Motor oil exposure may raise arthritis risk

NEW YORK (Reuters Health) – Occupational exposure to
mineral oil, primarily motor or hydraulic oil, is associated
with an increased risk of rheumatoid arthritis (RA), new
research indicates. This supports findings from animal studies
showing that these oils induce arthritis.

In the study, published in the medical journal Arthritis
Research & Therapy, investigators compared the level of oil
exposure between 1,419 individuals with RA and 1,674
individuals matched for age, sex and residential area who did
not have RA (control subjects). All of the study participants
lived in the southern part of Sweden from 1996 to 2003.

As it turned out, only men reported high levels of exposure
to mineral oils, so the study focused on 135 men with RA and
132 controls, lead author Dr. Berit Sverdrup, from the
Karolinska Hospital in Stockholm, and colleagues note.

In the overall analysis, mineral oil exposure raised the
risk of RA among men by 30 percent. Further analysis revealed
that this exposure only increased the risk of RA in subjects
positive for rheumatoid factor and anti-citrulline, blood tests
used to help diagnose RA.

Genetic analysis showed no relationship between the
subjects’ genetic profile and the elevated RA risk associated
with mineral oil exposure, the authors note.

Further exploration of the relationship between mineral
oils and RA may help to establish if other types of exposure —
to microbial or other occupational agents — can also induce
arthritis, the researchers conclude.

SOURCE: Arthritis Research & Therapy, September 23, 2005.