TABLE 2.
Summary of cross-sectional studies exploring associations between sodium to potassium ratio and blood pressure in adults using 24-h urinary collection1
| Reference, year, country, study type | Subjects (n, age, sex, BMI2, BP3) | Urinary Na and K4 | Na:K ratio | Regression coefficient (95% CI) (SBP and DBP)5 | Conclusions | Quality rating6 and level of evidence (NHMRC)7 |
|---|---|---|---|---|---|---|
| Jackson et al. (35) | Total n: 766 | Urinary Na | HT: 3.18 | SBP | Urinary Na:K associated with SBP | P, IV |
| 2018 | HT n: 235 | HT: 162.60 ± 3.04 mmol/day | Pre-HT: 2.90 | 1.72 [0.76-2.68]** | ||
| USA | Age: 52.3 ± 0.7y | Pre-HT: 154.51 ± 2.61 mmol/day | Optimal: 2.90 | DBP | ||
| Cross-sectional | BMI: 32.6 ± 1.0 kg/m2 | Optimal: 159.04 ± 3.19 mmol/day | 0.30 [−0.53 - 1.12] | |||
| Pre-HT n: 183 | Urinary K | |||||
| Age: 45.0 ± 1.2y | HT: 51.12 ± 1.10 mmol/day | |||||
| BMI: 31.2 ± 0.8 kg/m2 | Pre-HT: 53.35 ± 1.29 mmol/day | |||||
| Optimal n: 348 | Optimal: 55.24 ± 1.37 mmol/day | |||||
| Age: 37.0 ± 1.0y | ||||||
| BMI: 27.5 ± 0.5 kg/m2 | ||||||
| Stamler et al. (41) | Total including INTERMAP | Urinary Na | INTERMAP: 3.89 ± 2.11 | SBP | Urinary Na:K ratio associated with SBP and DBP | P, IV |
| 2018 | n: 4680; NT and HT | Total: 181.10 ± 72.42 mmol/day | INTERMAP: 2.43 [1.50-3.37]**** | |||
| Global (Japan, China, UK, USA) | Age: 49.17 ± 5.47y | US participants: 162.58 ± 59.37 mmol/day | US participants: 3.08 ± 1.23 | US participants: 2.46 [1.35- 3.58]**** | ||
| Cross-sectional | BMI: 26.37 ± 5.47 kg/m2 | Urinary K | DBP | |||
| SBP: 118.93 ± 14.69 mmHg | Total: 53.16 ± 20.02 mmol/day | INTERMAP: 0.92 [0.30- 1.54]** | ||||
| DBP: 73.84 ± 10.03 mm Hg | US participants: 57.65 ± 20.91 mmol/day | US participants: 1.20 (0.42-1.97)** | ||||
| US participants n: 2195 | ||||||
| Age: 49.14 ± 5.39y | ||||||
| BMI: 28.90 ± 5.92 kg/m2 | ||||||
| SBP: 118.60 ± 13.89 mmHg | ||||||
| DBP: 73.41 ± 9.68 mmHg | ||||||
| Farapti et al. (42) | Total n: 51 | Urinary Na | Total: 5.28 ± 1.68 | SBP | Urinary Na:K ratio associated with SBP not DBP | Ø,IV |
| 2017 | Female subjects | Total: 104.85 ± 59.3 mmol/day | NT: 4.74 ± 1.36 | 3.89 [1.18-6.6]* | ||
| Indonesia | Age: 56.98 ± 5.7y | NT: 94.6 ± 41.1 mmol/day | HT: 6.01 ± 1.89 | Excluding participants taking antihypertensive drugs: 4.89 [1.93-7.84]* | ||
| Cross-sectional | BMI: 25.96 ± 4.85 kg/m2 | HT: 120.5 ± 81.0 mmol/day | ||||
| SBP:132.25 ± 17.78 mmHg | Urinary K | |||||
