Background RA is the commonest autoimmune joint disease & the incidence is 0.5 – 2%. PsA is another common inflammatory condition, which affects women and men equally, with an incidence of 6 per 100,000 per year and a prevalence of about 1–2 per 1000. Metabolic syndrome increases the risk of inflammatory arthrides. This is also known as syndrome X and insulin resistance syndrome. Patients with chronic inflammatory arthritis such as RA and PsA are prone to accelerated atherosclerosis and its complications. We took this systematic review to establish the relationship between obesity & inflammatory arthritis
Objectives The primary aim of the study was to establish whether the obesity has any relationship with the development of inflammatory arthritis. We also looked for the relationship between obesity & serology of RA as well. Smoking & ACPA status also plays role in development of RA
Methods We searched Medline/EMBASE (1946 to July 2013) using the terms Arthritis, Psoriatic, Psoriatic arthritis, Rheumatoid, Rheumatoid Arthritis, seronegative arthritis.mp OR ankylosing spondylitis/ OR ankylosing spondylitis.mp OR spondyloarthritis.mp OR spondyloarthritis/ OR inflammatory arthritis.mp &Obesity/ OR Obesity.mp OR Body Mass Index/ OR Body Mass Index.mp OR BMI.mp. Observational studies were included in the review, which included case control, cohort & cross sectional for both RA and PsA, and the risk of inflammatory arthritis was reported. The data were used for the calculation of effect size ORs/RR with 95% CIs] in obese vs non obese. A Forest plot was created using the OR/RR for both RA & PsA.
Results Ten studies (from 113793 articles) met our inclusion criteria, comprising three case control (954 RA cases; 3273 individuals) & two cohort studies (1372 RA cases; 6419 individuals) & one Cross sectional studies (105 RA cases; 210 individuals) for RA and two cohort (1122 PsA cases and 164103 individuals), ultivariate logistic regression analysis (116137 individual and 350 RA and 644 PsA patients)Hierarchical Cox Regression mode design (250 PsA cases and 1193 individuals) for PSA were found. A significant correlation was found between obesity & the development of inflammatory arthritis.The summary OR for RA was 1.31 (1.09, 1.57) and for PsA was 1.70 (1.28, 4.75) in obese vs non obese patients. The data to establish any relationship between serology and obesity was not completely given in all studies included so it was not possible to conclude on that relationship. On sub group analysis the positive correlation between obesity& inflammatory arthritis was seen in case control studies of RA but for PsA, the relationship has been noted in all the studies included except one with somewhat less effect.
Conclusions This review has suggested a positive correlation with the development of inflammatory arthritis and obesity. These results are demonstrated in case control studies for RA and all studies for PsA. There were mixed results associated with presence and absence of ACPA and development of inflammatory arthritis in patients with high BMI. Further research is indicated using more cohort studies to show the correlation and also the more studies using ACPA/RF to determine the correlation with obesity.
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Acknowledgement DR Amit Saha, Dr Ian Scott
Disclosure of Interest None declared