Seasonal changes in free 25-(OH)D and vitamin D metabolite ratios and their relationship with psychophysical stress markers in male professional football players

Introduction: Novel markers of vitamin D status are currently being investigated, including free 25-(OH)D (25-(OH)DF) and the vitamin D metabolite ratio (24,25-(OH)2D3:25-(OH)D3; VMR). The VMR may provide additional functional information on vitamin D metabolism in athletes. Therefore, the main objective of the current study was to evaluate 25-(OH)DF, bioavailable 25-(OH)D (25-(OH)DB), VMR, and psychophysical stress markers during different training periods over a half-season. The second aim was to assess the association between vitamin D binding protein (VDBP), total and free 25-(OH)D, VMRs, and psychophysical stress markers in professional football players. Moreover, we examined the relationship between 25-(OH)D3 and vitamin D metabolites (24,25-(OH)2D3, 3-epi-25-(OH)D3) to determine if training loads in different training periods influenced the vitamin D metabolome. Methods: Twenty professional football players were tested at six different time points across half a year (V1-June; V2-July; V3-August; V4-October; V5-December; V6-January). Results: Analyses indicated a significant seasonal rhythm for VDBP, and total 25-(OH)D (25-(OH)DT), 25-(OH)DB, 24,25-(OH)2D3, 3-epi-25-(OH)D3, 25-(OH)D3:24,25-(OH)2D3, and 24,25-(OH)2D3:25-(OH)D3 VMRs throughout the training period. No correlation was detected between 25-(OH)DT, 25-(OH)DB, 25-(OH)DF, vitamin D metabolites, VMRs, VDBP, and ferritin, liver enzymes (aspartate transaminase [AST] and alanine transaminase [ALT]), creatine kinase (CK), cortisol, testosterone, and testosterone-to-cortisol ratio (T/C) in each period (V1-V6). However, there was a strong statistically significant correlation between 25-(OH)D3 and 24,25-(OH)D3 in each training period. Conclusion: In conclusion, a seasonal rhythm was present for VDBP, 25-(OH)DT, 25-(OH)DB, vitamin D metabolites (24,25-(OH)2D3, 3-epi-25-(OH)D3), and VMRs (25-(OH)D3:24,25-(OH)2D3, 25-(OH)D3:3-epi-25-(OH)D3). However, no rhythm was detected for 25-(OH)DF and markers of psychophysical stress (ferritin, liver enzymes, CK, testosterone, cortisol, and T/C ratio). Moreover, the relationships between free and total 25-(OH)D with psychophysical stress markers did not demonstrate the superiority of free over total measurements. Furthermore, training loads in different training periods did not affect resting vitamin D metabolite concentrations in football players.

Metabolism of vitamin D is not affected by sport activity

BACKGROUND

Higher levels of physical activity are related to higher 25-(OH)D levels. Total 25-(OH)D (25-(OH)DT) are routinely used in clinical practice to assess vitamin D, however novel biomarkers are currently being investigated as free 25-(OH)D (25-(OH)DF) or vitamin D metabolite ratios (VMRs). The primary aim of our study was to assess 25-(OH)DF, vitamin D metabolites and VMRs in inactive men and athletes. A secondary aim was to check whether regular physical activity influence on vitamin D metabolome. A tertiary aim was to determine the relationship between 25-(OH)DT, 25-(OH)DF, vitamin D binding protein (VDBP), vitamin D metabolites and VMRs in this cohort.

METHODS

A total of 69 participants (27 inactive men, 18 indoor and 24 outdoor athletes) participated in the study. Vitamin D metabolites (25-(OH)DT, 24,25-(OH)2D3, 3-epi-25-(OH)D3, and 1,25-(OH)2D) were assessed using LC-MS/MS. The 25-(OH)DF concentration was calculated based on serum albumin and VDBP levels.

RESULTS

There were no differences in vitamin D metabolites and VMRs between inactive men and between the two groups of athletes. We showed a strong relationship between 25-(OH)DT, 25-(OH)DF and 24,25-(OH)D3, 3-epi-25(OH)D3, 24,25-(OH)2D3:25-(OH)D3 VMR in each group. Analysis showed that 25-(OH)DT, 25-(OH)DF inversely associated with 25-(OH)D3:24,25-(OH)2D3, 25-(OH)D3:3-epi-25-(OH)D3, 1,25-(OH)2D:24,25-(OH)2D3 ratios in inactive men and athletes (indoor and outdoor).

