The Comparative Efficiency Of Denosumab Treatment In Patients With Postmenopausal Osteoporosis, Primary Hyperparathyroidism And Glucocorticoid-Induced Osteoporosis In Real Clinical Practice

Background: Denosumab is a highly effective and safe first-line treatment for osteoporosis. Primary hyperparathyroidism is a prevalent condition found in patients with osteoporosis. However, data regarding effectiveness of denosumab treatment in patients with PHPT are scarce. Aims: To estimate the comparative effects of denosumab to treat postmenopausal osteoporosis (PMO) and osteoporosis caused by primary hyperparathyroidism (PHPT) or glucocorticoid-induced osteoporosis (GIOP) in postmenopausal women in routine clinical practice. Materials and methods: Retrospective study based on the medical card records. Patients over 50 years of age with verified osteoporosis (based on bone mineral density (BMD) T-score ≤ -2.5 SD and/or low-trauma fracture), who had at least 3 denosumab injections were included in the study. Results: 162 patients were included and divided into three groups according to the etiology of osteoporosis. The first group consisted of postmenopausal women with osteoporosis (PMO) [(n=85); median age 70 [64;78]]. Patients with glucocorticoid-induced osteoporosis (GIOP) were enrolled in the second group [(n=16); male to female ratio =1:15; median age 60 [57,8; 66,3]]. The third group consisted of patients with PHPT and osteoporosis [(n=61); male to female=2:59; median age 68 [63; 75]]. Among all patients, denosumab treatment significantly increased BMD and decreased serum levels of calcium and CTx compared with baseline. PMO: the median increase in BMD according to the T-score was L1-L4 0,6 (p<0,001), femoral neck 0,2 (p<0,001); serum calcium -0,04 (p=0,004). PHPT: the median increase in BMD according to the T-score was L1-L4 0,6 (p<0,001), femoral neck 0,2 (p<0,001); radius 33% 0,25 (p=0,002), serum calcium -0,04 (p<0,001). In patients with GIOP, denosumab increased BMD in the lumbar spine L1-L4 0,5 (p=0,004). There was no difference in BMD increase or in levels of bone turnover suppression between the groups. A marked decline in levels of serum calcium was noted among patients with GFR less than 60 ml / min / 1.73 m2 (median Δ Са serum=0,24 p<0,001), compared to patients without CKD (median Δ Са serum=0,08 p<0,001).Conclusion: Denosumab treatment is similarly effective for increasing BMD and decreasing bone turnover markers in patients with PMO and PHPT among postmenopausal women. The hypocalciemic effect of denosumab is most significant in subjects with PHPT.