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, β -CTx, OC/ β -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/ β -CTx were higher in the group of professional football players than in the group of phys ically inactive men. The daily vitamin D and calcium intake in th e 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 ., K. Solarz ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Aged people are the most susceptible group to COVID-19 infection. Immunosenescence characterized by impairment of immune function with inflamm-aging contributes to pathophysiological alterations, among which endocrine and metabolic diseases are not exception. Diabetes, obesity along with impairment of disorders of thyroid functions are the most frequent ones, the common feature of which is failure of immune system including autoimmune processes. In the minireview we discussed how COVID-19 and aging impact innate and adaptive immunity, diabetes and selected neuroendocrine processes. Mentioned is also beneficial effect of vitamin D for attenuation of these diseases and related epigenetic issues. Particular attention is devoted to the role of ACE2 protein in the light of its intimate link with renin-angiotensin regulating system.
Recent studies reported association of sleep-disordered breathing (SDB) with testosterone and vitamin D deficiency. Low testosterone and vitamin D levels have been linked to fatigue and excessive daytime sleepiness (EDS). However, the impact of testosterone and vitamin D deficiency on EDS in subjects with SDB remains unknown. The aim of this study was to explore the predictors of EDS in habitual snorers. Role of testosterone, and vitamin D was studied in detail. We also looked for associations between testosterone, vitamin D, and sleep-related indices. We prospectively enrolled 291 consecutive male patients with habitual snoring. Baseline clinical characteristics were recorded on admission. Standard overnight polysomnography was performed to detect SDB, and Epworth Sleepiness Scale (ESS) was used to assess EDS. Blood samples were obtained in a fasting condition in the morning after polysomnography to determine levels of testosterone and vitamin D. Respiratory disturbance index (RDI) (95 % CI: 1.004-1.024, p=0.005) and the use of antihistamines (95 % CI: 1.083-11.901, p=0.037) were the only independent variables significantly associated with EDS in binary logistic regression analysis. In linear multiple regression analysis, body mass index (BMI) (Beta=-0.282, p˂0.001) and oxygen desaturation index (Beta=-0.150, p=0.043) were the only independent variables significantly associated with testosterone levels, and BMI (Beta=-0.142, p=0.016) was the only independent variable significantly associated with vitamin D. We failed to find any independent association of testosterone and vitamin D with subjectively rated EDS among habitual snorers. Our results suggest an independent association between the magnitude of nocturnal desaturation and testosterone levels., Pavel Šiarnik, Matúš Jurík, Miroslava Hardoňová, Katarína Klobučníková, Jakub Veverka, Pavol Šurda, Peter Turčáni, Branislav Kollár., and Obsahuje bibliografii
Osteoporóza je závažné onemocnění charakterizované vysokou morbiditou a mortalitou v důsledku atraumatických fraktur. Kromě vlivu vnějšího prostředí se v patogeneze osteoporózy uplatňují faktory vnitřní (hormonální nerovnováha a genetické pozadí). Článek podává přehled kandidátních genů pro osteoporózu, které klasifikuje podle metabolických okruhů regulujících minerální denzitu nebo kvalitu kosti (okruh estrogenní, RANKL/RANK/OPG, mevalonátový, okruh Wnt, geny pro kolagen a vitamin D). Zabývá se také perspektivou praktického využití farmakogenetiky (identifikace jednotlivých kandidátních genů pomocí PCR) nebo farmakogenomiky (plošné měření škály genů pomocí GWAS) při výběru optimální léčby osteoporózy. Potencionálními prediktory odpovědi na antiresorpční léčbu jsou geny pro ER, FDPS, Cyp19A1, VDR, Col 1A1 a gen pro signalizaci Wnt. Polymorfizmy genů CYP2C, ale také FDPS mohou naopak identifikovat nemocné s vysokým rizikem nežádoucí odpovědi na bisfosfonáty (osteonekróza čelisti). Limitujícím faktorem výzkumu genetiky osteoporózy je nedostatečný konsenzus výsledků asociačních studií. Vysvětlení kontroverzních výsledků lze hledat v rozdílných metodických přístupech (rozsah a homogenita souboru, etnické rozdíly nebo vazebná nerovnováha mezi geny). Klíčovým úskalím asociačních studií je nízká variabilita (7-10 %) kostních fenotypů, které souvisí se zkoumaným genem. Nicméně identifikace nových genů a ověřování jejich asociace s kostními parametry oběma metodami zůstává velkou výzvou s cílem optimalizace prevence a léčby osteoporózy., Osteoporosis is a serious disease characterized by high morbidity and mortality due to atraumatic fractures. In pathogenesis of osteoporosis, except environment, internal factors, such as hormonal dysbalance and genetic background, are also in play. In this review, candidate genes for osteoporosis are classified accorging to metabolic or hormonal pathways, which regulate bone mineral density/and or quality (estrogen, RANKL/RANK/OPG, mevalonate, Wnt