Sodium Watchers Program - Hypertension
Condition: Hypertension
MeSH terms: Hypertension
Study type: Interventional

Summary: 
      Hypertensive adults are a vulnerable population at high risk of developing cardiovascular
      disease. Despite the many interventions tested to reduce hypertension, it remains a major
      risk factor that is not appropriately managed in the population. Prior dietary interventions
      were successful on reduction of sodium intake, but the changes were not maintained after the
      end of the intervention. We propose that changing patients' salt taste preference and
      including family members will produce long-term changes in sodium intake and blood pressure.
      The Sodium Watchers Program (SWaP) proposed in this study is designed to improve adherence to
      a sodium restricted diet through education and self-care strategies for gradual taste
      adaptation to low salt foods. The purpose of this pilot is to test short-term effects of the
      SWaP intervention on adherence to the sodium restricted diet, blood pressure, salt taste
      preference, and dietary patterns in hypertensive adults. A total of 30 hypertensive adults
      will be randomly assigned to the intervention (n=20) or control group (n=10). The
      intervention group will receive 16-weeks of education and booster sessions remotely using a
      video conferencing program on mini-iPads. All participants will collect a 24-hour urine
      specimen for sodium excretion and complete assessments of blood pressure, salt taste
      preference testing using salt concentration solutions, and dietary pattern using VioScreen
      Food Frequency Questionnaire at baseline and post intervention at 4-months. Data will be
      analyzed using repeated measures analysis of variance.
    

Detailed description: 
      Hypertension or high blood pressure is known as a silent killer because it can exist for
      decades without producing symptoms while leading to chronic cardiovascular disease and
      stroke. The long-term objective of this program of research is to improve blood pressure
      control and prevent cardiovascular disease development in adults with hypertension by
      increasing adherence to a sodium-restricted diet (SRD). The Sodium Watchers Program is an
      innovative self-management intervention using a gradual sodium adaptation strategy that
      allows individuals to monitor, and over time, reduce sodium content in their food, thereby
      increasing the ability to maintain an SRD long term. The purpose of the proposed randomized,
      controlled trial is to test the effects of the Sodium Watchers
      Program-Hypertension(SWaP-Hypertension), designed to improve blood pressure control of
      hypertensive adults using a gradual sodium reduction adaptation strategy.

      The SWaP-Hypertension intervention consists of 14 weeks of education [4 weekly education
      sessions (45 minutes) followed by 5 bi-weekly sessions 5-20 minutes] that will be held at
      participants' preferred time delivered to their homes using a video conferencing program
      through a mini iPad. Using a 2-group design [SWaP-Hypertension (n=20) versus Usual care
      (n=10)], randomized, controlled trial with 30 hypertensive adults, the effects of the
      SWaP-Hypertension program on adherence to SRD, systolic and diastolic blood pressure, salt
      taste preference, and dietary patterns will be determined at 4 months. Data will be analyzed
      using repeated measures analysis of variance.

      Specific Aim 1: To compare sodium intake (as reflected by 24-hour urinary sodium excretion),
      systolic and diastolic blood pressure, salt taste preference, and dietary patterns in the
      SWaP-Hypertension intervention group with the usual care group at 4 months.

      Hypothesis 1: The intervention group will have a greater decline in 24-hour urinary sodium
      excretion and systolic and diastolic blood pressure, lower salt taste preference, and shift
      dietary patterns toward lower sodium foods than the usual care group at 4 months.

      High blood pressure (systolic blood pressure ≥140 mmHg or diastolic blood pressure≥ 90 mm
      Hg), is a leading risk factor for cardiovascular disease and stroke.1 More than 80 million
      adult Americans have high blood pressure and it is projected that 41.4% of US adults will
      have hypertension by 2030.

      Sodium restriction is believed to decrease blood pressure. According to a recent
      meta-analysis of 24 randomized controlled trials, dietary interventions (e.g., low sodium
      diet, low sodium/high potassium, low sodium/low calorie, Mediterranean diet, and DASH diet)
      were effective in reducing systolic blood pressure by an average of 3.07 mmHg and diastolic
      blood pressure by an average of 1.81 mmHg. These changes are minimal and are often not
      sustained due to the difficulty of following such diets.

      Most interventions for improving adherence to SRD have focused on increasing specific skills,
      including how to read food labels, choose low sodium foods when eating out, and engage family
      support. However, these interventions do not effectively address critical barriers to SRD
      adherence, which include preference of high salt food and habitual dietary patterns. Salt
      taste reception involves the sodium ion movement through sodium channels at the apical end of
      the taste bud. High salt foods become preferable when individuals' taste buds adapt to foods
      high in sodium. Preference for salty foods results in high levels of dietary sodium intake.

      These barriers are particularly salient for older patients as taste bud density decreases
      with age resulting in an increasing preference for salt and consumption of foods high in
      sodium. Combined, low palatability of low sodium foods and preference for high sodium foods
      make dietary changes difficult. Since at least 8-10 weeks of exposure to an SRD is required
      to alter sodium palatability (i.e., alter salt acuity and salt taste preference) abrupt and
      marked reductions in sodium intake are rarely sustained and can have the unintended
      consequence of exacerbating sodium-seeking behaviors. New approaches are needed to improve
      long-term adherence to SRD.

