Biomedical subjects

R Stupnicki

Publications and source records attributed to R Stupnicki.

At least 19 recordsLinked to original sources

PubMed2001

The assessment of frequency of iron deficiency in athletes from the transferrin receptor-ferritin index.

The transferrin receptor-ferritin index (sTfR/logFerr) was determined in 131 male and 121 female athletes in order to assess the frequency of iron deficiency (threshold value of that index taken as 1.8). Blood was drawn for determining morphological indices as well as sTfR, ferritin, iron, total iron binding capacity (TIBC), and haptoglobin. A significantly (p <.01) higher incidence of iron deficiency was observed in women (26%) than in men (11%). The iron deficiency was latent, since no subject was found to be anemic. The plasma iron was significantly lower and TIBC higher (p <.001) in both iron-deficient subgroups than in the non-deficient ones. This confirmed the latent character of iron deficiency. Some hematological indices (Hb, MCH, MCHC, MCV) were significantly lower in iron-deficient female athletes than in male athletes, which suggested a more profound iron deficiency in the former. The sTfR/logFerr index might thus be useful in detecting iron deficiency in athletes, especially in those with erythropoiesis disorders, since physical loads may affect the widely used ferritin levels.

Adolescent↗

PubMed2000

The effects of physical exercise on the concentrations of ferritin and transferrin receptor in plasma of female judoists.

The aim of the study was to assess the effect of physical exercise on the changes in concentrations of ferritin and soluble transferrin receptor (sTfR) in plasma in course of 10 consecutive days of a training camp. Ten female elite judoists, aged 17-23 years, participated in the study. Mean concentration of ferritin for the 10 day period was 62.8 x 1.633(+/-1) microg/l, the within-subject, day-to-day variability being very high (13-75%). Ferritin concentrations were significantly correlated with the training load on the preceding day (r = 0.397; p < 0.001). Mean level of sTfR was 2.56 x 1.291(+/-1) mg/l and its within-subject variability was much lower (4-16%). Although the training loads had an effect on the intravascular hemolysis as indicated by a significant, negative correlation between load scores and haptoglobin concentration (r = -0.282; p < 0.01), the latter was not correlated significantly with sTfR levels. It was concluded that the soluble transferrin receptor is a more stable indicator of iron status under high training loads since, unlike ferritin, it does not respond to the workload on the preceding day. Moreover, the intravascular hemolysis observed in athletes does not affect the sTfR levels in plasma.

Adolescent↗

PubMed2000

Iron status in female endurance athletes and in non-athletes.

Iron status was studied in 126 female endurance athletes and 52 control subjects, all aged 16-20 years. The study aimed at identifying factors responsible for iron deficiency. Twenty-six percent of athletes and 50% of controls had latent iron-deficiency without anemia symptoms. A too low intake of iron (especially heme iron: 0.3 mg daily), and of nutrients influencing iron metabolism, were identified as main causes of iron deficiency in control subjects. In athletes, whose iron intake was sufficient (14.6 mg), the principal cause of iron deficiency were blood losses due to menstruation. High level of physical activity, expressed as training volume and experience, did not adversely affect iron stores, as these were higher than in control subjects and the incidence of iron deficiency was much lower than in the control group. It was concluded that an increased intake of iron and of dietary factors involved in iron metabolism prevented possible exercise-induced losses of iron in young athletes.

Adolescent↗

PubMed1998

Interrelationships among food intake, somatic traits, and physical fitness in 10.5- to 15.5-year old children from Eastern Poland.

The aim of the study was to establish the relationships between energy intake and dietary quality with somatic variables and physical fitness. Energy intake and nutrition quality were assessed from 24-hr dietary recall questionnaires, and physical fitness was measured by applying the EIROFIT tests. Interrelationships between all those variables (simple, partial, and multiple correlation coefficients) were computed from standardized values. The somatic and physical fitness variables related more strongly on the nutrition quality than on the energy intake. Well-nourished children were taller, heavier, and more physically fit than the poorly nourished ones. We believe that dietary quality affected physical fitness indirectly by influencing somatic development. Energy intake did not contribute significantly to the total variance of the physical fitness factor.

Adolescent↗

PubMed1997

Reproductive hormonal responses to maximal exercise in endurance-trained men with low resting testosterone levels.

A cross-sectional study was conducted to compare the changes from rest and in response to a maximal exercise bout for select reproductive hormones between age matched groups of endurance trained (ET; distance runners) men with low resting testosterone and untrained (UT) men. Both ET and UT men completed two evaluation sessions: (a) resting hormonal profiling, and (b) a maximal treadmill exercise test to exhaustion. Serial blood samples were taken for four hours at each of the evaluation sessions. Resting and exercise hormonal concentrations were plotted and the area under the response curve (AUC) measured. Percentage change in AUC values were also calculated and compared (exercise vs. resting AUC values). Resting testosterone (16.6 +/- 2.4 vs. 23.9 +/- 3.1 nmol x 1(-1)) and prolactin (3.3 +/- 1.4 vs. 6.0 +/- 2.0 micrograms x 1(-1)) concentrations in the ET men were significantly lower (p < 0.05) than those in the UT men. All other resting hormonal levels did not differ between the groups (p > 0.05). Exercise produced a significant increase (p < 0.05) in the ET men for testosterone, LH, and prolactin AUC values, when compared to resting values. In the UT men the only significant change was a reduction (p < 0.05) in the exercise LH AUC versus the resting AUC value. AUC percentage change values showed between-group differences (p < 0.05) for testosterone, LH and prolactin. The level of change in each of these hormones was found to be greater in the ET than UT group (approximately 20 to 75%). The hormonal changes of the UT men were viewed as "control--reference" responses within a functioning hypothalamo-pituitary-testicular regulatory axis; therefore, it was concluded that the ET men displayed an "atypical" response to exercise to that of UT men relative to this axis.