CONCLUSIONS

On the basis of our results, we concluded that regular long-term physical activity has no effect on the concentration of vitamin D metabolites at rest. Furthermore, free vitamin D does not correlate more strongly with vitamin D metabolites and VMRs compared to total.

Effects of running a marathon on sclerostin and parathyroid hormone concentration in males aged over 50

The aim of our study was to verify whether running a marathon (32nd Wroclaw Marathon) was associated with changes in sclerostin and intact PTH (iPTH) concentration in middle-aged males. We enrolled 33 males who completed the marathon race. Blood samples were taken 60 minutes before (V1), immediately after (V2), and 7 days after the run (V3). The mean serum sclerostin concentration was 42.4 ± 10.8 pmol/L at V1, increased to 62.9 ± 12.6 pmol/L at V2 (t= -11.206; p < 0.001) and returned to baseline in V3 (t = 8.344; p < 0.001, V3 vs. V2). A similar trend was recorded for iPTH (t= -7.440; p < 0.001, for V2 vs. V1; t = 6.229; p < 0.001, for V3 vs. V2), at V3, iPTH levels remained significantly higher than V1 (t= -2.759; p = 0.010). The results of our study suggest that, in middle-aged males, running a marathon affects skeletal metabolism by activating two counteracting mechanisms, although temporarily overlapping: first, by a sudden inhibition of bone formation, through induction sclerostin expression and, secondly, by a long-lasting induction of PTH, which also guarantees the maintenance of adequate circulating levels of calcium. The net effect would be the maintenance of adequately high levels of circulating calcium to be used for neuromuscular activity and muscle contraction.

How Do Male Football Players Meet Dietary Recommendations? A Systematic Literature Review

The aim of this review was to determine whether male football players meet dietary recommendations according to a UEFA expert group statement and to identify priority areas for dietetic intervention, including training periodization and field position. A database search of PubMed, Web of Science, EBSCO and Scopus was performed. To be included within the final review, articles were required to provide a dietary intake assessment of professional and semi-professional football players. A total of 17 studies met the full eligibility criteria. Several studies showed insufficient energy and carbohydrate intake compared to the recommendations. A majority of athletes consume adequate protein and fat intakes compared to the recommendations. In addition, several studies showed the insufficient intake of vitamins and minerals. This systematic review showed that football players do not meet the nutritional recommendations according to the UEFA expert group statement. Future research should be focused on how to apply nutritional recommendations specific for athletes in accordance with training periodization and positions on the field.

Relationship Between Metabolites of Vitamin D, Free 25-(OH)D, and Physical Performance in Indoor and Outdoor Athletes

The potential effects of vitamin D in athletes have received considerable attention in the literature. However, little is known about vitamin D metabolites and their association with physical performance in athletes. Therefore, the aim of our study was to determine the relationship between metabolites of vitamin D, vitamin D binding protein (VDBP), free, bioavailable 25-(OH)D, and physical fitness tests in athletes. A total of 40 indoor and outdoor players (16 judoists and 24 football players) participated in the study. Vitamin D metabolites (25-(OH)D, 24,25-(OH)₂D₃, 3-epi-25-(OH)D₃, and 1,25-(OH)₂D) were assessed using LM-MS/MS. Free 25-(OH)D concentration was evaluated by calculation using serum albumin and VDBP levels. Athletic performance was assessed using handgrip and vertical jump. Our study showed a significant correlation between vitamin D metabolites and handgrip strength and vertical jump variables in indoor players. It demonstrated a significant association between 3-epi-25-(OH)D₃ and vertical jump parameters in outdoor players. The results of our study showed relationship between free, bioavailable 25-(OH)D, and vertical jump variables in indoor players. In conclusion, we provide novel information on the vitamin D metabolites and athletic performance in athletes. Based on the results of our study, we concluded that vitamin D metabolites might be involved in skeletal muscle function in relation to athletic performance.

