Publicação
Contribuição para o estudo do hipertiroidismo : a importância da densidade mineral óssea, da avaliação das fracturas por VFA (vertebral facture assessment) e da qualidade do osso por TBS (trabecular bone score)
| Resumo: | Hyperthyroidism is associated with severe heart and bone complications and may be caused by a toxic goiter, an autoimmune disease or iatrogenic through the ministration of excessive doses of thyroid hormones for the treatment of differentiated thyroid cancer or others like amiodarone. The bone complications of hyperthyroidism are osteoporosis and the osteoporotic fractures. The principal aims of these studies were to evaluate in cross-sectional and case-control study models, 1. the body composition, the bone mineral density (BMD) and the total fat and lean body masses, 2. the prevalence of silent vertebral fractures detected by Vertebral Fracture Assessment (VFA), a recent technic that uses the lateral toracolumbar spine images of DXA scans also to diagnose silent vertebral fractures; it is more comfortable for the patient and with low radiation dose, 3. the bone quality assessed by the Trabecular Bone Score (TBS), an indirect index of bone microarchitecture, obtained by the gray variations of lumbar spine DXA images using the variogram method, in Portuguese populations of 223 patients with clinical hyperthyroidism (etiology by toxic nodular goiter and autoimmune disease) and iatrogenic subclinical hyperthyroidism (by amiodarone and thyroid hormone in thyroid cancer and goiter) and in 223 healthy and normal individuals (control group) of the same gender, nationality and ethnicity and with similar age and stature. Groups of men aged less and more than 50 years, premenopausal and postmenopausal women with non-treated hyperthyroidism were selected from the Endocrinology Outpatient Clinic. To confirm the fractures, all patients had thoracolumbar spine X-ray (on frontal and lateral projections) on the same day or within a few days, which was reviewed by one radiologist. In a few instances where there was disagreement, a second radiologist was consulted. All patients and controls gave their informed consent, according to the approved protocol by the ethic committee of the institution and based on Helsinki declaration. Fasting blood samples were collected for measurement of serum chemistries and blood counts, hormones and bone markers, namely free T3, free T4, TSH, bone alkaline phosphatase, osteocalcin and beta-crosslaps (CTX). A- In Clinical Hyperthyroidism we found In men aged less than 50 years, significant decreases in the lean mass and in lumbar spine, femoral neck and all body BMD. Significant increase in the prevalence of reduced bone mass (54.1%) and osteoporosis (16.7%). The prevalence of silent vertebral fractures was 25%. In men with silent vertebral fractures, the mean total body BMD was 1.066 ± 0.04 cm/m2 vs 1.192 ± 0.02 cm/m2 as compared with those without fractures (P= 0.0047), so, this will probably be the limit BMD value for the occurrence of vertebral fractures. In men aged more than 50 years, significant reductions in the lean mass and distal radius BMD. Significant increase in the prevalence of reduced BMD (48.8%), osteoporosis (29.3%) and silent vertebral fractures (24.4%). Total alkaline phosphatase, osteocalcin e and beta-crosslaps (CTX) were significantly increased; in Graves´s disease we found less total body lean mass than in toxic goiter. In premenopausal women, we detected significant decreases in the lean mass and at the hip and whole body BMD, and significant increases in the prevalence of silent vertebral fractures (20%). The prevalence of reduced BMD was 42.5% and of osteoporosis was 5%. TBS was significant reduced but within the normal bone microarchitecture limits. Both total alkaline phosphatase and osteocalcin were significantly increased. In women with silent vertebral fractures, the mean lumbar spine BMD was 0.902 ± 0.1 cm/m2 vs 1.025 ± 0.1 cm/m2 as compared with those without fractures (P= 0.0124); so, this will probably be the limit BMD value for the occurrence of vertebral fractures. In postmenopausal women, significant reductions in all skeletal regions BMD and significant increases in the prevalence of reduced bone mass (42.9%), osteoporosis (45.7%) and silent vertebral fractures (42.9%). Lumbar spine BMD was significantly lower in Graves´s disease than in toxic goiter. BMD was significantly reduced in all skeletal regions of the TBS class groups classified as degraded and partially degraded bone microarchitecture. Significant increase in the total alkaline phosphatase. B- In Subclinical Iatrogenic Hyperthyroidism we found In men, significant decrease BMD at the hip and distal radius; the prevalence of reduced BMD was 53.8%, of osteoporosis 15.4% and of silent vertebral fractures 15.4%. In premenopausal women the prevalence of reduced BMD was 36.6% and of silent vertebral fractures was 16.7%. In postmenopausal women, the prevalence of reduced BMD was 52.5%, of osteoporosis 30% and of silent vertebral fractures 30%. The mean beta-crosslaps (CTX) was significantly increased; the women with fractures, were older and had a longer thyroid hormone treatment duration. |
