ABSTRACT Objective: To define serum parathyroid hormone (PTH) reference values in carefully selected subjects following the recommended pre-analytical guidelines. Subjects and methods: First, 676 adults who would be submitted to thyroidectomy were evaluated. Patients using interfering medications or with malabsorption syndrome, hypomagnesemia, hyper- or hypophosphatemia, hypo- or hypercalcemia, 25-hydroxyvitamin D < 30 ng/dL, estimated glomerular filtration rate < 60 mL/min/1.73 m2, urinary calcium/creatinine ratio ≥ 0.25, thyroid dysfunction, parathyroid adenoma detected during surgery were excluded. The sample consisted of 312 [...]

Secondary hyperparathyroidism (HPT) has a high prevalence in renal patients. Secondary HPT results from disturbances in mineral homeostasis, particularly calcium, which stimulates the parathyroid glands, increasing the secretion of parathyroid hormone (PTH). Prolonged stimulation can lead to autonomy in parathyroid function. Initial treatment is clinical, but parathyroidectomy (PTx) may be required. PTx can be subtotal or total followed or not followed by parathyroid tissue autograft. We compared the indications and results of these strategies as shown in the literature through […]

OBJECTIVE: To investigate if vitamin D deficiency is more prevalent in patients with Paget’s disease of bone (PDB) than in age-matched controls. SUBJECTS AND METHODS: We measured serum 25-OHD in 28 untreated patients with PDB and two control groups: 284 elderly men from an ongoing cohort from our department, and 151 postmenopausal women seen in our outpatient clinic for routine medical evaluation. RESULTS: The mean ± SD serum 25-OHD was significantly lower in subjects with PDB (23.76 ± 6.29 ng/mL) […]

The occurrence of osteoporotic fractures in the elderly is associated with reduced levels of vitamin D and resulting secondary hyperparathyroidism, and inpatients are the ones at a higher risk. In Brazil, given its high level of insolation, the population’s large amount of vitamin D is inferred to be adequate. In this study we aimed to assess the serum levels of 25-hydroxivitamin D (25OHD), parathormone (PTH) and ionized calcium (Cai), as well as to analyze the prevalence of both hypovitaminosis D […]

Sixty-three-year-old woman requested medical attention for osteoporosis. Bone densitometry revealed: Tspine (L1-L4)= -3.5 SD [Bone mineral density (BMD): 0.766 g/cm2]. Tfemoral neck= -2.4 SD (BMD: 0.716 g/cm2). She has been in calcium and vitamin D supplementation for 2 years. She informed a 5-year-history of hypothyroidism in levothyroxine replacement. Alendronate sodium 70 mg/week was initiated with significant increase in BMD in the first year (6.1% equally in spine and femoral neck). After a 5-year follow-up, the patient presented with weight loss, […]

INTRODUCTION: Intraoperative parathyroid hormone measurement (IO-PTH) was first described in 1988 and it’s potentially useful in predicting cure after parathyroidectomy. The aim of this study was to evaluate IO-PTH decay profile and the utility of this procedure in predicting cure in primary (PHH) and secondary (SHH) hyperparathyroidism due to renal disease. PATIENTS AND METHODS: 109 patients were evaluated from 06/2000 to 12/2004. 33 had PHH and 76 SHH (52 in dialysis, 24 with renal graft). IO-PTH was measured at times […]

Vitamin D is synthesized in skin through a reaction mediated by sunlight, and it is metabolized to 25-hydroxyvitamin D, in liver, and in 1,25-dihydroxyvitamin D, in kidney. This last reaction has a tight feedback mechanism. 1,25-dihydroxyvitamin D is the active hormone, and its actions are mediated mainly by nuclear receptors. Its major functions are in calcium metabolism and bone mass maintenance. Hypovitaminosis D, as a disease in adult people, manifests itself with hypocalcemia and secondary hyperparathyroidism with subsequent loss of […]

Hyperparathyroidism is a common complication of end-stage renal insufficiency, with a high morbi-mortality and difficult medical control. Classical indications for parathyroidectomy are: persistent hypercalcemia, especially after kidney transplantation, untreatable pruritus, pathologic fractures, bone pain refractory to medical treatment, and metastatic calcifications. Unfortunately, this latter complication does not respond to parathyroidectomy, and blood vessels calcifications are associated with increased mortality. Severe osteitis fibrosa and bone deformities also never disappear. Thus, new criteria for early parathyroidectomy are needed. Serum intact PTH higher […]