FRI0350 THE FREQUENCY OF LOW MINERAL DENSITY, FALLS AND FRACTURES IN PATIENTS WITH SYSTEMIC SCLEROSIS
Authors: Olga Dobrovolskaya, Nikolay Demin, Oxana Desinova, Natalia Toroptsova
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Systemic sclerosis (SSc) is a severe connective tissue disorder causing vascular, immune, and fibrotic changes in the skin and internal organs. Patients with SSc may have an increased risk of osteoporosis (OP) and fractures due to a chronic inflammatory state, latent malabsorption or malnutrition, immobilization, and use of corticosteroid therapy. Objectives: to determine the frequency of low mineral density, falls, low energy fractures and 10-year probability of new fracture in patients with SSc. <h3>Methods</h3> 191 patients with SSc were enrolled in the study: 160 women (mean age 51±13 yrs), among them 107 postmenopausal, and 31 men (mean age 53±14 yrs). Bone mineral density (BMD) was measured at lumbar spine (LS), femoral neck (FN) and total hip (TH) by dual energy X-ray absorptiometry (DXA, Hologic 4500A). BMD decreasing grade was determined in accordance to WHO criteria. All patients were interviewed on a special questionnaire and assessment of 10-year probability of new fracture by FRAX<sup>®</sup> was performed. Vitamin D level was measured in 104 patients. <h3>Results</h3> Low BMD was found in 68% women and 55% men: osteopenia in 30% and 32% and OP in 38% (21% in reproductive age and 50% in postmenopausal) and 23%, respectively. BMD in LS, FN and TH associated with body mass index (r=0,3, p=0,030; r=0,41, p=0,0027; r=0,49, p=0,0002, respectively) and duration of postmenopausal period in women (r=-0,56, p=0,023; r=-0,66, p=0,006; r=-0,63, p=0,009, respectively). BMD of LS and FN correlated with age (r=-0,22, p=0,045; r=-0,23, p=0,016, respectively), duration of SSc (r=-0,32, p=0,037; r=-0,31, p=0,046, respectively), glucocorticoid cumulative dose for LS only (r=-0,31, p=0,024). Mean 25(OH)D level was 19,83±11,06 ng/ml. Normal vitamin D level had 9% of SSc patients. No correlation between BMD and 25(OH)D level was found. 46 (24%) patients reported falls in the year prior to the interview, among them in 2 patients the fall led to fracture. A total of 48 (25%) patients had low energy fractures in the past, among them 8 (4%) of women had two or more fractures. Frequency of low energy fractures was 35%, 8% and 25% among postmenopausal women, women of reproductive age and men, respectively. The mean age at which the fracture occurred was 55±11 yrs. in postmenopausal women, 30±12 yrs. in young women and 60±12 yrs. in men. The most frequent were the fractures of distal forearm and vertebrae: 13 (7%) and 26 (14%) patients, respectively. Five patients each (3%) had ankle and humerus neck fractures and 7 – other localizations. Nobody reported the fracture of the proximal femur. Patients with abnormal BMD (OP or osteopenia) had a risk of falls and low energy fractures more than 2 times higher than patients with normal BMD (OR 2.93 [95% CI 1.11; 8.01], <i>p</i><i>=</i>0,016 and OR 2.58 [95% CI 1.04; 6.6], <i>p</i><i>=</i>0,025, respectively). 10-year probability of any major osteoporotic fracture was 18.4 ± 9.6% in women and 9.7 ± 8.6% in men and of hip fracture - 3.5 ± 3.7% and 1.5 ± 3.9%, respectively. Among all patients, 55% of women and 4% of men had a high risk of subsequent fractures using the FRAX® algorithm. <h3>Conclusion</h3> Low BMD was diagnosed in 68% of women and 55% of men with SSc. The correlations between BMD and age, body mass index, the duration of postmenopause were revealed. Additionally, we found associations with risk factors related to the disease itself: disease duration and glucocorticoid cumulative dose. Reduced BMD was associated with an increased risk of falls and fractures. 55% of women and 4% of men had a high risk of further fractures. <h3> Disclosure of Interests</h3> Olga Dobrovolskaya: None declared, Nikolay Demin: None declared, Oxana Desinova: None declared, Natalia Toroptsova Speakers bureau: Amgen, Lilly