Tailored Messaging to Reduce Sodium Intake

The proposed study will determine the effectiveness of a mobile application location-based tailored notification message system in helping hypertensive patients reduce dietary sodium intake and feel more confident in following a low sodium diet.

People with high blood pressure often get advice to lower their salt or sodium intake. High dietary sodium intake is linked to high blood pressure, stroke, heart failure and kidney disease. U.S. federal guidelines advocate daily sodium intake of less than 2,300 milligrams (mg). The estimated average sodium intake for Americans is 3,400 mg per day. In recent years, consumption of processed and restaurant foods has substantially increased. More than 75% of sodium in the average U.S. diet now comes from these sources. The mobile application will deliver tailored messages based on the user's location and previously identified high-sodium food items that they commonly consume. This 8-week research study at Visit 1 or baseline will consent and randomize 50 eligible adults with high blood pressure to use the mobile application daily or to follow their usual eating pattern with no access to the application. All participants will be asked to complete four surveys at baseline and Week 8: Block Food Frequency Questionnaire, Block Sodium Screener, Self-care Confidence in following a Low Sodium Diet and the Automated Self-administered 24-Hour Dietary Recall survey. All participants will be asked to provide a baseline and end of study 24-hour urine collection, regularly provide home blood pressure measurements and urine dipstick tests every two weeks.

Participants receive location-based tailored messaging via a mobile application throughout the 8-week research study.

Participants follow their usual eating pattern and will not have access to the application throughout the 8-week research study.

The mobile application works by providing tailored messages targeted to participant locations that can help individuals to choose lower sodium foods.

Change from baseline in Self-care Confidence in Following a Low-sodium Diet Scale (SCFLDS) at week 8. It assesses the participants' confidence in the ability to select and prepare low-sodium foods. The self-reported tool consists of 7 items with 4 response options per item. The score range is 1-4 (1=Not confident, 2=Somewhat confident, 3=Very confident, 4=Extremely confident) then added for each question. Possible scores range from 7 to 28 and the higher the score indicates greater confidence.

Estimated dietary sodium intake from Block Food Frequency Questionnaire (inter-group comparison at week 8, intra-group change from baseline-week 8)

Inclusion Criteria: > 18 years of age Hypertension Use of anti-hypertensive therapy for at least 3 months, with stable anti-hypertensive therapy (medication type and dose) for at least 2 weeks Daily sodium intake of >2,000 mg with sodium to kcal ratio > 1, estimated via Food Frequency Questionnaire Ownership and use of an Apple iPhone Exclusion Criteria: Chronic Kidney Disease Heart Failure Systolic Blood Pressure >180 mm Hg Diastolic Blood Pressure >110 mm Hg Use of a loop diuretic or corticosteroid Insulin dependent diabetes mellitus

Alhashimi L, Cordwin DJ, Dandu C, Hummel SL, Dorsch MP. Patient self-assessment of urine dipsticks to estimate sodium intake in patients with hypertension. Clin Nutr ESPEN. 2022 Oct;51:295-300. doi: 10.1016/j.clnesp.2022.08.011. Epub 2022 Aug 12.

Dorsch MP, Cornellier ML, Poggi AD, Bilgen F, Chen P, Wu C, An LC, Hummel SL. Effects of a Novel Contextual Just-In-Time Mobile App Intervention (LowSalt4Life) on Sodium Intake in Adults With Hypertension: Pilot Randomized Controlled Trial. JMIR Mhealth Uhealth. 2020 Aug 10;8(8):e16696. doi: 10.2196/16696.

Dorsch MP, An LC, Hummel SL. A Novel Just-in-Time Contextual Mobile App Intervention to Reduce Sodium Intake in Hypertension: Protocol and Rationale for a Randomized Controlled Trial (LowSalt4Life Trial). JMIR Res Protoc. 2018 Dec 7;7(12):e11282. doi: 10.2196/11282.