Hormonal Predictors Of Cardiovascular Outcomes And Mortality In Ageing Men: The Role Of Androgens And The IGF System.
Funder
National Health and Medical Research Council
Funding Amount
$125,035.00
Summary
As men age levels of testosterone and growth hormone fall while ill health increases. We do not know if low hormone levels directly cause heart disease. We will measure testosterone and IGF1, which reflects growth hormone, in 4,200 older men, and relate hormone levels to the future risk of ill health especially heart disease, stroke and large artery blockages. This will clarify whether low hormone levels increase risk of ill health, and the value of studies to test hormone therapy in older men.
Structural And Biomechanical Basis Of Differences In Bone Fragility In Asian And Caucasian Men And Women
Funder
National Health and Medical Research Council
Funding Amount
$188,500.00
Summary
Lay Summary Fractures occur less commonly in males than females because males have greater periosteal apposition than females during ageing. This increases bone size (reducing load per unit area - stress), and reduces net bone loss, more in males than females so that the increase in bone fragility with advancing age seen in both sexes is less in males than females. Few males than females have a fracture risk index for vertebral fractures (FRI or ratio of load-bone strength) above unity. The purp ....Lay Summary Fractures occur less commonly in males than females because males have greater periosteal apposition than females during ageing. This increases bone size (reducing load per unit area - stress), and reduces net bone loss, more in males than females so that the increase in bone fragility with advancing age seen in both sexes is less in males than females. Few males than females have a fracture risk index for vertebral fractures (FRI or ratio of load-bone strength) above unity. The purpose of this study is to define the structural and biomechanical basis responsible for the racial differences in fracture rates between Asians and Caucasians. Following the same biomechanical principles as published in Caucasian males and females, we hypothesise that racial differences in periosteal expansion during aging may contribute, in part, to the racial differences in bone fragility at the spine and hip. A cross-sectional study will be conducted in 500 healthy Chinese men and 500 Chinese women age ranged 18 to 90 years living in Melbourne, Australia. We have recruited larger numbers of Caucasian men and women in our Centre. BMD and bone size will be measured at the spine, hip and total body by using dual x-ray bone densitometer (DXA). Vertebral body width, depth, height, cross-sectional area (CSA), stress (load per unit CSA) and fracture risk index (load-strength) at the third lumbar vertebrae will be measured by PA and lateral scanning. Femoral neck periosteal-endocortical diameter, cortical thickness, cross-section moment of inertia (CSMI), section modulus buckling index will be measured by using hip structural analysis program. Just as insight into bone fragility in women has been obtained by studies in men, we believe that the results of this study will provide important insights into the pathogenesis of bone fragility in both racial groups.Read moreRead less