AB0818 INCIDENCE OF FRACTURES AND ASSOCIATED RISK FACTORS DURING THE DRUG HOLIDAYS PERIOD WITH BISPHOSPHONATES
Authors: Laura Bautista, Angel Delgado Zamorano, Asunción Salmoral, Inmaculada Gómez Gracia, Ladehesa Pineda Lourdes, Pérez Sánchez Laura, Gómez García Ignacio, Font Ugalde Pilar, María del Carmen Castro Villegas, Alejandro Escudero Contreras, Eduardo Collantes Estevez
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Biphophosnates are the most widely used treatment for osteoporosis. The optimal treatment duration, however, remains unclear. The occurrence of adverse effects, such as osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFF), has raised the issue of bisphosphonate discontinuation ("drug holiday") after a certain treatment period. <h3>Objectives</h3> To assess the incidence of fractures in patients during the drug holidays period with bisphosphonates, as well as to determine the risk factors are associated to it. <h3>Methods</h3> Analytical, observational, longitudinal, and ambispective study of a cohort of patients with postmenopausal osteoporosis or men over 50 years of age treated with oral bisphosphonates (at least for 5 years) or intravenous (at least for 3 years) and who had been at least for one year in a drug holidays period, from 01/01/2012 to 12/31/17. Patients treated with corticosteroids and/or with diseases with effects on bone metabolism were excluded. Statystical analysis included a descriptive study of the variables to assess the association between the incidence of fractures and various risk factors, as well as univariate and multivariate Cox regression analysis. <h3>Results</h3> 128 patients with osteoporosis were studied, of wich 19 (14.7%) suffered an osteoporotic fracture during the follow-up. Bivariate analysis showed in the group of patients with fractures a higher proportion of smoking patients (p = 0.004), osteopening treatment (p = 0.005) and a femoral neck t score lower at the beginning of the drug holidays period -2.07 (0.68) vs - 1.58 (0.63), p = 0.008. In addition, there was a higher proportion of patients with fracture with moderate risk before the start of the drug holidays period (p = 0.007). The fracture survival curves were lower in patients older than 75 years (p = 0.04). When applying the same treatment, for each year increase, the risk of fracture was increased by 6% (p = 0.04), while, for the same age, this risk was increased 4.33 times in patients who were treated with Risedronate versus those with Alendronate (p = 0.05). The multiple regression analysis showed that vertebral fracture was independently associated with Tabaco (HR 4,28 p=0,047). <h3>Conclusion</h3> Based on our results, it would be useful to follow closely those patients during drugs holidays period who are smokers, older than 75 years, with osteopening treatment, who present a low femoral neck tscore and/or have been previously treated with Risedronate. <h3>References</h3> [1] Silverman SL, et al. Osteoporos Int. 2016;27 (3):849-852. [2] Bindon B, et al. Endocr Pract. 2018;24(2):163-169. [3] Mignot MA, et al. Osteoporos Int. 2017;28(12):3431-3438. <h3>Disclosure of Interests</h3> Laura Bautista: None declared, Angel Delgado Zamorano: None declared, Asunción Salmoral: None declared, Inmaculada Gómez Gracia: None declared, Ladehesa Pineda Lourdes: None declared, Pérez Sánchez Laura: None declared, Gómez García Ignacio: None declared, Font Ugalde Pilar: None declared, María del Carmen Castro Villegas Paid instructor for: MSD, Abbvie, Pfizer, Janssen, Lilly, Roche, Alejandro Escudero Contreras: None declared, Eduardo Collantes Estevez: None declared