      An innovative dietary self-care intervention has been developed to overcome sensory barriers
      to adherence. Abrupt and marked reductions in sodium intake can lead to sodium-seeking
      behaviors, and thus, changing dietary preferences requires at least 8 weeks to reach a new
      hedonic state and to reset sodium taste buds. Thus, an intervention that uses a gradual
      adaptation strategy should produce the best long-term adherence results. Most educational
      interventions have focused on improving knowledge by teaching patients specific skills
      including how to read food labels, how to choose low sodium foods when eating out, and how to
      modify their usual diet.

      Design: A two-group, randomized, controlled design will be used to determine the effect of
      the SWaP-Hypertension on outcomes of hypertensive adults. A total of 30 eligible participants
      will be randomly assigned to intervention (n=20) or usual care group (n=10). We will assign
      20 participants in the intervention that is two times more than the usual care group in order
      to maximize limited funding sources. The intervention will be delivered for 14 weeks using
      video conferencing on an iPad device. Post-intervention will be measured at 4 months follow
      up to examine short-term effect. Dependent variables included adherence to the SRD, systolic
      and diastolic blood pressure, salt taste preference, and dietary patterns.

      Intervention: Sodium Watchers Program-Hypertension (SWaP-Hypertension): The SWaP- is an
      educational-behavioral intervention that uses an electronic salt monitoring device to promote
      both rural adults with high blood pressure and their family partner's ability to self-monitor
      sodium intake and gradually decrease their appetite for salt. The program consists of 14
      weeks education [4 weekly education sessions (45 minutes) followed by 5 bi-weekly sessions
      (15-20 minutes)] that will be held at the dyads' preferred time delivered to their homes
      using a video conferencing program through a mini iPad. Video conferencing technology is used
      to enhance the feasibility and decrease the burden of participating in the intervention.
      Bi-weekly booster sessions are added to provide on-going support to maintain acquired
      self-care behaviors and individual goals for reductions in dietary sodium. The booster
      sessions include positive reinforcement of success and identification of strategies to
      overcome ongoing or new challenges. A nurse interventionist who experienced in delivering the
      intervention will assist individual goal settings and reinforces strategies in each session.

      Usual care group: The usual care group receive their routine medical and nursing care for
      hypertension that consists of a recommendation to follow an SRD and take medications as
      ordered.

      Measures: Table 2 lists dependent variables and their measurement in the study. To completely
      characterize subjects and monitor potential intervening variables, data about the
      individuals' age, sex, race/ethnicity, education level, comorbidities, medications, and
      cognitive impairment will be collected from the participant interviews or using a structured
      questionnaire. Comorbidity will be measured using the Charlson Comorbidity Index. Data about
      medications will be self-report. Cognitive impairment will be assessed using the Mini-Cog.
      This 3-minute screening instrument consists of drawing a clock and three-word recall. It is
      sensitive, reliable and valid in individuals with low literacy and low socioeconomic status.
      Our research staff has extensive experience in all data collection proposed in this study.

      Procedure: Permission to conduct the study was obtained from the University of Kentucky,
      Institutional Review Board. Hypertensive adults are referred to this project by physicians
      and nurse practitioners from the outpatient cardiology and internal medicine services at the
      University of Kentucky HealthCare at Lexington. After referral, a trained research nurse will
      screen patients for eligibility by medical chart review. For eligible participants, the study
      requirements are explained and signed informed consents are obtained. After we obtain the
      informed consents from eligible participants, urine containers and collection devices
      (urinals for men and toilet "hats" for women) are provided before home visits. The
      participants are instructed how to collect the 24-hour urine specimen, and written standard
      instructions are also provided. Urine is kept in the container and does not need
      refrigeration. Research staff and participants set up the starting day of urine collection
      and pick up urine specimens in their home. During the home visit, they are assisted to
      complete all study questionnaires using the REDCap system and assessment of blood pressure
      and salt taste preference. A trained staff member will deliver education materials and an
      iPad to the participants in the intervention group and instruct them how to use the video
      conference program (i.e., Zoom Mobile app) on iPad by testing trial of a video-conferencing
      program. A toll-free phone number is to call at any time for assistance using the iPad is
      provided. The usual care group will receive a mini iPad with instruction of using emails and
      text message to contact research staff. All participants will follow the same data collection
      procedure as during the baseline assessment for 4-months follow-up time point.
    

Intervention name(s): Sodium Watcher Program-Hypertension; Usual Care
Intervention type(s): Behavioral; Behavioral
Intervention description(s): The Sodium Watcher Program -Hypertension intervention consists of 14 weeks of education [4 weekly education sessions (45 minutes)followed by 5 bi-weekly sessions 5-20 minutes] that will be held at the dyads' preferred time delivered to their homes using a video conferencing program through an iPad.; Participants in the usual care group receive their routine medical and nursing care for hypertension that consists of a recommendation to follow a sodium restricted diet and take medications as ordered. Usual care consists of recommendations to follow a sodium restricted diet, but without explicit skills training including instructions on gradual adaptation to sodium restricted diet, follow-up of progress or provision of monitoring.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Hypertension; Low Sodium Diet