Effects of current and discontinued XXXX replacement therapy on hip structural geometry: the study of @entity3604 .

@entity172 @entity1 @entity3604 @entity174 @entity604 @entity79
It is assumed that @entity172 influences bone strength and risk of @entity174 by affecting @entity79 ( @entity79 ). However, @entity172 may influence the mechanical strength of bones by altering the structural geometry in ways that may not be apparent in the density. Repeated dual energy X-ray absorptiometry (DXA) hip scan data were analyzed for bone density and structural geometry in elderly @entity1 participating in the @entity3604 ( @entity3604 ). Scans were studied with a hip structural analysis program for the effects of @entity172 replacement therapy (ERT) on @entity79 and structural geometry. Of the 3,964 @entity1 with ERT-use data, 588 used ERT at both the start and end of the approximately 3.5-year study, 1,203 had past use which was discontinued by clinic visit 4, and 2,163 @entity1 had never used ERT. All groups lost @entity79 at the femoral neck, but the reduced @entity79 among users of ERT was entirely due to subperiosteal expansion and not @entity604 , whereas both @entity604 and expansion occurred in past or nonusers. @entity79 increased 0.8%/year at the femoral shaft among ERT users but decreased 0.8%/year among nonusers. Section moduli increased at both the neck and shaft among ERT users but remained unchanged in past and nonusers. Current, but not past, use of @entity172 therapy in elderly @entity1 seems to increase mechanical strength of the proximal femur by improving its geometric properties. These effects are not evident from changes in femoral neck @entity79 .
