Dietary Sodium, Potassium, and Sodium to Potassium Ratio in Patients With Systemic Lupus Erythematosus

Abstract

The aim of this study was to investigate the association between dietary sodium, potassium, and sodium:potassium ratio and clinical disease activity parameters, damage accrual, and cardiovascular disease risk factors in a population of patients with systemic lupus erythematous (SLE). A cross-sectional study including a total of 280 patients was conducted (90.4% females; mean age 46.9 ± 12.85 years). Data collection: The SLE Disease Activity Index (SLEDAI-2K) and the SDI Damage Index were used to assess disease activity and disease-related damage, respectively. A 24- hour diet recall was used to estimate dietary intake of sodium and potassium. Dietary sodium intake was significantly associated with anti-dsDNA (β = .005; 95% CI [.002 .008]; p = .001) and complement C4 level (β = .002; 95% CI [ .003, .000]; p = .039). Dietary potassium intake was also significantly associated with complement C3 level (β = .004; 95% CI [ .007, .001]; p = .021). Multiple logistic regression models revealed a positive association between dietary sodium intake and the risk of having hsCRP > 3 (p = .005) and an inverse association between dietary potassium intake and the risk of having hsCRP > 3 (p = .004). SLE patients with higher dietary sodium and lower dietary potassium intakes had an increased risk of higher hsCRP. Dietary sodium intake was significantly associated with anti-dsDNA and complement C4 level, while dietary potassium intake was associated with complement C3 level, supporting that dietary sodium and potassium intakes might play a key role in markers related to disease activity in SLE patients.