Obesity and diabetes are associated with disability in women with hand osteoarthritis. Results from the EpiReumaPt nationwide study

ABSTRACT Background: Hand osteoarthritis (HOA) is a highly prevalent rheumatic disease that predominates in females and causes pain and loss of functional capacity. Obesity and metabolic syndrome have been previously suggested to associate with the severity of HOA, but clarity on these associations is yet to be achieved. Objective: Test the association between obesity and other components of the metabolic syndrome and disability in women with hand osteoarthritis (HOA). Design: Individuals from EpiReumaPt epidemiological community-based study (2011-2013) are representative of the Portuguese population. Women with diagnosis of primary HOA were included. Primary outcome: hand functional status, assessed by Cochin questionnaire. Secondary outcomes: hand pain, assessed by visual analogue scale and tender hand joint count (THJ). Explanatory variables: obesity, diabetes mellitus, arterial hypertension and hypercholesterolemia. Possible associations between obesity and the other components of metabolic syndrome with Cochin score, hand pain and THJ were tested in a multivariable linear regression model. Potential confounders considered: age, education level and countrywide distribution. Results: 473 women with primary HOA were included. Forty percent were overweight and 29% obese. Ninety-three (19.8%) participants had diabetes, 261 (55.8%) reported hypertension and 261 (55.9%) hypercholesterolemia. Mean Cochin score was 15.5±14.8, mean pain VAS was 4.7±2.6 and mean THJ 1.4±3. In the multivariable analysis, obesity (β 4.6 CI 0.7;8.5) and diabetes (β 4.0 CI 0.4;7.6) were found to significantly associate with HOA functional disability. In addition, diabetes, but not obesity, associated with hand pain. There was no association between obesity or diabetes with THJ. Conclusion: In a Portuguese female population with primary HOA, obesity and diabetes mellitus independently associated with a worse hand functional status. These data add to evidence suggesting a role of metabolic factors in the severity of HOA.