Background:Teriparatide has been shown to increase spine and hip bone mineral density (BMD) and to reduce vertebral and non-vertebral fractures. (1) It is currently not clear whether the effect of teriparatide is dependent on the baseline risk of fracture or osteoporosis (OP) type, a finding that could have an impact on our therapeutic decision.Objectives:Investigate if there is a relationship between teriparatide effect in BMD and baseline 10-year fracture probability, assessed using FRAX®, in primary and secondary OP patients.Methods:This is a longitudinal, retrospective study including consecutive patients with the diagnosis of OP treated with teriparatide for 24 months, with a ten-year follow-up period, at our rheumatology department. Demographic, clinical, laboratorial, BMD and occurrence of fracture data were collected. The 10-year risk of osteoporotic fracture was estimated using the fracture risk assessment tool (FRAX) v 4.1 with the Portuguese population reference. Statistical analysis was performed using the software SPSS 23.0. Correlations between continuous variables were evaluated with spearman coefficient. p<0.05 was considered statistically significant.Results:Eighty patients (88.8% female, median age 65.00 (59; 75)) were included. Forty-nine patients (61.3%) has secondary OP, mainly of cortisonic etiology (61.2%, n=30). Before treatment, median lumbar spine BMD was 0.870 [0.767, 0.964] g/cm2, median T-score of -2.60 (-3.30, -1.90); median total femur BMD was 0.742 [0.667, 0.863] g/cm2, median T-score of -2.10 (-2.80, -1.30); median femoral neck BMD was 0.671 [0.611, 0.787] g/cm2, median T-score of -2.50 [-3.20, -1.85]. Regarding fracture risk, median FRAX-based 10-year major fracture risk (with BMD) at baseline was 16% [10.0; 23], and median hip fracture risk was 7.2% [3.4; 13.8].The median variation of BMD, after finishing teriparatide treatment, in the spine was 0.107 [0.029; 0.228]; median BMD variation in total femur was 0.013 [-0.013; 0.068] and median BMD femoral neck was 0.046 [-0.002; 0.109]. We observed a numerically superior effect, albeit without any statistical significance, of teriparatide on bone mineral density gain in secondary OP (versus primary OP) at lumbar spine, total femur and femoral neck.Most patients continued anti-osteoporotic treatment with a bisphosphonate (81.2%, n=65) and, during follow-up, 17 patients had an incident fracture (8 hip fractures and 6 vertebral fractures), median of 5 [1.75, 8.25] years after ending teriparatide.We found a discrete correlation between FRAX-based hip fracture probability and the variation of bone mineral density in total femur (Spearman’s coefficient 0.248, p = 0.04). There was no correlation between FRAX-based major fracture probability and and the variation of bone mineral density in the spine or femur. When we separately analyze the relationship between the variation in total hip BMD and the FRAX-based fracture risk, depending on whether it is a secondary or primary OP, we find that the correlation is stronger and only remains in secondary OP (Spearman’s coefficient 0.348, p = 0.03).Conclusion:Our data suggest that teriparatide could be an important weapon in the treatment of secondary cause OP, particularly cortisonic, and in patients at high fracture risk, although further larger studies are needed to confirm these findings.References:[1]Kendler DL, Marin F, Zerbini CAF, Russo LA, Greenspan SL, Zikan V, Bagur A, Malouf-Sierra J, Lakatos P, Fahrleitner-Pammer A, Lespessailles E, Minisola S, Body JJ, Geusens P, Möricke R, López-Romero P. Effects of teriparatide and risedronate on new fractures in post-menopausal women with severe osteoporosis (VERO): a multicentre, double-blind, double-dummy, randomised controlled trial. Lancet. 2018 Jan 20;391(10117):230-240. doi: 10.1016/S0140-6736(17)32137-2.Disclosure of Interests:None declared.
Impact of serum magnesium and bone mineral density on systemic fractures in chronic hemodialysis patients
