Endocrine Abstracts

Bone loss in treated Addison’s disease (autoimmune hypoadrenalism) is often attributed to supraphysiological doses of glucocorticoid. The largest international survey to date (N=613) suggests that other factors are also likely to be associated with bone loss in these patients and that an intrinsic risk of bone loss in autoimmune hypoadrenalism cannot be ruled out. This survey also found significant rates of osteoarthritis among autoimmune hypoadrenalism patients. 13% of patients with autoimmune adrenal failure reported osteoporosis or osteopaenia (N=82). A further 12% reported osteoarthritis (N=73). A well-matched control group (N=612) reported less than 2% osteoporosis/osteopaenia and 3% osteoarthritis.¹ Analysis of the reported glucocorticoid dosage and years since diagnosis for those with osteoporosis/osteopaenia identified no significant correlation (correlation=0.06). Only 20% were on doses >30 mg hydrocortisone per day; whereas 34% were on doses of 20 mg or less. This is well below the mean dose (26 mg hydrocortisone) for the patient sample as a whole. 9% had both been diagnosed less than five years ago and took 20 mg hydrocortisone per day or less. Other researchers have identified an intrinsic risk of bone loss for diabetes (Selby PL, 1988), rheumatoid arthritis (Mueller MN 1976) and asthma (Reid DM et al. 1986). These factors do not appear to be correlated for the patients in this survey; premature ovarian failure, gender and age appear to be only weakly associated. Loss of adrenal androgens has been implicated in glucocorticoid-induced bone loss (Hampson G et al. 2002). Our data, drawn from the largest international survey of autoimmune hypoadrenalism to date, suggests that loss of adrenal androgens deserves analysis as a factor potentially contributing to an intrinsic risk of bone loss in autoimmune hypoadrenalism and that there is merit to screening patients for bone loss early in the course of their disease.

¹The control group were matched by age, gender. DEXA scans would undoubtedly reveal higher rates of steoporosis/osteopaenia among both groups. Hypoadrenalism patients are not routinely offered a bone scan in any of the countries participating in this survey.