradox, which means that in France and other mediterranean countries the morbidity and mortality due to ischaemic heart disease is significantly lower than in other developed countries, in spite of relatively high consumption of fat and saturated fatty acids. The cardio-protective mechanism of red wine, although incompletely understood, is connected on one hand with the presence of ethanol which increases high-density lipoprotein cholesterol (HDL) and inhibits platelet aggregation, and on the other hand with the presence of polyphenols that have desirable biological properties. These include flavonoids, phenolic acids and stilbenes which are reputed to have antioxidant, vasorelaxing and antiplatelet properties. There is a considerable body of evidence indicating that regular consumption of red wine at moderate doses (200-400 ml a day) exerts a protective effect against ischaemic heart disease, other cardiovascular diseases, and perhaps diabetes, osteoporosis or some cancers. But, since alcohol intake involves a potential danger (risk of dependence, alcoholism, many organic diseases, migraine, allergies) medical recommendations of red wine consumption should be formulated very carefully.

Heart Diseases↗

PubMed2000

[Physio-pathologic aspects of aging--possible influence of physical training on physical fitness].

Two physiological parameters seem to be of major importance in maintaining physical functioning in the elderly: a capacity to perform aerobic exercises (endurance fitness) and an ability to do anaerobic work, especially maximal muscle force and power. Regular physical activity helps in maintaining these parameters at levels enabling normal functioning at everyday's living, contributing therefore to preservation of functional autonomy and independence in the elderly.

Activities of Daily Living↗

PubMed1999

Influence of acute and chronic exercise on insulin-like growth factor-I in healthy active elderly men and women.

We examined the influence of physical activity (PA) and acute resistance exercise on insulin-like growth factor I (IGF-I) in 39 healthy, independent, community-dwelling elderly volunteers (14 men and 25 women) aged from 66 to 84. In a longitudinal non-interventional study, we compared the fluctuations in IGF-I levels and changes in habitual PA over a 6-month period. PA was evaluated by a questionnaire QAPSE (Questionnaire d'Activité Physique Saint-Etienne), and expressed by two activity indices: mean habitual daily energy expenditure (MHDEE), and daily energy expenditure corresponding to leisure time sports activities (sports activity index). In an experimental design we compared IGF-I levels before, at 1 and 15 minutes after short quadriceps muscle exertion (10 consecutive repetitions) carried out with optimal muscle power development. Changes in IGF-I levels over a 6-month period were positively related to changes in MHDEE (r = 0.41; p<0.01), and sports activity (r = 0.40; p<0.02). When analyzed by gender, these correlations were still statistically significant in women (r = 0.39; p = 0.05 and r = 0.41; p<0.05), but not in men (r = 0.36; p = 0.21 and r = 0.20; p = 0.50). No changes (p = 0.17) were observed in serum IGF-I concentrations after the acute exercise protocol. These findings indicate that IGF-I levels are positively related to fluctuations in habitual PA, at least in women. Further research is needed to establish the best intensity and duration of exercise training to induce these changes.

Aged↗

PubMed1999

Relationship of physical activity and fitness to lipid and lipoprotein (a) in elderly subjects.

PURPOSE: To determine, both by a cross-sectional and longitudinal study design, the relationship of maximal oxygen consumption (VO2max) and physical activity (PA) to blood lipids and lipoprotein(a) [Lp(a)] in a population of healthy and weight-stable elderly volunteers aged 66-84 yr. METHODS: In a cross-sectional study in 52 subjects (23 men and 29 women), all independent variables (age, anthropometric, VO2max, and PA indices) were used in a multiple stepwise regression analysis to select variables influencing lipid and lipoprotein parameters. In a prospective nonintervention study, 38 subjects (17 men and 21 women) were reexamined after 6 months. RESULTS: In a cross-sectional study, sports activity index contributed significantly to total cholesterol (TC), low density lipoprotein (LDL) cholesterol (LDL-C), TC/high density lipoprotein (HDL) cholesterol (HDL-C) ratio, and LDL-C/HDL-C ratio variance in men, whereas VO2max accounted for 23% variance of apolipoprotein A-I in women. In a prospective study, there was no indication that any measured variable was correlated with absolute or relative changes in PA indices in the total group or when analyzed by gender. CONCLUSIONS: These data confirm that favorable relationship between PA/fitness and blood lipid profile is visible in elderly people but spontaneous changes in habitual PA are not a sufficient stimulus to alter serum lipid and lipoprotein levels in this population. Furthermore, there is no direct association between Lp(a) levels and PA, fitness, or body composition in the elderly men and women.

Aged↗

PubMed1999

[Sarcopenia: definition and clinical implications].

Age-related decrease in skeletal muscle mass has been referred to as sarcopenia. This reduction in muscle mass is a direct cause of the age-related decrease in muscle strength and power. Reduced muscle strength and power is a major cause of functional dependence in the elderly, contributing also to the increase in the prevalence of many age-associated chronic diseases.

Adolescent↗

PubMed1999

[Aging, physical activity and free radicals].

A growing amount of evidence indicates that increasing with age imbalance between pro- and antioxidants is implicated in a premature ageing and a variety of diseases. Physical activity influences both the production of reactive oxygen species and physiological antioxidant defences. This paper reviews the current literature on the influence of physical exercise on the oxidative stress markers and antioxidant defence system in the elderly people.

Aging↗