High Birth Weight Leads to Rheumatoid Arthritis in Adulthood

A new study published in the Annals of the Rheumatic Diseases has found that infants who are born with a birth weight of more than ten pounds are twice as likely to develop rheumatoid arthritis when they are adults, compared to infants who are born with an “average” birth weight. Although researchers noted that the mechanism of this action is still unclear, the study was important in that it identified “a potentially modifiable risk factor and highlights a potential way to decrease the incidence of the disease.” This isn’t the first study to demonstrate that increased risk of adult-onset chronic disease is affected by the fetal environment; similar associations have been made in regards to risk of type 2 diabetes mellitus, coronary heart disease, and hypertension. However, the results of this study may turn physicians’ attention to potentially modifying the birth weight of infants who are approaching this weight in order to eliminate the risk of rheumatoid arthritis later in life. Lisa Mandl, MD, MPH, who led the study, explained that “In utero, the fetus will react appropriately to different stressors. However, this may preprogram the fetus so that when it gets out into the world, this preprogramming is not helpful out in the ‘real world.’”

Dr. Mandl pointed to the fact that the fetal environment potentially preprograms the brain or endocrine system to be maladapted later in life and that patients with rheumatoid arthritis are known for having a dysregulated hypothalamic-pituitary-adrenal (HPA) axis, and this axis may be affected in utero.

“If you look at this as a theoretic biologic underpinning for why this might be true, it might give basic scientists interesting ideas to think about regarding what causes rheumatoid arthritis, and provide support for a new hypothesis,” Dr. Mandl said.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases reports that about 2.1 million people in the United States suffer from rheumatoid arthritis, and that the condition is more common in women than in men. If Dr. Mandl’s findings do in fact bring science one step closer to forming a hypothesis as to why it is caused, then we will be one step closer to understanding and preventing this incurable disease.

Do you believe that more studies need to be done to determine what kinds of role the fetal environment plays in terms of developing certain diseases and conditions later in life? Would you support the idea of altering a fetus’ weight in order to help prevent complications later in life?