Increased vertebral morphometric fracture in patients with postsurgical hypoparathyroidism despite normal bone mineral density.

BACKGROUND: The mechanism behind parathyroid hormone (PTH) activation of bone remodeling is intimately dependent on the time of exposure of bone cells to hormone levels. Sustained high PTH levels trigger catabolism, while transitory elevations induce anabolism. The effects of hypoparathyroidism (PhPT) on bone are unknown. The objective was to study the impact of PhPT on bone mineral density (BMD), on the frequency of subclinical vertebral fracture and on mandible morphometry. METHODS: The study comprised thirty-three postmenopausal women, 17 controls (CG) and 16 with PhPT (PhPTG) matched for age, weight and height. Bone mineral density (BMD) of lumbar spine, total hip and 1/3 radius, radiographic evaluation of vertebral morphometry, panoramic radiography of the mandible, and biochemical evaluation of mineral metabolism and bone remodeling were evaluated in both groups. RESULTS: There were no significant differences in lumbar spine or total hip BMD between groups. There was marked heterogeneity of lumbar spine BMD in PhPTG (high = 4, normal = 9, osteopenia = 1, and osteoporosis = 2 patients). BMD was decreased in the 1/3 radius in PhPTG P < 0.005). The PhPTG group exhibited an increased frequency of morphometric vertebral fractures and decreased mandible cortical thickness. CONCLUSION: The study suggests that vertebral fragility occurs in PhPT despite normal or even high BMD. The current results encourage further studies to evaluate the use of panoramic radiography in the identification of osteometabolic disorders, such as PhPT and the development of a more physiological treatment for PhPT.

Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance.

OBJECTIVES: Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated. METHODS: This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT) and 21 controls (CG). Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels. RESULTS: A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01). Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%). The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005), but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass. CONCLUSION: These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

OBJECTIVES: Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated. METHODS: This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT) and 21 controls (CG). Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels. RESULTS: A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01). Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%). The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005), but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass. CONCLUSION: These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

Treatment of atrophic mandibular fracture related to implant placement in an oral bisphosphonate user: a case report / Tratamento de fratura em mandíbula atrófica com implantes em paciente usuário de bisfosfonato: umrelato de caso

Objectives: Atrophic mandibular fractures associated with placement of dental implants is an uncommon condition and to best of our knowledge this event in an oral bisphosphonate user was never described before. Case report: A 74-years-old woman presented a submandibular hematoma and mobility between two fragments on the right side of the body of the mandible after four implants placement. The patient reported the use of oralbisphosphonates for three years for treatment of osteoporosis. A titanium plate was placed at the base of the mandible to fix the fracture and the patient underwent a hyperbaric oxygen therapy for three months. Nine months after the surgery, the patient had no further complications and rehabilitation treatment was completed. Conclusions: The fracture fixation was effective in the treatment of atrophic mandibular fractures in an oral bisphosphonate user, with no occurrence of complications like osteonecrosis.In addition, the oral rehabilitation with prosthesisunder the remaining implants showed a satisfactory outcome.

Objetivo: Fraturas de mandíbula atrófica associadas à inserção de implantes é uma condição de ocorrência incomum e o objetivo desse relato de caso é descrever o tratamento de fratura de mandíbula atrófica associada à instalação de implantes em uma paciente usuária de bisfosfonato oral. Relato de caso: Paciente do sexo feminino com 74 anos apresentava presença de um hematoma submandibular e mobilidade entre dois fragmentos no corpo da mandíbula no lado direito após a instalação de 4 implantes. A paciente reportou uso de bisfosfonato por via oral a 3 anos para tratamento de osteoporose. A fratura foi reduzida e fixadacom uma placa de titânio na base da mandíbula e a paciente foi submetida a sessões de câmara hiperbárica por 3 meses. Após 9 meses do procedimento cirúrgico a paciente não apresentou complicações adicionais e o tratamento reabilitador foi finalizado. Conclusão: A fixação foi efetiva no tratamento da fratura em mandíbula atrófica em um paciente usuário de bisfosfonato oral e complicações com osteonecrose não foram detectadas. Adicionalmente, a reabilitação oral com próteses sobre implantes remanescente apresentaram um resultado satisfatório.