Tehran University Medical Journal

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Background: To evaluate the association between age, sex, BMI, waist/hip ratio, smoking, religion, ethnicity, education and knee osteoarthritis.

Methods: Eligible subjects were randomly included from participants of Tehran COPCORD study, of whom 480 subjects with knee osteoarthritis were compared to 490 subjects without (case-control study). Using a questionnaire developed by COPCORD group (Asia & Oceania), we enquired about the risk factors of knee osteoarthritis i.e. age, sex, BMI, Waist/Hip ratio, religion, ethnicity, education and smoking. Knee osteoarthritis was defined using ACR criteria. Each knee was unit of analysis using GEE technique to evaluate these associations.

Results: Age (OR 1.096 CI95%: 1.091-1.1 P: 0.00) and sex (OR 2.85 CI95%: 2.49-3.28 P: 0.00) showed significant association with knee osteoarthritis. Overweight (OR 1.81 CI95%: 1.28-2.55 P: 0.00) and obesity (OR 3.3 CI95%: 2.34-4.66 P: 0.00) both showed higher risk for knee osteoarthritis. The association between waist/hip ratio and knee osteoarthritis showed an OR of 5.28, CI95%: 0.89-31.44 P: 0.07. However, this association was only borderline significant. People with different religion or ethnicity and smokers had no extra risks for knee osteoarthritis. Higher education is a protective factor for knee osteoarthritis as people who had university education compared to people with no/primary education showed a lower risk for knee osteoarthritis (OR 0.54 CI95%: 0.38-0.78 P: 0.00).

Conclusions: Our study confirmed that elderly, females, overweight and obese people are at higher risk to develop knee osteoarthritis as found in western societies. Higher education is a protective factor against knee osteoarthritis. Ethnicity, religion and smoking showed no extra risk of knee osteoarthritis.

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Background: Osteoarthritis is the most common form of arthritis in the world. This study presents the evidence on the prevalence of symptomatic hand osteoarthritis in urban community. To add to the evidence on the prevalence of symptomatic hand osteoarthritis in urban community.
Methods: Inhabitants (age≥15 yrs) in 22 randomly selected districts (Tehran) participated in a Community-Oriented Program for Control of Rheumatic Diseases (COPCORD) evaluating major rheumatic disorders, including osteoarthritis. Eventually, 10, 291 inhabitants completed a Questionnaire (75% response-rate). Trained interviewers asked participants whether they had had any pain, swelling, tenderness, or morning stiffness in the right/ left hand during previous seven days. Participants underwent a complete physical examination if they had any musculoskeletal complaint or extra-articular manifestation of rheumatic disease. Osteoarthritis was defined as presence of palpable nodules (Heberden’s/ Bouchard’s nodes, CMC1’s squaring), pain, tenderness, swelling, or a combination of them on that joint (DIP-PIP-MCP-CMC1). Clinical hand osteoarthritis was positive if at least one joint showed osteoarthritis.
Results: Symptomatic hand osteoarthritis was present in 2.8%(CI 2.3-3.4) (52.6% female, mean age 37.1±16.3). Prevalence was higher in females (4.3% vs. 1.3%, p=0.000) and increased with age (0.1% in people <30 versus 23% in people >70, p=0.000). The most common signs in the DIP, PIP and CMC1 joints were bony enlargement, followed by tenderness and pain on movement.
Conclusions: our study confirms the evidence of high prevalence of symptomatic hand osteoarthritis in an urban community. The prevalence, pattern of hand joints involvement and relationship with age and sex in this study performed in an Eastern community resemble those in Westerners, which calls for further attention by appropriate services.