Background Females compared with males display greater sensitivity in response to noxious stimulation and especially the pressure pain and electrical stimulation are largest1). In rheumatoid arthritis (RA), females compared with males score significantly higher on ESR, patient's global assessment, tender joint count (TJC), HAQ, DAS28ESR, and DAS28CRP just before initiation of first biologics therapy2). Barnabe3) supports that treatment with disease-modifying therapy results improvement in mean pain scores for both sexes: however, female absolute scores remain higher in RA. But there is no article on a correlation between the TJC and the swollen joint count (SJC) in terms of sex in RA.
Objectives To investigate sex differences in the gaps between the TJC and the SJC in patients with RA.
Methods We detected the data of the patients who had more than 6 swollen joints and less than 10 years disease duration just before initiation of first biologics therapy. The TJC and the SJC were evaluated using 28 joints. We determined the gaps between the TJC and the SJC (TJSJ gap) using the following equation: TJSJ gap = TJC- SJC. Demographic data and disease activity parameters were collected at base line, 3 and 6 months after biologics treatment started. The differences between females and males were compared using a t-test and a Fisher's exact tests.
Results A total of 115 patients, of whom 25 were males and 90 females, were detected. Of these patients, 49 received infliximab treatment, 49 eternercept treatment, 8 adalimumab treatment, 5 tocilizumab treatment and 4 abatacept treatment and there are no sex differences in the sort of biologics treatment. At base line, there are no sex differences in age, disease duration, SJC, evaluator's global assessment, patient's global assessment, ESR, DAS28ESR, DAS28CRP, CDAI, SDAI, and concomitant prednisolone and methotrexate. But TJC and TJSJ gap were higher, and CRP was lower in females. There were no sex differences of all variable except higher TJSJ gap at 3 months and higher TJC at 6 months in females. The mean TJC for males and females, were 7.5, 10.7 at base line, and 3.0, 4.2 at 3 months, and 1.5, 3.8 at 6 months, respectively. The mean SJC for males and females, were 9.5, 9.2 at base line, and 4.0, 3.1 at 3 months, and 2.3, 2.7 at 6 months, respectively. The mean TJSJ gap for males and females, were -2.00, 1.53 at base line, and -1.05, 1.09 at 3 months, and -0.86, 1.05 at 6 months, respectively.
Conclusions Despite a similar disease activity, females compared with males had more tender joints than swollen joints, just before initiation of first biologics therapy in patients with RA. Sex differences in gaps between the tender joint count and the swollen joint count decreased over time after biologics therapy started.
Joseph L. Riley 3rd, et al.: Sex differences in the perception of noxious experimental stimuli: a meta-analysis. Pain 1998, 74(2-3): 181-187
Nienke Lesuis, et al.: Gender and the treatment of immune-mediated chronic inflammatory diseases: rheumatoid arthritis, inflammatory bowel disease and psoriasis: an observational study. BMC Med. 2012 Aug 1;10:82.
Cheryl Barnabe, et al.: Sex differences in pain scores and localization in inflammatory arthritis: A systematic review and metaanalysis. J Rheumatology 2012, 39: 1221-30.
Disclosure of Interest None declared