| DBP: 83.63 ± 10.3 mmHg | Total: 20.5 ± 9.7 mmol/day | |||||
| NT n: 32 | NT: 21.2 ± 10.18 mmol/day | DBP | ||||
| Age: 57.19 ± 6.85y | HT:19.50 ± 9.08 mmol/day | 1.72 [−0.189-3.63] | ||||
| BMI: 24.26 ± 5.24 kg/m2 | ||||||
| SBP: 121.09 ± 9.89 mmHg | ||||||
| DBP: 77.03 ± 6.33 mmHg | ||||||
| HT n: 19 | ||||||
| Age: 57.16 ± 3.45y | ||||||
| BMI: 28.82 ± 1.36 mmHg | ||||||
| SBP: 151.05 ± 10.75 mmHg | ||||||
| DBP: 94.74 ± 4.24 mmHg | ||||||
| Glatz et al. (43)□ | Total n: 1336 | Urinary Na | NT: 2.35 (2.29; 2.62) | SBP (quintiles of BP) | Urinary Na:K ratio associated with SBP | P, IV |
| 2017 | German n: 709 | German: 160 ±66 mmol/day | HT: 2.52 (2.43; 2.62) | Q1 (n = 265) | ||
| Switzerland | Age: 48.8 ± 18y | French: 151 ± 71 mmol/day | 2.32 (2.21; 2.44) | |||
| Cross-sectional | BMI: 25.3 ± 4.3 kg/m2 | Italy: 158 ±72 mmol/day | Q2 (n = 262) | |||
| SBP: 126.1 ± 15.9 mmHg | Urinary K | 2.27 (2.16; 2.38) | ||||
| DBP: 75.5 ± 10.2 mmHg | German: 68.0 ± 24.8 mmol/day | Q3 (n = 268) | ||||
| French n: 428 | French: 65.7 ± 24.1 mmol/day | 2.36 (2.24; 2.47) | ||||
| Age: 47.8 ± 18.1y | Italy: 63.3 ± 27.3 mmol/day | Q4 (n = 269) | ||||
| BMI: 25.5 ± 5.1 kg/m2 | 2.48 (2.38; 2.59) | |||||
| SBP: 122.5 ± 14.9 mmHg | Q5 (n = 272) | |||||
| DBP: 74.2 ± 9.8 mmHg | 2.53 (2.42; 2.65) | |||||
| Italian n: 199 | DBP | |||||
| Age: 45.3 ± 18.4 y | NR8 | |||||
| BMI: 24.5 ± 4.2 kg/m2 | ||||||
| SBP: 120.5 ± 15 mmHg | ||||||
| DBP: 69.9 ± 9.9 mmHg | ||||||
| Mohammadifard et al. (44)⌂ | Total n: 796 | Urinary Na | Total: 3.08 | SBP | Urinary Na:K ratio is significantly positively correlated with Pre-HT | P, IV |
| 2017 | Males n: 349 | Total: 176.94 ± 71.97 mmol/day | NT: 3.13 | Odds ratios (95% CI) of Pre-HTQ1 (Quartile of urinary Na:K ratio) | ||
| Iran | Females n: 447 | NT: 177 ± 73 mmol/day | Pre-HT: 3.24 | |||
| Cross-sectional | Age: 38.9 ± 11.4y | Pre-HT: 176.8 ± 66.1 mmol/day | ||||
| BMI: 25.7 ± 4.4 kg/m2 | Urinary K | 1.00 (0.45-2.21) | ||||
| SBP: 112.0 ± 10.9 mmHg | Total: 57.5 ±42 mmol/day | Q2 1.31 (0.62-2.77) | ||||
| DBP: 70.8 ± 8.7 mmHg | NT: 56.5 ± 42.3 mmol/day | Q3 2.15 (1.08-4.55) | ||||
| NT n: 309 | Pre-HT: 54.5 ± 39.7 mmol/day | P = 0.029 | ||||
| Age: 37.8 ± 11.0y | DBP | |||||
| BMI: 25.4 ± 4.5 kg/m2 | N/A | |||||
| SBP: 108.9 ± 8.5 mmHg | ||||||
| DBP: 68.1 ± 6.5 mmHg | ||||||
| Pre-HT n: 40 | ||||||
| Age: 43.6 ± 11.7y | ||||||
| BMI: 28.4 ± 4.5 kg/m2 | ||||||
| SBP: 126.2 ± 9.2 mmHg | ||||||
| DBP: 83.5 ± 5.7 mmHg | ||||||
