Osteoarthritis (OA) is a considerable health problem worldwide. It is known to be associated with certain occupational risk factors. We examined the prevalence rate of OA by occupational cluster. Data were collected from the Korea National Health and Nutrition Examination Surveys (2010–2013). The total number of unweighted sample size was 9,905 participants: 4,460 men and 5,445 women, and OA prevalence was 5.3% and 18.4% respectively. OA patients were defined as participants with knee/hip joint pain and radiographic change of knee/hip joint. Occupational type was classified as either white, pink, blue, or green collar based on the occupational characteristics following physical demand: white for manager and professionals; pink for clerks and service/sales workers; blue for craft/trade workers, machine operators and assemblers, and elementary manual workers; and green for agricultural/fishery workers. We calculated the odds ratios (ORs) and 95% confidence intervals (95% CI) for the odds of a participant’s having OA according to the occupational cluster, with gender stratification. The multiple logistic regression model showed that, compared to the white collar group, the ORs of the pink, blue, and green collar workers were 1.23 (95% CI 0.64–2.36), 1.85 (95% CI 1.18–2.88), and 2.91 (95% CI 1.86–4.54), respectively, in males, and 2.53 (95% CI 1.71–3.73), 2.86 (95% CI 1.94–4.21), and 3.90 (95% CI 2.60–5.83), respectively in females. The prevalence rate of OA was associated with the occupational cluster, in order from highest to lowest: green, blue, pink, and white collar.

Rheumatoid arthritis (RA) is known to be associated with coronary artery diseases (CAD). Previous studies of the association between RA and CAD were reported mainly in non-Asian groups. We aimed to examine the prevalence of RA and the relationship between RA and CAD in South Korea. We conducted a nationwide cross-sectional study by using the Korea National Health and Nutrition Examination Survey, which collected data for four years between 2008 and 2012. A total of 25,828 eligible participants were included. To balance the distribution of baseline characteristics, we used propensity score-matching. A multivariable logistic regression model was employed and we calculated the odds ratios (ORs) and 95% confidence intervals (CI) for the odds of the participants with RA on CAD prevalence. The prevalence of RA in Korea from 2008 to 2012 was 0.6% and RA was predominant among elderly women. The prevalence of CAD in patients with RA was significantly higher than in general population. After propensity score-matching to balance the confounding factors, RA was significantly associated with CAD (OR 2.97, 95% CI 1.15-7.68, P = 0.02). The prevalence of RA in South Korea was comparable to the worldwide data, and the presence of CAD in RA patients was more than two-fold.

Objective: Rebamipide has antioxidant effects and is a drug with a local rather than systemic mechanism of action. Oxidative stress and inflammation in chondrocytes are the major factors contributing to the development and progression of osteoarthritis (OA). Since OA is mainly developed in weight bearing or overused joints, the locally sustained therapy is effective for targeting inflammatory component of OA. We investigated the effects of intra-articular injection of rebamipide loaded nanoparticles (NPs) in OA rat model. Design: We fabricated rebamipide-loaded methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (mPEG-PDLLA) and poly(D, L-lactide- co-glycolide) (PLGA) NPs that allow the sustained release of rebamipide. In vitro, chondrocytes from rat were used to investigate the cytotoxicity and anti-inflammatory effect of rebamipide-loaded NPs. In vivo, monosodium iodoacetate (MIA)-induced OA rats were divided into 7 groups, consisting of healthy control rats and rats injected with MIA alone or in combination with NPs, rebamipide (1 mg)/NPs, rebamipide (10 mg)/NPs, rebamipide (10 mg) solution, or oral administration. Results: In vitro, rebamipide/NPs dose-dependently suppressed the mRNA levels of pro-inflammatory mediators, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, matrix metalloproteinase (MMP)-3, MMP-13, and cyclo-oxygenase-2. In vivo, the mRNA levels of pro-inflammatory components most markedly decreased in the intra-articularly injected rebamipide (10 mg)/NP group compared to other groups. Macroscopic, radiographic, and histological evaluations showed that the intra-articular injection of rebamipide/NPs inhibited cartilage degeneration more than rebamipide solution or rebamipide administration. Conclusions: Using a chemically induced rat model of OA, intra-articular delivery of rebamipide was associated with decreased local and systemic inflammatory response decreased joint degradation and arthritic progression.