Reliability of Serum Calcium to Phosphorus (Ca/P) Ratio as an Accurate and Inexpensive Tool to Define Disorders of Ca-P Metabolism

Azienda Ospedaliero-Universitaria di Modena

Status: Completed

Conditions: Phosphorus and Calcium Disorders

Treatments: Other: No intervention are provided

Study type: Observational

Funder types: Other

Identifiers

NCT03603444

0032443/15

Details and patient eligibility

About

BACKGROUND: Primary hyperparathyroidism (PHPT) is the third most common endocrine disorder. The Ca/P ratio is an accurate tool to differentiate patients with PHPT (>3.5 if Ca and P are expressed in mg/dl) from healthy subjects. The reliability of this index is based on the fact that serum Ca and P are inversely related together. However, other disorders of the Ca-P metabolism, such as hypophosphoremia (HypoP) not related to PHPT, might also impair the Ca/P ratio.

OBJECTIVE: To validate the accuracy of Ca/P ratio in the diagnosis of Ca-P metabolism disorders, including also patients with documented HypoP not related to PHPT.

METHODS: A single-center, retrospective, case-control study will be carried out.

Biochemical measurements will include parathormone (PTH), vitamin D, serum Ca and P, serum albumin and creatinine.

Enrollment: 606 patients

Sex: All

Ages: 18 to 90 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria:

• patients with diagnosis of primary hyperparathyroidism
• HIV-infected patients with reduced phosphorus but normal calcium
• subjects with normal Calcium-Phosphorus metabolism

Exclusion criteria for both cases and controls will be:

• age younger than 18 or older than 90 years
• severe renal and liver diseases (i.e. glomerular filtration rate (GFR) <30 ml/min)
• hyperparathyroidism secondary to Vitamin D deficiency
• active metabolic bone disease (e.g. Paget's disease of the bone, osteomalacia, rickets, etc)
• any type of cancer
• malnutrition
• severe obesity (BMI > 40 kg/m2)
• a history of gastrointestinal malabsorption
• sarcoidosis
• hypercortisolism
• diabetes insipidus
• hyperthyroidism
• pseudohypoparathyroidism
• familial hypocalciuric hypercalcemia (FHH)
• treatment with steroids, active forms of vitamin D (calcitriol, ergocalciferol, etc), thiazides, phosphate binders, lithium, cinacalcet, bisphosphonates, and denosumab.

Trial design

606 participants in 3 patient groups

First study group: patients with PHPT

Description:

Patients aged between 18-90 years old with primary hyperparathyroidism who had been diagnosed in the Unit of Endocrinology of the University of Modena and Reggio Emilia. Exclusion criteria for both cases and controls will be: age younger than 18 or older than 90 years; severe renal and liver diseases (i.e. glomerular filtration rate (GFR) \<30 ml/min); hyperparathyroidism secondary to Vitamin D deficiency; active metabolic bone disease (e.g. Paget's disease of the bone, osteomalacia, rickets, etc); any type of cancer; malnutrition; severe obesity (BMI \> 40 kg/m2); a history of gastrointestinal malabsorption; sarcoidosis; hypercortisolism, diabetes insipidus, hyperthyroidism, pseudohypoparathyroidism; familial hypocalciuric hypercalcemia (FHH); treatment with steroids, active forms of vitamin D (calcitriol, ergocalciferol, etc), thiazides, phosphate binders, lithium, cinacalcet, bisphosphonates, and denosumab.

Treatment:

Other: No intervention are provided

Second study group: patients with HypoP

Description:

Subjects with reduced serum P, but normal serum Ca, will be enrolled among HIV-infected patients on HAART treatment from the Modena cohort. Exclusion criteria for both cases and controls will be: age younger than 18 or older than 90 years; severe renal and liver diseases (i.e. glomerular filtration rate (GFR) \<30 ml/min); hyperparathyroidism secondary to Vitamin D deficiency; active metabolic bone disease (e.g. Paget's disease of the bone, osteomalacia, rickets, etc); any type of cancer; malnutrition; severe obesity (BMI \> 40 kg/m2); a history of gastrointestinal malabsorption; sarcoidosis; hypercortisolism, diabetes insipidus, hyperthyroidism, pseudohypoparathyroidism; familial hypocalciuric hypercalcemia (FHH); treatment with steroids, active forms of vitamin D (calcitriol, ergocalciferol, etc), thiazides, phosphate binders, lithium, cinacalcet, bisphosphonates, and denosumab.

Treatment:

Other: No intervention are provided

Control group

Description:

Patients that underwent biochemical examination by primary care physician or by endocrinologist in order to assess their calcium-phosphorus metabolism state with normal results. Exclusion criteria for both cases and controls will be: age younger than 18 or older than 90 years; severe renal and liver diseases (i.e. glomerular filtration rate (GFR) \<30 ml/min); hyperparathyroidism secondary to Vitamin D deficiency; active metabolic bone disease (e.g. Paget's disease of the bone, osteomalacia, rickets, etc); any type of cancer; malnutrition; severe obesity (BMI \> 40 kg/m2); a history of gastrointestinal malabsorption; sarcoidosis; hypercortisolism, diabetes insipidus, hyperthyroidism, pseudohypoparathyroidism; familial hypocalciuric hypercalcemia (FHH); treatment with steroids, active forms of vitamin D (calcitriol, ergocalciferol, etc), thiazides, phosphate binders, lithium, cinacalcet, bisphosphonates, and denosumab.

Treatment:

Other: No intervention are provided