Bone Metabolism and Parathyroid Hormone-related Protein (PTHrP) Lactation Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00430417
Recruitment Status : Completed
First Posted : February 1, 2007
Last Update Posted : October 31, 2013
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
Mara Horwitz, University of Pittsburgh

Brief Summary:
The primary aim of the study is to measure bone formation in both lactating and non-lactating post-partum women and compare these to those in healthy non-pregnant controls. The secondary aim is to obtain measurements of Parathyroid Hormone-related Protein (PTHrP), markers of bone resorption, and calcium and vitamin D metabolism in these subjects. The investigators believe that lactating women will have an increase in bone resorption but no increase in bone formation when compared to non-lactating post-partum women and normal controls.

Condition or disease
Bone Diseases, Endocrine

  Show Detailed Description

Study Type : Observational
Actual Enrollment : 49 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: A Prospective Cohort Pilot Study of Bone Metabolism in Lactating and Non-lactating Postpartum Women and Healthy Non-pregnant Women
Study Start Date : January 2007
Actual Primary Completion Date : June 2008
Actual Study Completion Date : June 2008

Resource links provided by the National Library of Medicine

3 groups
Group 1: post-partum breastfeeding women
Group 2
Group 2: post-partum bottlefeeding women
Group 3
Group 3: normal non-pregnant controls who are age and race-matched to Group 1

Primary Outcome Measures :
  1. Measurements of amino-terminal telopeptides of procollagen 1 (P1NP), a marker of bone formation, in lactating and non-lactating postpartum women both at 6-8 and at 12-14 weeks post-partum, and to compare these values to those of normal controls [ Time Frame: 4 months ]

Secondary Outcome Measures :
  1. Measurements of Parathyroid Hormone-related Protein (PTHrP), markers of bone turnover, calcium and vitamin D metabolism [ Time Frame: 4 months ]

Biospecimen Retention:   Samples Without DNA
archival blood serum and plasma

Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
New mothers who are either almost exclusively breast feeding or bottle feeding; normal controls to match those new mothers.

Inclusion Criteria:

  • Healthy Caucasian, Hispanic, or Asian women between the ages of 21-45.
  • Group 1: Postpartum (singleton pregnancy) women who are exclusively breastfeeding, defined as 1 or fewer bottles of supplemental formula/day.
  • Group 2: Postpartum (singleton pregnancy) women who are non-lactating, which is defined as bottle-feeding or having weaned their baby from breastfeeding for at least 4 weeks prior to study.
  • Group 3: Controls - Healthy, non-pregnant women who are race and age-matched to the breastfeeding women in group one. They may not have been lactating or pregnant within the last year.

Exclusion Criteria:

  • Subjects with cardiac, hypertensive, vascular, renal (serum creatinine of > 1.5), pulmonary, endocrine, musculoskeletal, hepatic, hematologic, or malignant or rheumatologic disease will be excluded from the study.
  • Smokers and those with a history of significant alcohol or drug abuse are excluded.
  • Baseline hypertension (systolic BP > 160 mm/Hg) or hypotension (systolic BP < 90 mm/Hg).
  • Subjects taking any chronic medications except stable doses of thyroid hormone, prenatal, vitamin supplements, or oral contraceptives.
  • Those who have received any investigational drug in past 90 days will be excluded from the study.
  • Women who are currently pregnant will be excluded from the study.
  • Women who became pregnant by in vitro fertilization IVF or any hormonal manipulation (i.e. fertility drugs such as clomid) are also excluded, as they may have an altered pre-pregnant hormonal state.
  • All women will have a urine pregnancy test performed at each of the two study visits and must not be pregnant in order to continue in the study.
  • Subjects are not allowed to donate blood between study visits.
  • In order to narrow the statistical variations in the study population, African-Americans are excluded because of demonstrated differences in renal excretion of calcium and vitamin D absorption.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00430417

United States, Pennsylvania
University of Pittsburgh
Pittsburgh, Pennsylvania, United States, 15213
Sponsors and Collaborators
University of Pittsburgh
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: Mara J Horwitz, MD University of Pittsburgh

Additional Information:

Responsible Party: Mara Horwitz, Associate Professor of Medicne, University of Pittsburgh Identifier: NCT00430417     History of Changes
Other Study ID Numbers: 0610073
R01DK073039 ( U.S. NIH Grant/Contract )
First Posted: February 1, 2007    Key Record Dates
Last Update Posted: October 31, 2013
Last Verified: October 2013

Keywords provided by Mara Horwitz, University of Pittsburgh:
Endocrine System Diseases
MusculoSkeletal System Disease
Physiologic Properties

Additional relevant MeSH terms:
Bone Diseases
Endocrine System Diseases
Bone Diseases, Endocrine
Musculoskeletal Diseases