Obesity associated with worse short-term disease activity in early RA
medwireNews: Among patients with early rheumatoid arthritis (RA), those who are obese are at increased risk for having worse disease activity, function, and health-related quality of life, according to an analysis of data from two UK cohorts.
Patients with newly diagnosed RA who were obese (body mass index [BMI]≥30 kg/m2) had a significantly higher Disease Activity Score at 28 joints (DAS28) at baseline compared with those in the normal weight or overweight category (BMI=18.5 to <30 kg/m2), with mean scores of 4.78 versus 4.50 points.
This difference was maintained at 2 years after the initiation of DMARDs, despite DAS28 decreases across all BMI categories. Logistic regression analysis indicated that being obese at baseline was associated with a significant 48% reduction in the adjusted odds of achieving a low disease activity state (DAS28 <3.2 points) at least once by year 2, a difference Elena Nikiphorou (King’s College London, UK) and colleagues describe as “likely to be clinically important.”
The analysis, reported in Rheumatology, also found that patients who were obese at baseline had significantly worse Health Assessment Questionnaire and Short Form 36 Health Survey physical component summary scores at year 2 than those who were of normal weight or overweight. All associations were, however, lost by year 5.
The study combined data from 2386 individuals included in two UK, multicenter, early RA inception cohorts, the Early RA Study (ERAS) and the Early RA Network (ERAN), in which patients were treated according to local practice. The current analysis was restricted to a period of 5 years.
Obesity was found to be increasingly prevalent at RA diagnosis over time, with a baseline prevalence of 14.3% in ERAS (which recruited participants from 1986 to 2001) and 25.7% in ERAN (2002–2012), giving a significant 80% increase in prevalence between the two cohorts. The prevalence of obesity continued to rise over the study period, with 5-year prevalence rates of 22.5% in ERAS and 37.2% in ERAN.
Similar to the negative short-term associations seen in patients who were obese at baseline, those who were obese at year 2 had worse outcomes at that timepoint and at the 5-year follow-up.
The researchers note that this was “in keeping with a concept of a real-time effect of obesity […] with immediate measurable consequences.”
They continue: “It follows that strategies to encourage and support patients to lose weight at any stage of the disease should lead to immediate RA-specific benefits as well as longer-term cardiovascular and general health benefits that might also be expected in people without RA.”
And the team concludes that their findings “argue strongly for the screening and management of obesity to become a central part of all treatment strategies for patients with RA.”
By Catherine Booth
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