Accelerated Bone Loss in Older Men: Effects on Bone Microarchitecture and Strength

Abstract

Accelerated bone loss (ABL) shown on routine dual-energy X-ray absorptiometry (DXA) may be accompanied by microarchitectural changes, increased cortical porosity, and lower bone strength. To test this hypothesis, we performed a cross-sectional study and used high-resolution peripheral quantitative computed tomography (HR-pQCT) scans (Scanco Medical AG, Brüttisellen, Switzerland) to measure estimated bone strength and microarchitecture in the distal radius and distal and diaphyseal tibia. We studied 1628 men who attended the year 14 exam of the Osteoporotic Fractures in Men (MrOS) study. We retrospectively characterized areal bone mineral density (aBMD) change from the year 7 to year 14 exam in three categories: "accelerated" loss, ≥10% loss at either the total hip or femoral neck (n = 299, 18.4%); "expected" loss, <10% (n = 1061, 65.2%), and "maintained" BMD, ≥0% (n = 268, 16.5%). The ABL cut-off was a safety alert established for MrOS. We used regression models to calculate adjusted mean HR-pQCT parameters in men with ABL, expected loss, or maintained BMD. Men who experienced ABL were older and had a lower body mass index and aBMD and experienced greater weight loss compared with other men. Total volumetric BMD and trabecular and cortical volumetric BMD were lower in men with ABL compared with the expected or maintained group. Men with ABL had significantly lower trabecular bone volume fraction (BV/TV), fewer trabeculae, and greater trabecular separation at both the distal radius and tibia than men with expected loss or who maintained aBMD, all p trend <0.001. Men with ABL had lower cortical thickness and lower estimated bone strength, but there was no difference in cortical porosity except at the tibia diaphyseal site. In summary, men with ABL have lower estimated bone strength, poorer trabecular microarchitecture, and thinner cortices than men without ABL but have similar cortical porosity. These impairments may lead to an increased risk of fracture. © 2018 American Society for Bone and Mineral Research.

External Bone Size Is a Key Determinant of Strength-Decline Trajectories of Aging Male Radii

“…Thus, the low strength of elderly male radii arose through different strength‐decline trajectories: The narrow radii showed low strength for young adults that was maintained with age, whereas the wide radii showed high strength for young adults, much of which was lost with age. Whole bone strength of elderly individuals varies with many factors such as sex, ethnicity/race, weight loss and frailty, and rates of bone loss . The current study provided evidence that external bone size also affects the strength of elderly male radii by influencing bone strength‐decline trajectories.…”

“…Whole bone strength of elderly individuals varies with many factors such as sex, (49)(50)(51)(52) ethnicity/race, (53) weight loss and frailty, (54) and rates of bone loss. (55) The current study provided evidence that external bone size also affects the strength of elderly male radii by influencing bone strength-decline trajectories. The biomechanical mechanisms that define how structural and material changes contributed to the different strengthdecline trajectories (Fig.…”

Biomechanical and tomographic differences in the microarchitecture and strength of trabecular and cortical bone in the early stage of male osteoporosis

“…Levels of plasma testosterone were quantified according to a previous method [31]. After surgery for 4 weeks, blood was collected from a tail vein of rats.…”

Comparison of periprosthetic bone remodeling after implantation of anatomic and tapered cementless femoral stems in total hip arthroplasty

“…Although innovative techniques as bone microarchitecture analysis (BMA) and high-resolution peripheral quantitative computed tomography (HRpQCT) have been developed to provide not merely BMD, but also more detailed information about the bone microarchitectural properties, DXA remains the most widely used and most thoroughly studied bone density measurement technology in research as well as in clinical practice. [ 35 , 36 ] As a sensitive technique for determining BMD, DXA may actually detect the minor changes of periprosthetic BMD after THA, and facilitate the evaluation of periprosthetic bone remodeling. [ 22 , 37 ] We will use the metal removal analysis algorithms of the Hologic Discovery instrument (Hologic Inc, Waltham, MA) to measure the periprosthetic BMD in 7 conventional regions of interest (ROIs) based on Gruen zones, which is the most often used protocol in evaluation of bone remodeling after the implantation of conventional femoral stems.…”