Vertebral fractures and bone mineral density in patients with idiopathic hypoparathyroidism on long term follow-up

• Published in: The journal of clinical endocrinology and metabolism Vol. 102; no. 1; pp. 251 - 258
• Main Authors: Chawla, Himika, Saha, Soma, Kandaswamy, Devasenathipathy, Sharma, Raju, Sreenivas, Vishnubhatla, Goswami, Ravinder
• Format: Journal Article
• Language: English
• Published: Washington, DC Endocrine Society 01.01.2017; Oxford University Press
• Subjects: Absorptiometry, Photon; Adult; Anticonvulsants; Biomarkers - analysis; Bone Density; Bone mineral density; Calcium; Calcium (blood); Case-Control Studies; Female; Follow-Up Studies; Forearm; Fractures; Hip; Hormone replacement therapy; Humans; Hyperphosphatemia; Hypocalcemia; Hypoparathyroidism; Hypoparathyroidism - physiopathology; India - epidemiology; Lumbar Vertebrae - injuries; Male; Menopause; Morphometry; Osteoporosis, Postmenopausal - physiopathology; Parathyroid; Parathyroid hormone; Phosphorus; Post-menopause; Prevalence; Prognosis; Seizures; Spinal Fractures - epidemiology; Spine; Spine (lumbar); Vertebrae
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2016-3292

Context:Bone mineral density (BMD) is increased in patients with idiopathic hypoparathyroidism (IH). PTH deficiency, hypocalcemic seizures and anticonvulsants could compromise skeletal health in IH leading to vertebral fractures. However, there is limited information on the prevalence of vertebral fractures in hypoparathyroidism.Objective:To assess the prevalence of vertebral fractures and related factors in a cohort of patients with IH and change in BMD during long-term follow-up.Design:Vertebral fractures were assessed using quantitative vertebral morphometry of thoracic and lumbar spine. BMD was assessed by DXA at lumbar spine, hip and forearm. Change in BMD was assessed in subset of 27 patients after 10 years follow-up interval.Setting:The Endocrine clinic of All India Institute of Medical Sciences, New Delhi,Patients and other participants:104 patients with IH and 64 healthy controls. Hypocalcemia, hyperphosphatemia, normal blood urea and serum creatinine and low serum intact-PTH levels were used as diagnostic criteria for IH.Results:Vertebral fractures were observed in 18.3% patients with IH and in 4.7% of controls (OR, 4.54, 95% CI=1.28-16.04). Longer use of anticonvulsants and menopause were significantly associated (P < 0.05) with vertebral fractures. Mean BMD at lumbar spine and hip were higher by 21.4% and 8.6 % in IH than controls (P <0.001). BMD significantly increased during follow-up at all three sites. Change in BMD correlated with serum calcium/phosphorus ratio maintained during follow-up.Conclusions:Despite increased BMD, prevalence of vertebral fractures is more in patients with IH especially in post-menopausal women and in those on anticonvulsant therapy.