Bone Accrual and Hormones in Response to Lactation

This is a prospective observational trial of healthy postpartum women to investigate changes in bone density and markers of bone turnover during lactation. The study hypothesis is that women who breast-feed 5 months or more will lose bone density and subsequently regain the bone density after weaning. This study seeks to define determinants of the regain in bone density.

Study Overview

• Status: Completed
• Conditions: Lactation

Detailed Description

This is a prospective observational trial enrolling healthy postpartum women, ages 20 years and older with the intent to breast-feed from the UNC outpatient obstetrical clinics and the UVA outpatient obstetrical clinics. These women were studied at 3-5 visits in the year following their delivery to assess bone density, nutritional intake, exercise, and breast-feeding choices. The number of study visits depended on the timing of return of menses and interest in participating in the follow-up study (timepoints are: immediate postpartum, 3 months postpartum, return of menses, 6 months after return of menses and follow-up visit 6 months after final visit). Blood was taken for analysis of bone-related hormones, bone turnover and calcium homeostasis markers. The study focuses on women with extended lactation (at least 5 months of lactation) whereas women who cease lactation prior to 3 months will be the primary comparison group.

• Study Type: Observational
• Enrollment (Actual): 141

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Postpartum women from outpatient obstetrical/gynecology clinics.

Description

Inclusion Criteria:

• age >20 at the time of delivery
• singleton pregnancy and
• <2 prior pregnancies that were >20 weeks gestation.

Exclusion criteria:

• maternal rheumatologic disorders
• maternal anorexia nervosa
• maternal endocrinologic disorders,
• medications known to affect bone density such as corticosteroids, thyroid hormone use, anticonvulsant therapy, bisphosphonates, long-term GnRH agonists use and calcitonin.
• Subsequent pregnancy during the study

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
The association of change in bone density and change in IGF-1 axis hormones during lactation and weaning	~Two Years

Secondary Outcome Measures

Outcome Measure	Time Frame
The association of changes in bone density and change in bone turnover markers during lactation and weaning.	~Two years

Collaborators and Investigators

• Sponsor: University of Virginia
• Collaborators: University of North Carolina
• Investigators: Principal Investigator: Sue Brown, MD, UVA

Study record dates

Study Major Dates

• Study Start: January 1, 2003
• Primary Completion (Actual): August 1, 2010
• Study Completion (Actual): August 1, 2010

Study Registration Dates

• First Submitted: March 22, 2012
• First Submitted That Met QC Criteria: March 22, 2012
• First Posted (Estimated): March 26, 2012

Study Record Updates

• Last Update Posted (Actual): November 30, 2023
• Last Update Submitted That Met QC Criteria: November 27, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Bone Turnover Markers; Lactation; Bone Density
• Other Study ID Numbers: 12441

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Deidentified IPD may be available by direct request of Principal Investigator.