Clinical trial NCT03747029: Serum Calcium to Phosphorous (Ca/P) Ratio in the Diagnosis of Ca-P Metabolism Disorders: a Multicentre Study
Official title: Serum Calcium to Phosphorous (Ca/P) Ratio in the Diagnosis of Ca-P Metabolism Disorders: a Multicentre Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Phosphorus and Calcium Disorders
Parathyroid Diseases
Hyperparathyroidism
Hypoparathyroidism
Lead sponsor: Azienda Ospedaliero-Universitaria di Modena
Sponsor class: OTHER
First posted: 2018-11-20
Enrollment: 1038
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
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 hypoparathyroidism) and controls.

Brief summary: Primary hyperparathyroidism (PHPT) and Hypoparathyroidism (HP) are two of the most frequent disorder of Calcium-Phosphorus (Ca-P) metabolism. The Ca/P ratio is an accurate tool to differentiate patients with PHPT from healthy subjects, according to a previous single-centre study. The reliability of this index is based on the fact that serum Ca and P are inversely related together either in healthy subjects or in patients with PHPT and HP.

Detailed description: The aim of this study is to investigate the accuracy and diagnostic value of Ca/P ratio in the diagnosis of primary hyperparathyroidism and hypoparathyroidism. The definition of a valid cut-off of serum Ca/P ratio for patients with these disorders will be of help especially in those patients with apparently normal biochemical profile, but suggestive for primary hyperparathyroidism and hypoparathyroidism.

Eligibility criteria: Inclusion Criteria:

* patients with diagnosis of primary hyperparathyroidism
* patients with diagnosis of hypoparathyroidism
* 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.

Primary outcomes:
measure: Serum Calcium to Phosphorus ratio
timeFrame: Assessed only once at the diagnosis (from January 2005 to January 2018)
Secondary outcomes:
measure: Serum Calcium
timeFrame: Assessed only once at the diagnosis (from January 2005 to January 2018)
measure: Serum Phosphorus
timeFrame: Assessed only once at the diagnosis (from January 2005 to January 2018)
measure: Serum Parathormone
timeFrame: Assessed only once at the diagnosis (from January 2005 to January 2018)
Other outcomes:
Locations:
city: Modena
country: Italy
facility: Azienda Ospedaliero - Universitaria di Modena
Study officials:
References:
citation: Madeo B, De Vincentis S, Repaci A, Altieri P, Vicennati V, Kara E, Vescini F, Amadori P, Balestrieri A, Pagotto U, Simoni M, Rochira V. The calcium-to-phosphorous (Ca/P) ratio in the diagnosis of primary hyperparathyroidism and hypoparathyroidism: a multicentric study. Endocrine. 2020 Jun;68(3):679-687. doi: 10.1007/s12020-020-02276-7. Epub 2020 Mar 31.