Conditions: Osteoporosis
Keywords: postmenopausal, bone, dietary supplement, mind-body exercise
Allocation: RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 171
Healthy volunteers: yes

Brief summary:
Osteoporosis is a major health problem in postmenopausal women. Our long-term goal is to develop a new alternative treatment that include a dietary supplement (green tea extract) and a mind-body exercise (Tai Chi) for lessening bone loss in postmenopausal women with low bone mass. A combination of dietary supplement and moderate intensity exercise now becomes a new alternative treatment in reducing bone loss in postmenopausal women with low bone mass, due to the possible stronger effects of the combination than individual treatments. Objective: To test a CAM intervention including green tea polyphenol (GTP) and Tai Chi (TC) exercise for feasibility, and to quantitatively assess their individual and conjugate effects on postmenopausal women with osteopenia. Hypotheses: (1) 24 weeks of GTP supplement, TC exercise, and their combination will benefit bone remodeling as measured by bone biomarkers and muscle strength/physical function in postmenopausal women with osteopenia compared to those receiving placebo only, and (2) the changes in bone biomarkers associated with bone remodeling will be correlated with the changes in oxidative stress.

Detailed description:
This is a 24-week, randomized, and placebo-controlled intervention trial to investigate the effects of green tea polyphenols (GTP) and Tai Chi (TC) on relevant primary and secondary endpoints in postmenopausal women with osteopenia. Women at least 2 years after menopause, with osteopenia, will be recruited primarily from local senior independent/assisted living facilities, municipal senior community centers, and obstetrics and gynecology clinics. After screening, qualified participants will be matched for age and will be randomly assigned to one of the four treatment groups: placebo, GTP, placebo+TC, and GTP+TC. During the 24-week intervention, all participants will be provided with calcium and vitamin D daily. The participants in the placebo group will receive medicinal starch for 24 weeks. The GTP participants will receive GTP for 24 weeks. The placebo+TC participants will receive both placebo and TC treatments for 24 weeks. The GTP+TC participants will receive both GTP and TC treatments for 24 weeks. Participants will receive the primary and secondary outcome measures at baseline, 4, 12, and 24 weeks. The primary outcome measures are concentrations of bone biomarkers. The secondary outcome measure is a biomarker of oxidative stress DNA damage. Additional secondary outcome is muscle strength/physical function. Investigators evaluating the endpoints will be blinded to intervention allocation.

Arms:
arm 1: 24 weeks of placebo. arm 2: 24 weeks of green tea polyphenols arm 3: 24 weeks of placebo plus Tai Chi exercise. arm 4: 24 weeks of green tea polyphenols plus Tai Chi exercise.

Interventions: intervention 1: Placebo intervention 2: Green Tea Polyphenols (GTP) intervention 3: Placebo+Tai Chi (TC) intervention 4: GTP+TC
Intervention descriptions: intervention 1: 500 mg medicinal starch pills daily intervention 2: 500 mg green tea polyphenols daily intervention 3: 500 mg medicinal starch daily and Tai Chi (3x/week) for 24 weeks intervention 4: 500 mg GTP daily plus TC exercise (3x/week) for 24 weeks

Protocol document: