Effect of physical training on parathyroid hormone and bone turnover marker profile in relation to vitamin D supplementation in soccer players.

The aim of the study was to assess the impact of vitamin D supplementation and regular physical activity on 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH) and bone turnover marker concentrations in healthy male athletes. Twenty-five youth soccer players were divided into groups: non-supplemented (GN) and supplemented (GS) with a vitamin D dose of 20 000 IU twice a week for 8 weeks. The study was conducted during an 8-week preseason period, from mid-January to mid-March. At baseline (T1) and at the end of this period (T2), the serum concentrations of 25(OH)D, (PTH), osteocalcin (OC) and ß-isomerized C-terminal telopeptide of type I collagen (ß-CTx) were measured. At T2, 25(OH)D increased by 70% in GS (p = 0.004) and by 6% in GN (p > 0.05). Significant differences between GS and GN groups were observed throughout the study in the group-by-time interaction and changes of 25(OH)D (p = 0.002; η 2 p = 0.36) and OC (p = 0.008; η 2 p = 0.26). Increased OC (ES = 0.74; moderate) and ß-CTx (ES = 1.31, large) in GN athletes who had an optimal baseline vitamin D level (GO) were observed. In GN, at T2, ß-CTx positively correlated with PTH and OC (p = 0.007 and p = 0.002). In GS, ß-CTx positively correlated with OC at both time points (T1, p = 0.027 and T2, p = 0.037). A negative correlation between 25(OH)D and PTH was observed at T2 (p = 0.018). The obtained results suggest that the 20 000 IU vitamin D3 dose applied twice a week for 8 weeks is effective for vitamin D compensation and sufficient to maintain the correct PTH concentration, as revealed by changes in the bone marker concentrations. In conclusion, the results suggest that the applied vitamin D supplementation dose in athletes leads to intensive bone remodelling and has protective effects on bone under intensive physical effort.

Effects of physical activity on sclerostin concentrations.

Osteoporosis is a serious medical and socioeconomic problem of the 21st century. Mechanical load is a key regulator which controls bone formation and remodelling, with participation of osteocytes. Sclerostin is produced and released by mature osteocytes into bone surface, where it inhibits the conveyance of osteoblast proliferation and differentiation activating signals from mesenchymal cells, thus suppressing new bone formation. The goal of the study was an evaluation of the effects of a 12-week physical training programme on the levels of bone turnover markers [Sclerostin, Osteocalcin (OC), C-terminal telopeptide of type I collagen (ß-CTX)] in blood serum of women with osteopenia. MATERIALS & METHODS: The study included 50 women of the Regional Menopause and Osteoporosis Centre of the WAM Teaching Hospital, at the age of 50-75 years with the diagnosis of osteopenia, obtained on the basis of hip and/or lumbar spine densitometry (T-score from -1.0 to -2.5 SD). During the initial 12 weeks (between point 1 and 2), the patients maintained their previous, normal level of physical activity. During subsequent 12 weeks (between point 2 and 3), a programme of exercise was implemented. The programme included the interval training on a bicycle ergometer, three times a week for 36 minutes. During the entire study duration, all the patients received a supplementation of calcium (500 mg) and vit. D3 (1800 IU) once daily. Serum levels of OC, alkaline phosphatase (ALP), ß-CTX and sclerostin were assayed at 3 time points. RESULTS: After the course of the exercise cycle, the OC concentration was increased, sclerostin levels decreased, while no statistical differences were observed in ß-CTX levels vs. the period of physical inactivity. No correlations were found between sclerostin level changes and osteocalcin level changes during the training time, because of too small groups. Neither statistically significant were the differences in alkaline phosphatase, calcium and phosphorus levels. CONCLUSIONS: The obtained results emphasise the role of physical training as an effective stimulation method of bone formation processes in women with osteopenia. Sclerostin can be a marker of physical activity. < /p > < p >.

Evaluation of vitamin D concentration in a population of young, healthy women - the effects of vitamin D supplementation.

