Table 2.
Summary statistics of the study population divided into quartiles of the sodium to potassium ratio.
| Variables | Q1 | Q2 | Q3 | Q4 | p-Difference | p-Trend a |
|---|---|---|---|---|---|---|
| n | 2356 | 2356 | 2356 | 2356 | ||
| (Sodium and potassium variables) | ||||||
| Sodium intake (mg/day) | 2578.22 | 3783.20 | 4770.62 | 7000.64 | 0.000 b | (+) 0.000 |
| Potassium intake (mg/day) | 3638.99 | 3113.01 | 2919.98 | 2746.57 | 0.000 b | (−) 0.000 |
| Sodium to potassium ratio (Na/K) | 0.74 | 1.22 | 1.64 | 2.57 | 0.000 b | (+) 0.000 |
| (Health-related variables) | ||||||
| Hypertension (%) | 19.27 | 18.00 | 19.44 | 21.52 | 0.023 | (+) 0.025 |
| Body mass index (kg/m2) | 22.88 | 22.78 | 22.87 | 22.93 | 0.438 | (+) 0.668 |
| Walking exercise | 0.71 | 0.65 | 0.67 | 0.67 | 0.270 | (−) 0.001 |
| Smoking status (%) | 9.00 | 13.92 | 16.72 | 18.38 | 0.000 | (+) 0.000 |
| Drinking status (%) | 44.57 | 54.07 | 57.60 | 56.88 | 0.000 | (+) 0.000 |
| Daily stress level (%) | 22.71 | 23.64 | 25.47 | 26.15 | 0.022 | (+) 0.002 |
| Use of nutrition label (%) | 31.96 | 30.35 | 31.62 | 26.83 | 0.000 | (−) 0.001 |
| Family history of hypertension (%) | 39.26 | 37.61 | 38.37 | 34.25 | 0.002 | (−) 0.001 |
| (Socio-demographic variables) | ||||||
| Female (%) | 77.42 | 68.42 | 64.52 | 62.39 | 0.000 | (−) 0.000 |
| Age (year) | 48.17 | 45.62 | 44.70 | 45.99 | 0.000 | (−) 0.000 |
| Marital status (%) | 13.88 | 15.15 | 17.83 | 16.60 | 0.001 | (+) 0.001 |
| Manual worker (%) | 18.97 | 21.86 | 23.09 | 26.06 | 0.000 | (+) 0.000 |
| Household income (million won/month) | 4.53 | 4.52 | 4.54 | 4.27 | 0.588 | (−) 0.000 |
| Education (year) | 12.15 | 12.39 | 12.49 | 12.15 | 0.001 | (+) 0.757 |
| (Other dietary variables) | ||||||
| Energy intake (kcal/day) | 1886.51 | 1992.44 | 2025.98 | 2016.89 | 0.000 | (+) 0.000 |
| Protein intake (g/day) | 64.76 | 71.97 | 74.26 | 73.96 | 0.000 | (+) 0.000 |
| Fat intake (g/day) | 36.54 | 43.45 | 45.81 | 45.01 | 0.000 | (+) 0.000 |
| Carbohydrate intake (g/day) | 321.50 | 316.61 | 310.31 | 309.18 | 0.001 | (−) 0.007 |
| Fiber intake (g/day) | 9.43 | 7.17 | 6.86 | 7.12 | 0.000 | (−) 0.000 |
| Cereals and cereal products (kcal/day) | 891.22 | 1008.12 | 1029.62 | 1083.04 | 0.000 | (+) 0.000 |
| Potatoes and starches (kcal/day) | 86.91 | 41.56 | 32.34 | 19.73 | 0.000 | (−) 0.000 |
| Vegetables (kcal/day) | 83.87 | 87.56 | 88.01 | 91.44 | 0.001 | (+) 0.000 |
| Fruits (kcal/day) | 174.04 | 103.45 | 75.99 | 57.96 | 0.000 | (−) 0.000 |
| Meat and meat products (kcal/day) | 133.22 | 189.94 | 208.58 | 199.43 | 0.000 | (+) 0.000 |
a Nonparametric test for trend was estimated with Stata’s nptrend command; b Adjusted for energy intake.