Women with obesity, higher body fat at greater risk for RA
Obesity, higher body fat and higher waist circumference are associated with a greater risk for rheumatoid arthritis among women, according to findings published in Arthritis Care & Research.
“About 1% of the western population is suffering from RA, which affects physical and mental health, fitness for work and even life expectancy,” Asta Linauskas, MD, of Aarhus University Hospital in Denmark, told Healio Rheumatology. “Every step towards revealing risk factors of rheumatoid arthritis is very important. It contributes to the development of preventive measures.”
To determine the association between total body fat percentage, waist circumference and BMI and the development of RA, the researchers conducted a population-based, prospective cohort study of 55,037 patients who had been enrolled in the Danish Diet, Cancer and Health cohort. Data on lifestyle factors, socioeconomic status, anthropometric measures – including bio-impedance – were collected from each patient in the cohort at enrollment.
Linauskas and colleagues identified patients who developed RA by linking the cohort’s data with information in the Danish National Patient Registry. They then used Cox proportional hazards regression models, stratified by gender, to determine the relationships between body fat percentage, waist circumference, BMI and incident RA.
According to the researchers, 210 men and 456 women developed RA over a median follow-up period of 20.1 years. Among women, the overall risk for RA was 10% greater for each 5% increment of total body fat (HR = 1.1; 95% CI, 1.02-1.18). In addition, the risk for RA among women increased 5% for every 5-cm increment of waist circumference (HR = 1.05; 95% CI, 1.01-1.1), and almost 50% greater in patients who were obese, compared with those with a normal BMI (HR = 1.46; 95% CI, 1.12-1.9). These associations were found for the “other RA” serological subtype. No clear associations between body fat percentage, waist circumference, BMI and RA were found among men. In addition, no significant associations were found for “seropositive RA” in women or men.
“A higher body fat percentage, higher waist circumference and obesity were associated with a higher risk of overall RA and other RA in women, indicating that excess total body fat volume per se rather than abdominal obesity is associated with RA risk,” Linauskas and colleagues wrote. “It remains unknown whether the association of the development of RA with excess adipose tissue simply reflects the presence of inflammatory activity as a part of the metabolic syndrome or whether it contributes to the development of autoimmune inflammatory joint disease.” – by Jason Laday
Disclosure: Linauskas reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.