Spot urine-guided salt reduction is effective in Japanese cardiology outpatients

Abstract

Dietary salt restriction is recommended for the prevention of cardiovascular disease in patients with hypertension and heart failure as well as in the general population. However, salt reduction is very difficult without knowing the daily salt intake of individual patients. A total of 524 subjects (72 ± 10 year old, 246 female) who visited an outpatient cardiology clinic were included in this study. Daily dietary salt intake was estimated based on the sodium and creatinine concentrations of spot urine at the time of enrollment and during follow-up for 8-26 weeks. The attending physicians explained the individual data to the patients and encouraged them to reduce their salt intake through simple counseling. The baseline estimated salt excretion was 9.6 ± 2.7 (range: 3.5-22.1) g per day, which decreased to 8.7 ± 2.3 (3.7-18.0) g per day during follow-up. The systolic blood pressure decreased from 127.0±15.4 (range: 80-170) to 125.6±14.5 (80-172) mm Hg (P ¼ 0.026), and the diastolic blood pressure decreased from 73.4 ± 11.0 (range: 40-106) to 71.5 ± 10.8 (50-102) mm Hg (Po0.001). In conclusion, the estimation of salt intake by spot urine was a useful method for motivating patients to reduce their salt intake; however, achieving salt reduction to the level recommended by the guideline could be a challenge.

Effects of single-session dietary counseling by dieticians on salt reduction in cardiology outpatients who consumed large amounts of salt

“…A total of 72 patients were included in this study. The baseline characteristics of the patients are presented in Table I; these characteristics were similar to those reported in previous studies (3,4), with the exception that the salt excretion levels were considerably higher. There were no differences in the characteristics between patients who received dietary counseling and those who did not (the control group).…”

“…Furthermore, control patients were retrospectively included. However, the control patients were well matched with the case patients for age, gender, body mass index and daily salt excretion (Table I), and the changes in salt excretion were consistent with those previously reported (3,4). Thus, it is considered that selection bias was not sufficiently large to affect the main conclusions of the study.…”

“…The present study has certain limitations. First, the estimation of daily urinary salt excretion using a spot urine sample may be less accurate than that using 24-h urine collection, as previously noted (3,4). However, it is difficult to collect 24-h urine in real-world practice.…”

“…However, salt reduction is challenging to achieve in the real world, particularly in countries in which salt consumption is extremely high, such as Japan. We have previously reported that the estimation of salt intake using the spot urine method may be a useful tool to motivate patients to reduce their salt intake for 8-26 weeks (3), and the efficacy of this method was found to be maintained at long-term (up to 2 years) follow-up (4). However, the percentage of patients who could achieve a reduction in salt intake to the recommended level was very low (<10-15%) (3,4).…”

“…We have previously reported that the estimation of salt intake using the spot urine method may be a useful tool to motivate patients to reduce their salt intake for 8-26 weeks (3), and the efficacy of this method was found to be maintained at long-term (up to 2 years) follow-up (4). However, the percentage of patients who could achieve a reduction in salt intake to the recommended level was very low (<10-15%) (3,4). In particular, patients who habitually consume large amounts of salt at baseline find it difficult to reduce salt intake to the recommended level regardless of gender, age and body weight (4).…”