Users of low-dose glucocorticoids have increased bone loss rates: a longitudinal study.

Although high doses of glucocorticoids are believed to cause bone loss, the effects of low glucocorticoid doses are still controversial. Our study examined the effects of low-dose glucocorticoids on the rate of bone loss at three appendicular bone sites. The study population was a cohort of elderly Japanese-Americans, 1094 women and 1378 men. The women were all postmenopausal. At the baseline examination the mean age of the women was 64 years (range 45-81), and the mean age of the men was 68 years (range 61-82). Glucocorticoid users (19 women and 21 men) had used oral systemic or inhaled glucocorticoids on a regular schedule for more than 1 month (mean use was 2.1 years for the women and 1.9 years for the men). The most common dose was equivalent to 5 mg/day of prednisone; fewer than 15% of users had taken doses equivalent to 10 mg/day or more. Changes in bone mass at the calcaneus, distal radius, and proximal radius were documented using bone densitometry at 1 to 2-year intervals over an 8-year period. The initial bone mass of the glucocorticoid users and controls was similar at the baseline examination. The subsequent loss rates among females during glucocorticoid use, however, were approximately double that of the controls. Among males, bone loss rates during glucocorticoid use were 2-3 times that of controls for the calcaneus and radius sites. The differences between glucocorticoid users and controls persisted after adjusting for confounding variables such as age and use of thiazides and estrogens.(ABSTRACT TRUNCATED AT 250 WORDS)