Adult↗

PubMed1997

Effects of hypobaric-hypoxia on the salivary cortisol levels of aircraft pilots.

INTRODUCTION: There has been limited characterization of the endocrine stress reactivity of aircraft pilots under the adverse environmental condition of hypobaric-hypoxia. This seems especially true with respect to using the non-invasive technique of salivary hormonal analysis. Thus, the purpose of this study was to characterize the salivary cortisol response to such an environmental stress. METHODS: Some 53 pilots were exposed to 30 min of hypobaric-hypoxia (final pressure, 540 hPa). The salivary cortisol levels were measured at baseline (0 min), at 15 and 30 min into exposure (+15 and +30 min) and 30 min after the exposure ended (+60 min). The cortisol response of each pilot was classified according to the difference between the +30 min and 0 min values. Responder categories were: increase (I), decrease (D) or no change (N). RESULTS: Subjects were not evenly distributed among the three response categories (p < 0.05). The distributions were as follows; D = 5 pilots (9.4%), N = 17 pilots (32.1%), and I = 31 pilots (58.5%). Further, significant (p < 0.05) changes in cortisol levels were noted over the sampling times for the D (+15 min to +60 min < 0 min) and 1 (+15 min to +60 min > 0 min) responders, as well as between the D, N, and I responders at the +15 to +60 min sampling times. CONCLUSIONS: We conclude that no single consistent change in salivary cortisol level occurred among the different subjects in response to the level and duration of hypobaric-hypoxia studied.

Adult↗

PubMed1997

Comparison of the testosterone-to-cortisol ratio values obtained from hormonal assays in saliva and serum.

Testosterone (T) and cortisol (C) were determined in serum and saliva, sampled simultaneously, from triathletes and karate athletes, in order to determine the T:C ratios in those body fluids and the relationship between them, as well as to assess the salivary T:C ratio as a measure of the so-called anabolic-catabolic index. Mean salivary T:C (value (1.67 +/- 0.85) was nearly 3-fold lower than that obtained for serum (4.87 +/- 1.86). Salivary and serum values were strongly correlated with one another (r = 0.874, p < 0.001) but the relationship depended on the range of cortisol concentrations in serum, the slope of the salive-serum regression line being significantly lower for serum cortisol concentrations over 600 nmol.l-1 than for concentrations below that value (0.305 and 0.380, p < 0.05, respectively). It has been concluded that the salivary T:C ratio, based on values reflecting the levels of biologically active fractions of T and C in circulation, is a better measure of metabolic equilibrium conditioned by those hormones than the corresponding ratio obtained from total concentrations in serum.

Adult↗

PubMed1997

Effect of acceleration stress on salivary cortisol and plasma cortisol and testosterone levels in cadet pilots.

The effects of acceleration (Gz) on changes in the levels of cortisol in saliva and of cortisol and testosterone in serum have been studied in 48 cadet pilots exposed to a linear acceleration gradient (0.2 G/s) until a loss of coordination when the mean G value was found to be 5.94 +/- 0.57. Three patterns of salivary cortisol responses were discerned based on Gz-induced significant changes: increase (I; n = 20), decrease (D; n = 8), the magnitude of changes being dependent on the pre-Gz values. Fifteen min after the Gz load, the mean salivary cortisol was significantly higher from the pre-Gz value in all subjects combined. In 19 subjects, who consented to blood sampling, significant increases in serum cortisol were observed both 3 and 15 min post-Gz (by 37 and 57% respectively) while, a significant increase in serum testosterone concentration has been observed only 3 min post-Gz. Testosterone levels 3 min post-Gz were significantly correlated with the final Gz values (r = 0.54; p < 0.05). A significant correlation was also observed between all salivary and serum cortisol values combined (r = 0.696; p < 0.001). It has been concluded that acceleration stress, although of very short duration, proved very potent in eliciting glucocorticoid and androgen responses.

Acceleration↗

PubMed1996

Effect of temperature and pH on the magnitude of the free fraction of cortisol in serum.

