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To the Editor:

Grossman and colleagues are to be commended for the work they put into the 2010 American College of Rheumatology recommendations for the prevention and treatment of glucocorticoid-induced osteoporosis (Grossman JM, Gordon R, Ranganath VK, Deal C, Caplan L, Chen W, et al. American College of Rheumatology 2010 recommendations for the prevention and treatment of glucocorticoid-induced osteoporosis. Arthritis Care Res (Hoboken) 2010;62:1515–26). In categorizing risk based on major fractures (high risk is defined as ≥20% 10-year risk for major fractures) as calculated using the FRAX tool (FRAX. WHO Fracture Risk Assessment Tool. URL: http://www.shef.ac.uk/FRAX/), the authors appear to have overlooked the fact that, in FRAX, glucocorticoid use increases hip fracture risk more than major fracture risk. This results in patients being at high risk based on hip fractures (high risk is defined as ≥3% 10-year risk for hip fractures), but at intermediate risk based on major fractures (10–20% 10-year risk), and would likely result in patients being at intermediate risk for hip fracture, but low risk for a major fracture. For example, a 50-year-old white woman with no risk factors other than glucocorticoid use would be at high risk for hip fracture with a T score of −2.6, but would only reach the high-risk threshold for major fractures with a T score of −3.6.

Table 1 shows, as a function of age, T scores for women and men with a body mass index of 25 kg/m2 and no other risk factors in FRAX, at which hip and major fractures would register a high risk (using FRAX version 3.3). In each case, high risk is reached at a lower T score for hip fracture than for major fractures.

Table 1. T scores at which hip and major fractures would register as a high risk in patients with a body mass index of 25 kg/m2*
 Age, years
505560657075808590
  • *

    For the examples given for hip fracture risk, in some scenarios the risk is not exactly 3% but ranges between 2.9% and 3.2%.

White women         
 Hip fracture (2.9–3.2%)−2.6−2.4−2.2−2.0−1.6−1.1−0.6−0.2−0.3
 Major fracture (=20%)−3.6−3.1−2.6−2.4−2.1−1.9−1.3−1.3−2.2
White men         
 Hip fracture (2.9–3.2%)−2.3−2.1−2.0−1.8−1.5−1.0−1.3−0.2−0.6
 Major fracture (=20%)−3.4−3.1−2.9−2.9−2.8−2.8−2.7−2.9−4.0
African American women         
 Hip fracture (2.9–3.2%)−3.2−3.1−2.9−2.7−2.5−2.1−1.7−1.5−1.7
 Major fracture (=20%)−4.4−4.3−4.1−3.9−3.7−3.5−3.2−3.2−3.9
African American men         
 Hip fracture (2.9–3.1%)−2.9−2.9−2.8−2.7−2.6−2.3−1.9−1.9−2.4
 Major fracture (=20%)−4.3−4.2−4.3−4.5−4.6−4.6−4.6−4.8−6.1

It is important to recognize that patients receiving glucocorticoids consistently reach high risk for hip fracture before they reach high risk for major fractures.

Acknowledgements

Dr. Watts is Director and Cofounder of and owns stock and/or holds stock options in OsteoDynamics, and he has received consultant fees, speaking fees, and/or honoraria (less than $10,000 each) from Amgen, Novartis, Warner Chilcott, Baxter, Bristol-Myers Squibb, Imagepace, Lilly, Medpace, Merck, Orexigen, and Pfizer/Wyeth, research support from Amgen, Merck, and NPS, and has served as a paid consultant with investment analysts on behalf of Guidepoint Global, GLG, and Leerink Swann.

Nelson B. Watts MD*, * University of Cincinnati, Cincinnati, Ohio.