Background High prolactin (PRL) levels have been reported in systemic lupus erythematosus (SLE) patients to be associated with disease activity; they have also been described in patients with chronic diseases like chronic renal failure and chronic liver disease. To our knowledge, an association between disease damage and PRL levels in SLE patients has not been previously evaluated.
Objectives To determine whether PRL levels are independently associated with disease damage in SLE patients.
Methods This cross-sectional study was conducted in consecutive SLE patients seen in our Rheumatology Department from January to December 2012. An interview, chart review, physical examination and laboratory tests were performed. SLE was defined using the revised and updated ACR criteria; disease activity was ascertained using the SLEDAI and disease damage with the SLICC/ACR damage index (SDI). Use of steroids was recorded as current dose of prednisone and time of exposure. Chronic liver disease was defined as the presence of cirrhosis or chronic hepatitis. The association between PRL levels and SDI was evaluated using Spearman’s correlation. Subsequently, a linear regression model was performed to evaluate the association between PRL levels and SDI, adjusting for age, gender, disease duration, disease activity, thyroid-stimulating hormone (TSH), use of steroids, chronic liver disease and serum creatinine level.
Results 130 patients were evaluated, 119 (91.5%) were female; their average (SD) age was 42.6 (13.2) years. Disease duration was 7.3 (6.1) years; almost all patients were mestizo. The mean SLEDAI was 5.9 (4.6), the SDI was 0.9 (1.3), 57 (43.8%) patients had at least one point in the SDI. Mean current prednisone dose was 7.8 (4.6) mg/d, and time of exposure to steroids was 7.1 (6.0) years. Mean creatinine level was 1.3 (1.8) mg/dl, 3 (2.3%) patients had chronic liver disease. TSH was 5.2 (10.5) mIU/l, 37 (28.5%) had TSH above upper normal limit. Mean PRL level was 20.0 (14.4) ng/ml, 38 (29.2%) had a PRL level above upper normal limit. In univariate analysis, PRL level was associated with a higher SDI (Rho: 0.29, p: 0.001). In the adjusted model, PRL level remained associated with SDI (β: 0.37, p<0.001).
Conclusions In our SLE patients, we found a positive association between the prolactin level and SDI, independently of age, gender, disease duration, disease activity, TSH, use of steroids, chronic liver disease and creatinine level. Longitudinal studies are needed to sort out the role of this variable in disease damage in lupus.
Disclosure of Interest: None Declared