Concomitant effects of temperature and pH on changes in the magnitude of the free, unbound fraction of cortisol in human serum were studied at temperatures and pH ranging from 36 to 39 degrees C and from 6.9 to 7.4, respectively. Free fraction increased with increasing temperature and decreasing pH, the two factors acting synergically: a rise in temperature from 36 to 39 degrees C caused an about 30% increase in the free fraction at pH = 7.4, and at pH 6.9--over 2.2-fold. At highest temperature-acidity combination, i.e. at 39 degrees C, pH = 6.9, the free fraction was as much as 2.5-fold higher, relative to standard conditions (ph 7.4, 37 degrees C). This implies that in vivo the free, biologically active fraction of cortisol may increase due to e.g. hyperthermia and acidosis at a constant total concentration of this hormone.

Acidosis↗

PubMed1995

Pre-exercise serum cortisol concentration and responses to laboratory exercise.

Relationships between the postexercise values of blood lactate concentration, pH, oxygen uptake, heart rate, power output on the one hand, and the pre- and postexercise blood cortisol concentrations on the other, were studied in 74 male and 40 female athletes (wrestlers and senior and junior rowers), performing graded exercise of increasing intensity. The senior rowers, junior rowers and wrestlers had different exercise protocols. The senior rowers of both sexes had significantly higher rest concentrations of serum cortisol than the junior athletes. A significant correlation between postexercise lactate concentrations and pre-exercise cortisol concentrations was found in all the male groups ("common" r = 0.515, P < 0.001), but not in the female ones (r = 0.162). It was concluded that the pre-exercise cortisol concentrations might condition anaerobic-glycolytic metabolism in physical exercise.

Adolescent↗

PubMed1994

Effects of music treatment on salivary cortisol in patients exposed to pre-surgical stress.

The response of the adrenal cortex to a stressor consisting of information about a surgery to be performed the following day was studied in 34 patients by monitoring changes in salivary cortisol. From those, 18 patients were subjected to an individually selected 1 h music program, applied immediately following receipt of the information, and the remaining 16 patients formed a reference group. Another 10 patients, not awaiting surgery, served as controls. Saliva was sampled before the stressor and 5 more samples were collected at 15 min intervals. The stressor produced a 50% rise in salivary cortisol within 15 min. In patients not exposed to music, cortisol levels gradually decreased but after one hour they were markedly higher than the initial level. Listening to music resulted in a marked reduction in salivary cortisol level and after one hour the relative decrease was similar to that observed in control (non-surgical) patients.

Adult↗

PubMed1992

Glucocorticoid response to exercise as measured by serum and salivary cortisol.

Serum and salivary cortisol concentrations were studied in 78 elite athletes engaged in different sports, by subjecting them to high-intensity laboratory exercise. The mean difference in the pre-exercise cortisol concentrations in the seven groups studied were more marked in serum (from 311 to 768 nmol.l-1) than in saliva (from 17.9 to 22.7 nmol.l-1, only one group reaching 40 nmol.l-1). Judging from the correlation coefficients based on total variances, the post-/pre-exercise differences in cortisol concentrations in serum depended chiefly on pre-exercise values, while those in saliva tended to depend more on the postexercise concentrations. The coefficients of correlation between that difference and either the pre- or postexercise values were -0.71 and 0.47, respectively, for serum, and -0.51 and 0.58, respectively, for saliva. This would suggest that salivary cortisol concentration might be a more suitable variable for assessing glucocorticoid activity in exercise than serum cortisol concentration, probably being less sensitive to pre-exercise emotional state.

Adolescent↗

PubMed1991

Radioimmunoassay of cortisol in saliva.

A direct (without extraction) radioimmunoassay of cortisol in saliva has been developed. The samples of saliva were subjected to four freezing-thawing cycles in order to decrease viscosity which may interfere with the determination. The method is simple, has good specificity and reproducibility. The determination in saliva has also the merit of noninvasiveness, and besides, the level of cortisol in saliva reflects the free, biologically active fraction of the hormone in blood serum. The volume of saliva required does not exceed 25 microliters per tube and the range of concentrations is between 0.6 and 15 nanograms per milliliter (1.5-40 nmol/l).

Charcoal↗

PubMed1987

HME--a novel derivative for direct iodination in steroid radioimmunoassays.

Steroid derivatives containing histidine methyl ester (HME), instead of histamine, were prepared by mixed anhydride coupling. The derivatives were crystalline, and when labelled in microgram quantities by using Iodo-gen (exposure time 1 h) the yield of the immunoreactive fraction was 40-50%. The products were similar in immunoreactivity and stability to the known histamine derivatives. Assay parameters obtained with HME-derivatives were compared with those obtained with tritiated steroids and with analogous TME-derivatives. A heterologous assay of progesterone (3 antisera against 12 alpha-succinyl-BSA, and methylsuccinyl derivatives for labelling substituted at 11 alpha-position), and a homologous assay of cortisol (4 antisera against 21-succinyl-BSA, and 21-carbonyl-derivatives for labelling) were studied. The HME-derivatives produced logit-log curves with slopes comparable to those in tritium-based assays. The sensitivity, as expressed by ED50 values, was by 66% higher than in tritium assays, and by 50% higher than for the tyramine derivative in a similar heterologous assay. The HME-based assay for cortisol was by 26% less sensitive compared to tritium, but several times more sensitive than in case of analogous TME-based assay.

Histidine↗

PubMed1986