Background/Purpose:  Osteoporosis and osteoporotic fractures are significant comorbidities in patients with systemic lupus erythematosus (SLE). Hip fractures are being increasingly recognized as a complication of dialysis raising concern for similar events among patients with SLE who progress to end-stage renal disease (ESRD). The intention of this study was two-fold: (1) to compare the frequency of incident osteoporotic fractures in patients with ESRD with and without SLE, and (2) to identify risk factors for osteoporotic fractures in patients with SLE and ESRD.

Methods:  A retrospective cohort of adults starting dialysis between 2006-2008 enrolled in Medicare Part D without a previously filled prescription for osteoporosis medications were selected from the U.S. Renal Data System (USRDS). The International Classification of Diseases, 9th Revision (ICD-9) codes were used to identify patients in the hospital claims dataset with a diagnosis of SLE prior to starting dialysis. A 5% control sample was randomly selected for comparison due to a sizable proportion of patients without a diagnosis of SLE. Potential risk factors for osteoporotic fractures including demographic and clinical factors and medication use were determined using ICD-9 codes from hospital claims, Medical Evidence Report and Medicare Part D. Incident fracture was defined as an ICD-9 code for a non-traumatic, non-pathologic fracture within 5 years of follow-up. Fractures were grouped by location: upper extremity, lower extremity (excluding hip), hip and vertebral.

Results:  There were 1,311 (0.5%) patients starting dialysis between 2006-2008 with a diagnosis of SLE. After applying exclusion criteria and including random selection of 5% of controls, there were 649 patients with SLE and 3,992 patients in the control group. Fractures occurred in 10.5% of SLE patients compared to 11.9% of controls. In multivariable analyses, there was no significant difference in the incidence of osteoporotic fractures in patients with SLE compared with controls (p=0.08, RR 0.40, CI 0.66-1.08). Among patients with SLE, fractures of the hip were most common (46%) followed by those of the upper extremity (21%), vertebrae (19%) and lower extremity (14%). In the control group, fractures of the hip (49%) outnumbered those of the lower extremity (25%), upper extremity (17%) and vertebrae (9%). In multivariable adjusted analyses, female gender (p=0.05, RR 2.08, CI 1.00-4.32) and older age (p=0.03, RR 1.02, CI 1.00-1.04) were associated with increased fracture risk. However, race, ethnicity, dialysis type, tobacco and alcohol use, BMI, Charlson Comorbidity Index, prevalent fractures or medication use (corticosteroids, opioids, selective serotonin reuptake inhibitors, proton pump inhibitors, anticonvulsants, diuretics, sedatives, oral hypoglycemics) (p>0.10 for all) were not significantly associated with fracture risk.

Conclusion:  Patients with SLE and ESRD do not have an increased risk for osteoporotic fractures compared to patients with ESRD alone. Hip fractures are the most common fracture site in patients with SLE and ESRD. In patients with SLE and ESRD, female gender and older age are associated with increased fracture risk.

« Back to 2016 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/risk-factors-for-incident-fractures-in-patients-with-systemic-lupus-erythematosus-on-dialysis/