Comparison of Calcium Metabolism in Caucasian and Asian Postmenopausal Women of Chinese Descent and the Use of Strontium as a Qualitative Marker of Calcium Metabolism

Not Applicable

Completed

• Conditions: Calcium Metabolism
• Interventions: Other: Ca-41(isotope tracer); Other: Sr-84 (isotope tracer); Dietary Supplement: Vitamin D

• Registration Number: NCT02565602
• Lead Sponsor: National University of Singapore

Brief Summary

This study aims to: 1) quantitatively assess parameters of bone calcium balance in healthy postmenopausal Asian women of Chinese descent; 2) assess possible ethnic differences in calcium metabolism by direct comparison of acquired data in Chinese postmenopausal women with those acquired earlier in Caucasian postmenopausal women using the same methodology; 3) assess differences in calcium and strontium metabolism in parallel to evaluate if strontium stable isotopes can be used for tracing bone calcium metabolism qualitatively

Detailed Description

The study will follow closely the protocol that was used previously by the PI at ETH Zurich to study calcium metabolism in healthy postmenopausal women. Calcium metabolism will be studied after a single oral administration of a calcium tracer (Ca-41) and by following the excretion of the tracer in urine over 6 months. Obtained data will be used to assess parameters of calcium metabolism (flux rates and sizes of body calcium compartments) by kinetic modelling. A strontium tracer (Sr-84) will be administered in parallel and its urinary excretion pattern compared to Ca-41 excretion to determine if strontium tracers can be used to assess calcium metabolism qualitatively. Subjects will be supplemented with Vit D throughout the study. Vit D supplementation will commence 1 month before isotope administration.

Study Timeline

• Study Start: 2014-02
• Study First Submitted: 2015-09-21
• Study First Submitted QC: 2015-09-29
• Study First Posted: 2015-10-01
• Primary Completion: 2016-09
• Study Completion: 2016-09
• Status Verified: 2016-10
• Last Update Submitted: 2016-10-13
• Last Update Posted: 2016-10-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 10

Inclusion Criteria

1. Last menstrual bleeding was at least 5 years ago.
2. Between the ages of 50 and 75 years old.
3. Both parents and 4 grandparents are/were of Chinese descent. It is not a necessity for the participant, participant's parents and grandparent's to be born and raised in Singapore to participate in this study.
4. BMI above 16 and below 30

Exclusion Criteria

1. Diagnosed with osteoporosis
2. Presence of significant liver disease, malignancy (excluding myeloma in the study group), malabsorption syndrome, hypoparathyroidism, hyperparathyroidism, sarcoidosis or hyperthyroidism (from toxic multinodular goitre or Graves disease), Paget's disease osteosarcoma, acromegaly, Cushing's syndrome, hypopituitarism, diabetes mellitus or severe chronic obstructive pulmonary disease.
3. Current smoking and an alcohol intake exceeding one standard drink per day
4. Undergoing treatment with any of the following drugs (within the last 12 months) i) adrenocorticoid steroids (3 months or longer at anytime or >10 days of treatment within the previous 12 months) ii) anticonvulsant therapy iii) pharmacological doses of thyroid hormone (causing decline of TSH below normal) iv) bisphosphonates v) calcitonin vi) synthetic parathyroid hormone vii) selective estrogen receptor modulators viii) strontium ranelate ix) estrogen therapy x ) chemotherapeutic agents xi) sodium fluoride (any history of treatment with fluoride) xii) medications known to affect calcium metabolism (diuretics, antacids, calcium channel blockers etc.).
5. Presence of any other chronic illnesses.
6. Any other significant medical, psychiatric and/or social issue as determined by the investigator that would compromise subject's safety and/or compliance with trial procedure.
7. Any other clinically significant screening laboratory abnormality (as determined by the investigators).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Ca-41 & Sr-84 (isotope tracers) & vit D	Sr-84 (isotope tracer)	Dosages: 3.7 kBq (100 nCi) Ca-41, 5 mg of Sr-84 and 400IU of vitamin D (daily)
Ca-41 & Sr-84 (isotope tracers) & vit D	Vitamin D	Dosages: 3.7 kBq (100 nCi) Ca-41, 5 mg of Sr-84 and 400IU of vitamin D (daily)
Ca-41 & Sr-84 (isotope tracers) & vit D	Ca-41(isotope tracer)	Dosages: 3.7 kBq (100 nCi) Ca-41, 5 mg of Sr-84 and 400IU of vitamin D (daily)

Primary Outcome Measures

Name	Time	Method
Time changes in urinary tracer excretion (Ca-41 and Sr-84)	6 months post dose	Urine samples collected from participants are analysed for calcium and strontium content as well as Ca-41 and Sr-84 excretion.

Secondary Outcome Measures

Name	Time	Method
Comparison between flux rates and relative compartment sizes for calcium and strontium in each individual subject	6 months post dose	Flux rates (mg/day), and calcium and strontium distribution between compartments (% body calcium and strontium ) will be obtained by compartmental modelling of urinary tracer data
Flux rates and relative compartment sizes (mineralized bone, exchangeable bone calcium, plasma calcium) of the study population	6 months post dose	Flux rates (mg/day) and calcium distribution between compartments (% body calcium) will be obtained by compartmental modelling of urinary tracer data. Obtained data will be compared to a mirroring study conducted earlier in Caucasian postmenopausal women.

Trial Locations

Locations (1)

Investigational Medicine Unit; 🇸🇬 Singapore, Singapore