Effects of a Novel Contextual Just-In-Time Mobile App Intervention (LowSalt4Life) on Sodium Intake in Adults With Hypertension: Pilot Randomized Controlled Trial

BACKGROUND

High dietary sodium intake is a significant public health problem in the United States. High sodium consumption is associated with high blood pressure and high risk of cardiovascular disease.

OBJECTIVE

The aim of this study was to evaluate the effect of a just-in-time adaptive mobile app intervention, namely, LowSalt4Life, on reducing sodium intake in adults with hypertension.

METHODS

In this study, 50 participants aged ≥18 years who were under treatment for hypertension were randomized (1:1, stratified by gender) into 2 groups, namely, the App group (LowSalt4Life intervention) and the No App group (usual dietary advice) in a single-center, prospective, open-label randomized controlled trial for 8 weeks. The primary endpoint was the change in the 24-hour urinary sodium excretion estimated from spot urine by using the Kawasaki equation, which was analyzed using unpaired two-sided t tests. Secondary outcomes included the change in the sodium intake measured by the food frequency questionnaire (FFQ), the 24-hour urinary sodium excretion, blood pressure levels, and the self-reported confidence in following a low-sodium diet.

RESULTS

From baseline to week 8, there was a significant reduction in the Kawasaki-estimated 24-hour urinary sodium excretion calculated from spot urine in the App group compared to that in the No App group (-462 [SD 1220] mg vs 381 [SD 1460] mg, respectively; P=.03). The change in the 24-hour urinary sodium excretion was -637 (SD 1524) mg in the App group and -322 (SD 1485) mg in the No App group (P=.47). The changes in the estimated sodium intake as measured by 24-hour dietary recall and by FFQ in the App group were -1537 (SD 2693) mg and -1553 (SD 1764) mg while those in the No App group were -233 (SD 2150) mg and -515 (SD 1081) mg, respectively (P=.07 and P=.01, respectively). The systolic blood pressure change from baseline to week 8 in the App group was -7.5 mmHg while that in the No App group was -0.7 mmHg (P=.12), but the self-confidence in following a low-sodium diet was not significantly different between the 2 groups.

CONCLUSIONS

This study shows that a contextual just-in-time mobile app intervention resulted in a greater reduction in the dietary sodium intake in adults with hypertension than that in the control group over a 8-week period, as measured by the estimated 24-hour urinary sodium excretion from spot urine and FFQ. The intervention group did not show a significant difference from the control group in the self-confidence in following a low sodium diet and in the 24-hour urinary sodium excretion or dietary intake of sodium as measured by the 24-hour dietary recall. A larger clinical trial is warranted to further elucidate the effects of the LowSalt4Life intervention on sodium intake and blood pressure levels in adults with hypertension.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03099343; https://clinicaltrials.gov/ct2/show/NCT03099343.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/11282.

Insufficient Calorie Intake Worsens Post-Discharge Quality of Life and Increases Readmission Burden in Heart Failure

OBJECTIVES

The purpose of this study was to evaluate the relationship between calorie intake and post-discharge outcomes in hospitalized patients with heart failure (HF).

BACKGROUND

Malnutrition increases adverse outcomes in HF, and dietary sodium restriction may inadvertently worsen nutritional intake.

METHODS

In a dietary intervention trial, baseline nutritional intake in HF inpatients was estimated using the Block Food Frequency Questionnaire (FFQ), and the Nutritional Risk Index (NRI) was calculated. Insufficient calorie intake was defined as <90% of metabolic needs, and a 15-point micronutrient deficiency score was created. Adjusted linear, logistic, and negative binomial regression were used to evaluate associations between insufficient calorie intake and quality of life (using the Kansas City Cardiomyopathy Questionnaire Clinical Summary [KCCQ-CS]), readmission risk, and days rehospitalized over 12 weeks.

RESULTS

Among 57 participants (70 ± 8 years of age; 31% female; mean body mass index 32 ± 8 kg/m²); median sodium and calorie intake amounts were 2,987 mg/day (interquartile range [IQR]: 2,160 to 3,540 mg/day) and 1,602 kcal/day (IQR: 1,201 to 2,142 kcal/day), respectively; 11% of these patients were screened as malnourished by the NRI. All patients consuming <2,000 mg/day sodium had insufficient calorie intake; this group also more frequently had dietary micronutrient and protein deficiencies. At 12 weeks, patients with insufficient calorie intake had less improvement in the KCCQ-CS score (β = -14.6; 95% confidence interval [CI]: -27.3 to -1.9), higher odds of readmission (odds ratio: 14.5; 95% CI: 2.2 to 94.4), and more days rehospitalized (incident rate ratio: 31.3; 95% CI: 4.3 to 229.3).

CONCLUSIONS

Despite a high prevalence for obesity and rare overt malnutrition, insufficient calorie intake was associated with poorer post-discharge quality of life and increased burden of readmission in patients with HF. Inpatient dietary assessment could improve readmission risk stratification and identify patients for nutritional intervention. (Geriatric Out of Hospital Randomized Meal Trial in Heart Failure [GOURMET-HF] NCT02148679).

Abstract P3029: A Randomized Controlled Trial Evaluating a Novel Just-In-Time Contextual Mobile Application Intervention to Reduce Sodium Intake in Hypertension: The Lowsalt4life Trial

Introduction: Interventions that lower sodium intake can decrease blood pressure and improve cardiovascular outcomes.

