Ca&Bone

[The effects of thyroid hormones on bone]

BAJNOK Éva, LAKATOS Péter

AUGUST 20, 2003

Ca&Bone - 2003;6(04)

[The effects of thyroid hormones on bone tissue are of fundamental importance.They are required for skeletal development and later for normal bone metabolism.Their action is dose-dependent and also depends on the degree of differentiation of the target tissue. In childhood, thyroid hypofunction manifests itself in growth retardation, whereas hyperfunction will accelerate bone maturation.The exact mechanism of action of thyroid hormones on bone in later years is poorly understood, and their clinical relevance on the risk of bone fracture, the most important complication, is also unclear. In adults with hypothyroidism, bone mineral density (BMD) remains unchanged or even becomes increased, but the risk of fractures is elevated. In hyperthyroidism the bone turnover is increased, which may lead to a decrease in BMD and a higher risk of fracture. However, the results are inconsistent for endogenous subclinical hyperthyroidism, where BMD may also decrease and fractures may occur more frequently.Treatment of hypothyroidism may temporarily result in increased fragility but this phenomenon seems to be only transient. During L-T4 replacement therapy the TSH level should be kept in the normal range, while with suppression, it should be set to the lower end of the normal range. During treatment of hyperthyroidism BMD temporarily increases and the risk of fractures decreases.The most effective way of preventing osteoporosis and bone fractures in all cases is the early recognition and treatment of thyroid diseases.The presence of other osteoporosis risk factors should always be considered. In some cases adjuvant therapy may be necessary to stop bone loss.]

COMMENTS

0 comments

Further articles in this publication

Ca&Bone

[Assessment of quality of life in postmenopausal women with osteoporosis - A comparative study on the Hungarian adaptations of EuroQoL and Nottingham Health Profile]

PÉNTEK Márta, LICKER-FÓRIS Edit, LOVAS Kornélia, KALÓ Zoltán, TÓTH Miklós, TULASSAY Zsolt, RATKÓ István, GENTI György

[INTRODUCTION - After a brief introduction to the definition of quality of life and the importance of its measurement, two questionnaires, the EQ-5D and the Nottingham Health Profile are presented. PATIENTS AND METHODS - Fifty postmenopausal women with osteoporosis were included in the two-year prospective study to assess quality of life by the two generic questionnaires. Correlations were sought between the results of the EQ-5D and the Nottingham Health Profile, as well as between bone fractures and changes in quality of life.The validated Hungarian version of the Nottingham Health Profile was applied for the first time in postmenopausal osteoporosis. RESULTS - With the treatments applied, quality of life dimensions did not change significantly during the follow-up period and no significant correlation was found between the incidence of bone fractures and changes in quality of life.The pain, physical mobility, emotional reactions and energy dimensions of the validated Hungarian Nottingham Health Profile and its derivated index showed significant correlations with those of the EQ-5D. CONCLUSION -The validated Hungarian version of the Nottingham Health Profile quality of life questionnaire is a useful and applicable measurement tool in postmenopausal osteoporosis which correlates with the EQ-5D health state measure.]

Ca&Bone

[Renal stone formation after parathyroidectomy in patients with primary hyperparathyroidism]

BERCZI Csaba, BALÁZS György, LUKÁCS Géza, TÓTH Csaba

[INTRODUCTION - The incidence of renal stone formation was studied in patients with primary hyperparathyroidism after parathyroidectomy. PATIENTS AND METHODS - Ninety-two patients operated on for hyperparathyroidism were included in the study. In Group 1 the patients (n=44) had kidney stones before parathyroidectomy. Patients with no history of nephrolithiasis (n=48) before the operation were assigned to Group 2. After the operation the occurrence of renal stones was assessed for both groups.The presence of any association between the recurrence of renal stones and various clinical parameters was analysed. RESULTS - The serum concentration of Ca and parathormone decreased to the normal range in both groups after the operation. Stone formation was observed in nine cases in five patients during follow-up. All five patients belonged to Group 1.Thirty-three % of these recurrent stones were diagnosed within the first year and 89% within 5 years. Statistical analysis did not reveal any significant association between recurrent stone formation and gender, age, preoperative serum levels of Ca and parathormone or the histology of parathyroid glands. CONCLUSION - The incidence of recurrent renal stones after successful parathyroidectomy significantly decreased in patients with primary hyperparathyroidism.]

Ca&Bone

[FORTHCOMING CONGRESS]

Ca&Bone

[Dear Colleagues and Readers!]

HORVÁTH CSABA

Ca&Bone

[Quality of life and osteoporosis]

BÁLINT Géza

All articles in the issue

Related contents

LAM KID

[Alterations in bone metabolism associated with gastrointestinal diseases]

LŐRINCZY Katalin, LAKATOS Péter László, MIHELLER Pál, RÁCZ Károly

[Osteoporosis is commonly associated with certain gastrointestinal diseases. Osteoporosis occurs most often in patients with coeliac disease, inflammatory bowel disease, chronic liver disease and following gastric surgery. Prevention, diagnosis and therapy are based on the experiences with elderly and postmenopausal patients with osteoporosis. In this review, we summarise the clinical data regarding bone loss associated with gastrointestinal diseases.]

