Changes in the Urinary Sodium-to-Potassium Ratio Are Associated with Blood Pressure Change in Older Japanese Adults: A 7-Year Longitudinal Study

Abstract

Studies on the association between sodium-to-potassium (Na/K) ratio changes and blood pressure (BP) changes among older adults are limited. This 7-year longitudinal study examined the association between Na/K ratio changes (evaluated using spot urine tests) and BP changes among older Japanese adults. Data were collected from 432 participants (mean age: 70.3±4.4; range: 65–84 years) in 2012 and 2019. Changes in BP and the Na/K ratio over 7 years were calculated by subtracting baseline values from values noted during a follow-up survey. The median systolic and diastolic BP (SBP) and (DBP) changes after 7 years were 4 (IQR, −7, 14) and −1 (IQR, −9, 5) mmHg, respectively. The median Na/K ratio was changed during the follow-up period by −0.2 (IQR, −1.3, 0.7). A generalized linear model indicated that Na/K ratio changes were positively associated with SBP (B = 2.03, p < 0.001) and DBP (B = 0.62, p = 0.021) changes. In the non-antihypertensive medication-using group, urinary Na/K ratio changes were associated with SBP and DBP changes (B = 2.39, p = 0.001; B = 0.99, p = 0.033). In the antihypertensive medication user group, urinary Na/K ratio changes were associated with SBP changes (B = 1.62, p = 0.015). We confirmed the association between changes in the Na/K ratio and changes in BP.

Association between spot urinary sodium-to-potassium ratio and blood pressure among Chinese adults aged 18–69 years: the SMASH study

“…presented that the association was more significant in older groups (18). The possible reason may be attributed to salt sensitivity.…”

“…To improve the dietary consumption of high sodium and low potassium, restricting sodium intake and simultaneously increasing potassium intake are urgently needed in China. Currently, the sodium-to-potassium ratio has been regarded as a better monitoring indicator than the ion alone (17)(18)(19)(20)(21). Clarifying the relationship between the urinary Na/K ratio and BP will aid in developing effective public health strategies.…”

Association between sodium-to-potassium ratio in spot urine and hospitalization due to heart failure in high-risk Japanese patients

“…Mean (median) Na/K ratios in Western and Asian population were approximately 1–3 and 3–5 [16] . In the population survey, the mean Na/K ratios were 1.0–1.3 in the National Health and Nutritional Examination Survey (NHANES, using 24-h dietary recalls [17] ) in USA, 1.8 in Norway (24-h urine) [18] , 2.40 in Iran (spot urine) [19] , 4.1 in China (24-h urine) [20] , 2.5 (spot urine) [8] and 5.4 (spot urine) [7] in Japan. Based on the results of the INTERSALT study findings using 24-h urinary collection, Stamler, et al recommended the Na/K target level of 1.0 to reduce the risk of CV diseases [21] .…”

“…A randomized controlled trial conducted in Taiwan [3] reported that patients who were assigned to receive potassium-enriched salt (49 % sodium chloride and 49 % potassium chloride) showed a significant reduction (41 %) in CV mortality as compared to the patients who received regular salt, suggesting that increased potassium intake plays a substantial role in addition to reduced sodium intake. Several studies have reported a positive association between the sodium-to-potassium (Na/K) ratio and hypertension and CV disease [1] , [2] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] . Furthermore, a stronger association was found between the Na/K ratio and CV disease than between sodium and potassium alone [1] , [2] .…”

Organic small-molecule fluorescent probe-based detection for alkali and alkaline earth metal ions in biological systems

“…28 However, poor eating habits often lead to sodium intake far exceeding the normal value, which is also one of the reasons for the increased risk of hypertension, heart disease, osteoporosis, asthma, and gastric cancer. [29][30][31][32][33][34][35] The imbalance of sodium ions in the human body can lead to stroke, diabetes and even kidney disease. Therefore, it is highly significant to develop a series of fluorescent probes for sodium ion detection in vitro and in vivo.…”