A woman seeks your advice. She is peri-menopausal, 49 years old and getting hot flushes, which are tolerable. She did not have any menstrual periods for the six years she was at university and in the cross-country orienteering team. Two of her cousins have breast cancer. Her mother died post-operatively after a fractured neck of femur at age 64 years, sustained slipping in the supermarket. Her children are 10 and 14 years old. She wants to remain fit and healthy 'to look after my grandchildren, so I don't want breast cancer or osteoporosis!'
What is osteoporosis?
What should you ask and what tests should you do?
What can she do to reduce her risk?
Osteoporosis is a major problem with one in three women aged over 50 years and one in twelve men having one or more osteoporotic fracture.1 The classic osteoporotic fractures are hip, vertebral and wrist fractures. The cost of osteoporotic fracture is high. For example, the cost for hip fractures worldwide is estimated to be US $34 800 million in 1990 and to reach $131 500 million in 2050.2 The lifetime risk in the United States for a hip, spine or forearm fracture at the age of 50 years has been estimated to be 40% in women and 13% in men.3 In Sweden, the corresponding figures are 46% for women and 22% for men. Women need to understand the multifactorial aetiology of osteoporosis in order to maximize their bone strength in the post-menopausal period (Figure 44.1).
Pathogenesis of osteoporosis: LBM = low bone mass.
Osteoporosis is defined in a National Institutes of Health consensus statement as 'a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture'.4 Bone strength reflects the integration of two main features: bone density and bone quality. Bone density is expressed as grams of mineral per area or volume and, in any given individual, is determined by peak bone mass and amount of bone loss. Bone quality refers to architecture, turnover, damage accumulation (for example, microfractures) and mineralization.
On the basis of the measurement of bone mineral density (BMD) (Table 44.1), the World Health Organization's definitions, applied to post-menopausal women, result in 30% of this population being classified as having osteoporosis.5 The T-score is that number of standard deviations (SD) by which the bone in question differs from the young, normal mean.
Table 44.1Definitions of osteoporosis according to the World Health Organization |Favorite Table|Download (.pdf) Table 44.1 Definitions of osteoporosis according to the World Health Organization
|Description ||Definition |
|Normal ||A person has a BMD value between –1 SD and +1 SD ...|