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| Autores principais: | Barbosa, Ana Paula Gouveia dos Santos, 1964- |
| Assunto: | Hipertiroidismo Densidade óssea Osso esponjoso Osso e ossos Endocrinologia Teses de doutoramento - 2018 |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Hyperthyroidism is associated with severe heart and bone complications and may be caused by a toxic goiter, an autoimmune disease or iatrogenic through the ministration of excessive doses of thyroid hormones for the treatment of differentiated thyroid cancer or others like amiodarone. The bone complications of hyperthyroidism are osteoporosis and the osteoporotic fractures. The principal aims of these studies were to evaluate in cross-sectional and case-control study models, 1. the body composition, the bone mineral density (BMD) and the total fat and lean body masses, 2. the prevalence of silent vertebral fractures detected by Vertebral Fracture Assessment (VFA), a recent technic that uses the lateral toracolumbar spine images of DXA scans also to diagnose silent vertebral fractures; it is more comfortable for the patient and with low radiation dose, 3. the bone quality assessed by the Trabecular Bone Score (TBS), an indirect index of bone microarchitecture, obtained by the gray variations of lumbar spine DXA images using the variogram method, in Portuguese populations of 223 patients with clinical hyperthyroidism (etiology by toxic nodular goiter and autoimmune disease) and iatrogenic subclinical hyperthyroidism (by amiodarone and thyroid hormone in thyroid cancer and goiter) and in 223 healthy and normal individuals (control group) of the same gender, nationality and ethnicity and with similar age and stature. Groups of men aged less and more than 50 years, premenopausal and postmenopausal women with non-treated hyperthyroidism were selected from the Endocrinology Outpatient Clinic. To confirm the fractures, all patients had thoracolumbar spine X-ray (on frontal and lateral projections) on the same day or within a few days, which was reviewed by one radiologist. In a few instances where there was disagreement, a second radiologist was consulted. All patients and controls gave their informed consent, according to the approved protocol by the ethic committee of the institution and based on Helsinki declaration. Fasting blood samples were collected for measurement of serum chemistries and blood counts, hormones and bone markers, namely free T3, free T4, TSH, bone alkaline phosphatase, osteocalcin and beta-crosslaps (CTX). A- In Clinical Hyperthyroidism we found In men aged less than 50 years, significant decreases in the lean mass and in lumbar spine, femoral neck and all body BMD. Significant increase in the prevalence of reduced bone mass (54.1%) and osteoporosis (16.7%). The prevalence of silent vertebral fractures was 25%. In men with silent vertebral fractures, the mean total body BMD was 1.066 ± 0.04 cm/m2 vs 1.192 ± 0.02 cm/m2 as compared with those without fractures (P= 0.0047), so, this will probably be the limit BMD value for the occurrence of vertebral fractures. In men aged more than 50 years, significant reductions in the lean mass and distal radius BMD. Significant increase in the prevalence of reduced BMD (48.8%), osteoporosis (29.3%) and silent vertebral fractures (24.4%). Total alkaline phosphatase, osteocalcin e and beta-crosslaps (CTX) were significantly increased; in Graves´s disease we found less total body lean mass than in toxic goiter. In premenopausal women, we detected significant decreases in the lean mass and at the hip and whole body BMD, and significant increases in the prevalence of silent vertebral fractures (20%). The prevalence of reduced BMD was 42.5% and of osteoporosis was 5%. TBS was significant reduced but within the normal bone microarchitecture limits. Both total alkaline phosphatase and osteocalcin were significantly increased. In women with silent vertebral fractures, the mean lumbar spine BMD was 0.902 ± 0.1 cm/m2 vs 1.025 ± 0.1 cm/m2 as compared with those without fractures (P= 0.0124); so, this will probably be the limit BMD value for the occurrence of vertebral fractures. In postmenopausal women, significant reductions in all skeletal regions BMD and significant increases in the prevalence of reduced bone mass (42.9%), osteoporosis (45.7%) and silent vertebral fractures (42.9%). Lumbar spine BMD was significantly lower in Graves´s disease than in toxic goiter. BMD was significantly reduced in all skeletal regions of the TBS class groups classified as degraded and partially degraded bone microarchitecture. Significant increase in the total alkaline phosphatase. B- In Subclinical Iatrogenic Hyperthyroidism we found In men, significant decrease BMD at the hip and distal radius; the prevalence of reduced BMD was 53.8%, of osteoporosis 15.4% and of silent vertebral fractures 15.4%. In premenopausal women the prevalence of reduced BMD was 36.6% and of silent vertebral fractures was 16.7%. In postmenopausal women, the prevalence of reduced BMD was 52.5%, of osteoporosis 30% and of silent vertebral fractures 30%. The mean beta-crosslaps (CTX) was significantly increased; the women with fractures, were older and had a longer thyroid hormone treatment duration. |
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