Correlative studies on vitamin D and total, free bioavailable testosterone levels in young, healthy men

The relationship between vitamin D levels and testicular hormonal function in men has not been clearly established. Therefore, we aimed to investigate the relationship between deficiency/insufficiency levels of 25(OH)D and luteinizing hormone (LH), follicle-stimulating hormone (FSH), total (TT), free (FT), and bioavailable testosterone (BT), and sex hormone binding globulin (SHBG) in young, healthy men. We enrolled 176 healthy, active young men aged 18–35 years from a genetically homogenous population of Lower Silesia, Poland. Serum levels of 25(OH)D, LH, FSH, and TT were measured by electrochemiluminescence (ECLIA). FT levels were measured by enzyme-linked immunosorbent assay (ELISA). BT levels were calculated from TT, SHBG, and albumin. SHBG was measured by chemiluminescent immunoassay CLIA. We did not find any significant differences between the mean hormonal values (LH, FSH, TT, FT, BT, and SHBG) and the status of 25(OH)D level (deficient and insufficient). Based on our results, we concluded that there is no relationship between deficient and insufficient 25(OH)D concentration and androgen levels in young, healthy men.

Assessment of the Dietary Intake of High-Rank Professional Male Football Players during a Preseason Training Week

A well-balanced diet is one of the main factors that may play a supportive role in enhancing acute training stimuli in optimal training adaptation. The aim of the present study was to examine the energy and macro- and micronutrient intake including and excluding supplements among top-level Polish football players during one week of the general preparatory period. In addition, the study looked at whether athletes consume carbohydrates in recommended amounts, depending on the completed training sessions. A total of 26 professional football players were included in the study. The preseason dietary intake was assessed using a 7-day estimated food record. The energy value of the diet and the amounts of the dietary ingredients were assessed using the software Dieta 6.0. The average consumption of energy, vitamin B₂, vitamin C, vitamin E, folate, and calcium was lower than recommendations, and average intake of sodium and potassium was higher than the norm in the diets of the athletes. The results of this study do not confirm the justification for adding protein preparations to diets of the studied players. Furthermore, football players dietary carbohydrate intake was relatively low in comparison to requirements based on training loads. Based on our results we conclude that further work is necessary to reinforce education about nutritional habits and adjust nutritional strategies to individual needs to enhance athletic performance.

Calcium-Sensing Receptor Gene Polymorphisms (CASRV1 and CASRV2) and the Physical Activity Level of Men in Lower Silesia, Poland

Calcium-sensing receptors (CASR) are a dimeric family of C-class G-protein-coupled receptors that play a crucial role in bone and mineral metabolism by regulating parathyroid hormone (PTH) secretion, skeletal development, and urinary Ca²⁺ excretion. Genetic factors mainly impact bone mineral density (BMD). However, many variable factors may affect bone health, including physical activity. The aim of our study was to investigate the potential associations between calcium-sensing receptor gene polymorphisms (CASRV1 and CASRV2) and the level of physical activity in adult males from Lower Silesia, a region in the south of Poland. A total of 428 adult male inhabitants of Lower Silesia were included in the study. Their physical activity was evaluated using the International Physical Activity Questionnaire. The CASRV1 (rs 1801725, G>T, A986S) and CASRV2 (rs 761486, T>G, non-coding region) polymorphisms were determined using polymerase chain reaction (PCR) and mini-sequencing. The polymorphisms were identified with GeneScan software ver. 3.1.2. We did not observe any statistically significant differences between the total energy expenditure (total MET) and the CASRV1 and CASRV2 polymorphisms. We did not find any association between the level of physical activity and the frequency of genotypes at the polymorphic locus of the calcium-sensing receptor genes CASRV1 and CASRV2. We found that the number of hours the subjects spent in a sitting position was unrelated to the genotypes at the polymorphic locus of the calcium-sensing receptor gene CASRV1. Based on our studies, we concluded that there were no associations between CASR and physical activity in the men inhabiting Lower Silesia in Poland. Our results do not suggest any influence of the assessed genetic factors in the population variability of the level of physical activity of adults.

