B6.052 Prework 4: Intro to Osteoporosis Flashcards
osteopenia
decreased bone mineral density
T score = -1 to -2.5
osteoporosis
osteopenia severe enough to significantly increase fracture risk
T score = less than -2.5
signals of osteoporosis
atraumatic or vertebral compression fracture
results of osteoporosis on bone
thinning of cortex
reduced trabecular bone mass
loss of trabecular connectivity
all contribute to elevated risk of fracture
key mediators of osteoporosis
resorption > formation
- defects in signaling
- age related changes
- endocrine related changes
when do you reach PBM
early adulthood after cessation of skeletal growth
when does bone mass start to decline
begins in 40s, resorption > formation
steady decline in skeletal mass
epidemiology of osteoporosis
ten million individuals > 50 yo have evidence of hip osteoporosis
1.5 x 10^6 osteoporotic fractures/year
lifetime risk, osteoporotic fracture after 50: 1/2 for women, 1/5 for men
sex differences in bone loss with aging
1) short phase (3-5 y post menopause): rapid loss of mainly trabecular bone in women
2) longer phase (10-20 y): slower loss (age-related bone loss), both cortical and trabecular compartments, women and men
reasons for sex differences in bone loss
bone architecture: boys have wider bones with thicker cortical regions
role of sex hormones in bone remodeling
factors associated with increased risk of osteoporosis in post menopausal women
age maternal history of fracture face- Hispanic and Asian current cortisone user current/former smoker
factors associated with decreased risk of osteoporosis in post menopausal women
elevated BMI regular exercise race- lower in AAs alcohol use current/former estrogen use
why does elevated BMI present a decreased risk of osteoporosis
mechanical stress inhibits sclerostin release, allows for increased bone formation
excess adipose presents with and increase in estrogen because of increased aromatase
primary osteoporosis
women with natural menopause and older men
secondary osteoporosis
result of other disease, condition, or drug induced