RA and High Sodium Intake Are Associated With Increased Risk of MACE in Korean Population

A study of the adult Korean population found high salt intake was associated with an increase in major adverse cardiovascular events (MACE) in patients with rheumatoid arthritis (RA).

High salt intake is associated with major adverse cardiovascular events (MACE) in patients with rheumatoid arthritis (RA), according to a study published in BMJ Open. Previous research has identified the harmful effect high salt intake has on hypertension.

The retrospective, cross-sectional study evaluated adults in Korea using data of the seventh Korean National Health and Nutrition Examination Survey (2016–2018). The researchers used 24-hour urinary sodium excretion (24HUNa) as a surrogate marker of dietary sodium intake. They analyzed data on 13,464 adults (weighted n = 90,425,889).

In the adult Korean population, there is a 3.7% prevalence of MACE, and individuals with MACE were older, predominantly male, residents of rural areas, and more likely to be smokers and non-drinkers compared with individuals without MACE. Those with MACE also had lower socioeconomic status, higher body mass index, and more comorbidities. The estimated 24HUNa using the Tanaka formula was significantly higher in patients with MACE (3.229 ± 0.040 vs 3.070 ± 0.001, P < .001).

Only 1.7% of the adults in the study had self-reported RA and these individuals had more comorbidities and a significantly higher prevalence of MACE (11.5% in RA vs 3.6% in non-RA, P < .001).

Individuals with extremely high estimated 24Una (≥ 6 g/day) had the highest risk for MACE. Furthermore, a multivariate logistic regression analysis found that RA and extremely high estimated 24Una were significantly associated with MACE.

“As expected, participants with MACE showed significantly higher prevalence of RA, depression, hypertension, [type 2 diabetes] and dyslipidaemia,” the authors wrote. “Patients with RA also had more comorbidities such as hypertension, dyslipidaemia, [type 2 diabetes], MACE and depression, as previous studies have confirmed.”

The authors noted several limitations, such as the cross-sectional nature of the study, which meant causal relationships between variables could not be evaluated. In addition, the researchers were not able to adjust for drugs that could affect urinary sodium excretion or MACE because this information was not available in the data set.

“In addition to the management of traditional risk factors, it is necessary to promote awareness regarding avoidance of extremely high sodium intake and to consider RA as an important risk factor for MACE,” the authors concluded. “Our results could help in the recommendation of a policy for salt reduction policy for the Korean population and patients with RA to achieve potential cardiovascular benefits.”


Bae J-H, Shin M-Y, Ha Kang E, Jong Lee Y, Ha Y-J. Association of rheumatoid arthritis and high sodium intake with major adverse cardiovascular events: a cross-sectional study from the seventh Korean National Health and Nutrition Examination Survey. BMJ Open. Published online December 20, 2021. doi:10.1136/bmjopen-2021-056255