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

NCT03603444 | Completed

• 1 other identifier: 0032443/15
• Study Type: observational
• Target: 606
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Phosphorus and Calcium Disorders

Outcome Measures

Primary Outcomes (1)

• Serum Calcium to Phosphorus ratio

  Calculated formula (serum calcium to serum phosphorus ratio)

  Assessed only once at the diagnosis (from January 2005 to January 2018)

Secondary Outcomes (3)

• Serum Calcium

  Assessed only once at the diagnosis (from January 2005 to January 2018)

• Serum Phosphorus

  Assessed only once at the diagnosis (from January 2005 to January 2018)

• Serum Parathormone

  Assessed only once at the diagnosis (from January 2005 to January 2018)

Study Arms (3)

First study group: patients with PHPT

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.

Other: No intervention are provided

Second study group: patients with HypoP

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.

Other: No intervention are provided

Control group

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.

Other: No intervention are provided

Interventions

No intervention are provided OTHER

Control group; First study group: patients with PHPT; Second study group: patients with HypoP

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Serum Calcium to Phosphorus ratio will be compared among patients with different disorders of calcium-phosphorus metabolism (primary hyperparathyroidism and hypophosphoremia) and controls.

You may qualify if:

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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Azienda Ospedaliero-Universitaria di Modena: lead

Study Sites (1)

Azienda Ospedaliero - Universitaria di Modena

Modena, 41124, Italy

Location

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: July 10, 2018
• First Posted: July 27, 2018
• Study Start: January 1, 2011
• Primary Completion: January 1, 2018
• Study Completion: January 1, 2018
• Last Updated: July 27, 2018

Record last verified: 2018-07

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)