COPENHAGEN — Patients who develop rheumatoid arthritis undergo an unexplained drop in their serum cholesterol level during the years immediately preceding their diagnosis, based on a study of more than 500 patients.
The finding may eventually add to a better understanding of the atherogenic process in patients with rheumatoid arthritis (RA), Dr. Elena Myasoedova said at the annual European Congress of Rheumatology. Serum levels of LDL cholesterol also fell before—as well as following—RA diagnosis, whereas serum levels of HDL cholesterol rose both before and after RA diagnosis, said Dr. Myasoedova, who did her research while she was a Fulbright scholar at the Mayo Clinic in Rochester, Minn.
Dr. Myasoedova and her associates studied residents of Olmsted County, Minn., who were enrolled in the Rochester Epidemiology Project. They identified 577 Olmsted County residents, aged 18 years or older, who were diagnosed with RA during 1988-2008.
In the 5 years before diagnosis, their serum levels of both LDL cholesterol and total cholesterol fell significantly, by an average of 24 mg/dL for LDL cholesterol and an average of 23 mg/dL for total cholesterol. During the same period, HDL cholesterol levels rose by 3 mg/dL.
In the 5 years after RA diagnosis, their total and LDL cholesterol levels underwent a smaller decline, with LDL cholesterol dropping by another 8 mg/dL. HDL cholesterol increased by an additional 5 mg/dL after the diagnosis.
To better assess the relationship of these changes to RA, the researchers ran a similar analysis on 540 control residents.
The comparison showed that people who were never diagnosed with RA also had a drop in their total and LDL cholesterol levels over the same period, Dr. Myasoedova said, but the extent of the cholesterol reduction was substantially steeper and more pronounced among those who eventually developed RA.
The study was funded in part with a grant from Roche Laboratories, Dr. Myasoedova said. She had no other disclosures for herself or her coworkers.