The effectiveness of an educational intervention for sodium restriction in patients with hypertension: study protocol for a randomized controlled trial

Abstract

BackgroundThe effectiveness of nonpharmacological interventions in blood pressure reduction has been evidenced by several studies. Nevertheless, as adherence to a low-sodium diet is poor, interventions regarding habit changing should be of a motivational nature in order to develop the ability of overcoming obstacles regarding sodium-restriction behavior.The present study aims to describe the protocol and randomization of a clinical trial design in order to evaluate the effectiveness of an educational intervention based on Dietary Sodium Restriction Questionnaire (DSRQ) scores. The effectiveness measures are the DSRQ score variation and reduction in urinary sodium values from baseline to after 2 and 6 months.Methods/designThis parallel, randomized clinical trial will include 120 participants, recruited and randomized as follows: 60 of them to be allocated to a sodium-restriction educational intervention group whose results are based on the DSRQ application; and the other 60 allocated to a control group with usual care. Educational orientation and usual care sessions will be conducted once a month for a period of 6 months. Both spot urine collection – estimating sodium intake – and the DSRQ will be applied at the baseline, in the eighth week and at the end of the follow-up. There will also be blood collection and 24-h ambulatory blood pressure monitoring (ABPM) at the beginning and end of the follow-up. Anthropometric measurements, blood pressure measurement and 24-h food recall will be collected during follow-up.DiscussionThe study “The effectiveness of an educational intervention to sodium restriction in patients with hypertension” is based on the results of the DSRQ application, whose objective is to evaluate aspects related to nonadherence to the recommendation of a low-sodium diet, identifying adherence barriers and facilitators, contributing to the planning of interventions for improving the adoption of a low-sodium diet and, consequently, hypertension control.Trial registration numberClinicalTrials.gov, Identifier: NCT02848690. Registered retrospectively on 27 July 2016.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-017-2091-4) contains supplementary material, which is available to authorized users.

Efficacy of an Educational Intervention for Sodium Restriction in Patients with Hypertension: A Randomized Controlled Trial

“…After a 6-week intervention, the results of a study [25] conducted on patients with heart failure showed an improvement in attitude subscale scores, which suggests a positive shift in their attitudes toward adhering to a low-sodium diet. Our findings agree with other studies regarding participants perceiving fewer barriers to sodium restriction, improving the ability to read labels, choose foods and eat meals, and reinforcing the perceived ability to deal with possible obstacles [26,27]. Participants presented positive attitudes toward following a low-sodium diet.…”

“…Prior to enrollment, participants provided informed consent, and the study protocol (protocol number 150496) was approved by the hospital's institutional review board. Additionally, the study protocol has been registered at ClinicalTrials.gov (NCT02848690) and published [22].…”

“…These recommendations included reducing sodium intake, avoiding high-sodium foods and alcoholic beverages, and losing weight if a body mass index was greater than 25 kg/m 2 . The DSRQ [22] was administered at baseline, three months after the randomization, and at the end of the follow-up period. Anthropometric and office BP measurements were performed monthly during 30-min face-to-face appointments throughout the follow-up period.…”

Home blood pressure measurement days and changes in urinary sodium-to-potassium ratio, estimated salt and potassium intakes and blood pressure: 1-year prospective study

“…[30] evaluated the effects of nutrition education on decreasing sodium intake and increasing potassium intake in prehypertensive or untreated hypertensive Korean patients and found that education was effective in reducing sodium intake but not in increasing potassium. A recent meta-analysis also reported that global mean potassium intake (2.25 g/day) falls below the recommended intake level of >3.5 g/day, with the lowest mean potassium intake reported in Asia (1.89 g/day) and the highest mean intake in Eastern and Western Europe (3.53 g/day and 3.29 g/day, respectively) [31]. These findings, together with ours, indicate the importance of raising awareness about high potassium intake to effectively lower BP, especially in Asia.…”