TABLE 4.
HRs for incident hypertension by quintiles of sodium intake, potassium intake, and Na/K ratio1
| Quintiles of intake |
|||||
| Lowest | Second | Third | Fourth | Highest | |
| Sodium intake | |||||
| Range (g/d) | <3.2 | 3.2–4.3 | 4.4–5.52 | 5.6–7.52 | ≥7.62 |
| HR (95% CI)3 | 1.00 | 0.99 (0.84, 1.18) | 1.20 (1.01, 1.42)2 | 1.37 (1.16, 1.62)2 | 1.84 (1.56, 2.16)2 |
| Potassium intake | |||||
| Range (g/d) | <1.2 | 1.2–1.4 | 1.5–1.7 | 1.8–2.12 | ≥ 2.22 |
| HR (95% CI)3 | 1.00 | 0.83 (0.71, 0.97)2 | 0.94 (0.80, 1.10) | 0.74 (0.63, 0.87)2 | 0.66 (0.56, 0.78)2 |
| Na/K ratio | |||||
| Range | <1.8 | 1.8–2.5 | 2.6–3.4 | 3.5–4.8 | ≥4.9 |
| Average [HR (95% CI)] | 1.00 | 1.12 (0.93, 1.35) | 1.27 (1.06, 1.53)2 | 1.64 (1.37, 1.97)2 | 2.14 (1.79, 2.55)2 |
| North [HR (95% CI)]4 | 1.00 | 1.27 (0.88, 1.85) | 1.74 (1.17, 2.58)2 | 1.31 (0.89, 1.93) | 2.08 (1.40, 3.08)2 |
| Central [HR (95% CI)]4 | 1.00 | 1.18 (0.85, 1.63) | 1.05 (0.76, 1.46) | 1.59 (1.16, 2.17)2 | 1.90 (1.41, 2.56)2 |
| South [HR (95% CI)]4 | 1.00 | 1.00 (0.75, 1.32) | 1.28 (0.97, 1.69) | 1.82 (1.39, 2.40)2 | 2.37 (1.81, 3.12)2 |
1
HRs were adjusted for energy intake, age, sex, education, income, region, BMI, physical activity, smoking status, and alcohol consumption. Flexible parametric models for survival-time data and the macro %EMICM in SAS 9.2 (SAS Institute) were used to compute HRs and the survival curves. Na/K ratio, ratio of sodium to potassium.
2
Significant result.
3
HRs were additionally adjusted for sodium intake.
4
Estimates are linear combinations of coefficients from a model including Na/K ratio quintiles by region interaction terms, likelihood ratio test (model with compared with without the interaction term, P = 0.08).