Smoking, genes linked to RA

STOCKHOLM, Sweden, Oct. 7 (UPI) -- Swedish researchers say they have found evidence a combination of smoking and a specific gene protein sequence may trigger rheumatoid arthritis.

In a study published in the October issue of Arthritis & Rheumatism, the researchers focused on 612 women and 246 men diagnosed with the disease and averaging 49 years of age. They also recruited 1,048 healthy individuals to serve as controls.

Participants donated blood samples for DNA genotyping and filled out lifestyle questionnaires.

The researchers found among those with the gene producing the suspect protein sequence, smokers were 7.5 more likely to develop RA.