| Ndanuko et al. (39) | Total n: 328 | Urinary Na6 [mean (95% CI)] | 1.9 (1.5-2.4) | SBP | Urinary Na:K ratio associated with SBP | P, IV |
| 2017 | NT/HT | 139 (99.2-180) mmol/day | Correlation coefficient = 0.1, P = 0.02 | |||
| Australia | Male n: 27 | Urinary K [mean (95% CI) | ||||
| Cross-sectional | Females n: 73 | 74 (96.7-154.3)] mmol/day | DBP | |||
| Age: 43.6 ± 8y | NR | |||||
| BMI: 32.4 ± 4.2 kg/m2 | ||||||
| SBP: 124.9 ± 14.5 mmHg | ||||||
| DBP: 73.3 ± 9.9 mmHg | ||||||
| Rhee et al. (45) | Total n: 524 | Urinary Na | Total: 3.10 ± 1.22 | SBP | Urinary Na:K ratio associated with SBP | Ø, IV |
| 2017 | Age: 48.1 ± 9.8 y | Total: 159.8 ± 61.5 mmol/day | NT: 3.05 ± 1.21 | All subjects: | ||
| Korea | BMI: 23.9 ± 3.3 kg/m2 | NT: 154.8 ± 59.9 mmol/day | HT: 3.13 ± 1.25 | β coefficient = 1.278 | ||
| Cross-sectional | Casual SBP: 116.7 ± 12.9 mmHg | HT: 166.8 ± 63.1 mmol/day | (P = 0.006) | |||
| Casual DBP: 75.0 ± 9.7 mmHg | Urinary K | HTs: | ||||
| 24-h SBP: 116.6 ± 11.0 mmHg | Total: 55.9 ± 20.7 mmol/day | β coefficient = 1.446 | ||||
| 24-h DBP: 75.9 ± 9.8 mmHg | NT: | (P = 0.047) | ||||
| AoSBP: 110.7 ± 13.1 mmHg | 54.3 ± 18.8 mmol/day | DBP | ||||
| AoDBP: 76.6 ± 10.0 mmHg | HT:58.3 ± 23.0 mmol/day | NR | ||||
| NTs n: 305 | ||||||
| Age: 45.1 ± 9.6y | ||||||
| BMI: 23.1 ± 3.1 kg/m2 | ||||||
| Casual SBP: 110.9 ± 10.0 mmHg | ||||||
| Casual DBP: 70.4 ± 7.0 mmHg | ||||||
| 24-h SBP: 110.8 ± 7.0 mmHg | ||||||
| 24-h DBP: 70.3 ± 6.1 mmHg | ||||||
| AoSBP: 104.8 ± 10.1 mmHg | ||||||
| AoDBP: 72.0 ± 7.4 mmHg | ||||||
| HTs n: 219 | ||||||
| Age: 52.1 ± 8.5y | ||||||
| BMI: 25.1 ± 3.2 kg/m2 | ||||||
| Casual SBP: 124.8 ± 12.3 mmHg | ||||||
| Casual DBP: 81.5 ± 9.2 mmHg | ||||||
| 24-h SBP: 124.6 ± 10.6 mmHg | ||||||
| 24-h DBP: 83.7 ± 8.7 mmHg | ||||||
| AoSBP: 118.8 ± 12.5 mmHg | ||||||
| AoDBP: 83.1 ± 9.6 mmHg | ||||||
| Vallejo et al. (46) | Total n: 711 | Urinary Na | Male: 3.2 ± 1.2 | SBP | Urinary Na:K ratio not associated with SBP or DBP | P, IV |
| 2017 | NTs | Male: 162±64 mmol/day | Female: 2.9 ± 1.1 | −0.2 [−0.7, 0.5] | ||
| Mexico | Age: 37.4 ± 9.0y | Female: 125 ± 48.2 mmol/day | DBP | |||
| Cross-sectional | BMI: 27.1 ± 4.4 kg/m2 | Urinary K | 0.1 [−0.4, 0.6] | |||
| SBP: 106.2 ± 10.2 mmHg | Male: 54 ± 18.5 mmol/day | |||||
| DBP: 70.6 ± 7.9 mmHg | Female: 46.5 ± 16.4 mmol/day | |||||
| Male n: 228 | ||||||
| Age: 36.0 ± 8.9y | ||||||
| BMI: 27.2 ± 4.3 kg/m2 | ||||||
| SBP: 110.5 ± 9.8 mmHg | ||||||
