Clinical trial NCT00244907: Isoflavones for Promoting Calcium Absorption and Preventing Bone Loss in Post Menopausal Women
Official title: Metabolism and Bone Health
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Osteoporosis
Osteopenia
Keywords: Bone Resorption
Phytoestrogens
Calcium
Genistein
Equol
Lead sponsor: Purdue University
Sponsor class: OTHER
Collaborators: name: National Center for Complementary and Integrative Health (NCCIH)
name: Office of Dietary Supplements (ODS)
First posted: 2005-10-27
Enrollment: 23
Sex: FEMALE
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: Estrogen is a hormone that helps prevent calcium loss and bone breakdown. During menopause, estrogen levels decrease. Insufficient amounts of estrogen may lead to bone loss and possibly osteoporosis. Isoflavones are natural compounds found in soy plants that may help provide protection against bone loss. This study will evaluate the effect of soy isoflavones on calcium absorption and bone loss in post menopausal women.

Detailed description: Estrogen is a hormone that activates bone-forming cells and prevents calcium loss and bone breakdown. During menopause, estrogen levels decrease. Insufficient amounts of estrogen may accelerate bone breakdown and inhibit the body's ability to create new bone, thereby leading to bone loss and possibly osteoporosis. Various treatments have been developed to decrease bone loss in post-menopausal women. Actonel, for example, is an FDA-approved drug used to help prevent bone loss.

Phytoestrogens are plant compounds with a structure similar to estrogen. They have also been shown to help reduce the negative effects of menopause. Isoflavones are a particular type of phytoestrogens that are found in soy plants and may act like estrogen in providing possible protection against bone loss. This study will compare the effects of isoflavones (including genistein, a type of isoflavone) versus Actonel on calcium absorption and bone loss in post-menopausal women.

Participants in this double-blind cross-over study will first complete a screening process, which will include answering questions about their health habits, medical history, physical activity, and food patterns. They will then eat one soy bar daily for 3 days. On Day 4, a urine sample will be taken to assess their ability to metabolize phytoestrogen from soybeans. Participants will be randomly assigned to a specific treatment order. Participants will receive 1-4 unique soy isoflavones, followed by Actonel. Treatment phases will be separated by a 50-day washout period. All participants will also take calcium and vitamin D supplements throughout the study. Assessments will include bone density measurements, calcium absorption tests, and blood and urine tests. The study will last approximately 2.5 years.

Eligibility criteria: Inclusion Criteria:

* At least 4 years post-menopausal

Exclusion Criteria:

* Not currently taking estrogen replacement therapy or undergoing any treatment for osteoporosis
* Diagnosis of breast cancer
* Results of mammogram suggesting breast cancer

Primary outcomes:
measure: Urinary markers of bone resorption; measured at the end of each treatment phase
timeFrame: Every 50 days
Secondary outcomes:
measure: Serum markers of bone resorption and calcium absorption; measured at the end of each treatment phase
timeFrame: Every 50 days
Other outcomes:
Locations:
city: West Lafayette
country: United States
facility: Purdue University
state: Indiana
Study officials:
affiliation: Purdue University
name: Connie M. Weaver, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Spence LA, Lipscomb ER, Cadogan J, Martin B, Wastney ME, Peacock M, Weaver CM. The effect of soy protein and soy isoflavones on calcium metabolism in postmenopausal women: a randomized crossover study. Am J Clin Nutr. 2005 Apr;81(4):916-22. doi: 10.1093/ajcn/81.4.916.
citation: Jackson GS, Weaver C, Elmore D. Use of accelerator mass spectrometry for studies in nutrition. Nutr Res Rev. 2001 Dec;14(2):317-34. doi: 10.1079/NRR200129.
citation: Pawlowski JW, Martin BR, McCabe GP, McCabe L, Jackson GS, Peacock M, Barnes S, Weaver CM. Impact of equol-producing capacity and soy-isoflavone profiles of supplements on bone calcium retention in postmenopausal women: a randomized crossover trial. Am J Clin Nutr. 2015 Sep;102(3):695-703. doi: 10.3945/ajcn.114.093906. Epub 2015 Aug 5.
citation: Nakatsu CH, Armstrong A, Clavijo AP, Martin BR, Barnes S, Weaver CM. Fecal bacterial community changes associated with isoflavone metabolites in postmenopausal women after soy bar consumption. PLoS One. 2014 Oct 1;9(10):e108924. doi: 10.1371/journal.pone.0108924. eCollection 2014.