Dietary Sodium Reduction Research Articles

Effects of Dietary Sodium Reduction on Blood Pressure in Subjects With Resistant Hypertension: Results From a Randomized Trial

Effects of Dietary Sodium Reduction on Blood Pressure in Subjects With Resistant Hypertension: Results From a Randomized Trial

Effects of Dietary Sodium Reduction on Blood Pressure in Subjects With Resistant Hypertension: Results From a Randomized Trial

Effects of Dietary Sodium Reduction on Blood Pressure in Subjects With Resistant Hypertension: Results From a Randomized Trial

Effect of a 6-month Low Sodium Diet on the Salt Taste Perception and Pleasantness, Blood Pressure and the Urinary Sodium Excretion in Female College Students

The study aim was to examine the effect of sensory responses of subjects after 6-month dietary sodium reduction with the aid of nutritional education. Fourteen female college students voluntarily restricted their sodium intake for 6 months, during which time they received nutritional education on the low sodium diet. As a control group, 10 students, whose anthropometric measurement, sodium intake behavior, and blood pressure were not different from those of the experimental group, were maintained on a normal diet. For the sensory responses of subjects, the salt taste perception and pleasantness for graded (0.15-1.3%) NaCl solutions were measured by a 9-point hedonic scale. The optimum sodium concentration, urinary sodium excretion, and blood pressure were measured. All the measurements were done at the beginning and end of the experiment. The sensory evaluation revealed an absence of any difference between the two groups in salt taste perception and pleasantness responses at the beginning. After 6-month adaptation, the experimental group subjects showed higher responses to low NaCl solution (0.15, 0.3, 0.5%) in salt taste perception and pleasantness evaluation while the control group subjects exhibited the opposite response. The optimum sodium concentration was reduced from 105.6 m㏖ to 80.7 m㏖ (p = 0.015) and the urinary sodium excretion was also reduced from 1,398 ㎎ to 906 ㎎ (p = 0.041) only in the experimental group. Systolic blood pressure was significantly reduced in the experimental group, although there was no correlation between the urinary sodium excretion and blood pressure. The optimum sodium concentration was negatively correlated with the urinary sodium excretion (r = 0.418, p = 0.053), indicating that adaptation to low sodium diet can reduce sodium intake. Further study on the individual responses of subjects on a low sodium diet by periodical evaluation may provide useful data for setting the duration needed to stabilize a lowered appetite for sodium.

The Key to Life Nutrition Program: results from a community-based dietary sodium reduction trial

Evaluation of a dietary Na reduction trial in a community setting. Community-based randomized trial. Ten-week nutrition intervention activities focused on lifestyle modification to decrease dietary Na intake, under the supervision of a registered dietitian. Twenty-four hour urine specimens were collected at baseline and follow-up visits to determine 24 h urinary Na excretion. The University of Pittsburgh Center for Healthy Aging, Key to Life Nutrition Program. Hypertensive adults at least 65 years of age. Mean age of participants was 75 years. Twenty-four hour mean urinary Na excretion at baseline was 3174 mg/d. This reduced to 2944 mg/d (P = 0.30) and 2875 mg/d (P <or= 0.03) at 6- and 12-month follow-ups, respectively. In a sub-sample (urine volume of >or=1000 ml, baseline to 12 months), mean urinary Na excretion decreased from 3220 mg/d to 2875 mg/d (P <or= 0.02). Significant reductions in mean 24 h urinary Na were reported, but results fell short of the recommended guidelines of 1500 mg/d for at-risk individuals. Our results reiterate the difficulty in implementing these guidelines in community-based programmes. More aggressive public health efforts, food industry support and health policy changes are needed to decrease Na levels in older adults to the recommended guidelines.