Hypertension and nephrology

[Genetics of isolated steroid-resistant nephrotic syndrome - results of the two decades around the turn of the millennium]

TORY Kálmán, KERTI Andrea, REUSZ György

[Childhood steroid-resistant nephrotic syndrome (SRNS) is a devastating clinical condition which progresses to end-stage renal disease in 30-40% of the cases after a follow up of 10 years. Based on its etiology, two forms can be distinguished, an immune and a genetic form. During the last two decades, mutations of ten genes - encoding mainly podocyte proteins - were identified in the latter group. As the treatment in the immune and genetic forms are different, and only the identification of the causative mutation can reliably distinguish them, it is important to be familiarized with the genotype-phenotype correlations. The aim of the present review is to summarize our current knowledge on the phenotypes linked to the identified genes.]

Clinical Neuroscience

[Genetics and hemostasis in young stroke patients]

PONGRÁCZ Endre, TORDAI Attila, CSORNAI Márta, NAGY Zoltán

[Background and purpose - The classical risk factors did not explain all the possible ethiology of cerebral stroke. Genetic polymorphisms responsible for thrombophilia were implicated recently as risk factors of stroke. In this geneticoepidemiological study the author’s aim was to analyse the tendency of genetic polymorphisms to cluster in a cohort of young and elderly stroke patients and in healthy subjects in Hungary. Methods - 253 patients with stroke were compared with 173 healthy blood donors on the basis of genetic polymorphisms of platelet GP IIb/IIIa receptor (33 LeuPro), prothrombin gene G20210A, Factor V Leiden mutation, ACE I/D, methylenetetrahydrofolate reductase (MTHFR) and β fibrinogen gene G455A. These data were acquired using PCR. Questionnaires were used to investigate the family history and to determine the risk factor profile. The subtypes of stroke were analysed in a stroke cohort grouped according to different polymorphisms. Results - An increased frequency of GP IIIa heterozygousity was found as compared to a West-European stroke cohort (31% versus 19%). The prothrombin gene variant (2.9% European and 4.8% in Hungary) was also found to increase in frequency. In young stroke patients (age <50) compared with control subjects the odds ratios were higher: in prothrombin gene (OR: 4.9), in Leiden mutation (OR: 1.67), in fibrinogen gene (OR: 1.64) and in MTHFR(+/+) (OR: 1.58). Clustering of two polymorphisms could only be detected in young patients. These clustering polymorphisms were GP IIb/IIIa with prothrombin G20210A variant (OR: 6.74, 95% CI 1.1-18.2) and prothrombin gene variant with MTHFR (OR: 5.3, CI95 1.2-8.3). Conclusion - Selected and clustered genetic polymorphisms of haemostatic factors could be responsible for the high stroke morbidity in Central Europe. The presence and clustering tendency of these factors have been described in young stroke victims.]

LAM Extra for General Practicioners

[THE IMPORTANCE OF VITAMIN D DEFICIENCY IN PRACTICE]

TAKÁCS István

[The effects of vitamin D in bone health have been known since the 1920s. Recently, it has been proven that its role in the body is much more complex. Activated vitamin D is a steroid hormone that regulates transcription of more than 200 human genes through its receptor that is detectable in almost all types of cells. In contrast to the former conceptions, it can be activated not only in the kidneys; moreover, local 1-α-hydroxylation plays a greater role in its extraskeletal effects. Vitamin D deficiency, currently defined as serum levels of <30 ng/ml, is caused by the lack of ‘effective’ sunlight exposition. Thus, vitamin D deficiency is one of the most frequent deficiencies in the developed world that plays a role not only in the development of skeletal conditions but many other diseases, as well. A low vitamin D level causes a reduced calcium absorption, a higher bone remodelling rate and increased bone loss. It also reduces muscle strength and increases the risk of falling. Normal vitamin D status is required for the effectiveness of drugs for osteoporosis treatment; however vitamin D treatment in itself is not effective in osteoporosis. An increasing number of studies show the benefits of vitamin D supplementation and treatment in extraskeletal conditions. Vitamin D plays an important role in the prevention of several auto-immune diseases, infections, cardiovascular diseases, and cancers. Therefore, all UV-B radiation-deprived adults require an intake of vitamin D to maintain a level of >30 ng/ml. Vitamin D3 treatment is safe. The necessary dose can be reliably approximated by the calculation that an incremental consumption of 100 IU/day raises serum vitamin levels by 1,0 ng/ml. Clinical trials suggest that for the vast majority of individuals, a prolonged intake of 10,000 IU/day does not pose any risk.]

Hypertension and nephrology

[Symptomes and genetics of nephronophthisis]

TORY Kálmán, VÁRKONYI Ildikó, BERNÁTH Mária, RÉMI Salomon, SOPHIE Saunier, MARIE-CLAIRE Gubler, CORINNE Antignac, TULASSAY Tivadar, REUSZ György

[Nephronophthisis is an autosomal recessive, chronic tubulointerstitial nephropathy, responsible for 6-10% of childhood chronic renal failure cases. Its first symptoms, polyuria-polydipsia, anaemia and failure to thrive precede the development of end-stage renal disease by years. Increased echogenicity with loss of corticomedullary differentiation are the key findings on ultrasound, the lack of cysts does not rule out the diagnosis. Histologically, it is characterized by interstitial fibrosis and irregularities of the tubular basal membrane. Genetically, it is highly heterogeneous. Ten nephronophthisis genes have already been identified in 60% of the patients. The encoded proteins - similarly to other proteins mutated in cystic kidney diseases - are localized to primary cilium-basal body-centrosomal complex.]