Compliance with long-term dietary salt restriction in hypertensive outpatients

Sodium Toxicity in the Nutritional Epidemiology and Nutritional Immunology of COVID-19

Dietary factors in the etiology of COVID-19 are understudied. High dietary sodium intake leading to sodium toxicity is associated with comorbid conditions of COVID-19 such as hypertension, kidney disease, stroke, pneumonia, obesity, diabetes, hepatic disease, cardiac arrhythmias, thrombosis, migraine, tinnitus, Bell's palsy, multiple sclerosis, systemic sclerosis, and polycystic ovary syndrome. This article synthesizes evidence from epidemiology, pathophysiology, immunology, and virology literature linking sodium toxicological mechanisms to COVID-19 and SARS-CoV-2 infection. Sodium toxicity is a modifiable disease determinant that impairs the mucociliary clearance of virion aggregates in nasal sinuses of the mucosal immune system, which may lead to SARS-CoV-2 infection and viral sepsis. In addition, sodium toxicity causes pulmonary edema associated with severe acute respiratory syndrome, as well as inflammatory immune responses and other symptoms of COVID-19 such as fever and nasal sinus congestion. Consequently, sodium toxicity potentially mediates the association of COVID-19 pathophysiology with SARS-CoV-2 infection. Sodium dietary intake also increases in the winter, when sodium losses through sweating are reduced, correlating with influenza-like illness outbreaks. Increased SARS-CoV-2 infections in lower socioeconomic classes and among people in government institutions are linked to the consumption of foods highly processed with sodium. Interventions to reduce COVID-19 morbidity and mortality through reduced-sodium diets should be explored further.

Acceptability of sodium-reduced research diets, including the Dietary Approaches To Stop Hypertension diet, among adults with prehypertension and stage 1 hypertension

OBJECTIVE

Examine the acceptability of sodium-reduced research diets.

DESIGN

Randomized crossover trial of three sodium levels for 30 days each among participants randomly assigned to one of two dietary patterns.

PARTICIPANTS/SETTING

Three hundred fifty-four adults with prehypertension or stage 1 hypertension who were participants in the Dietary Approaches to Stop Hypertension (DASH-Sodium) outpatient feeding trial.

INTERVENTION

Participants received their assigned diet (control or DASH, rich in fruits, vegetables, and low-fat dairy products), each at three levels of sodium (higher, intermediate, and lower) corresponding to 3,500, 2,300, and 1,200 mg/day (150, 100, and 50 mmol/day) per 2,100 kcal.

MAIN OUTCOME MEASURES

Nine-item questionnaire on liking and willingness to continue the assigned diet and its level of saltiness using a nine-point scale, ranging from one to nine.

STATISTICAL ANALYSES PERFORMED

Generalized estimating equations to test participant ratings as a function of sodium level and diet while adjusting for site, feeding cohort, carryover effects, and ratings during run-in.

RESULTS

Overall, participants rated the saltiness of the intermediate level sodium as most acceptable (DASH group: 5.5 for intermediate vs 4.5 and 4.4 for higher and lower sodium; control group: 5.7 for intermediate vs 4.9 and 4.7 for higher and lower sodium) and rated liking and willing to continue the DASH diet more than the control diet by about one point (ratings range from 5.6 to 6.6 for DASH diet and 5.2 to 6.1 for control diet). Small race differences were observed in sodium and diet acceptability.

CONCLUSIONS

Both the intermediate and lower sodium levels of each diet are at least as acceptable as the higher sodium level in persons with or at risk for hypertension.

