Adrenal effects of teriparatide in the treatment of severe postmenopausal osteoporosis

Summary The aim of our study was to investigate the effects of teriparatide on the hypophysis–adrenal axis in postmenopausal women. Treatment with teriparatide increased plasmatic and urinary levels of cortisol after 6 and 12 months. Our paper demonstrates a possible direct secretagogue effect of teriparatide on adrenals in osteoporotic postmenopausal women. Introduction Teriparatide, recombinant human parathyroid hormone (1-34) (rhPTH [1-34]), is approved for the treatment of osteoporosis in men and postmenopausal women at high risk for fracture. In literature, data regarding the secretagogue effect of PTH on adrenocortical cells are present on in vitro, but not on in vivo, studies. The aim of our study was to investigate the effects of teriparatide on the hypophysis–adrenal axis in postmenopausal women. Methods Twenty postmenopausal women with severe osteoporosis were treated with teriparatide in a regimen of 20 μg daily, self-administered injections at bedtime for 12 months and a calcium and vitamin D supplementation. At the same time, 20 osteopenic women matched for age and body mass index with the patients were enrolled and treated only with calcium and vitamin D. In all subjects, calcium, adrenocorticotropic hormone (ACTH), and plasmatic and urinary cortisol were evaluated at baseline and after 6 and 12 months. Results Treatment with teriparatide increased plasmatic and urinary levels of cortisol after 6 and 12 months, reaching statistical significance only after 1 year. Plasmatic levels of ACTH did not change significantly. Conclusions Our paper, for the first time, demonstrates a possible direct secretagogue effect of teriparatide on adrenals in osteoporotic postmenopausal women.