INTRODUCTION: The goal of the study was an evaluation of serum vitamin D concentrations in healthy young women. MATERIAL AND METHODS: A total of 106 healthy women, aged 20-30 years, were included in the study. Monthly evaluation - for three months - of the effects of calcium (500 mg) and vitamin D (1500 IU) administration in women with baseline values of vitamin D < 20 ng/mL (Group 1) plus the effects of an 800 IU/d dose in women with the baseline value of D > 20 ng/mL (Group 2). Additionally, calcium and PTH concentrations were assessed at the study onset and after a three-month supplementation. Only 67 women adhered to the prescribed therapeutic regime during the three months of observation. RESULTS: The mean vitamin D concentration in the entire study group was 16.56 ng/mL, being 12.6 ng/mL in Group 1 and 25.22 ng/mL in Group 2. In the course of vitamin D administration, its concentration increased statistically significantly, both in the entire group and in the subgroups, at all time points compared with the study onset. Moreover, its concentration in the whole population and in Group 1 was significantly higher in each of the time points not only in relation to the baseline, but also in comparison with the results of the previous measurements (after 1 and 2 months of supplementation). In Group 2, vitamin D levels also increased systematically throughout the whole study period, and after 3 months its concentration was significantly higher than after 1 and 2 months. Although there were no differences in calcium concentration after those three months, a statistically significant drop of PTH (p < 0.05) was recorded in the entire population and in Group 1. CONCLUSIONS: A moderate deficiency of vitamin D was observed in the studied population of young women. A supplementation with calcium plus vitamin D brought about an increase of vitamin D concentration as early as in the first month of administration. The optimal concentration of > 30 ng/mL was achieved in Group 1 after three months of vitamin D administration in 1500 IU/d dose.

The role of selenium in thyroid gland pathophysiology.

It is now assumed that proper functioning of the thyroid gland (TG), beside iodine, requires also a number of elements, including selenium, iron, zinc, copper, and calcium. In many cases, only an adequate supply of one of these microelements (e.g. iodine) may reveal symptoms resulting from deficits of other microelements (e.g. iron or selenium). Selenium is accounted to the trace elements of key importance for homeostasis of the human system, in particular, for the proper functioning of the immune system and the TG. Results of epidemiological studies have demonstrated that selenium deficit may affect as many as one billion people in many countries all over the world. A proper sequence of particular supplementations is also worth emphasising for the significant correlations among the supplemented microelements. For example, it has been demonstrated that an excessive supplementation of selenium may enhance the effects of iodine deficit in endemic regions, while proper supplementation of selenium in studied animals may alleviate the consequences of iodine excess, preventing destructive-inflammatory lesions in the TG. This paper is a summary of the current knowledge on the role of selenium in the functionality of the TG.

Assessment of OPG, RANKL, bone turnover markers serum levels and BMD after treatment with strontium ranelate and ibandronate in patients with postmenopausal osteoporosis.

INTRODUCTION: The aim of this study was to evaluate quantitative changes in OPG and RANKL proteins after treatment with strontium ranelate (SR) and ibandronate in patients with postmenopausal osteoporosis. MATERIAL AND METHODS: A total of 89 women with postmenopausal osteoporosis (PO), aged 51-85 years, patients of the Outpatient Clinic of Osteoporosis of the Military Teaching Hospital in Lodz, were enrolled in the study. The patients were randomly assigned to different therapies: ibandronate and (SR). Patients of the control group received only calcium and vitamin D3 supplements. The patients' visits were repeated after three and six months. Measurements of beta-CTX (C-terminal Telopeptide of type 1 collagen), osteocalcin, RANKL, osteoprotegerin (OPG), alkaline phosphatase concentrations in serum, as well as of total 24-hour calcium and phosphate levels in serum and urine, were carried out in material collected at baseline and after three and six months of therapy. Left hip and lumbar spine densitometry was done twice (at baseline visit and after six months). RESULTS: In all three groups there were no significant differences noted in the concentrations of OPG and RANKL serum protein levels during the study period. Both negative and positive correlations or tendencies of correlations were found between OPG serum concentrations and BMD changes in the SR group. CONCLUSIONS: Both ibandronate and SR do not seem to cause any significant changes in OPG and RANKL protein serum levels during the first six months of treatment. OPG may play a role in osteoclast activity suppression in the course of treatment with ibandronate in patients with PO. OPG may play an important role in the mechanism of SR therapy and may be viewed as a potentially valuable parameter for monitoring and predicting the course of treatment with SR in PO.

Assessment of OPG/RANK/RANKL gene expression levels in peripheral blood mononuclear cells (PBMC) after treatment with strontium ranelate and ibandronate in patients with postmenopausal osteoporosis.