Vitamin D, Skeletal Muscle Function and Athletic Performance in Athletes-A Narrative Review

The active form of vitamin D (calcitriol) exerts its biological effects by binding to nuclear vitamin D receptors (VDRs), which are found in most human extraskeletal cells, including skeletal muscles. Vitamin D deficiency may cause deficits in strength, and lead to fatty degeneration of type II muscle fibers, which has been found to negatively correlate with physical performance. Vitamin D supplementation has been shown to improve vitamin D status and can positively affect skeletal muscles. The purpose of this study is to summarize the current evidence of the relationship between vitamin D, skeletal muscle function and physical performance in athletes. Additionally, we will discuss the effect of vitamin D supplementation on athletic performance in players. Further studies are necessary to fully characterize the underlying mechanisms of calcitriol action in the human skeletal muscle tissue, and to understand how these actions impact the athletic performance in athletes.

The quality of semen among a sample of young, healthy men from Lower Silesia (AndroLS)

INTRODUCTION

Contrary to other parts of the continent, little information is available regarding semen quality among subjects from central and eastern Europe.

MATERIAL AND METHODS

We evaluated semen profiles among a sample of men from an industrialised region of Poland. We directly invited 5000 healthy inhabitants of the region (aged 18-35 years; with unchecked fecundity) to participate in the study. Among the 500 who were eligible and willing to participate, we acquired detailed information and semen and blood samples from 177 subjects.

RESULTS

Semen volume, sperm concentration, and total sperm count were, respectively, (mean ± SD): 3.1 ± 1.5 ml, 60 ± 44 x 106/ml and 170 ± 137 x 106/ml. Percentage of normal forms was 14.7 ± 6.5%.

CONCLUSIONS

Due to the relatively low sperm motility (mean ± SD: 54 ± 16%) and vitality (mean ± SD: 60 ± 15%) values, these variables require special attention during routine evaluations. The WHO 2010 criteria for these two parameters were met in only 60% and 66% of the samples, respectively. Further studies on men with different educational levels, social environments, or living conditions are needed to confirm our results.

Trends in the prevalence of autoimmune thyroiditis in the leading private health-care provider in Poland

BACKGROUND

Autoimmune thyroiditis (AT) is one of the most common endocrine disorders affecting a significant percent of the population, especially women. It may have serious and long-lasting consequences. The etiology of AT is multifactorial and it arises from an interplas between environmental and genetic factors. Tendencies in AT prevalence and incidence are unclear. In Poland there are no national registers covering the data on AT prevalence.

OBJECTIVES

The aim of the investigation was to assess changes in diagnosing AT in the largest chain of outpatient medical centers in Poland.

MATERIAL AND METHODS

We compared freqnancy at which AT and hypothyroidism diagnoses were made during endocrinology consultations in the period 2006-2013. The data was extracted from the database of LUXMED (part of BUPA).

RESULTS

Within 8 years, the prevalence of newly diagnosed AT dropped from 10.4% to 4.8% (p < 0.001) alongside with a decrease in the prevalence of newly diagnosed hypothyroidism from 17.8% to 7.7% (p < 0.00001). AT was widespread in young women aged 20-39. There were relatively more cases in the southern areas of Poland.

CONCLUSIONS

The analyzed data does not support a hypothesis indicating a growing incidence of AT in the last years. Detailed epidemiological studies would be helpful in designing screening strategies for patients with this common disorder.

25(OH)D3 Levels Relative to Muscle Strength and Maximum Oxygen Uptake in Athletes

Vitamin D is mainly known for its effects on the bone and calcium metabolism. The discovery of Vitamin D receptors in many extraskeletal cells suggests that it may also play a significant role in other organs and systems. The aim of our study was to assess the relationship between 25(OH)D₃ levels, lower limb isokinetic strength and maximum oxygen uptake in well-trained professional football players. We enrolled 43 Polish premier league soccer players. The mean age was 22.7±5.3 years. Our study showed decreased serum 25(OH)D₃ levels in 74.4% of the professional players. The results also demonstrated a lack of statistically significant correlation between 25(OH)D₃ levels and lower limb muscle strength with the exception of peak torque of the left knee extensors at an angular velocity of 150°/s (r=0.41). No significant correlations were found between hand grip strength and maximum oxygen uptake. Based on our study we concluded that in well-trained professional soccer players, there was no correlation between serum levels of 25(OH)D₃ and muscle strength or maximum oxygen uptake.