circuit, genes for collagen and vitamin D). Authors discuss the perspectives of practical utilization of pharmacogenetics (identification of single candidate genes using PCR) or pharmacogenomics (using genome wide association studies) in choise of optimal treatment of osteoporosis. Potentional predictors of effectivity of antiresorption therapy are genes ER, FDPS, Cyp19A1, VDR, Col1A1 and gene of Wnt pathway. Moreover, polymorphisms of CYP2C gene, but also FDPS may identify patients with high risk of undesirable effects of bisphosphonates (osteonecrosis of jaw). Unfortunately, results of the most association studies has not been confirmed by other investigators. The controversial results could be explained by different methodic approches in individual studies (different sample size, homogenity of investigated groups, ethnic differences or linkage disquilibrium between genes). Key cliff of association studies is low variability (7-10 %) of bone phenotypes associated with investigated genes. Nevertheless, identification of new genes and verification their association with bone denzity and/or quality using both PCR and genome wide association studies remain to be a great challenge targeting optimal prevention and treatment of osteoporosis., and Ivana Žofková, Radoslav Omelka
Resistance to vitamin D has been known for decades as vitamin D resistant rickets, caused by mutations of the gene encoding for vitamin D receptor (VDR). Findings of extra-skeletal effects of vitamin D and learning of the molecular mechanisms used by its biologically active metabolite calcitriol revealed other ways leading to its impaired sensitivity. Calcitriol takes advantage of both genomic and non-genomic mechanisms through its binding to vitamin D receptor, located not only in the cell nuclei but also in a perinuclear space. On the genomic level the complex of calcitriol bound to VDR binds to the DNA responsive elements of the controlled gene in concert with another nuclear receptor, retinoid X receptor, and expression of the VDR itself is controlled by its own ligand. These elements were found not only in the promotor region, but are scattered over the gene DNA. The gene expression includes a number of nuclear transcription factors which interact with the responsive elements and with each other and learning how they operate would further contribute to revealing causes of the impaired vitamin D sensitivity. Finally, the examples of major disorders are provided, associated with impairment of the vitamin D function and its receptor., L. Máčová, M. Bičíková, R. Hampl., and Obsahuje bibliografii
In this review the authors outline traditional antiresorptive pharmaceuticals, such as bisphosphonates, monoclonal antibodies against RANKL, SERMs, as well as a drug with an anabolic effect on the skeleton, parathormone. However, there is also a focus on non-traditional strategies used in therapy for osteolytic diseases. The newest antiosteoporotic pharmaceuticals increase osteoblast differentiation via BMP signaling (harmine), or stimulate osteogenic differentiation of mesenchymal stem cells through Wnt/β-catenin (icarrin, isoflavonoid caviunin, or sulfasalazine). A certain promise in the treatment of osteoporosis is shown by molecules targeting non-coding microRNAs (which are critical for osteoclastogenesis) or those stimulating osteoblast activity via epigenetic mechanisms. Vitamin D metabolites have specific antiosteoporotic potencies, modulating the skeleton not only via mineralization, but markedly also through the direct effects on the bone microstructure., I. Zofkova, J. Blahos., and Obsahuje bibliografii
Secondary hyperparathyroidism (SHPT) may contribute to the systemic illness that accompanies chronic heart failure (CHF). Healthy elderly with vitamin D deficiency who did not develop hyperparathyroidism (functional hypoparathyroidism, FHPT) had lower mortality than those who di d. This study was designed to examine determinants of the PTH response in the vitamin D insufficient CHF patients. Sixty five vitamin D insufficient males with NYHA class II and III and 20 control subjects age ≥ 55 years were recruited. Echocardiography, physical performance, NT-pro-BNP, PTH, 25-hydroxyvitamin D (25(OH)D), adiponectin and bone activity surrogat e markers (OPG, RANKL, OC, β-CTx) were assessed. Increased NYHA cl ass was associated with SHPT, while physical performance was inferior compared to FHPT. SHPT was associated with lower left ventricular ejection fraction (LVEF) and flow mediated dilatation, but with higher left heart dimensions, left ventricular mass index and right ventricular systolic pressure. CHF patients with SHPT had increased NT-pro-BNP, adiponectin and bone markers, but decreased 25(OH)D compared to those with FHPT. Independent determinants for SHPT in CHF patients with vitamin D insufficiency were LVEF, adiponectin and β-CTx, irrespective of renal function and serum vitamin D levels. In conclusion, increased PTH levels, but not low vitamin D, demonstrated close relation to CHF severity., B. Bozic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Parathyroid hormone (PTH) increases the