Smoking and obesity in patients with rheumatoid arthritis (RA) are factors preventing patients from reaching sustained remission, according to findings presented at the European League Against Rheumatism Annual Congress (EULAR 2016) June 8-11 in London. The take-home message from the study is clear: Smoking cessation and weight loss support should be part of any treatment strategy for an RA patient to become free of symptoms.
“Despite the high prevalence of excess body weight and smoking among RA patients, relatively little is known about whether and to what extent these modifiable lifestyle factors impact the likelihood of achieving sustained remission,” said study investigator Dr. Susan Bartlett from McGill University in Montreal, Canada. “Our findings show that not smoking and a healthy body weight – lifestyle factors which can be modified by patients – can have a significant impact on becoming symptom-free.”
Titled “How Much Of A Barrier Is Excess Weight And Smoking For Achieving Sustained Remission In Early RA? Results From The Canadian Early Arthritis Cohort,” the study followed 1,008 patients enrolled in the Canadian Early Arthritis Cohort (CATCH).
While a majority of the patients, 72 percent, were female, men tended to be overweight and smoked more often, but obesity was equally distributed among the groups, making up 33 percent of from each gender.
Since the study used a “real-world” sample of people, all analyses were adjusted for age, ethnicity, baseline disability, pain, and early use of methotrexate. Three years of follow-up showed that the number of patients achieving sustained remission constantly increased, but both men and women who were overweight, obese, or smoked had a much smaller chance of conquering the disease.
The impact of smoking and excess weight could be seen for both factors independently, as well as in combination. Using this information, the research team calculated probabilities for hypothetical individuals, who were typical representatives of the sample, to achieve sustained remission, defined as a score of less than 2.6 on the DAS28 RA symptom screening tool during two successive visits.
The prototypical individual was 53 years old, white, with some higher education, two comorbid conditions, experiencing symptoms for five months, a DAS28 score of 5, and initially treated with methotrexate and steroids.
If this typical individual was a man with a healthy weight who didn’t smoke, his chance of achieving remission was calculated at 41 percent within three years. If, on the other hand, he was obese and smoked, his chances dropped to 15 percent.
In the same way, a normal weight, non-smoking woman with these characteristics had a 27 percent likelihood of going into remission within three years, while smoking and obesity made the chances drop to only 10 percent.
A graphic representation demonstrated that for individuals who were overweight, but did not classify as obese, the likelihood of achieving remission fell between the two extremes.