Bone mineral density in retired rugby players: initial findings from the UK Rugby Health project

Abstract

Introduction Regular exercise that delivers impact forces to the skeleton are positively associated with bone strength. Athletes from high impact sports such as rugby have higher bone density than non-athletes ( Hind et al., 2015 ). Engaging in regular impact exercise is widely suggested as a means for reducing the risk of osteoporosis in later life ( Heinonen et al., 1996 ). However, to date there have been few studies of the bone density of retired athletes and none in retired rugby players. Objective To investigate bone mineral density (BMD) at the hip and spine, and the prevalence of low BMD, in a cohort of retired rugby players. Methods Retired rugby players (77 males; 25.8 years competitive rugby; 10.6 years since retirement; 36 former professional; 41 former amateur level) were separated into two groups: over 50 years of age (n = 27; 57.2 ± 7 years; 175.8 ± 7.6 cm; 94.9 ± 16.9 kg) and under 50 years (n = 50; 40.1 ± 6.2 years; 182.1 ± 6.4 cm; 101.9 ± 13.8 kg). Each participant received dual energy X-ray absorptiometry scans (Lunar iDXATM; GE Healthcare, WI; Encore software version 15.0) of the dual femur and the lumbar spine. BMD for the lumbar spine, femoral neck and total hip were derived. T-scores were evaluated for participants aged over 50 years, and Z-scores for those aged under 50 years ( ISCD, 2015 ). Results Eight (30%) retired players aged over 50 years had osteopenia (T-score Conclusion Our findings suggest that participation in high impact sports during young adulthood might not be sufficient to reduce the risk of osteoporosis in later life. Further research is needed to identify why some former rugby players have low BMD and others don't. This research would have the potential to inform assumptions on the role of exercise for bone health throughout the lifespan. Bone mineral density, T-scores or Z-scores for male retired rugby players, mean, SD (range) Retired rugby players aged Femoral Neck BMD (g.cm−2) n=50 Total Hip BMD (g.cm−2) n=50 Lumbar Spine BMD (g.cm−2) n=48† Hip Z-score n=49* Lumbar Spine Z-score n=47†* Lowest Z-score n=49* 1.135 ± 0.146 1.192 ± 0.151 1.319 ± 0.139 0.3 ± 1.1 0.3 ± 1.2 -0.1 ± 1.0 (0.814 – 1.502) (0.924 – 1.611) (1.040 – 1.677) (-1.7 – 3.5) (-2.1 – 3.3) (-2.1 – 3.5) *no reference score for n=1 participant (non-white) †n=2 lumbar spine scans unreportable due to Retired rugby players aged >50 years Femoral Neck BMD (g.cm−2) n=27 Total Hip BMD (g.cm−2) n=27 Lumbar Spine BMD (g.cm−2) n=20‡ Hip T-score n=27 Lumbar Spine T-score n=20‡ Lowest T-score n=27 1.018 ± 0.180 1.099 ± 0.179 1.226 ± 0.164 -0.4 ± 1.4 0.1 ± 1.4 -0.6 ± 1.2 (0.650 – 1.421) (0.699 – 1.459) (0.822 – 1.512) (-3.2 – 2.7) (-3.2 – 2.4) (-3.2 – 1.5) ‡n=7 lumbar spine scans unreportable due to