Study finds polycyclic aromatic hydrocarbons to be strongly linked to raised rheumatoid arthritis risk

The amount of environmental exposure to polycyclic aromatic hydrocarbons, or PAH for short, is strongly linked to a person’s risk of developing rheumatoid arthritis, suggests research published in the open access journal BMJ Open.

These chemicals, formed from the burning of coal, oil, gas, wood, or tobacco as well as the flame grilling of meat and other foods, also seem to account for most of smoking’s impact on risk of the disease, the findings indicate.

To try and shed some light on the potential role of environmental exposure on rheumatoid arthritis risk, the researchers drew on responses to the nationally representative US National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016.

The study included 21,987 adults, 1418 of whom had rheumatoid arthritis and 20,569 of whom didn’t. The odds of rheumatoid arthritis were highest among those in the top 25% of bodily PAH levels, irrespective of whether or not they were former or current smokers.

After accounting for potentially influential factors, including dietary fibre intake, physical activity, smoking, household income, educational attainment, age, sex, and weight (BMI), only one PAH-1-hydroxynaphthalene-was strongly associated with higher odds (80%) of the disease.

Further analysis showed that bodily PAH level accounted for 90% of the total effect of smoking on rheumatoid arthritis risk.

Reference:

Polycyclic aromatic hydrocarbons and risk of rheumatoid arthritis: a cross sectional analysis of the National Health and Nutrition Examination Survey, 2007-2016,BMJ Open, DOI 10.1136/bmjopen-2022-071514