Assessment of Bone Geometry in Postmenopausal Women with Osteoporosis of the Spine Before and After a 6 Month Aquatic Exercise Program

Abstract

<p>Background: Increased physical activity has a modest effect on the spatial distribution of bone mineral. The risks and benefits of exercise for women with osteoporosis at high risk to fracture are not known. The decompression of aquatic exercise is an option to increase exercise compliance. The dual energy absorptiometry (DXA) vertebral fracture assessment (VFA) images 2D bone geometry however measurement properties have not been established for this outcome.</p> <p>Purpose: To determine relative and absolute intra-rater reliability of DXA-based vertebral height (VH) measures and to assess the feasibility of investigating bone outcomes in women with established osteoporosis before and after a 6 month aquatic exercise program.</p> <p>Methods: DXA VFA scans of 32 women over 60 years old were analyzed on 2 occasions, 4 weeks apart. Relative reliability, intraclass correlation coefficient (95% CI) and absolute reliability, standard error of measurement (95% CI) were estimated for visible anterior, middle and posterior VHs from T4 to L4. Women with osteoporosis at high risk to fracture (clinical practice guidelines used) were recruited from two osteoporosis clinics. Feasibility of recruitment, adherence to the exercise, adherence to the assessment protocols (DXA, pQCT, physical performance measures), safety and retention were assessed.</p> <p>Results: Intra-rater reliability ICC >0.87 (0.74, 0.94) and SEM <1.17 from T10 to L4. Recruitment of 9 women in 10 weeks; average adherence 68%; pQCT data loss 46%; 1 fracture after class; retention 89% at 12 months.</p> <p>Conclusion: Further study of measurement properties of VH and protocols for recruitment, data management and safety are required.</p>