Biomedical subjects

Z Radikova

Publications and source records attributed to Z Radikova.

9 recordsLinked to original sources

PubMed2006

Decreased pituitary response to insulin-induced hypoglycaemia in young lean male patients with essential hypertension.

Essential hypertension is associated with changes in central catecholaminergic pathways which might also be reflected in the pituitary response to stress stimuli. The aim of this study was to determine whether the response of pituitary hormones, cortisol, plasma renin activity, aldosterone and catecholamines to insulin-induced hypoglycaemia is changed in hypertension. We studied 22 young lean male patients with newly diagnosed untreated essential hypertension and 19 healthy normotensive, age- and body mass index (BMI)-matched controls. All subjects underwent an insulin tolerance test (0.1 IU insulin/kg body weight intravenously) with blood sampling before and 15, 30, 45, 60 and 90 min after insulin administration. Increased baseline levels of norepinephrine (P<0.05), increased response of norepinephrine (P<0.001) and decreased response of growth hormone (P<0.001), prolactin (P<0.001), adrenocorticotropic hormone (P<0.05) and cortisol (P<0.001) were found in hypertensive patients when compared to normotensive controls. Increased norepinephrine levels and a decreased pituitary response to metabolic stress stimuli may represent another manifestation of chronically increased sympathetic tone in early hypertension.

Adult↗

PubMed2006

Insulin sensitivity indices: a proposal of cut-off points for simple identification of insulin-resistant subjects.

Demanding measurement of insulin sensitivity using clamp methods does not simplify the identification of insulin resistant subjects in the general population. Other approaches such as fasting- or oral glucose tolerance test-derived insulin sensitivity indices were proposed and validated with the euglycemic clamp. Nevertheless, a lack of reference values for these indices prevents their wider use in epidemiological studies and clinical practice. The aim of our study was therefore to define the cut-off points of insulin resistance indices as well as the ranges of the most frequently obtained values for selected indices. A standard 75 g oral glucose tolerance test was carried out in 1156 subjects from a Caucasian rural population with no previous evidence of diabetes or other dysglycemias. Insulin resistance/sensitivity indices (HOMA-IR, HOMA-IR2, ISI Cederholm, and ISI Matsuda) were calculated. The 75th percentile value as the cut-off point to define IR corresponded with a HOMA-IR of 2.29, a HOMA-IR2 of 1.21, a 25th percentile for ISI Cederholm, and ISI Matsuda of 57 and 5.0, respectively. For the first time, the cut-off points for selected indices and their most frequently obtained values were established for groups of subjects as defined by glucose homeostasis and BMI. Thus, insulin-resistant subjects can be identified using this simple approach.

Adolescent↗

PubMed2005

Peptide hormones and histamine in plasma and synovial fluid of patients with rheumatoid arthritis and osteoarthrosis.

OBJECTIVES: Hormones other than adrenal and gonadal steroids may play also a significant role in the pathogenesis of rheumatoid arthritis. The aim of this study was to investigate the levels of selected peptide hormones and histamine in synovial fluid of knee joints and in plasma of patients with rheumatoid arthritis and with osteoarthrosis. METHODS: The concentrations of insulin, C-peptide, prolactin, growth hormone, free triiodothyronine (FT3), thyrotropin (TSH), and histamine were determined in synovial fluid and plasma of 27 patients with rheumatoid arthritis (RA) and in 12 patients with osteoarthrosis (OA). RESULTS: The presence of peptide hormones in synovial fluid was demonstrated. The levels of TSH and growth hormone were lower in synovial fluid than in plasma in both groups, while those of prolactin were comparable in synovial fluid and in plasma. The levels of C-peptide (p < 0.05), insulin and FT3 were higher in synovial fluid than in plasma of OA patients, but lower in synovial fluid of RA patients as compared to their levels in plasma. Significant positive correlations between the levels in plasma and synovial fluid were observed in prolactin (p < 0.001, r = 0.741) and TSH (p < 0.05, r = 0.88) only. After age adjustment, no significant differences in synovial fluid and in plasma levels of all hormones were found between OA and RA patients. The levels of histamine in plasma were similar in RA and OA patients, in synovial fluid of both groups histamine was found in almost undetectable amounts. CONCLUSIONS: The selected peptide hormones, e.g. insulin, C-peptide, prolactin, growth hormone, FT3 and TSH, are present in synovial fluid of RA and OA patients, some of them in the concentrations comparable to these in plasma. The role of the locally present hormones in pathogenesis of RA has to be investigated in further studies and analyses.