Another Major Role for Dietary Sodium Reduction

Resistant hypertension, defined as blood pressure (BP) above goal in spite of the current use of 3 antihypertensive agents of different classes, is a common problem in general medical practice as well as specialty hypertension clinics.1 The prevalence of resistant hypertension is uncertain. Recent trials suggest a prevalence of 20% to 30%,2 which might be an overestimate because of selection procedures and enrollment criteria. If one applies a prevalence of 10% to the estimated 65 million Americans with hypertension, then ≈6.5 million Americans have resistant hypertension. The cause of this condition is almost always multifactorial. Common factors include lifestyle factors (eg, excess sodium intake, obesity, high alcohol intake), drug-related causes (eg, non-narcotic analgesics, sympathetic agents), and secondary causes of hypertension (eg, obstructive sleep apnea, primary aldosteronism, chronic kidney disease, and renal artery stenosis). In contrast to most of these conditions, a high sodium intake is ubiquitious and provides an opportunity to improve BP control, even when other factors coexist. Evidence linking salt (sodium chloride) intake with elevated BP is substantial and indisputable. Sodium reduction has been shown to lower BP in persons with prehypertension, untreated Stage 1 hypertension, and medication-treated hypertension.3 The effects of sodium reduction in hypertensive individuals on multiple medications, with or without controlled BP, has received scant attention, probably because of challenges related to accrual of participants and ethical issues related to prolonged assignment to a high-sodium control condition. In this issue of Hypertension , Pimenta and colleagues document the benefits of sodium reduction in patients with resistant hypertension.4 Pimenta and colleagues are to be congratulated for designing and implementing this challenging but informative and likely influential study. One cannot overestimate the logistical difficulties of recruiting eligible and interested participants, feeding them every meal over an extended …

Effects of Dietary Sodium Reduction on Blood Pressure in Subjects With Resistant Hypertension

Observational studies indicate a significant relation between dietary sodium and level of blood pressure. However, the role of salt sensitivity in the development of resistant hypertension is unknown. The present study examined the effects of dietary salt restriction on office and 24-hour ambulatory blood pressure in subjects with resistant hypertension. Twelve subjects with resistant hypertension entered into a randomized crossover evaluation of low (50 mmol/24 hours x 7 days) and high sodium diets (250 mmol/24 hours x 7 days) separated by a 2-week washout period. Brain natriuretic peptide; plasma renin activity; 24-hour urinary aldosterone, sodium, and potassium; 24-hour ambulatory blood pressure monitoring; aortic pulse wave velocity; and augmentation index were compared between dietary treatment periods. At baseline, subjects were on an average of 3.4+/-0.5 antihypertensive medications with a mean office BP of 145.8+/-10.8/83.9+/-11.2 mm Hg. Mean urinary sodium excretion was 46.1+/-26.8 versus 252.2+/-64.6 mmol/24 hours during low- versus high-salt intake. Low- compared to high-salt diet decreased office systolic and diastolic blood pressure by 22.7 and 9.1 mm Hg, respectively. Plasma renin activity increased whereas brain natriuretic peptide and creatinine clearance decreased during low-salt intake, indicative of intravascular volume reduction. These results indicate that excessive dietary sodium ingestion contributes importantly to resistance to antihypertensive treatment. Strategies to substantially reduce dietary salt intake should be part of the overall treatment of resistant hypertension.

Pleiotropic Benefits of Moderate Salt Reduction

The report by He and colleagues provides additional support for reducing daily salt intake from the ≈9 g/d typical of UK and US populations to <6 g recommended by health authorities in both countries.1,2 In their study, moderate sodium reduction lowered clinic blood pressure −4.8/−2.2 mm Hg and daytime ambulatory blood pressure a nearly identical −4.7/−2.2 mm Hg. The blood pressure benefits of moderate sodium restriction were clinically and statistically significant in middle-aged hypertensive adults with predominantly Stage 1 disease. And, the blood pressure changes were significant not only in self-identified blacks and whites, which is consistent with previous reports,2 but also Asians, which adds new information. The mean sodium intake on slow sodium and placebo in this study were comparable to the high (target 150 mmol/d) and intermediate (100 mmol/d) intake in DASH sodium.2 …