| DBP: 73.4 ± 7.9 mmHg | ||||||
| Female n: 483 | ||||||
| Age: 38.1 ± 8.9y | ||||||
| BMI: 27.1 ± 4.5 kg/m2 | ||||||
| SBP: 104.2 ± 9.7 mmHg | ||||||
| DBP: 69.3 ± 7.6 mmHg | ||||||
| Ware et al. (16)9 | Total n: 2722 | Urinary Na | Low salt: 2.7 (2.3) | SBP | Urinary Na:K ratio not associated with SBP and DBP | Ø,IV |
| 2017 | NTs/HTs | Median (IQR) | Medium salt: 3.6 (2.1) | NR | ||
| South Africa | Low salt n: 164 | Low salt: 62.7 (28.8) mmol/day | High salt: 3.7 (2.4) | SBP | ||
| Cross-sectional | Data below are median (IQR) | Medium salt: 115.3 (37.3) mmol/day | NR | |||
| Age: 59 (18)y | High salt: 217 (118.7) mmol/day | |||||
| BMI: 28.0 (9.8) kg/m2 | Urinary K | |||||
| SBP: 132 (25) mmHg | Median (IQR) | |||||
| DBP: 81 (17) mmHg | Low salt: 22.2 (16.4) mmol/day | |||||
| Medium salt n: 195 | Medium salt: 33.0 (24.2) mmol/day | |||||
| Age: 57 (19)y | High salt: 67.0 (43.2) mmol/day | |||||
| BMI: 28.5 (8.1) kg/m2 | ||||||
| SBP: 127 (25) mmHg | ||||||
| DBP: 78 (16) mmHg | ||||||
| High salt n: 167 | ||||||
| Age: 49 (26)y | ||||||
| BMI: 30.4 (10.6) kg/m2 | ||||||
| SBP: 128 (24) mmHg | ||||||
| DBP: 80 (16) mmHg | ||||||
| Xu et al. (28) | Total n: 2281 | Urinary Na | 6.8 (1.5) | SBP | Urinary Na:Kratio associated with SBP and DBP | P, IV |
| 2017 | NTs/HTs | 166.9 ± 25.6 mmol/day | β coefficient (95% CI): | |||
| China | Age: 42.1 ± 13.4y | Urinary K | 0.97 [0.36 to 1.58]*** | |||
| Cross-sectional | BMI classification: | 25.3 ± 3.4 mmol/day | DBP | |||
| Normal n: 982 | β coefficient (95% CI): | |||||
| 43.1% (95% CI: 41.0,45.1) | 0.65 [0.26 to 1.04]*** | |||||
| Overweight n: 860 | ||||||
| 37.7% (95% CI: 35.7, 39.7) | ||||||
| Obese: (n = 439) | ||||||
| 19.2% (95% CI: 17.6, 20.9) | ||||||
| SBP: 131.4 ± 19.9 mmHg | ||||||
| DBP:83.6 ± 11.9 mmHg | ||||||
| Male n: 1135 | ||||||
| Age: 42.2 ± 13.5y | ||||||
| BMI: | ||||||
| Normal n: 480 | ||||||
| 42.3% (95% CI: 39.4, 45.2) | ||||||
| Overweight n: 458 | ||||||
| 40.4% (95% CI: 37.5, 43.2) | ||||||
| Obese n: 197 | ||||||
| 17.3% (95% CI: 15.2, 19.6) | ||||||
| SBP:134.6 ± 18.0 mmHg | ||||||
| DBP:85.9 ± 11.9 mmHg | ||||||
| Female: (n = 1146) | ||||||
| Age: 41.9 ± 13.4y | ||||||
| BMI classification | ||||||
| Normal n = 502 | ||||||
| 43.8% (95% CI: 40.9, 46.7) | ||||||
| Overweight n = 402 | ||||||
| 35.1% (95% CI: 32.3, 37.8) | ||||||
| Obese n: 242 | ||||||
| 21.1% (95% CI: 18.8, 23.5) | ||||||
| SBP: 128.2 ± 21.1 mmHg | ||||||
| DBP: 81.3 ± 11.5 mmHg | ||||||