Long-term compliance with salt restriction in Japanese hypertensive patients

The purpose of the present study was to investigate the long-term compliance with salt restriction in Japanese hypertensive patients. Subjects included 389 patients, 230 women and 159 men, mean age 58+/-11 years, who underwent successful 24-h home urine collection more than three times over an interval of a year. Urinary salt, potassium, and creatinine were measured. Additionally, family history, habitual alcohol intake, smoking habit, physical activities, and job status were assessed by use of a questionnaire. During the follow-up period (average 3.5 years), participants underwent urine collection 4.6 times in average. Urinary salt excretion at the last visit was significantly lower than that at the first visit (8.7+/-3.4 vs. 9.6+/-4.1 g/day; p<0.01). Urinary potassium excretion also decreased significantly during this period (from 2.0+/-0.7 to 1.9+/-0.7 g/day; p<0.05). Among the mean 4.6 urine collections, 45.2% (men 34.6%, women 52.6%) of the patients successfully achieved <6 g (100 mmol of sodium)/day of salt excretion on at least one occasion. The rate of achievement of averaged urinary salt excretion <6 g/day dropped to 10.3% (men 4.4%, women 14.3%). Only 2.3% (men 0.6%, women 3.5%) of the patients achieved <6 g/day on all occasions. There were no significant differences in age, habitual alcohol intake, smoking habit, physical activities, or job status between patients who complied with the salt-restricted diet and those who did not. Results suggest that long-term compliance with salt restriction is poor in Japanese hypertensive patients. Since no specifically defining characteristics were found in the compliant patients, repeated measurements of urinary salt excretion seem to be important to encourage salt restriction.

Relationship between the Awareness of Salt Restriction and the Actual Salt Intake in Hypertensive Patients

A 24-h home urine collection was conducted to estimate accurate salt intake in hypertensive outpatients. Using 24-h urinary creatinine excretion as a criterion for success, urine samples were obtained from 534 hypertensive patients. The urinary salt excretion of hypertensive outpatients ranged widely from 1.5 to 23.4 g/day (mean value 9.7 +/- 3.9 g/day). Urinary salt excretion was higher in males than in females (10.6 +/- 4.0 vs. 9.2 +/- 3.7 g/day, p<0.01). Based on the questionnaires, the patients were divided into salt-conscious patients, or those who were careful to reduce their daily salt intake, and non-salt-conscious patients. It was found that urinary salt excretion was lower in the salt-conscious group than in the non-salt-conscious group (9.4 +/- 3.8 vs. 10.6 +/- 4.0 g/day, p<0.01), but that urinary salt excretion adjusted for body weight was not significantly different between the two groups (0.16 +/- 0.06 vs. 0.17 +/- 0.07 g/kg/day). Our results suggest that there was no obvious reduction in the actual salt intake in salt-conscious patients, suggesting the importance of monitoring salt intake by 24-h home urine collection and informing patients of their actual salt intake as a means of encouraging the achievement of salt restriction.

Quality of clinical reports on behavioral interventions for hypertension

PURPOSE

The purpose of this study was to provide clinicians with the confidence to employ behavioral interventions for hypertension and to guide researchers in the development and reporting of studies.

METHODS

We systematically reviewed English language articles (1970-1999) describing behavioral interventions for hypertension, evaluating aspects of design, analysis, reporting of results, and factors that were associated with higher quality of these studies.

RESULTS

Of 100 articles, 49 were randomized controlled trials (RCT), 33 were observational studies with control groups, and 18 were observational studies without control groups; mean (SE) quality scores were 69.2 (1.6), 57.6 (5.3), and 60.3 (2.2), respectively. RCTs were more likely than observational studies to attain high scores in descriptions of appropriateness of control group, inclusion and exclusion criteria, study population, and the intervention protocol. In multivariate analysis, date of publication, reported funding source, and intervention type were independently associated with greater quality scores: 7.4 [95% CI: 0.03, 14.7] points greater for articles published 1990-1999 vs 1970-1979, 6.5 [95% CI: 1.4, 11.6] points greater for articles reporting government funding vs those not reporting funding sources, and 8.6 [95% CI: 0.3, 17.1], 12.9 [95% CI: 3.4, 22.4], and 14.2 [4.1, 24.4] points greater for articles examining patient education/support, change in delivery system, and mass health campaigns vs articles examining patient reminders, respectively.

CONCLUSIONS

While quality has improved over time, there is considerable room for improvement. Investigators should pay particular attention to description of study population and allocation of subjects, the use of standardized outcomes reporting, and appropriate statistical analysis.

[Compliance in antihypertensive therapy: analyses in scientific articles]

The aim of this study was to evaluate scientific articles published between 1991-1995, in order to identify the compliance in antihypertensive therapy, One hundred seven scientific articles were evaluated. The results showed that 68% were related to patient, 63% to pharmacological treatment, 62% general, 39% non pharmacological treatment, 34% organizational factors, and 8% related to disease. Compliance with antihypertensive therapy was the major challenge of hypertension management and to know how this aspect was focalized in scientific articles possible reduce non compliance in hypertension.