Background/AimsThe aim of this study was to compare the sleep quality between rheumatoid arthritis (RA) patients and healthy controls; and to evaluate the relationship between RA disease activity and sleep quality in Korea.MethodsA total of 130 RA patients and 67 age- and sex-matched healthy controls were enrolled in a comparative study of sleep quality using the Pittsburgh Sleep Quality Index (PSQI). Age, gender, concomitant medication, erythrocyte sedimentation rate, serum C-reactive protein, Beck Depression Inventory second edition (BDI-II), 28 joints disease activity score (DAS28), pain visual analog scale (VAS), and PSQI were analyzed as covariates. We also analyzed the sleep quality of RA patients according to the disease activity (DAS28 ≤ 3.2, 3.2 < DAS28 < 5.1, and DAS28 ≥ 5.1, respectively).ResultsThe total PSQI score and the frequency of poor sleep quality, were higher in the RA patients (5.62 ± 4.19, 38.5%) than in the control subjects (3.57 ± 2.17, 13.4%). The patients with poor sleep quality (PSQI > 5) were older and had a higher BDI-II and VAS score than the patients without sleep disturbance (PSQI ≤ 5). The score in subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, daytime dysfunction, total PSQI, and frequency of poor sleep quality were increased when RA activity was high.ConclusionsSleep disturbance was observed in RA patients (38.5%), and high RA disease activity was associated with poor sleep quality in Korea.

Background/Aims:Grape seed proanthocyanidin extract (GSPE) has been reported to have a beneficial effect on regulating inf lammation. However, the anti-inflammatory mechanism of GSPE remains unclear. The aim of this study was to verify the influence of GSPE on the Toll-like receptor 4 (TLR4)-mediated signaling pathway in the regulation of murine autoimmune arthritis.Methods:Collagen-induced arthritis (CIA) was induced in dilute brown non-agouti (DBA)/1J mice. The mice were treated with GSPE (0 or 100 mg/kg) intraperitoneally. The severity of arthritis was assessed clinically, biochemically, and histologically. Immunostaining for TLR4 was performed. The expressions of TLR4 and downstream signaling molecules were analyzed by Western blot. The effect of GSPE on lipopolysaccharide (LPS)-induced TLR4 activation was also evaluated using RAW264.7 cells and fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis and from those with osteoarthritis.Results:GSPE attenuated the clinical severity of arthritis and decreased histological damage. GSPE treatment reduced the number of TLR4-stained cells in the synovium of mice with CIA. GSPE also downregulated the expression of TLR4, myeloid differentiation factor 88 (MyD88) and phosphorylated IκBα synovial protein in CIA mice. Concurrently, GSPE inhibited the nuclear translocation of nuclear factor-κB (NF-κB) subunits (p65 and p50). LPS-induced TLR4 activation was suppressed by GSPE in human FLS as well as in murine macrophages in vitro.Conclusions:Our results demonstrated that GSPE ameliorated CIA by regulating the TLR4-MyD88-NF-κB signaling pathway.

Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P < 0.05). This reduction in BF was maintained until day 7, and BF started to recover gradually from day 9. In the infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.Graphical Abstract

Background/Aims:We aimed to investigate the prevalence and possible causes of hypouricemia in the Korean population and to compare our findings with published results of other populations.Methods:We examined the serum uric acid levels of 30,757 subjects who had their uric acid values measured at least once during a 1-year period. All individuals with hypouricemia (serum uric acid < 2.0 mg/dL, n = 424) were reviewed with respect to medical drug history and concomitant diseases previously identified as being associated with hypouricemia.Results:The prevalence of hypouricemia was 4.14% (299/7,223) among inpatients and 0.53% (125/23,534) among outpatients, for an overall prevalence of 1.39% (424/30,757). Possible causes associated with hypouricemia were found to be solid or hematologic malignancies (n = 86), diabetes mellitus (n = 56), and therapeutic drugs (n = 29). The medications were allopurinol (n = 11), angiotensin II receptor blockers (n = 10), salicylates (n = 6), febuxostat (n = 1), and warfarin (n = 1). In the remaining 226 individuals, the cause of hypouricemia was not identified.Conclusions:Hypouricemia is relatively common in the Korean population compared to those of other countries. The possible causes associated with hypouricemia are related to underlying diseases and medications.

Background/AimsSleep disturbance is prime concern in patients with Behcet disease. The purpose of this study was to find out the effects of sleep quality, in Korean patients suffering from Behcet disease. We further investigated the relationship between depression, quality of life and the clinical findings of Behcet disease.MethodsThe study was performed by the cross-sectional design. Sleep quality was assessed by the Korean version of Pittsburgh sleep quality index (PSQI). Disease activity of Behcet disease was evaluated by Behcet disease current activity form (BDCAF). Depression was assessed by the Korean version of Beck depression inventory second edition (BDI-2). Quality of life was assessed by the Korean version of the Leeds Behcet disease quality of life measure (BDQoL).ResultsAmong the 100 patients studied, 42% reported poor sleep quality (PSQI ≥ 9). These patients have a higher BDI-2, total BDCAF and pain visual analogue scale (VAS) score (p < 0.001, p = 0.022, and p = 0.005). Considering BDCAF, the frequency of genital ulcer was significantly higher (p = 0.01). Behcet was higher in females. The BDQoL was lower in poor sleeper group (p = 0.004 and p < 0.001). Among 7 PSQI components, daytime dysfunction was higher in patients with high disease activity (p = 0.03). Total PSQI score were strongly correlated with BDCAF, BDI-2, BDQoL, and pain VAS score (p = 0.02, p < 0.001, p < 0.001, and p < 0.001, respectively).ConclusionsLow sleep quality is directly associated with disease activity, depression, and quality of life in Korean patients with Behcet disease.