A behavior change intervention for breast cancer survivors based on the social cognitive theory is feasible and results in potentially meaningful improvements in physical activity and selected health outcomes. Confirmation in a larger study is warranted.

Purpose: We previously reported the effectiveness of a 12-week physical activity behavior change intervention for breast cancer survivors postintervention with this report, aiming to determine delayed and/or persistent effects 3 months after intervention completion. Methods: Forty-one sedentary women with stage I, II, or IIIA breast cancer currently receiving hormonal therapy were randomly assigned to receive the 12-week Better Exercise Adherence after Treatment for Cancer intervention or usual care. Assessments occurred at baseline, postintervention, and 3 months postintervention.Results: Weekly minutes of greater than or equal to moderate intensity physical activity measured by accelerometer showed a significant group by time interaction (F = 3.51; P = 0.035; between group difference in the mean change from baseline to 3 months postintervention, 100.1 minute, P = 0.012). Significant group by time interactions also showed sustained improvements from baseline to 3 months postintervention in strength (F = 3.82; P = 0.027; between group difference, 11.2 kg; P = 0.026), waist-to-hip ratio (F = 3.36; P = 0.041; between group difference, À0.04; P = 0.094), and social well-being (F = 4.22; P = 0.023; between group difference, 3.9; P = 0.039). A delayed reduction in lower extremity dysfunction 3 months postintervention was noted (F = 3.24; P = 0.045; between group difference in the mean change from postintervention to 3 months followup; P = À7.6; P = 0.015). No group by time effect was noted for fitness, body mass index, percent fat, bone density, total quality of life (Functional Assessment of Cancer Therapy-General), fatigue, endocrine symptoms, cognitive function, or sleep. Conclusions: The intervention resulted in sustained improvements in physical activity, strength, central adiposity, and social well-being with lower extremity function benefits appearing 3 months after intervention completion. Testing translation in a multisite study is warranted.

This study was designed to assess the effects of 18 months of resistance exercise on regional and total bone mineral density (BMD) and soft tissue lean mass (STL) in premenopausal women aged 28-39 randomly assigned to an exercise or control group. Twenty-two exercise and 34 control subjects completed the 18-month training study. All subjects were previously inactive and untrained women. Initial, 5-, 12- and 18-month assessments were made of total and regional BMD and total and regional STL using dual energy X-ray absorptiometry. All subjects consumed a 500 mg/day elemental calcium supplement throughout the study. Initial Ca intake without supplement averaged 1,023 mg/day in total sample. Serum levels of bone osteocalcin and dietary assessments using 12 randomly assigned days of diet records were also completed. Muscular strength was assessed from both 1 repetition maximum (RM) testing of 10 weightlifting exercises and by peak torque for hip abduction/adduction and knee extension/flexion. Training increased strength by 58.1% based on 1 RM testing and by 33.8% based on isokinetic testing at 18 months versus baseline. BMD increased significantly above baseline at the lumbar spine for the exercise group at 5 months (2.8%), 12 months (2.3%), and 18 months (1.9%) as compared with controls. Femur trochanter BMD increased significantly (p < 0.05) in the exercise group at 12 months (1.8%) and 18 months (2.0%) but not at 5 months (0.7%) as compared with controls. No changes in total BMD, arm BMD, or leg BMD were found. There was a 20% increase in BGP in the exercise group as compared with controls at 5 months and this difference was maintained throughout the study. For STL, significant increases for total, arm, and leg were found at 5, 12, and 18 months for the exercise group versus control ranging from 1-6% over baseline. These results support the use of strength training for increasing STL and muscular strength with smaller but significant regional increases in BMD in the premenopausal population.

There is conflicting information on the physiological role of growth hormone (GH) in the control of aging. This study reports dual-energy x-ray absorptiometry (DXA) measurements of body composition and bone characteristics in young, adult, and aged long-lived GH receptor knockout (GHR-KO) and normal mice to determine the effects of GH resistance during aging. Compared to controls, GHR-KO mice showed an increased percentage of body fat. GHR-KO mice have reduced total-body bone mineral density (BMD), bone mineral content, and bone area, but these parameters increased with age. In addition, GHR-KO mice have decreased femur length, femur BMD, and lower lumbar BMD compared to controls in all age groups. These parameters also continued to increase with age. Our results indicate that GH resistance alters body composition, bone growth, and bone maintenance during aging in GHR-KO mice.

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