Track and Field Practice and Bone Outcomes among Adolescents: A Pilot Study (ABCD-Growth Study)

BACKGROUND: Osteoporosis is considered a public health problem with high worldwide prevalence. One approach to prevention is through the promotion of physical activity, especially exercise, during adolescence. METHODS: This study compared bone variables in different body segments in adolescents according to participation in track and field. The study included 34 adolescents (22 boys), of whom 17 were track and field athletes and 17 were control subjects. Bone mineral density (BMD, g/cm2) and bone mineral content (BMC, g) were analyzed using dual energy X-ray absorptiometry (total body stratified by body segments). Peak height velocity was used to estimate somatic maturation. RESULTS: Athletes had higher BMD (P=0.003) and BMC (P=0.011) values in the lower limbs and higher whole body BMD (P=0.025) than the control group. However, when adjusted for confounding factors, the difference was not maintained. The groups had similar lean soft tissue values (P=0.094). Training overload was positively correlated with BMD in the upper limbs (r=0.504; 95% confidence interval, 0.031-0.793). Although track and field athletes had higher BMD and BMC values in the lower limbs, these differences were not significant when adjusted for confounding factors. CONCLUSIONS: Track and field participation in adolescence appears to influence BMD and BMC in lower limbs, and fat-free mass seems to mediate this effect. Also, higher training loads were found to be positive for bone health in upper limbs.

A Case of Aortic Valve Rereplacement due to Complications of Autoimmune Hemolytic Anemia / 日本心臓血管外科学会雑誌

A 64-year-old man who underwent aortic valve replacement with a 25mm Bjork-Shiley valve in 1993 began to have severe anemia and required repeated transfusions by November 2003. Doppler echocardiography showed only mild aortic regurgitation, but revealed turbulent flow around the mechanical valve. Autoimmune hemolytic anemia (AIHA) was diagnosed and he was treated with prednisolone (PSL) starting May 2004. Because of unremitting hemolysis requiring multiple transfusions and the occurrence of renal dysfunction, he underwent rereplacement of the aortic valve with a 25-mm Freestyle valve. His hemolysis and general condition immediately improved. This case suggests the possibility that mild regurgitant jet and turbulent jet stress can cause severe hemolysis when AIHA develops.