High Sodium Intake Linked to Risk of RA Save

Diet has long been considered a potential risk factor for the onset or pathogenesis of rheumatoid arthris. Obesity and the microbiome are being intensively studied as risk factors for RA.

Now a group of Spanish investigators have reported their study of 18,555 persons from the general population were enrolled in the SUN (Seguimiento Universidad de Navarra) cohort launched in 1999. Participants returned questionnaires regarding medical history, physician-diagnosed health conditions, diet, lifestyle and sociodemographic data, BMI and physical activity. Women who consumed between 800 and 3,500 kilocalories per day and men who consumed between 800 and 4,000 kilocalories per day were included, and self-reported daily consumption of 136 individual food and pinches of salt used to calculate each participants’ daily sodium intake.

The amount of dietary sodium consumed per day was associated with an increase in the odds for self-reported RA. Multivariate logistic modeling adjusted for age, sex, total energy intake, cardiovascular diseases, diabetes, cancer, BMI smoking, participation in a restricted diet and other factors showed the association continued. The trend was linear and dose-dependent.

Median daily sodium intake (estimated from foods plus added salt) was 3.47 (P25-75: 2.63-4.55) grams. Those with the highest sodium intake, in the fourth quartile, showed a significant association with RA (fully adjusted odds ratio 1.5; 95% CI 1.1-2.1, P for trend = 0.02). Never smokers with high sodium intake had higher association than ever smokers with high sodium intake (P for interaction = 0.007). Dose-dependent association was replicated in the case-control study. High sodium intake may be associated with a diagnosis of rheumatoid arthritis.