Arthritis, Rheumatoid↗

PubMed2005

Attenuated insulin response and normal insulin sensitivity in lean patients with ankylosing spondylitis.

Chronic low-grade inflammation is associated with insulin resistance. The aim of this study was to determine insulin response to intravenous glucose load and insulin sensitivity in patients with ankylosing spondylitis (AS). Fourteen nonobese male patients with AS and 14 matched healthy controls underwent frequent-sampling intravenous glucose tolerance test (FSIVGTT). Insulin secretion and insulin sensitivity were calculated using the computer-minimal and homeostasis-model assessment 2 (HOMA2) models. Fasting glucose, insulin, cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol, triglyceride levels, HOMA2, glucose effectiveness, insulin sensitivity and insulin response to FSIVGTT did not differ between patients and controls. Tumor necrosis factor-alpha and interleukin (IL)-6 concentrations tended to be higher in AS patients than in controls. Second-phase beta-cell responsiveness was 37% lower (p = 0.05) in AS patients than in controls. A negative correlation was found between the percentage of beta-cell secretion and IL-6 in all subjects (r = -0.54, p = 0.006). We found normal insulin sensitivity but attenuated glucose utilization in the second phase of FSIVGTT in AS patients. Our results indicate that elevated IL-6 levels may play a pathophysiological role in attenuating beta-cell responsiveness, which may explain the association between elevated IL-6 levels and increased risk for type 2 diabetes.

Adult↗

PubMed2004

Hypothalamic-pituitary-adrenal axis function in ankylosing spondylitis.

OBJECTIVE: To assess basal function and responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in patients with ankylosing spondylitis during dynamic testing. METHODS: Insulin induced hypoglycaemia (IIH) (Actrapid HM 0.1 IU/kg, as intravenous bolus) was induced in 17 patients and 11 healthy controls matched for age, sex, and body mass index. Concentrations of glucose, adrenocorticotrophic hormone (ACTH), cortisol, insulin, dehydroepiandrosterone sulphate (DHEAS), 17alpha-hydroxyprogesterone, interleukin 6 (IL-6), and tumour necrosis factor alpha (TNFalpha) were determined in plasma. RESULTS: Comparable basal cortisol levels were found in the two groups, with a trend to be lower in ankylosing spondylitis. In the ankylosing spondylitis group, there were higher concentrations of IL-6 (mean (SEM): 16.6 (2.8) pg/ml v 1.41 (0.66) pg/ml in controls; p<0.001) and TNFalpha (8.5 (1.74) pg/ml v 4.08 (0.42) pg/ml in controls; p<0.01). Glucose, insulin, ACTH, DHEAS, and 17alpha-hydroxyprogesterone did not differ significantly from control. The IIH test was carried out successfully in 11 of the 17 patients with ankylosing spondylitis, and the ACTH and cortisol responses were comparable with control. General linear modelling showed a different course of glycaemia (p = 0.041) in the ankylosing spondylitis patients who met the criteria for a successful IIH test compared with the controls. CONCLUSIONS: The results suggest there is no difference in basal HPA axis activity and completely preserved responsiveness of the HPA axis in patients with ankylosing spondylitis. The interpretation of the different course of glycaemia during IIH in ankylosing spondylitis requires further investigation.

17-alpha-Hydroxyprogesterone↗

PubMed2004

Does orthostatic stress influence the neuroendocrine response to subsequent hypoglycemia in humans?