CONTEXT: Recent research results have confirmed the high significance of the OPG/RANK/RANKL system in the development of bone diseases. AIM: The aim of the reported study was to assess gene expression levels of the OPG/RANK/RANKL system in peripheral blood mononuclear cells (PBMCs) after strontium ranelate (SR) and ibandronate administered to patients with postmenopausal osteoporosis. PATIENTS AND METHODS: A total of 89 postmenopausal women, aged 51 to 85 years, patients of the Outpatient Clinic of Osteoporosis of the Military Teaching Hospital in Lodz, were enrolled into the study. The patients were randomly assigned to different medical therapies: ibandronate and SR. Patients of the control group received only calcium and vitamin D3 supplements. Patient visits were repeated after 3 and 6 months. Measurements of serum alkaline phosphatase concentrations and of RNA expression in PBMCs as well as of total serum calcium and phosphate levels and of their 24-hour urine excretion rates were carried out in material, collected at baseline and after 3 and 6 months of the therapy. Densitometry of the left hip and of the lumbar spine was done at the baseline visit and after 6 months. RESULTS: The differences in gene expressions of RANKL and RANK were not significant during the study period and did not differ between the groups in a statistically significant manner. No OPG gene expression was observed in PBMCs of patients in any of the studied groups and at any time point. The tendency of correlation (P = .07) was observed between decreasing RANK gene expression and increasing bone mineral density in the patients treated with SR. CONCLUSIONS: Both ibandronate and SR do not seem to cause any significant changes in gene expression levels of OPG/RANK/RANKL in PBMCs during the first 6 months of treatment.

Effects of certain antioxidants on lipid peroxidation process in lung homogenates of L thyroxine-receiving rats.

OBJECTIVE: A possible role of antioxidants in thyreotoxicosis was investigated. We examined the parameters of lipid peroxidation (LPO): conjugated dienes (CD), malondialdehyde (MDA), Schiff bases (SB) in lung homogenates of male Wistar rats. METHODS: Two control groups were created: Group 1 - intact animals and Group 2 - animals injected with 0,9% NaCl. In Experiment I, the animals received L-thyroxin (LT4) i.p. (Groups 3-7). After one week the rats received additionally: Group 4 - melatonin (MEL); Group 5 - propylthiouracil (PTU); Group 6 - Ambroxol (AMB); Group 7 - N-acetylocysteine (NAC). In Experiment II, the animals received only antioxidants. RESULTS: In Experiment I, we noticed a significantly higher MDA and SB level in Group 2, compared to that in Group 1. Moreover, we observed a significantly higher MDA and SB level in Group 3, vs. that in Group 1, but SB level was lower in Group 3 than in Group 2. Melatonin, PTU and NAC reduced CD; PTU, AMB diminished MDA and MEL, AMB lowered SB levels as compared to Group 3. In Experiment II, we observed significantly higher MDA and SB level in Group 2, vs. that in Group 1. Melatonin, AMB and NAC decreased MDA and SB level, when compared to Group 2 but PTU elevated MDA and SB level vs. that in Group 1. CONCLUSIONS: 1) L-T4 suppresses LPO, 2) MEL, AMB and NAC protect against LPO, 3) PTU is an antioxidant in thyreotoxicosis, however, when administered alone, it enhances LPO, 4) stress accelerate LPO.

Potassium iodide changes the levels of thyroid hormones in goitrogenic rats on selenium deficient diet.

OBJECTIVE: A possible link was proposed between selenium [Se(-)], iodine deficiency and thyroid pathology. The aim of the study was to examine changes in FT3 and FT4 concentrations, weights of the thyroid glands and ioduria after potassium iodide (KI) in normal and goitrogenic rats on Se(-) diet. METHODS: Wistar rats in Group 1 received the standard diet. Other animals remained (3 months) either on a Se(-) diet alone [Groups 2-5] or supplemented with selenium [Se(+)] (Group 6-8). After 9 weeks, Groups 3, 4, 6, 7 received sodium perchlorate [I(-); 1 month]. KI (1 mg/rat) was injected in Groups 4, 5, 7, 8. The animals were decapitated 3 days after the injections. RESULTS: FT4 was higher in serum of Se(-) rats than in that of Se(+). The differences of FT3 were not statistically significant. In I(-) Groups, the levels of FT3 and FT4 were very low. KI increased both thyroid hormones in I(-) rats but the effect was especially pronounced for FT3. KI decreased the weights of the glands, enlarged in the I(-) animals, both on Se(-) and Se(+) diet. Urine iodide concentrations were lower in Se(-) animals; KI increased ioduria. CONCLUSIONS: These data demonstrate that selenium and iodine deficiencies may play an essential role in thyroid hormone metabolism.