| Yan et al. (29) | Total n: 1948 | Urinary Na | 6.8 | SBP | Urinary Na:K ratio associated with increased of SBP and DBP | P, IV |
| 2015 | HTs (23%) | 235.7 (SD NR) mmol//day | (SD NR) | β coefficient (95% CI): | ||
| China | Age: 41.4 ± 13.9y | Urinary K | 0.37 [0.26 to 0.49]*** | |||
| Cross-sectional | BMI: NR | 40.5 (SD NR) mmol/day | DBP | |||
| SBP: NR | β coefficient (95% CI): | |||||
| DBP: NR | 0.16 [0.03 to 0.29]* | |||||
| Huggins et al. (40) | Total n: 738 | Urinary Na | 1.99 ± 0.83 | SBP | Urinary Na:K ratio associated with increased SBP | P, IV |
| 2011 | HTs (43%) | 155.1 ± 63.1 mmol/day | β coefficient (95% CI): | |||
| Australia | Age: 64.0 ± 6.3y | Urinary K | 1.8 [0.2 to 3.4]* | |||
| Cross-sectional | Male n: 376 | 82.3 ± 27.9 mmol/day | DBP | |||
| BMI: 28.4 ± 4.0 kg/m2 | β coefficient (95% CI): | |||||
| SBP: 133.0 ± 13.1 mmHg | 0.40 [−0.69 to 1.48] | |||||
| DBP: 76.1 ± 9.2 mmHg | ||||||
| Female n: 407 | ||||||
| BMI: 28.0 ± 4.9 kg/m2 | ||||||
| SBP: 129.5 ± 16.8 mmHg | ||||||
| DBP: 66.6 ± 10.4 mmHg | ||||||
| Zhao et al. (15) | Total n: 839 | Urinary Na | North: 7.6 ± 2.4 | SBP | Urinary Na:K ratio associated with increased SBP and DBP | P, IV |
| 2004 | North n: 561 | North: 271±88 mmol/day | South: 3.7 ± 1.5 | Coefficient for difference between North and South (95% CI NR) 3.30*** | ||
| China | HTs = 22% | South: 139±57 mmol/day | ||||
| Cross-sectional | Age: 48.9 ± 5.8y | Urinary K | ||||
| BMI: 23.8 ± 3.5 kg/m2 | North: 37.1 ± 11.5 mmol/day | |||||
| SBP: 123.7 ± 18.4 mmHg | South: 40.6 ± 14.7 mmol/day | |||||
| DBP: 75.5 ± 10.4 mmHg | ||||||
| South n: 278 | ||||||
| HTs = 7% | ||||||
| Age: 49.1 ± 5.7y | ||||||
| BMI: 21.8 ± 2.6 kg/m2 | ||||||
| SBP: 116.3 ± 14.1 mmHg | ||||||
| DBP: 68.6 ± 8.0 mmHg | ||||||
| Xie et al. (30) | Total n: 353 | Urinary Na | Male: 6.1 ± 2.3 | SBP | Urinary Na:K ratio associated with increased SBP and DBP | P, IV |
| 2001 | NTs/HTs | Male: 152.9 ± 62.5 mmol/day | Female: 6.1 ± 2.6 | β coefficient (95% CI NR): | ||
| China | Male n: 191 | Female: 123.3 ± 59.3 mmol/day | Male: 1.167** | |||
| Cross-sectional | Age: 40.0 ± 16.5y | Urinary K | Female: 1.310** | |||
| BMI: 22.0 ± 2.3 kg/m2 | Male: 28.7 ± 17.2 mmol/day | DBP | ||||
| SBP: 116.9 ± 13.1 mmHg | Female: 23.7 ± 14.3 mmol/day | β coefficient (95% CI NR): | ||||
| DBP: 74.3 ± 8.9 mmHg | Male: 0.573* | |||||
| Female n: 162 | Female: NR | |||||
| Age: 36.7 ± 15.7y | ||||||
| BMI: 22.7 ± 2.8 kg/m2 | ||||||
