Factores relacionados con la respuesta inadecuada al tratamiento osteoformador (teriparatida/PTH 1-84) en pacientes con osteoporosis severa: resultados preliminares

The aim of this study was to evaluate the long-term bone mineral density (BMD) response rate to osteoanabolic treatment in patients with severe osteoporosis and the factors related to "inadequate" response (IR). Methods: 49 patients (46F:3M) with a mean age of 69.5 +/- 11.1 years treated with teriparatide (41) or PTH1-84 (8) during 18/24months were included (84% had vertebral fractures and 84% had previously received bis-phosphonates). Previous skeletal fractures and antiosteoporotic treatment, risk factors and cause of osteoporosis were recorded in all patients. Bone turnover markers (BTM) and 25-OH vitamin D (25OHD) levels were assessed before and at 3, 6, 12 and 18/24 months. Lumbar and femoral BMD and spinal X-ray were assessed at baseline and at 12 and 18/24 months. IR was defined by a lumbar BMD change <3% at 18/24 months. Results: 29% of patients showed IR to therapy. No significant differences were observed in age, baseline BMD and BTM and 25OHD levels between patients with or without IR. 92% of IR patients had been previously treated with bisphosphonates (vs 79%, p=0.34) during 7 +/- 4.8 years (vs 4.9 +/- 4.2 years, p=0.19). No significant differences were observed between groups in the magnitude of changes in BTM throughout the study. Conclusions: 29% of patients with severe osteoporosis presented IR to osteoanabolic therapy. Although no predictive factors related to this finding were identified, previous prolonged therapy with bisphosphonates may play a role.