Sclerostin as a novel marker of bone turnover in athletes

Sclerostin is a protein secreted by osteocytes that acts as an inhibitor of bone formation. It has been shown that physical activity affects sclerostin concentration and thus bone remodelling. The aim of the study was to evaluate serum concentrations of sclerostin, selected bone turnover markers (PTH, P1NP), 25(OH)D3 and the intake of calcium and vitamin D in physically active versus sedentary men. A total of 59 healthy men aged 17-37 were enrolled in the study (43 athletes and 16 non-athletes). The mean sclerostin concentration in the group of athletes (A) was significantly higher than in non-athletes (NA) (35.3±8.9 vs 28.0±5.6 pmol·l^-1, p= 0.004). A compared with NA had higher concentrations of P1NP (145.6±77.5 vs 61.2±22.3 ng·ml^-1, p= <0.0001) and 25(OH)D3 (16.9±8.4 vs 10.3±4.3 ng·ml^-1, p= 0.004) and lower concentrations of PTH (25.8±8.3 vs 38.2±11.5 pg·ml^-1, p= <0.0001). Vitamin D deficiency was found in 77% of A and 100% of NA. A and NA had similar daily energy intake. They did not differ as to the intake of calcium and vitamin D. We observed a negative correlation between the serum concentrations of sclerostin and calcium in the studied subjects. Our results suggest that regular, long-lasting physical training may be associated with higher concentration of sclerostin. It seems that increased sclerostin is not related to other bone turnover markers (PTH, P1NP).

An evaluation of the levels of 25-hydroxyvitamin D3 and bone turnover markers in professional football players and in physically inactive men

Vitamin D is synthesised in the skin during exposure to sunlight and its fundamental roles are the regulation of calcium and phosphate metabolism and bone mineralisation. The aim of our study was to evaluate serum levels of 25-hydroxyvitamin D3, PTH and bone turnover markers (P1NP, OC, beta-CTx, OC/beta-CTx) and the intake of calcium and vitamin D in Polish Professional Football League (Ekstraklasa) players and in young men with a low level of physical activity. Fifty healthy men aged 19 to 34 years were included in the study. We showed that 25(OH)D3 and P1NP levels and OC/beta-CTx were higher in the group of professional football players than in the group of physically inactive men. The daily vitamin D and calcium intake in the group of professional football players was also higher. We showed a significant relationship between 25(OH)D3 levels and body mass, body cell mass, total body water, fat-free mass, muscle mass, vitamin D and calcium intake. Optimum 25(OH)D3 levels were observed in a mere 16.7% of the football players and vitamin D deficiency was observed in the physically inactive men. The level of physical activity, body composition, calcium and vitamin D intake and the duration of exposure to sunlight may significantly affect serum levels of 25(OH)D3.

Polymorphic variants of neurotransmitter receptor genes may affect sexual function in aging males: data from the HALS study

BACKGROUND/AIMS

Human behavior is influenced by a number of brain neurotransmitters. Central dopamine, serotonin and melanocortin systems have special importance for male sexual function. We searched for associations between male aging symptoms and polymorphic sites of serotonin (5-HTR1B), melanocortin (MC4R) and dopamine (DRD2, DRD4) receptors.

METHODS

In a population-based sample, genotyping of 5-HTR1B (polymorphism: G861C), MC4R (polymorphisms: C-2745T, Val103Ile), DRD2 (polymorphism: C313T) and DRD4 (polymorphism: 48-bp VNTR) was performed in 387 healthy men. The Aging Males' Symptoms (AMS) scale was used to evaluate specific ailments of aging men. We analyzed answers to questions from the AMS scale. Five points of the questionnaire addressed sexual symptoms of the aging male: feeling of passing one's peak, decrease in beard growth, decrease in ability/frequency to perform sexually, decrease in the number of morning erections, and decrease in sexual desire/libido (lacking pleasure in sex, lacking desire for sexual intercourse). Relations between reported symptoms and variants of the polymorphic sites of the studied genes were assessed.

RESULTS

After adjusting for confounding factors (education, arterial hypertension, physical activity, weight, waist circumference) an association between the sexual dimension of AMS and genetic variants of 5-HTR1B G861C (p = 0.04) was observed.

CONCLUSIONS

Variability of neurotransmitter receptor genes may be associated with sexual symptoms of aging in men.