Salt and high blood pressure

HBP (high blood pressure) is the leading risk of death in the world. Unfortunately around the world, blood pressure levels are predicted to become even higher, especially in developing countries. High dietary salt is an important contributor to increased blood pressure. The present review evaluates the association between excess dietary salt intake and the importance of a population-based strategy to lower dietary salt, and also highlights some salt-reduction strategies from selected countries. Evidence from diverse sources spanning animal, epidemiology and human intervention studies demonstrate the association between salt intake and HBP. Furthermore, animal studies indicate that short-term interventions in humans may underestimate the health risks associated with high dietary sodium. Recent intervention studies have found decreases in cardiovascular events following reductions in dietary sodium. Salt intake is high in most countries and, therefore, strategies to lower salt intake could be an effective means to reduce the increasing burden of HBP and the associated cardiovascular disease. Effective collaborative partnerships between governments, the food industry, scientific organizations and healthcare organizations are essential to achieve the WHO (World Health Organization)-recommended population-wide decrease in salt consumption to less than 5 g/day. In the milieu of increasing cardiovascular disease worldwide, particularly in resource-constrained low- and middle-income countries, salt reduction is one of the most cost-effective strategies to combat the epidemic of HBP, associated cardiovascular disease and improve population health.

Reducing dietary sodium and decreases in cardiovascular disease in Canada

Increases in dietary sodium increase blood pressure, whereas emerging evidence confirms that the reduction in dietary sodium results in reduced cardiovascular events. To estimate the effect that reducing dietary sodium can have on cardiovascular events in Canada. Based on published meta-analyses of randomized controlled trials, blood pressure reductions associated with different levels of reduction in dietary sodium were used in the model. The RR for cardiovascular events associated with the blood pressure reduction was modelled based on a meta-analysis of diuretic trials. Assumptions were made that controlled hypertensive patients would or would not have similar reduction in blood pressure as the normotensive population. Cardiovascular events in Canada for 2002 were used to estimate the decrease in cardiovascular events. A reduction in daily sodium intake of 1840 mg/day was estimated to prevent 11,550 cardiovascular disease events per year. This varied from about 7300 to 10,700 events per year when hypertension control rates were varied from 13% to 66%. Reduction in cardiovascular events ranged from 8300 to 16,800 per year for a reduction in dietary sodium from 1200 mg/day to 2400 mg/day. Reducing dietary sodium can substantially reduce cardiovascular disease events in Canada. This information can aid policy makers in assessing the importance of public health policy and to monitor the health impact of changes in dietary sodium in Canada.

Salt Sensitivity

Although increases in dietary NaCl (referred to as salt in this article) intake expand extracellular fluid volume and elevate mean arterial pressure (MAP) even in healthy subjects, the magnitude of the response varies with some individuals demonstrating remarkable resistance to the hypertensive effects of salt intake despite ingestion of very high doses.1 Salt sensitivity therefore refers to the propensity for changes in salt intake to produce meaningful increases in mean arterial pressure (MAP). The endless debate regarding whether the amount of salt ingested affected blood pressure sufficiently to alter life span was effectively curtailed by the Trials of Hypertension Prevention studies, which showed that dietary salt reduction decreased the long-term risk of cardiovascular events by 25% in patients who had prehypertension, confirming an important effect of salt intake on the cardiovascular system.2 In addition, the landmark work of Weinberger and colleagues provided convincing evidence that normotensive subjects who demonstrated salt sensitivity had a subsequent cumulative mortality that rivaled that of hypertensive patients.3 How salt intake alters cardiovascular function remains …

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

The final nail for sodium reduction

Introduction: This paper addresses the remaining objection to the advocacy of universal dietary sodium reduction: the absence of morbidity and mortality data on its long-term safety and efficacy. Data from long-term randomized controlled trials that provide hard outcome data are the standard requirement for adoption of any therapy. For people with a disease, surrogate endpoints (ie, reduction of blood pressure) may be adequate for acceptance of a therapy. But when the object of therapy is the entire population, which obviously includes many people who don’t need the therapy, evidence of longterm safety and efficacy must be available before such therapy can be recommended. Many therapies have been offered and then found to be either unsafe (eg, postmenopausal estrogen) or ineffectual (eg, vitamin E). Therefore, data on safety and efficacy of dietary sodium restriction are welcomed.

