---
title: "Serum Calcium to Phosphorous (Ca/P) Ratio in the Diagnosis of Ca-P Metabolism Disorders: a Multicentre Study"
nct_id: NCT03747029
overall_status: COMPLETED
sponsor: Azienda Ospedaliero-Universitaria di Modena
study_type: OBSERVATIONAL
primary_condition: Phosphorus and Calcium Disorders
countries: Italy
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT03747029.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT03747029"
ct_last_update_post_date: 2021-02-09
last_seen_at: "2026-05-12T06:24:20.585Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Serum Calcium to Phosphorous (Ca/P) Ratio in the Diagnosis of Ca-P Metabolism Disorders: a Multicentre Study

**NCT ID:** [NCT03747029](https://clinicaltrials.gov/study/NCT03747029)

## Key Facts

- **Status:** COMPLETED
- **Study Type:** OBSERVATIONAL
- **Target Enrollment:** 1038
- **Lead Sponsor:** Azienda Ospedaliero-Universitaria di Modena
- **Conditions:** Phosphorus and Calcium Disorders, Parathyroid Diseases, Hyperparathyroidism, Hypoparathyroidism
- **Start Date:** 2017-11-28
- **Completion Date:** 2018-12-31
- **CT.gov Last Update:** 2021-02-09

## 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

- **Minimum age:** 18 Years
- **Maximum age:** 90 Years
- **Sex:** ALL
- **Healthy Volunteers:** Yes

```
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.
```

## Arms

- **Patients with hyperparathyroidism** — Patients aged between 18-90 years old with primary hyperparathyroidism. No intervention is provided.
- **Patients with hypoparathyroidism** — Patients aged between 18-90 years old with diagnosed hypoparathyroidism. No intervention is 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.

No intervention is provided.

## Interventions

- **No intervention is provided** (OTHER) — No intervention is provided

## Primary Outcomes

- **Serum Calcium to Phosphorus ratio** _(time frame: Assessed only once at the diagnosis (from January 2005 to January 2018))_ — Calculated formula (serum calcium to serum phosphorus ratio)

## Secondary Outcomes

- **Serum Calcium** _(time frame: Assessed only once at the diagnosis (from January 2005 to January 2018))_
- **Serum Phosphorus** _(time frame: Assessed only once at the diagnosis (from January 2005 to January 2018))_
- **Serum Parathormone** _(time frame: Assessed only once at the diagnosis (from January 2005 to January 2018))_

## Locations (1)

- Azienda Ospedaliero - Universitaria di Modena, Modena, Italy

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.azienda ospedaliero - universitaria di modena|modena||italy` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT03747029.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT03747029*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*