Hormone Replacement Therapy (HRT) or etidronate for osteoporosis in postmenopausal asthmatics on glucocorticoids: a randomised factorial trial

Introduction The study was designed to establish the effects of HRT on osteoporosis and fractures over five years in postmenopausal women with asthma receiving regular glucocorticoids and to compare with etidronate.

Methods Postmenopausal patients receiving inhaled and/or oral glucocorticoids were randomly assigned to HRT, cyclical etidronate, HRT plus cyclical etidronate or no treatment for five years. The trial was multi-centre and aimed to recruit 750 patients. Outcomes were fractures and changes in bone mineral density (BMD).

Results For reasons detailed in the discussion section of the text, only 50 patients were entered. Three did not fulfil the eligibility criteria and were excluded from the analysis. Among the remaining 47 patients, three (6%) experienced new, symptomatic fractures, one on etidronate and two in the no treatment group. New or worsening morphometric fractures of the thoracolumbar spine occurred in 50% of the 22 patients with spinal radiographs on entry and at five years (one HRT, three etidronate, two HRT plus etidronate and five on no treatment). BMD improved by approximately 1% per annum in those receiving HRT and/or etidronate; comparisons of HRT vs no HRT tended to favour HRT but were only statistically significant at proximal femur. The same trends emerged in the etidronate vs no etidronate comparison, but none reached the 5% level of statistical significance.

Discussion For postmenopausal patients receiving glucocorticoids for asthma, HRT appears as effective as etidronate in preventing loss of BMD over five years and may have a similar effect on fracture prevention.