| SBP: 117.6 ± 17.5 mmHg | ||||||
| DBP: 74.8 ± 11.1 mmHg | ||||||
| Tian et al. (31) | Total n: 663 | Urinary Na | Male: 6.6 ± 2.2 | SBP | Urinary Na:K ratio associated with increased SBP and DBP in females and both sexes combined | P, IV |
| 1995 | NTs/HTs | Male: 257.8 ± 86.0 mmol/day | Female: 6.1 ± 2.4 | β coefficient ± SE | ||
| China | Male n: 328 | Female: 249.2 ± 81.4 mmol/day | Male: 0.735 ± 0.402 | |||
| Cross-sectional | Age: 43.6 ± 13.6 y | Urinary K | Female: 0.956 ± 0.380* | |||
| BMI: 23.4 ± 3.4 kg/m2 | Male: 42.4 ± 17.0 mmol/day | Total: 0.795 ± 0.277** | ||||
| SBP: 126 ± 18 mmHg | Female: 45.0 ± 18.2 mmol/day | DBP | ||||
| DBP: 81 ± 11 mmHg | β coefficient ± SE | |||||
| Female n: 335 | Male: 0.261 ± 0.253 | |||||
| Age: 43.5 ± 13.3y | Female: 0.561 ± 0.213** | |||||
| BMI: 23.6 ± 4.4 kg/m2 | Total: 0.400 ± 0.164* | |||||
| SBP: 121 ± 20 mmHg | ||||||
| DBP: 78 ± 11 mmHg | ||||||
| He et al. (32) | Total n: 419 | Urinary Na | High-mountain Yi: | SBP | Urinary Na:K ratio associated with increased SBP and DBP | Ø, IV |
| 1991 | NTs | High-mountain Yi: | 1.45 ± 0.92 | β coefficient 0.928**** | ||
| China | High-mountain Yi | 73.9 ± 50.3 mmol/day | Mountainside Yi: | (95% CI NR): | ||
| Cross-sectional | Age: 30.9 ± 11.5y | Mountainside Yi: | 3.45 ± 2.50 | DBP | ||
| BMI: 19.3 ± 2.2 kg/m2 | 117.9 ± 55.4 mmol/day | Country Yi: | β coefficient 0.645**** | |||
| SBP: 99.4 ± 7.8 mmHg | Country Yi: | 6.87 ± 3.79 | (95% CI NR): | |||
| DBP: 63.2 ± 7.4 mmHg | 159.4 ± 62.6 mmol/day | Country Han: | ||||
| Country Han: | 7.00 ± 2.23 | |||||
| Mountainside Yi | 186.0 ± 73.0 mmol/day | |||||
| Age: 36.4 ± 14.3y | Urinary K | |||||
| BMI: 19.4 ± 1.6 kg/m2 | High-mountain Yi: | |||||
| SBP: 101.8 ± 9.1 mmHg | 58.6 ± 31.0 mmol/day | |||||
| DBP: 62.2 ± 8.2 mmHg | Mountainside Yi: | |||||
| Country Yi | 48.5 ± 28.1 mmol/day | |||||
| Age: 39.3 ± 12.7y | Country Yi: | |||||
| BMI: 20.4 ± 2.1 kg/m2 | 28.3 ± 13.6 mmol/day | |||||
| SBP: 108.6 ± 9.2 mmHg | Country Han: | |||||
| DBP: 71.3 ± 8.2 mmHg | 29.0 ± 10.4 mmol/day | |||||
| Country Han | ||||||
| Age: 36.4 ± 12.1y | ||||||
| BMI: 20.8 ± 2.7 kg/m2 | ||||||
| SBP: 107.3 ± 12.1 mmHg | ||||||
| DBP: 69.6 ± 8.9 mmHg | ||||||
| Staessen et al. (37) | Total n: 301 Males | Urinary Na | Daytime: 2.4 ± 1.0 | SBP | Urinary Na:K ratio associated with increased SBP and DBP | Ø, IV |
| 1991 | NTs/HTs | Daytime: 120 ± 46 mmol/12h | Nighttime: 3.5 ± 1.6 | Whole day urine: | ||