Melanocortin-4 receptor gene polymorphism and the level of physical activity in men (HALS Study)

Melanocortin plays an important role in the energy balance in humans. Actions of melanocortin are exerted through activation of five receptors among which the melanocortin-4 receptor (MC4R) is especially abundant within the central nervous system (CNS). It has been proved that genetic variations of the MC4R gene are associated with the energy intake. Recent data has suggested that MC4R gene polymorphism might influence physical activity/energy expenditure as well. Our aim was to search for associations between MC4R polymorphisms and the level of physical activity. We genotyped MC4R in a population-based cohort of 311 men. The level of physical activity was determined with use of the International Physical Activity Questionnaire. We have found that physical effort expressed as log METs-min/week (corrected for age, BMI and educational status) was 6.61 in men declaring low, 7.56-moderate and 8.96-high level of physical activity. We have not found any associations between the C-2745T MC4R polymorphism and the level of physical activity (P = 0.53). There were no interactions between the level of physical activity and the C-2745T polymorphisms either (P = 0.47). We conclude that the C-2745T genetic polymorphism of the MC4R gene does not influence the level of physical activity in healthy, adult men.

[The CAG repeat polymorphism in androgen receptor gene repeat and frequency of chosen parameters of metabolic syndrome in 45-65 aged men in Wroclaw population]

INTRODUCTION

The activity of androgen receptor (AR) is modulated by a polymorphic CAG trinucleotide repeat in receptor gene. There are suggestion, that there are association between polymorphism androgen receptor gene and the occurrence typical features of metabolic syndrome in men. The metabolic syndrome is more frequent with aging. We knows, that polymorphism androgen receptor gene is associated with risk of prostate cancer and with occurrence Kennnedy's syndrome. However the association of this polymorphism for occurrence of hypertension, obesity and lipid and glucose concentration disturbance is not examined.

MATERIAL AND METHODS

The original study population consisted 268 randomly selected wroclaw population men aged 45-65. The physician examination include mensuration of blood pressure and antropometrical analysis. The men were coming on an empty stomach between 8.00 and 10.00 am for blood taken. The blood were taken for biochemical measurements and for genetic analysis CAG repeat in androgen receptor gene.

RESULTS

There is statistical significant differences between number of CAG repeat in men with normal and higher concentration of cholesterol LDL. There were no significant differences between number of CAG repeat in men in dependent of value of blood pressure and concentration of insulin, glucose, cholesterol HDL, total cholesterol and triglicerides.

CONCLUSIONS

The investigation results are not unambiguous with regard to influence of polymorphism androgen receptor gene for occurrence of metabolic syndrome in men. We found only association between number of CAG repeat an androgen receptor gene and concentration of cholesterol LDL (which it is as we knows atherogenic factor).

Impact of recreational physical activity on bone mineral density in middle-aged men

Physical activity is known to exert beneficial effects on general health status of young, adult and elderly populations. Exercise (aside from genetic, hormonal, nutritional and pathological factors) also influences bone mineral density (BMD). Unfortunately, the association between physical exercise and BMD in adult population is controversial. Our aim was to assess relations between recreational physical activity and BMD in middle-aged men. We performed densitometry and hormonal measurements (total testosterone, free testosterone, dehydroepiandrosterone sulfate, estradiol) in a homogenous group of 38 subjects. Among them, we distinguished 22 who had not engaged in any physical activity, and 16 who had recreationally exercised for about 10 years. Both groups did not differ in regard to hormonal status. Similarly, densitometry did not reveal any statistically significant differences in BMD between both groups of men. Upon our observation, we can hypothesize that recreational physical activity does not affect bone mineral density in middle-aged men.

[Concentration of cysteine proteinase inhibitors in urine, amniotic fluid and serum from women in pregnancy complicated by EPH-gestosis]

Cysteine proteinase inhibitors (IPC) concentration was measured by the modified Barrett method using papaine in urine, amniotic fluid and serum obtained from the healthy labored women and from labored women in pregnancy complicated by EPH-gestosis. It was noticed the statistically significant increase in the IPC concentration in the material from the pregnant women with EPH-gestosis comparing to the women, which pregnancy had the physiologically normal course.