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Long-Term Benefits of Dietary Sodium Reduction

Randomized trials among patients with and without hypertension have shown reductions in blood pressure with decreased sodium intake. However, data are

Estimate of the benefits of a population-based reduction in dietary sodium additives on hypertension and its related health care costs in Canada

Hypertension is the leading risk factor for mortality worldwide. One-quarter of the adult Canadian population has hypertension, and more than 90% of the population is estimated to develop hypertension if they live an average lifespan. Reductions in dietary sodium additives significantly lower systolic and diastolic blood pressure, and population reductions in dietary sodium are recommended by major scientific and public health organizations. To estimate the reduction in hypertension prevalence and specific hypertension management cost savings associated with a population-wide reduction in dietary sodium additives. Based on data from clinical trials, reducing dietary sodium additives by 1840 mg/day would result in a decrease of 5.06 mmHg (systolic) and 2.7 mmHg (diastolic) blood pressures. Using Canadian Heart Health Survey data, the resulting reduction in hypertension was estimated. Costs of laboratory testing and physician visits were based on 2001 to 2003 Ontario Health Insurance Plan data, and the number of physician visits and costs of medications for patients with hypertension were taken from 2003 IMS Canada. To estimate the reduction in total physician visits and laboratory costs, current estimates of aware hypertensive patients in Canada were used from the Canadian Community Health Survey. Reducing dietary sodium additives may decrease hypertension prevalence by 30%, resulting in one million fewer hypertensive patients in Canada, and almost double the treatment and control rate. Direct cost savings related to fewer physician visits, laboratory tests and lower medication use are estimated to be approximately $430 million per year. Physician visits and laboratory costs would decrease by 6.5%, and 23% fewer treated hypertensive patients would require medications for control of blood pressure. Based on these estimates, lowering dietary sodium additives would lead to a large reduction in hypertension prevalence and result in health care cost savings in Canada.

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

Objective To examine the effects of reduction in dietary sodium intake on cardiovascular events using data from two completed randomised trials, TOHP I and TOHP II.Design Long term follow-up assessed...

Effects of Carvedilol Treatment in Dogs with Chronic Mitral Valvular Disease

Stimulation of the sympathetic nervous system occurs during the development of heart failure in dogs with chronic mitral valvular disease (CMVD). The use of beta-blockers to modulate the activation of the sympathetic nervous system would be useful in dogs with CMVD. Group A included 13 dogs who received the conventional treatment (digoxin, benazepril, a reduced sodium diet, and codeine, and a diuretic when indicated), and group B included 12 dogs who received the protocol above plus carvedilol (0.3 mg/kg q12h). Blinded, placebo, controlled study. The main echodopplercardiographic variables, heart rate, biochemical data, functional classification (FC) (New York Heart Association) and quality of life score (functional evaluation of cardiac health questionnaire) were assessed at baseline (TO) and after 3 months (T1). Only group B showed improvement in score of quality of life (13.8 +/- 8.8 versus 6.0 +/- 6.3; P < .001), in FC (2.4 - 0.9 versus 1.8 +/- 0.7; P = .032) and a reduction in systolic blood pressure (151.2 +/- 18.3 versus 124.5 +/- 23.4; P = .021). Two deaths from group A and 1 from B were related to CMVD. The studied dose of carvedilol in this group did not improve the sympathetic activation and echocardiographic variables over 3 months of chronic oral treatment. However, the results suggested a beneficial effect on the quality of life score, functional classification, and a reduction on systolic blood pressure.

Dietary Factors in Reducing Risk of Cardiovascular Diseases

Diet influences many modifiable risk factors for cardiovascular diseases (CVDs). Considering this, moderation of total dietary fat, particularly trans and saturated fats, as well as cholesterol is recommended. Dietary fats should come mainly from plants and fatty fish, providing monounsaturated and polyunsaturated (including omega-3) fatty acids. Carbohydrate sources to emphasize include whole grains, legumes, vegetables, fruits, and other fiber-rich sources, rather than sugars. Although vitamins such as E, C, and some B vitamins are associated with reduced CVD risk, data do not support the use of supplements, but foods rich in these nutrients are advocated. Dietary minerals such as potassium, magnesium, and calcium may be beneficial to heart health, while reduction of dietary sodium decreases risk of hypertension. A large variety of phytonutrients are also associated with reduced CVD risk. Other dietary factors receiving research attention regarding CVD risk. Other dietary factors receiving research attention regarding CVD risk include caffeine, alcobol, and meal frequency, although more work is needed in these areas. In contrast, data are quite robust to support the importance of healthy body weight management in cardiovascular health. In general, diets based on a variety of less processed foods, mainly of plant origin, in the context of an active lifestyle, are conducive to heart health.