AB0714 THE ROLE OF AGE, DURATION OF THE DISEASE AND CUMULATIVE GLUCOCORTICOID DOSE IN THE FORMATION OF DISORDERS OF THE STRUCTURAL AND FUNCTIONAL STATE OF BONE TISSUE IN MEN WITH ANKYLOSING SPONDYLITIS
Authors: S. Shevchuk, O. Pavliuk
Journal: Annals of the Rheumatic Diseases (2020)

Background: In recent years, it is becoming increasingly clear that osteoprosis (OP) holds the important place among complications of ankylosing spondylitis (AS). The frequency of emergence of OP, according to the data of last investigations, ranges from 18.7 to 62%, osteopenic syndrome – from 50 to 92%. It is known that decrease of bone mineral density (BMD) in patients with AS is caused not only by the action of traditional risk factors (age, sex, genetic predisposition, low body mass, and others) but also by the action of factors associated with the disease itself such as: duration of AS, activity of the inflammatory process, administration of glucocorticoids (GC), deficiency of Vitamin D, low physical activity of patients and so on. However, until now there are no clear data about the role of each of them in the formation of disorders of bone metabolism in men with AS. In the Ukrainian population of patients with AS such investigations have not been conducted. Objectives: To investigate the role of age, duration of disease and cumulative glucocorticoid dose in the formation of disorders of bone mineral density (BMD) in men with AS. Methods: The investigation of 108 men with AS at the age of 40.74 ± 0.87 years and 25 normal control subjects of the same age and sex has been carried out. The diagnosis of AS was established on the basis of modified New York criteria. BMD of the lumbar spine and femoral neck was determined by dual-energy X-ray absorptiometry on the apparatus ‘Hologic Discovery Wi’ (S / N 87227). The diagnosis of osteoporosis in men over 50 years was considered in case of decrease of BMD by T-score ≤ – 2.5 SD, osteopenia corresponded to T-score from –1 to –2.5 SD, for men under the age of 50, the Z-score was used, and its decrease ≤ – 2.0 SD and more indicated the significant loss of bone mass. Results: A decrease of BMD at the level of the lumbar spine and femur neck was found in 61 (56.5%) patients, of these 29 (27.7%) had osteoporosis, 31 (29.5%) had osteopenia. In the control group, decrease of BMD was detected in 6 (24%) patients, of these osteoporosis was diagnosed in 1 (4%), and osteopenia was diagnosed in 5 (20%) patients. In the age group of below 35 years, 18 (64.3%) patients had a decrease in BMD, 35 (56.5%) patients – in the 36-55 age group, and 8 (53.3%) patients – over the age of 45. The index of BMD also did not differ significantly between the groups. As for the duration of the disease, the largest proportion of 33 (75%) patients with decreased BMD was found in the group of patients with duration of the disease from 5 to 10 years. In the group of patients with duration of the disease up to 5 years, patients with decrease in the Z-score were 11 (55%), and in the group with duration of the disease more than 10 years - 17 (41.6%) patients. Decrease of BMD was associated with cumulative glucocorticoid dose . In particular, in the group of patients with a cumulative dose of glucocorticoids less than 12.6 g Z-score at the level of the lumbar spine was -0.98 ± 0.17 SD, in the group with a cumulative dose of GC 12.6-21.6 g Z-score was equal to –0.43 ± 0.40 SD, and in the group with cumulative glucocorticoid dose – above 21.6 g the Z-score was –1.69 ± 0.30 SD. As the glucocorticoid dose increased, the proportion of patients with decreased BMD increased. In the group of patients with the highest dose of GC there were 67.7% such patients, while in the group with the lowest dose – only 30 (57.6%). Significant correlation (r = -0.24) was established between Z-score of the lumbar spine and the total dose of GC. Conclusion: In 61 (56.5%) patients with AS decreased BMD at the level of the lumbar spine and neck of the femur is revealed. Decrease of BMD in patients with AS does not depend on the age and duration of the disease, but is associated with the cumulative dose of GC. Disclosure of Interests: Sergii Shevchuk Grant/research support from: Celltrion, Inc, Oksana Pavliuk: None declared