Table 2

Relationship between 24-hour urinary electrolyte excretion and socioeconomic status (SES) among participants aged 4–12 years (n=570)*

ModelSodium (mmol/day)Potassium (mmol/day)Na:K (molar ratio)
Β (95% CI)p ValueAdjusted p value†Β (95% CI)p ValueAdjusted p value†Β (95% CI)p ValueAdjusted p value†
Model 1
Low SES (reference)
 Mid SES−10.4 (−19.0 to 1.8)0.0190.0560.7 (−3.4 to 4.9)0.7271.00−0.3 (−0.5 to 0.4)0.0930.278
 High SES−10.7 (−20.3 to 1.1)0.0300.091−1.3 (−5.1 to 2.6)0.5131.00−0.2 (−0.4 to 0.1)0.1770.531
Model 2§
Low SES (reference)
 Mid SES−11.7 (−20.8 to 2.6)0.0130.0400.3 (−3.7 to 4.2)0.8791.00−0.3 (−0.6 to 0.0)0.0800.241
 High SES−10.0 (−17.8 to 2.1)0.0140.041−0.5 (−3.7 to 2.7)0.7351.00−1.9 (−0.4 to 0.0)0.1020.307
Model 3
Low SES (reference)
 Mid SES−11.9 (−21.0 to 2.7)0.0120.0360.2 (−3.7 to 4.2)0.9081.00−0.3 (−0.6 to 0.0)0.0800.241
 High SES−8.8 (−16.6 to 0.0)0.0280.084−0.1 (−3.2 to 2.9)0.9421.00−0.2 (−0.4 to 0.0)0.1090.326
  • *Multiple linear regression used to assess differences in urinary electrolyte excretion by SES, as defined by parental educational attainment. In all models, low SES is the reference category. Β represents the beta-coefficient for the difference in urinary electrolyte excretion between the subgroup (ie, mid to low SES and high to low SES).

  • †p Value adjusted for multiple comparisons between subgroups using Bonferroni correction.

  • ‡Model 1: unadjusted.

  • §Model 2: adjusted for age, sex and day of urine collection.

  • ¶Model 3: adjusted for model 2+BMI z-score.