Thursday, July 28, 2005

Do inhaled steroids cause osteoporosis? One case control article does not answer the question

A nested case control study published in The January 2005 issue of Chest and commented on in the July/August issue of the ACP Journal Club found no increase in non-vertebral fractures in a group of United Health Care patients. Although a nested case control study has theoretical advantages (limiting selection and recall bias) over a plain vanilla case control, the design of this study seemed destined to provide no new useful information to an important question. I say this because we are given data about low dose, short term use of inhaled corticosteroids (ICS) and only consider non-vertebral fractures. The concern with osteoporosis and fractures is with longer term steroid treatment in patients some of whom already are at higher risk of bone loss (COPD patients).
The commentary by Dr. Frank Thien correctly points out that "the endpoint of a nonvertebral fracture as a risk out come with[the time frame chosen] is unrealistic". "Realistic safety data require longer-term follow-up with accurate estimation of the effective delivered dose". It seems to me this article "answers" a question we really did not need to ask. We do not worry particularly about short term, low dose steroid in regard to osteoporosis less alone fractures.
The editorial in Chest quotes a meta-analysis regarding this issue which found increased risk of fractures and increased frequency of several surrogate markers of bone loss. It should not go unnoticed that the authors of the article failed to mention that systematic review.One could easily come away from the chest article ( not the editorial) with the impression that ICS are not a problem in regard to bones. This is clearly not the case and the editorial makes that clear. Patients on long term ICS for asthma or osteoporosis should be assessed for risk of bone loss, bone density measurements made when appropriate and preventive measures instituted. The complication of a painful spinal compression fracture in COPD patient is very serious and something doctors want to avoid. In this new day of greatly increased skepticism regarding articles sponsored by drug manufacturers, it should be noted that a manufacturer of an ICS product sponsored the Chest article. Two years ago I'll admit that the source of funding was not a fact that I looked for in medical articles but now I've gotten paranoid about it.

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