Methods: This single center, prospective, open-label study evaluated a new mobile app to reduce sodium intake. Patients > 18 years of age diagnosed with hypertension and on antihypertensive therapy for at least 3 months were enrolled. Participants were randomized 1:1, stratified by gender, to receive the mobile app, or usual dietary advice for 8 weeks. The app provides a multifaceted intervention based on just-in-time contextual tailored messages. The primary endpoint was the change in 24-hour urinary sodium excretion. Secondary outcomes included the change in estimated sodium intake from a Block Food Frequency Questionnaire (FFQ), 24-hr dietary recall, Self-care Confidence in Following a Low-Sodium Diet (SCFLSD) survey and blood pressure (BP).

Results: Fifty patients (24 App, 26 No App) were randomized. Baseline demographics were similar between the groups. The average age was 57 years and BP 131/83 mmHg. The reduction in 24-hour urinary sodium excretion from baseline was greater in the App compared to No App group (p=0.30). The reduction in FFQ (p=0.008) and 24-hr dietary recall (p=0.11) sodium intake from baseline were greater in the App compared to No App group. Systolic BP was reduced from baseline in the App compared to No App group (-7.5 vs. -0.7 mmHg, p=0.12). No significant change was shown in the SCFLSD survey.

Conclusions: Patients randomized to the app had a greater reduction in measures of sodium intake and systolic BP from baseline to 8 weeks compared to those that did not receive the application. Further studies are needed to confirm these results.

Development of exchange lists for Mediterranean and Healthy Eating diets: implementation in an intervention trial

BACKGROUND

There has been little research published on the adaptation of diabetic exchange list diet approaches for the design of intervention diets in health research despite their clinical utility. The exchange list approach can provide clear and precise guidance on multiple dietary changes simultaneously. The present study aimed to develop exchange list diets for Mediterranean and Healthy Eating, and to evaluate adherence, dietary intakes and markers of health risks with each counselling approach in 120 subjects at increased risk for developing colon cancer.

METHODS

A randomised clinical trial was implemented in the USA involving telephone counselling. The Mediterranean diet had 10 dietary goals targeting increases in mono-unsaturated fats, n-3 fats, whole grains and the amount and variety of fruits and vegetables. The Healthy Eating diet had five dietary goals that were based on the US Healthy People 2010 recommendations.

RESULTS

Dietary compliance was similar in both diet arms, with 82-88% of goals being met at 6 months, although subjects took more time to achieve the Mediterranean goals than the Healthy Eating goals. The relatively modest fruit and vegetable goals in the Healthy Eating arm were exceeded, resulting in fruit and vegetable intakes of approximately eight servings per day in each arm after 6 months. A significant (P < 0.05) weight loss and a decrease in serum C-reactive protein concentrations were observed in the overweight/obese subgroup of subjects in the Mediterranean arm in the absence of weight loss goals.

CONCLUSIONS

Counselling for the Mediterranean diet may be useful for both improving diet quality and for achieving a modest weight loss in overweight or obese individuals.

Relationships between serum and colon concentrations of carotenoids and fatty acids in randomized dietary intervention trial

Little is known about the effect of preventive diets on colonic nutrient concentrations. This study randomized 120 persons at increased risk of colon cancer to a Mediterranean versus a Healthy Eating diet for six months. The former targeted increases in whole grains, fruits, vegetables, monounsaturated, and n3 fats. The Healthy Eating diet was based on Healthy People 2010 recommendations. At baseline, dietary fat and carotenoid intakes were poorly associated (Spearman ρ < 0.4) with serum and colon concentrations. Strong associations were observed between serum and colon measurements of β-cryptoxanthin (ρ = 0.58; P < 0.001), α-carotene (ρ = 0.48; P < 0.001), and β-carotene (ρ = 0.45; P < 0.001). After six months, the Healthy Eating intervention increased serum lutein, β-, and α-carotene significantly (P < 0.05). In the Mediterranean arm, the significant increases were in serum lutein, β-cryptoxanthin, β-carotene, monounsaturated, and n3 fats. A significant group-by-time interaction (P = 0.03) was obtained for monounsaturated fats. Colonic increases in carotenoids and n3 fats were significant only in Healthy Eating arm, whereas the group-by-time interaction was significant for β-carotene (P = 0.02) and α-carotene (P = 0.03). Changes in colon concentrations were not significantly associated with reported dietary changes. Changes in colon and serum concentrations were strongly associated for β-cryptoxanthin (ρ = 0.56; P < 0.001) and α-carotene (ρ = 0.40; P < 0.001). The associations between colonic and serum concentrations suggest the potential use of using serum concentration as a target in dietary interventions aimed at reducing colon cancer risk.

A Mediterranean dietary intervention in persons at high risk of colon cancer: recruitment and retention to an intensive study requiring biopsies

This study recruited persons at increased risk of colon cancer to an intensive dietary intervention study that required biopsies of the colon by flexible sigmoidoscopy at baseline and after six months of intervention. A total of 1314 individuals contacted the study, and only 16 individuals indicated that the sigmoidoscopy procedure was an obstacle to study participation. A total of 270 individuals completed a screening visit and signed a screening consent form. Inquiries about the study tended to be fewer in the winter and late summer. Failure to return food records was the most common reason for exclusion. Dietary recall at enrollment indicated that subjects were consuming significantly more vegetables, lower sodium and a lower glycemic load on the day before starting the study vs. during the eligibility phase which might have an impact on biomarker measures. This makes it important to capture dietary changes in the period between determination of eligibility and enrollment. Subjects (n=120) were randomized to follow a Healthy Eating or a Mediterranean Diet, each of which required substantial dietary record-keeping. The study completion rate was 78%, and subjects reported high satisfaction with study participation. Of the 93 individuals who completed the study, only one refused the flexible sigmoidoscopy at the final visit. These findings suggest that flexible sigmoidoscopy does not appear to be a barrier for recruitment of high-risk individuals to an intensive dietary intervention trial, but that completing food records can be.