Studying Phosphorus Metabolism
Studies in Phosphorus Metabolism
Phosphorus and phosphate irons play critical roles in bone structure and essential cellular functions.
The purpose of this study is to learn more about the factors and hormones that regulate phosphorus in the body by collecting blood and urine samples from patients with disorders of phosphate control.
Both children and adults will be enrolled in this study. Researchers will collect blood and urine samples from participants on multiple occasions (2 to 6 times). Some blood specimens will be taken after an overnight fast and participants may be asked to collect all their urine during a 24-hour period. Researchers will analyze these blood and urine samples to better understanding how the body handles phosphorus.
Descripción general del estudio
Estado
Condiciones
Descripción detallada
Phosphorus and phosphate ions play an important role in cellular metabolism as well as bone structure. Scientific evidence suggests that, in addition to Vitamin D and PTH systems, novel factors, such as Fibroblast Growth Factor 23 (FGF-23) and Matrix extracellular phosphoglycoprotein (MEPE), may play an important role in phosphorus regulation. These factors have been best studied in rare genetic and acquired phosphate wasting disorders such as tumor induced osteomalacia (TIO), X linked hypophosphatemia (XLH) and autosomal dominant hypophosphatemic rickets (ADHR). Patients with other abnormal phosphate regulating states such as hyperparathyroidism and hypoparathyroidism, pseudohypoparathyroidism etc. undergoing phosphorus-altering interventions may provide important insight into the role of these hormones.
We are proposing an observational study with collection of blood and urine samples to study both established (e.g. mineral ions, bone markers, PTH-Vit D system, TMP-GFR) and novel (e.g. FGF-23 and MEPE) constituents of the phosphorus metabolism pathway. Patients with abnormal phosphorus regulating states will be enrolled and we will study the natural history of their disease and the effects of specific interventions that are likely to change phosphorus balance.
The outcome will potentially aid understanding of this new field of mineral regulating hormones and generate both interest and research in phosphorus metabolism. It is hoped that this will also encourage clinical trials in treatment of phosphate wasting disorders.
Tipo de estudio
Inscripción
Contactos y Ubicaciones
Ubicaciones de estudio
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Maryland
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Bethesda, Maryland, Estados Unidos, 20892
- National Institute of Dental and Craniofacial Research (NIDCR)
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Criterios de participación
Criterio de elegibilidad
Edades elegibles para estudiar
- Niño
- Adulto
- Adulto Mayor
Acepta Voluntarios Saludables
Géneros elegibles para el estudio
Descripción
INCLUSION CRITERIA:
Patients of any age, gender or ethnicity who will help fulfill the objectives laid out in Section II.
We propose to study patients primarily enrolled in other clinical center protocol(s). They will continue to receive treatment/ interventions per the original protocols.
EXCLUSION CRITERIA:
Patients with significant cognitive impairment who are unable to give informed consent or patients having other significant mineral disturbances that could confound the parameters being studied will be excluded.
Plan de estudios
¿Cómo está diseñado el estudio?
Colaboradores e Investigadores
Publicaciones y enlaces útiles
Publicaciones Generales
- Murer H, Forster I, Hernando N, Lambert G, Traebert M, Biber J. Posttranscriptional regulation of the proximal tubule NaPi-II transporter in response to PTH and dietary P(i). Am J Physiol. 1999 Nov;277(5):F676-84. doi: 10.1152/ajprenal.1999.277.5.F676.
- Cai Q, Hodgson SF, Kao PC, Lennon VA, Klee GG, Zinsmiester AR, Kumar R. Brief report: inhibition of renal phosphate transport by a tumor product in a patient with oncogenic osteomalacia. N Engl J Med. 1994 Jun 9;330(23):1645-9. doi: 10.1056/NEJM199406093302304. No abstract available.
- Jonsson KB, Mannstadt M, Miyauchi A, Yang IM, Stein G, Ljunggren O, Juppner H. Extracts from tumors causing oncogenic osteomalacia inhibit phosphate uptake in opossum kidney cells. J Endocrinol. 2001 Jun;169(3):613-20. doi: 10.1677/joe.0.1690613.
Fechas de registro del estudio
Fechas importantes del estudio
Inicio del estudio
Finalización del estudio
Fechas de registro del estudio
Enviado por primera vez
Primero enviado que cumplió con los criterios de control de calidad
Publicado por primera vez (Estimar)
Actualizaciones de registros de estudio
Última actualización publicada (Estimar)
Última actualización enviada que cumplió con los criterios de control de calidad
Última verificación
Más información
Términos relacionados con este estudio
Palabras clave
Otros números de identificación del estudio
- 030254
- 03-D-0254
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