Systemic lupus erythematosus (SLE) patients with chronic renal failure who are using anticoagulants or antiepileptics are at higher risk for osteoporosis and fragility fractures, according to a study, “Risk factors for osteoporosis and fragility fractures in patients with systemic lupus erythematosus,” published in the journal Lupus Science & Medicine.

Osteoporosis (OP) and fragility fractures (FFx) are a known comorbidity in SLE patients, and glucocorticoid (GC) therapy is thought to play a central role in OP predisposition. Evidence from studies also reveal that the thresholds of vertebral bone mineral density (BMD) for FFx are higher at any site in women under chronic GC treatment, compared with other postmenopausal women.

To examine the prevalence of osteoporosis and fragility fractures in a cohort of SLE patients, and the risk factors associated with both osteoporosis and fragility fractures, Marta Mosca from the Department of Clinical and Experimental Medicine, University of Pisa in Italy, and colleagues collected data from 186 patients. Of these, 175 were women and 11 were men, with a mean age of 46.4 years and mean disease duration of 14.9 years.

All patients had been treated with glucocorticoids for at least six months prior to inclusion in the study. A total of 155 took 500mg calcium and vitamin D supplements. In addition to a detailed clinical assessment, patients were examined with dual-energy X-ray absorptiometry for bone mineral density (BMD) of the lumbar spine and non-dominant hip (total hip and femoral neck).

Patients’ mean serum value of Calcifediol (or 25-hydroxyvitamin D, 25OH-D) was of 21.8 ng/mL, and serum calcium was of 9.3 mg/dL. Vitamin D deficiency was observed at least once in 147 patients, 97 patients were fully vitamin D deficient, and 50 patients had insufficient levels of vitamin D. The results revealed that at their last visit, 97 patients (52.2 percent) had a reduced bone mineral density and 52 (27.9 percent) had osteoporosis. A total of 22 patients (11.8 percent), all women, had at least one fragility fracture, and six (27.3 percent) of them were premenopausal. Of the patients with fragility fractures, 45.5 percent had a history of anticoagulant use, 27.3 percent had been treated with antiepileptic medication, and 27.3 percent had chronic renal failure.

Results from univariate analysis showed that age, cumulative glucocorticoid use, therapy with antiepileptic medications, and cumulative use of anticoagulants were correlated with osteoporosis. After multivariate logistic regression, the association remained consistent for age, postmenopausal status, and antiepileptic therapy. Levels of 25OH-D at last observation were not correlated with bone mineral density values.

“In conclusion, low BMD is frequently observed in patients with SLE chronically treated with GC, with FFx additionally observed also in premenopausal patients. A higher risk profile for OP and FFx seems to be related with age, disease duration, post-menopausal status and the cumulative GC dose as well as the presence of CRF and a chronic treatment with AC or antiepileptics,” the researchers wrote.