Rheumatoid Arthritis and Birth Weight
Heavier Babies May Face Higher Risk of Arthritis Later in Life
May 15, 2003 -- Although the cause of rheumatoid arthritis remains unknown, a new study suggests certain factors surrounding a person's birth may affect the risk of developing the potentially disabling disease as an adult.
Rheumatoid arthritis usually develops after age 50 and affects nearly twice as many women as men. When it strikes, the disease causes a person's immune system to attack the tissues in the joints, which leads to inflammation and pain.
Researchers say little is known about the cause of rheumatoid arthritis, but a combination of genetic and environmental factors are suspected.
The study, published in the May 17 issue of the British Medical Journal, looked at a group of 77 adults with rheumatoid arthritis born between 1940 and 1960 in Malmö, Sweden, and compared their birth records with a group of 308 similarly matched healthy adults born during the same time in the same city. Researchers analyzed information about birth weight, mother's age, length of hospital stay after birth, start of breastfeeding, and the occupation of the father.
The study found babies who had a birth weight of more than 8.82 pounds were more than three times as likely to have rheumatoid arthritis later in life, but having a low birth weight didn't seem to affect the risk of rheumatoid arthritis.
Low frequency of breastfeeding while in the hospital after delivery also slightly increased the likelihood of rheumatoid arthritis as an adult, as well as having a father employed in manual labor.
No other birth-related factors appeared to affect rheumatoid arthritis risk.
Researchers say this is the first study that looks at markers of infant health before and after birth in relation to the development of rheumatoid arthritis as an adult. They say more research is needed to see what these factors might reveal about the development and causes of rheumatoid arthritis.
SOURCE: British Medical Journal, May 17, 2003.