Table 3.
Association Between Tertiles of Urinary Sodium (Na) and Blood Pressure in the Pooled Data From Both Visits
| Measurement Methods | Systolic Blood Pressure | Diastolic Blood Pressure | ||||
|---|---|---|---|---|---|---|
| Tertile 1 | Tertile 2 βa (95% CI) | Tertile 3 βa (95% CI) | Tertile 1 | Tertile 2 βa (95% CI) | Tertile 3 βa (95% CI) | |
| Estimated daily Na+ from first morning urine sample (N=651) | ||||||
| Unadjusted | Ref | 0.33 (−1.33, 1.99) | 0.81 (−1.69, 3.31) | Ref | 0.28 (−0.38, 0.93) | 0.28 (−1.48, 2.05) |
| Adjusted for visit, age, sex, and BMI | Ref | 0.01 (−0.98, 0.99) | −0.64 (−2.29, 1.00) | Ref | 0.02 (−1.01, 1.06) | −0.34 (−0.81, 0.13) |
| Full adjusted modelb | Ref | 0.04 (−1.00, 1.09) | −0.72 (−2.41, 0.97) | Ref | −0.04 (−1.00, 0.92) | −0.50 (−0.98, −0.02) |
| Estimated daily Na+ from second morning urine sample (N=739) | ||||||
| Unadjusted | Ref | 2.84 (1.45, 4.24) | 3.22 (0.48, 5.96) | Ref | 1.75 (0.60, 2.89) | 1.58 (−0.61, 3.77) |
| Adjusted for visit, age, sex, and BMI | Ref | 3.03 (1.32, 4.72) | 2.81 (0.29, 5.33) | Ref | 1.78 (0.43, 3.13) | 1.44 (−1.78, 3.05) |
| Full adjusted modelb | Ref | 3.01 (1.31, 4.70) | 2.77 (0.41, 5.14) | Ref | 1.70 (0.42, 2.98) | 1.34 (−0.19, 2.86) |
| Measured 24 h urinary Na+ (N=733) | ||||||
| Unadjusted | Ref | 0.71 (−2.12, 3.54) | 0.56 (−2.10, 3.21) | Ref | −0.17 (−1.70, 1.37) | 0.03 (−1.63, 1.70) |
| Adjusted for visit, age, sex, and BMI | Ref | 0.83 (−2.26, 3.92) | 0.85 (−2.26, 3.92) | Ref | −0.20 (−1.81, 1.41) | −0.13 (−1.71, 1.46) |
| Full adjusted modelb | Ref | 0.74 (−2.21, 3.70) | 0.81 (−1.92, 3.53) | Ref | −0.21 (−1.79, 1.37) | −0.11 (−1.74, 1.51) |
| Complete measured 24 h urinary Na+ (N=733) | ||||||
| Unadjusted | Ref | 0.98 (−1.77, 3.72) | 0.51 (−1.66, 3.72) | Ref | 0.14 (−1.43, 1.71) | 0.09 (−1.21, 1.39) |
| Adjusted for visit, age, sex, and BMI | Ref | 1.55 (−1.55, 4.66) | 1.25 (−1.26, 3.76) | Ref | 0.22 (−1.38, 1.82) | 0.04 (−1.20, 1.30) |
| Full adjusted modelb | Ref | 1.44 (−1.42, 4.31) | 1.23 (−1.16, 3.62) | Ref | 0.26 (−1.24, 1.77) | 0.08 (−1.19, 1.35) |
BMI indicates body mass index.
First morning void was collected on the second day and vice versa. Estimated daily Na+ from first morning urine; tertile 1: <110 mmol/d, tertile 2: ≥110 to <129 mmol/d; tertile 3: ≥129 to 322 mmol/d. Estimated daily Na+ from second morning urine; tertile 1: <112.5 mmol/d, tertile 2: ≥112.5 to <131.9 mmol/d; tertile 3: ≥131.9 to 333 mmol/d. Measured 24‐h urinary Na+; tertile 1: <96.2 mmol/d, tertile 2: ≥96.2 to <152.1 mmol/d; tertile 3: ≥152.1 to 468 mmol/d.
Refers to differences in mean blood pressure (in mm Hg) of participants compared with reference category, obtained from linear regression.
Model adjusted for visit, age, sex, BMI, physical activities and smoking status, alcohol consumption, sleep hours, religion, and household wealth.