| UK | Age: 45 ± 6y | Nighttime: 54 ± 29 mmol/12h | Whole day: 2.5 ± 10 | β coefficient ± SE | ||
| Cross-sectional | BMI: 24.1 ± 2.8 kg/m2 | Whole day: 174 ± 557 mmol/day | 2.110 ± 0.895* | |||
| SBP: 126 ± 16 mmHg | Urinary K | DBP | ||||
| DBP: 78 ± 11 mmHg | Daytime: 56 ± 20 mmol/12 hr | Whole day urine: | ||||
| Nighttime: 18 ±11 mmol/12h | β coefficient ± SE | |||||
| Whole day: 73±22 mmol/day | 2.084 ± 0.653** | |||||
| Kesteloot et al. (33) | Total n: 2008 | Urinary Na | M10 North: 6.56 ± 2.55 | SBP | Urinary Na:K ratio associated with increased SBP and DBP in northern China, while only with SBP in southern China | Ø, IV |
| 1987 | NTs/HTs | M North: 226.9 ± 88.8 mmol/day | M South: 6.73 ± 2.41 | β coefficient range: | ||
| China | Male n: 1002 | M South: 179.4 ± 72.9 mmol/day | F North: 5.92 ± 2.27 | 0.650 to 0.967* | ||
| Cross-sectional | North: | F11 North: 204.6 ± 82.1 mmol/day | F South: 6.15 ± 2.28 | DBP | ||
| Age: 40.4 ± 14.4 y | F South: 172.4 ± 70.6 mmol/day | β coefficient range: | ||||
| SBP: 125.7 ± 17.6 mmHg | Urinary K | 0.402 to 0.751 | ||||
| DBP: 83.1 ± 12.1 mmHg | M North: 37.5 ± 15.8 mmol/day | |||||
| South: | M South: 28.8 ± 13.0 mmol/day | |||||
| Age: 40.4 ± 14.4y | F North: 37.5 ± 17.1 mmol/day | |||||
| SBP: 118.1 ± 12.6 mmHg | F South: 29.7 ± 11.6 mmol/day | |||||
| DBP: 77.6 ± 9.8 mmHg | ||||||
| Female n: 1006 | ||||||
| North: | ||||||
| Age: 40.2 ± 14.4y | ||||||
| SBP: 122.0 ± 21.7 mmHg | ||||||
| DBP: 80.4 ± 14.7 mmHg | ||||||
| South: | ||||||
| Age: 40.5 ± 14.3y | ||||||
| SBP: 112.3 ± 14.3 mmHg | ||||||
| DBP: 75.0 ± 10.2 mmHg | ||||||
| Chan et al. (34) | Total n: 126 | Urinary Na | Males: 4.0 ± 1.7 | SBP | Non-significant association between urinary Na:K ratio with SBP and DBP (data not shown) | Ø, IV |
| 1998 | NTs/HTs | Male: 145.2 ± 48.7 mmol/day | Female: 3.5 ± 1.4 | NR | ||
| China | Males n: 42 | Female: 135.3 ± 45.8 mmol/day | DBP | |||
| Cross-sectional | Age: 41.8 ± 16.4y | Urinary K | NR | |||
| SBP: 113.4 ± 14.7 mmHg | Male: 40.4 ± 15.1 mmol/day | |||||
| DBP: 113.4 ± 14.7 mmHg | Female: 41.3 ± 14.3 mmol/day | |||||
| Female n: 84 | ||||||
| Age: 41.6 ± 10.9y | ||||||
| SBP: 106.0 ± 16.4 mmHg | ||||||
| DBP: 106.0 ± 16.4 mmHg | ||||||
| Kim et al. (51)9 | Total n: 740 | Urinary Na (median, 25th, 75th percentile) | 2.9 (2.2, 3.7) | SBP | Urinary Na:K associated with BP in older population | P, IV |
| 2019 | HTs = 40% | β coefficient (95% CI) | ||||