Neuroendocrine response to stress stimuli is influenced by previous stimuli of different nature. The aim of the study was to test whether antecedent orthostatic stress may affect the neuroendocrine response to subsequent hypoglycemia. A group of 12 (6 men, 6 women) nonobese, healthy volunteers aged 19 to 27 y (mean 24 +/- 0.8) participated in the study in two sessions: controlled insulin-induced hypoglycemia to 2.7 mmol/L for 15 min either with or without antecedent orthostatic stress (30 min of 60 degrees head-up tilt before insulin administration). Orthostatic stress caused a significant decrease in plasma volume (-9.6%; P < 0.001) and a significant increase in plasma renin activity, aldosterone, norepinephrine (P < 0.01), and adrenocorticotropic hormone (ACTH) concentrations (P < 0.05) in all subjects. Growth hormone response to hypoglycemia was diminished in women (P < 0.01). The epinephrine response to hypoglycemia was diminished in women in comparison to men (P < 0.001), but was unaffected by antecedent orthostatic stress. Hypoglycemia failed to induce the ACTH release after its elevation during orthostatic stress. ACTH response to moderate hypoglycemia without previous orthostatic stress was evident only in men in comparison to women (P < 0.05). We conclude that the epinephrine, growth hormone, and ACTH responses to hypoglycemia were diminished in women. Except ACTH, the neuroendocrine response to mild hypoglycemia was not affected by previous orthostatic stress in healthy subjects. In the case of ACTH, the first stress stimulus is consequential for the subsequent response of this hormone, probably due to short-loop negative feedback effects.

Adult↗

PubMed2003

Body position and the neuroendocrine response to insulin-induced hypoglycemia in healthy subjects.

Changes in body fluid distribution are known to influence neuroendocrine function. The aim of the present study was to test the hypothesis that changes in plasma volume affect the counterregulatory neuroendocrine response to hypoglycemia. The tests were performed in 12 subjects in two situations: 'head-up' (+60 degrees head-up tilt standing for 30 min and hypoglycemia in sitting position afterwards) and 'leg-up' (leg-up position for 30 min and hypoglycemia in leg-up position afterwards) in a random order. Insulin-induced hypoglycemia was adjusted to 2.7 mmol/l for 15 min by glucose infusion. Plasma volume was greater by 2.2% (p < 0.001) in leg-up and lower by 9.6% (p < 0.001) in head-up position compared to the basal value in sitting position. Head-up position was associated with increases in ACTH, aldosterone, norepinephrine levels and plasma renin activity (p < 0.01). Leg-up position resulted in decreases in plasma growth hormone and epinephrine concentrations (p < 0.05). Except epinephrine, the neuroendocrine response to hypoglycemia, if any, was mild. Hypoglycemia failed to activate ACTH release after head-up position. Body fluid redistribution did not modify hormonal changes during insulin hypoglycemia. In conclusion, we suggest that body position and accompanying plasma volume changes do not appear to affect neuroendocrine and counterregulatory responses to moderate, short duration hypoglycemia in healthy subjects.

Adrenocorticotropic Hormone↗

PubMed2003

Thyroid function and cholesterol level: paradoxical findings in large groups of population with high cholesterol food intake.

