Motor Oil Linked to Rheumatoid Arthritis
Occupational Exposure to Mineral Oils May Raise Rheumatoid Arthritis Risk in Men
Sept. 23, 2005 -- People who work with mineral oils, such as motor oil and
hydraulic oil, may be more likely to develop rheumatoid arthritis.
A new study shows that men who had occupational exposure to mineral oils had
a 30% higher risk of rheumatoid arthritis.
Researchers say rheumatoid arthritis is a disease that depends on several
genetic as well as environmental factors, and these results suggest that
occupational exposure to motor and hydraulic oils may increase the risk of
rheumatoid arthritis in people with a family history of the disease.
The American College of Rheumatology specifies that in order to diagnose
rheumatoid arthritis, four out of the following seven criteria must be present,
observed by a doctor, and verified by patient history:
- Joint stiffness in the mornings lasting at least one hour
- Arthritis of three or more joints
- Arthritis of hand joints
- Symmetric arthritis of same joint on both sides of the body
- Rheumatoid nodules
- Rheumatoid factor positive in blood tests
- X-ray findings consistent with rheumatoid arthritis
Mineral Oils Raise Arthritis Risks
In the study, which appears in Arthritis Research & Therapy,
Swedish researchers looked at the link between exposure to mineral oils and the
risk of developing rheumatoid arthritis in a group of about 1,400 people
diagnosed with the disease and about 1,600 similarly matched healthy people who
served as a comparison group.
All of the participants filled out a questionnaire with information
regarding occupational exposure to a variety of mineral oils, including motor
oil, hydraulic oil, cutting oil, form oil, and asphalt.
Only men reported high occupational exposure to mineral oils. In comparing
the groups, researchers found men with high occupational exposure to motor or
hydraulic oil, such as auto mechanics, had a 30% higher risk of developing
rheumatoid arthritis than men not exposed to mineral oils.
Exposure to mineral oils was linked to those with rheumatoid-factor-positive
rheumatoid arthritis. Occupational exposure to motor and hydraulic oil was also
associated with a 60% increased risk of another type of the disease known as
anticitrulline-positive rheumatoid arthritis.
Researchers say the results support previous studies that showed animals
developed arthritic disease after exposure to mineral oils. The findings also
raise questions about potential links between occupational exposure to other
agents and an increased risk of rheumatoid arthritis.