| South Korea | Data below is median (25th, 75th percentile) | 153.9 (116.3, 197.5) mmol/day | 0.0364 [−0.0308 to 0.1035] | |||
| Cross-sectional | Older group (≥55 years) | |||||
| Cross-sectional | Age: 48 (41, 56) y | Urinary K (median, 25th, 75th percentile) | 0.1325 [0.0031 to 0.2620]* | |||
| BMI: 23.5 (21.5, 25.6) kg/m2 | 54.9 (43.0, 69. 8) mmol/day | DBP | ||||
| HT n: 299 | β coefficient (95% CI) | |||||
| SBP: 115.3 (107.9, 122.8) mmHg | 0.0317 [−0.0322 to 0.0955] | |||||
| DBP: 75.5 (68.4, 82.2) mmHg | Older group (≥55 years) | |||||
| 0.1234 [0.0025 to 0.2444]* | ||||||
| Libianto et al. (38) | Total n: 116 | Urinary Na | 2.5 ± 1.1 | SBP | Urinary Na:K associated with SBP | P, IV |
| 2017 | NTs/HTs | 169±77 mmol/day | β coefficient (95% CI): | |||
| Australia | Age: 65 ± 12y | Urinary K | −2.373 [−4.447 to −0.299]* | |||
| Cross-sectional | BMI: 31±5 kg/m2 | 70±25 mmol/day | DBP | |||
| SBP: 130 ± 14 mHg | β coefficient (95% CI): | |||||
| DBP: NR | N/A | |||||
| M'buyamba-Kabangu | Total n: 416 | Urinary Na | 3.1 (0.3-13.3) | SBP | Urinary Na:K associated with both SBP and DBP | P, IV |
| et al. (47)9 | NTs/HTs | Mean 87 (range minimum- maximum 8 to 312) mmol/day | 1.02* (95% CI NR) | |||
| 1986 | Age: 32 ± 12y | DBP | ||||
| Zaire | SBP: 124 ± 20 mmHg | Urinary K | 0.68* (95% CI NR) | |||
| Cross-sectional | DBP: 72 ± 14 mmHg | Mean 33 (range minimum- maximum 3 to 132) mmol/day |
1
*P < 0.05. **P < 0.01.***P < 0.001. ****P < 0.0001. Electrolytes: □ Na: K ratio reported as adjusted (for age, BMI, sex and linguistic region) means (95% confidence limits); association of Na: K ratio with SBP reported by sex-specific quintile (Q) of systolic blood pressure P value < 0.001. ⌂ Quartiles (Q) based on urinary sodium to potassium ratio, SBP: P < 0.001, DBP: P = 0.003. AoSBP, aortic systolic blood pressure; AoDBP, aortic diastolic blood pressure; BMI, body mass index; DBP, diastolic blood pressure; HT, hypertensive; NR, not reported; NT, normotensive; Pre-HT, pre-hypertensive; SBP, systolic blood pressure.
2
Body mass index is Mean ± SD unless otherwise indicated;
3
Blood pressure is Mean ± SD unless otherwise indicated;
4
Mean ± SD in mmol/day;
5
β coefficient (95% CI) unless specified;
6
Quality rating: P = Positive, Ø = Neutral, − = Negative;
7
NHMRC (National Health and Medical Research Council) rating is classified as I, III-1, III-2, III-3 OR IV;
8
NR: Not reported;
9
Subjects data and Na, K, Na: K ratio presented as median (IQR, interquartile range);
10
M: Male
11
F: Female