OBJECTIVE: To compare the levels of serum cholesterol with thyroid function as estimated by the level of thyrotropin and free thyroxine with possible participation of thyroperoxidase antibodies in large number of adults examined within large field surveys focused on the evaluation of thyroid status of Slovak rural population. SUBJECTS AND METHODS: Serum level of cholesterol and thyrotropin (TSH) was estimated in a total of 2786 adults. In addition, in 2038 of them also the level of free thyroxine (FT4), total triiodothyronine (TT3), cholesterol, triglycerides and phospholipids was measured. The levels of TSH, anti-TPO and FT4 were estimated by supersensitive electrochemiluminiscent immunoassay using the automatic system Elecsys (Roche, Switzerland). RESULTS: A total of 2786 adults was stratified into 7 groups according to the range of TSH level as related to generally recognized level of thyroid function, e.g. 1. TSH <0.10 mU/L (overt hyperthyroidism, N=41), 2. TSH 0.11-0.30 mU/L (overt or subclinical hyperthyroidism, N=149), 3. TSH 0.31-2.50 mU/L (normal level, N=1750), 4. TSH 2.51-4.50 ("high normal" level, N=607), 5 TSH 4.51-6.50 (mild or incipient subclinical hypothyroidism, N=137), 6. TSH 6.51-10.00 mU/L (mild hypothyroidism, N=50), 7. TSH 10.01-99.00 mU/L (severe hypothyroidism, N=53). The average levels of cholesterol in all groups were very similar ranging from 5.53 to 6.17 mmol/L and no interrelations with TSH level were found. In addition, no considerable differences between these groups were found when considering the levels of medians, upper quartiles and 90th percentiles of individual groups. When male and female subjects were divided into age groups according to the decades, an age dependent increase of cholesterol level was found in both sexes. The fraction of 2038 subjects was divided into the same TSH related groups as defined above. Similarly as above, no considerable differences in cholesterol, triglycerides and phospholipids level were observed. However, the levels of FT4 and TT3 were significantly decreasing with the increase of TSH level which confirmed the continuing decrease of thyroid function. The frequency of positive anti-TPO in subjects with TSH >6.5 mU/l (71/86 = 82.5%) was significantly higher than that in subjects with TSH <6.5 mU/l (468/1952 = 23.9%). CONCLUSIONS: No difference in the level of cholesterol and triglycerides was found in large groups of rural adults from Slovakia with various thyroid function as estimated by the level of TSH, FT4, TT3 and anti-TPO. It is assumed that this interrelation resulted from very high cholesterol intake due to inappropriate general nutritional status of rural population resulting from the consumption of unhealthy foods.

Adult↗

PubMedDate not supplied

Hormone concentrations in synovial fluid of patients with rheumatoid arthritis.

OBJECTIVE: Alterations in local concentrations of hormones, affecting directly synovial cells, could be involved in the modulation of the rheumatic inflammatory processes. The aim of present study was to investigate the levels of selected hormones (steroids, peptide and thyroid hormones) in synovial fluid of knee joint of patients with rheumatoid arthritis (RA) and control individuals with non-rheumatic exudate (with osteoarthrosis, OA). METHODS: Thirty-eight patients, 22 female and 16 males, with rheumatoid arthritis (RA) and 12 subjects with osteoarthrosis (OA, control group, 6 females and 6 males) participated in the study. Concentrations of cortisol (CS), 17-beta-estradiol (ES), dehydroepiandrosterone (DHEA), progesterone (PRG), aldosterone ALD), prolactin (PRL), insulin (INS), and C-peptide were determined by radioimmunoassay in synovial fluid. Insulin binding to isolated cell membrane of cells from synovial sediment was estimated by using radioiodine labeled insulin. In a group of patients (10 with RA and 4 with OS), the levels of free threeiodothyronine (FT3), TSH and growth hormone (GH) were also determined in synovial fluid. RESULTS: Increased levels of ES in synovial fluid of RA patients were observed, and higher differences were noted in men. TE concentrations were moderately elevated in synovial fluid of RA patients, however the ratio of ES/TE was significantly higher in male RA compared to OA patients. Higher levels of PRG, ALD and growth hormone were noted in synovial fluid of RA patients. Besides the steroid hormones the presence of insulin and C-peptide was noted in synovial fluid and the correlation between the levels of these two peptides was highly significant. The concentrations of INS and C-peptide in synovial fluid of patients from RA and OA group were not significantly different, however, highly significant increase of insulin binding to isolated membrane of synovial cells was found. Concentrations of cortisol, dehydroepiandosterone, prolactin, TSH and FT3 in synovial fluid were not significantly different in RA and OA groups. CONCLUSIONS: Besides the steroids also insulin, c-peptide, GH and FT3 were found in synovial fluid. The elevated ALD and GH levels in synovial fluid of RA patients and the presence of INS in synovial fluid with increase of INS binding to plasma membranes of cells from synovial fluid of RA patients suggest that besides the gonadal steroids also these hormones may affect the local inflammatory processes.

Arthritis, Rheumatoid↗