title: Are improvements in bone and physical performance from an 8-month high-intensity exercise program maintained in postmenopausal women with low bone mass? 3-year follow-p of the LIFTMOR trial
Creators: name: Myers, Kirt B
Publisher: name: Griffith University
Year: 2019
Subjects: subject: LIFTMOR
subject: high-intensity exercise
subject: postmenopausal women
subject: low bone mass

description: Introduction: In Australia, 1 in 4 women over 50 and 1 in 2 over 80 suffer from osteoporosis. There are 8.9 million osteoporosis-related fractures worldwide each year. Current recognised treatment is primarily confined to medications which are not without side effects. The discovery of an effective, non-pharmacological management strategy for osteoporosis will help reduce the financial burden on the healthcare system, and potentially reduce mortality, pain and suffering related to osteoporosis. The skeletal response to mechanical loading is dependent on the nature of the applied load. Optimal osteogenic loads induce high-magnitude strains at high rates. A high-intensity resistance and impact training program (HiRIT) was therefore designed and tested as a potential intervention for postmenopausal women with osteoporosis or osteopenia - the LIFTMOR trial. Despite concerns about inherent risks to a fragile skeleton, HiRIT in the LIFTMOR trial was observed to improve bone without causing fractures in this at-risk population. It was not known if HiRIT delivered in a non-research supervised clinical setting maintained the same level of safety and efficacy. The primary aim of the current observational study was to determine the effects of cessation, continuation or uptake of HiRIT on bone and functional outcomes for postmenopausal women with low to very low bone mass who participated in the LIFTMOR trial. Secondarily, the study assessed the safety of a HiRIT program for postmenopausal women with low to very low bone mass who participated in the LIFTMOR trial. Methods: Of the 101 postmenopausal women who enrolled in the 8-month LIFTMOR trial (for which data was collected at baseline [T0] and completion [T1]), 86 completed and were invited for retesting. Participants underwent the identical testing protocol as the LIFTMOR trial at three-year follow-up (T2). Bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN)(DXA), and physical performance measures (back extensor strength [BES], lower limb strength [LES], functional reach test [FRT], timed up-and-go test [TUGT], five times sit-to-stand [FTSTS] and maximal vertical jump [VJ]) were remeasured. Participants were designated to four groups based on HiRIT participation both during and after cessation of the LIFTMOR trial. Participants initially randomised to CON in the LIFTMOR trial who did or did not adopt HiRIT thereafter were designated CON-HIRT and CON-CON, respectively. Those initially randomised to HiRIT who did or did not adopt HiRIT thereafter were designated HiRIT-HiRIT and HiRIT-CON, respectively. The statistical analysis was conducted using the SPPS software (Version 25; SPSS Inc., Chicago, IL). Descriptive statistics were generated for participant characteristics, biometrics, and all dependent variables. A simple ANCOVA was performed to examine between-group differences in change from the original follow-up. Results: Fifty women (65±5 years, 161.8±4.0 cm, 61.9±6.1 kg) agreed to participate in follow-up re-testing (3.2±0.6 years). LS BMD improved more in HiRIT-HiRIT (8.63±5.29%, n=7) than HiRIT-CON (2.18±5.65%, p=0.042, n=16). LS BMD improved more in CON-HiRIT (8.54±4.08%, n=11) than HiRIT-CON (2.18±5.65%, p=0.046). FN BMD improved more in HiRIT-HiRIT (3.67±4.45%) than HiRIT-CON (2.85±5.79%, p=0.014). LES improved more in CON-HiRIT (7.1±25.7%) than HiRIT-CON (-8.8±-24.4%, p=0.012), HiRIT-HiRIT (2.8±22.8%, p=0.024), and CON-CON (3.1±26.5%, p=0.022, n=16). TUG improved more in CON-HiRIT (15.6±7.9%) than HiRIT-HiRIT (1.4±12.3%, p=0.001), HiRIT-CON (7.8±8.2%, p=0.021). FTSTS improved more in CON-HiRIT (7.1±12.9%) than HiRIT-CON (-6.4±20.5%, p=0.018) and CON-CON (3.9±10.9%, p=0.029). VJ improved more in CON-HiRIT (17.23±11.49%) than CON-CON (-22.95±9.58%, p=0.020). Conclusion: The LIFTMOR trial was the first to show that a brief, supervised HiRIT exercise program was efficacious and safe for improving bone at clinically-relevant sites, stature and functional performance in postmenopausal women with low bone mass. The current 3-year follow-up study demonstrated that participants who began HiRIT training after being initially randomised to CON improved bone and other outcomes in a similar way to those allocated to HiRIT in the LIFTMOR trial. LIFTMOR participants allocated to HiRIT during the trial who continued HiRIT after trial cessation continued to improve BMD and functional performance. LIFTMOR participants allocated to HiRIT but who ceased HiRIT after trial cessation continued to exhibit overall BMD and functional performance gains from baseline, but the effects had diminished. LIFTMOR participants allocated to CON who did not take up HiRIT training after the trial increased BMD and functional performance, but improvements were not as notable as those in the HiRIT groups. Although representing only 58% of the original LIFTMOR participants, to the extent that our conclusions are tempered by sample size, our follow-up analyses suggest that musculoskeletal and functional benefits from HiRIT may endure for some years. Nevertheless, ongoing participation appears to be necessary for meaningful, sustained effect.