Diagnosis and management of osteoporosis

Abstract

Osteoporosis is a common condition characterised by low bone mineral density (BMD) and an increased risk of fragility fractures. It affects up to 30% of women and 12% of men at some point in their lives. Two of the most important risk factors are increasing age and female gender, although other common and potentially modifiable risk factors include long-term corticosteroid therapy, chronic inflammatory disease, malabsorption and untreated premature menopause. The diagnosis of osteoporosis can be confirmed by DEXA but this should only be performed in patients who have an increased risk of fracture on the basis of clinical risk factors. DEXA should be considered if the 10-year risk of major osteoporotic fracture is > 10%. If the BMD T-score values by DEXA at the lumbar spine, femoral neck or total hip are at or below -2.5 then the diagnosis of osteoporosis is confirmed. Vertebral fractures are generally taken as diagnostic of osteoporosis, even if spine BMD values are not in the osteoporotic range. Oral bisphosphonates are the first-line treatment. If they are contraindicated or not tolerated then parenteral therapy should be considered. There is evidence that fractures occur in glucocorticoid-induced osteoporosis at higher levels of BMD than in postmenopausal osteoporosis so therapy should be considered in patients with a BMD T-score of <-1.5. Although it is useful to have a DEXA scan before starting treatment to provide a baseline value to assess response, this investigation is not absolutely necessary to initiate bone protective therapy, especially in those aged above 65 since the vast majority of these patients will have a T-score of -1.5 or below. In younger individuals where BMD is likely to be higher DEXA is useful in determining if bone protective treatment is needed immediately or if it could be delayed until the T score falls below -1.5.