Bone Abstracts

Introduction: Most studies to date have focus on the effect of exercise interventions on bone remodeling. Furthermore, inflammation has been associated with those critical for bone physiology and remodeling. However, investigations analyzing the relationship between objective physical activity and bone metabolism and inflammatory markers and the potential interactions with BMD and body composition in older men are limited, which is the aim of the present study.

Methods/design: Cross-sectional study (approved by local Ethical Committee) of serum osteocalcin, CTX, OPG and RANKL, hs-CRP, IL6, TNF-α, and IFN-γ measured in 35 older men (age 61–79 years): lower physically active (LPA, n=17) group, higher physically active (HPA, n=18); BMD and body composition were assessed by DXA. Seven-day moderate to vigorous intensity physical activity (MVPA) was measurement by accelerometers and aerobic capacity with the 6-min walk test. Dietary intake was assessed using 4-day diet records.

Results: Lumbar spine and femoral neck BMD did not differ between activity groups. Hs-CRP, RANKL and IL6 were higher in the LPA group (P<0.05). HPA group was more aerobically fit (P=0.004) and had less body fat (P=0.036) then the LPA group. MVPA and aerobic capacity were not correlated with BMD. There was a significant inverse correlation between MVPA and hs-CRP (r=−0.424, P=0.04), RANKL (r=−0.506, P=014), and IL6 (r=−0.433, P=0.038). Aerobic capacity was also negatively correlated with hs-CRP. Unexpected, OPG was negatively correlated with MVPA (r=−0.463, P=0.026) and aerobic capacity (r=−0.451, P=0.031).

Conclusion: These data provide preliminary evidence that daily MVPA may induce suppression of hs-CRP, RANKL and IL6. Additional studies with larger sample sizes will be needed to explore the association between MVPA and OPG and to determine the potential mechanism by which exercise may correlate negatively with OPG-RANKL-RANKL system.