release of serum calcium through osteoclasts, which leads to bone resorption. Primary, PTH stimulates osteoblasts leading to increase RANKL (receptor activator for nuclear factor kappa-B ligand) expression and thus differentiation of osteoclasts. In kidneys, PTH increases calcium and decrease phosphate reabsorption. In kidneys, PTH stimulates 1alpha-hydroxylase to synthesize active vitamin D. Primary hyperparathyroidism (PHPT) is characterized by skeletal or renal complications. Nowadays, the classical form of PHPT is less seen and asymptomatic or subclinical (oligo symptomatic) forms are more frequent. Previously, it was thought that cortical bone is preferably affected by PHPT and that predispose bones to fracture at sites with a higher amount of cortical bone. However, an increased risk of vertebral fractures has been found by most of the studies showing that also trabecular bone is affected. Bone Mass measurement (BMD) at all skeletal sites is advised, but another specific tool for fracture assessment is needed. Trabecular bone score (TBS), an indirect measure of trabecular bone, maybe a useful method to estimate fracture risk. TBS is associated with vertebral fractures in PHPT regardless of BMD, age, BMI and gender. Furthermore, there is an association between TBS and high resolution peripheral quantitative computed tomography (HR-pQCT) parameters in the trabecular and cortical compartment. However, studies considering the effect of PHPT treatment on TBS are more conflicting. Secondary hyperparathyroidism caused by vitamin D deficiency was associated with impaired bone microarchitecture in all age categories, as measured by TBS and Hr-pQCT with further improvement after treatment with vitamin D. and Martin Kužma, Peter Jackuliak, Zdenko Killinger, Juraj Payer.
a1_Osteoporosis is a serious disease characterized by high morbidity and mortality due to atraumatic fractures. In the pathogenesis of osteoporosis, except environment and internal factors, such as hormonal imbalance and genetic background, are also in play. In this study candidate genes for osteoporosis were classified according to metabolic or hormonal pathways, which regulate bone mineral density and bone quality (estrogen,RANKL/RANK/OPG axis, mevalonate, the canonical circuit and genes regulating the vitamin D system). COL1A1 and/or COL1A2 genes, which encode formation of the procollagen 1 molecule, were also studied. Mutations in these genes are well-known causes of the inborn disease‘ osteogenesis imperfecta’. In addition to this, polymorphisms in COL1A1 and/or COL1A2 have been found to be associated with parameters of bone quality in adult subjects. The authors discuss the perspectives for the practical utilization of pharmacogenetics (identification of single candidate genes using PCR) and pharmacogenomics (using genome wide association studies (GWAS) to choose optimal treatment for osteoporosis). Potential predictors of antiresorptive therapy efficacy include the following well established genes: ER, FDPS, Cyp19A1, VDR, Col1A1, and Col1A2, as well as the gene for the canonical (Wnt) pathway. Unfortunately, the positive outcomes seen in most association studies have not been confirmed b y other researchers. The controversial results could be explained by the use of different methodological approaches in individual studies (different sample size, homogeneity of investigated groups, ethnic differences, or linkage disequilibrium between genes). The key pitfall of association studies is the low variability (7-10 %) of bone phenotypes associated with the investigated genes., a2_Nevertheless, the identification of new genes and the verification of their association with bone density and/or quality (using both PCR and GWAS), remain a great challenge in the optimal prevention and treatment of osteoporosis., I. Zofkova, P. Nemcikova, M. Kuklik., and Obsahuje bibliografii
Autoři pojednávají o vitamínu D, který má mezi ostatními vitamíny specifické postavení, poněkud z jiného úhlu pohledu. Přibližují jeho evoluční původ a historii jeho objevování. Nedostatek vitaminu D vyvolává křivici, nemoc, která je doložena už od starověku. V této souvislosti upozorňují autoři na světově uznávané zásluhy významného, dnes už téměř zapomenutého českého vědce E. H. Kodíčka. Přehledně také popisují metabolismus a transport vitaminu D v organismu a upozorňují, že vitamin D také hraje důležitou úlohu při vzniku chronických nesdělných chorob, jejichž počet celosvětově stále vzrůstá., The authors discuss vitamin D, which has a special position among vitamins, from a somewhat different perspective. They clarify its evolutionary origin and the history of its discovery. A deficiency of vitamin D causes rickets, a disease that has been documented since antiquity. In this context, the authors draw attention to a nearly forgotten Czech scientist E. H. Kodíček of significant merit. They also briefly describe the metabolism and transport of vitamin D in the body and point out that vitamin D also plays an important role in the development of non-communicable chronic diseases, the number of which is increasing worldwide., and Petr Šíma, Bohumil Turek.