Variations In Salt Intake Research Articles

Salt intake across the hypertension care cascade in the Bangladeshi adult population: a nationally representative cross-sectional study

ObjectivesThis study aimed to examine the distribution of daily salt intake across the hypertension care cascade and assess the proportional distribution of these care cascade categories across various salt consumption...

An Assessment of Usual Salt Intake among Older Normotensive Adults in Atonsu, a Suburb of Kumasi in the Ashanti Region of Ghana.

Background Globally, sodium intake has been found to be far above the normal level required by the body. Within countries, variations in salt intake exist between rural communities and urban communities. Experimental and epidemiological studies as well as studies involving clinical trials show the existence of adverse effect of salt consumption on the blood pressure of adults. The study evaluated salt intake among older normotensive adults in Atonsu, a suburb of Kumasi in the Ashanti region of Ghana. Methods Participants were randomly selected from five churches which constituted cluster samples. A questionnaire was administered to participants for demographic information and dietary and lifestyle assessments. The study targeted 100 participants, twenty from each of the five churches. Eighty-two individuals gave their informed consent. Out of the 82 who gave their informed consent, 15 withdrew and 67 completed the course. The 67 participants comprised 36 (53.7%) men and 31 (46.3%) women. Systolic and diastolic blood pressure, BMI, urinary sodium, urinary potassium, serum creatinine, serum sodium, and serum potassium concentrations were also measured. Results Participants' mean age was 52.3 ± 8.7 years. Participants had 24 hr urinary sodium excretion of 153.0 ± 26.9 mmol/day. All participants indicated that they consume foods high in salt even though none of them added salt to their diet at table. Mean 24 hr urinary potassium was 52.5 ± 12.9 mmol/day. Mean systolic blood pressure was 119.9 ± 10.8 mmHg and mean diastolic blood pressure was 72.5 ± 7.3 mmHg. Their mean BMI was 23.7 ± 3.5 kg/m2. Conclusion The participants who can be described as quite old and normotensive were high salt consumers, indicated by their dietary assessment and urinary sodium excretion, even though they had normal blood pressure.

Salt intake, blood pressure, and socioeconomic disparities among government employees in Sri Lanka: a cross-sectional study.

Our study estimated salt intake, examined the association between blood pressure (BP) and salt intake, and explored the socioeconomic variations in salt intake among administrators (government employees). This is a cross-sectional study. We studied 168 randomly selected administrators aged 30-60years attached to government offices in Colombo, Sri Lanka. Self-administered questionnaire gathered information on socio-demographic, work-related information, lifestyle practices, and medical history. BP, 24-hour urine collection, and anthropometric indices were measured. Mean salt intake levels measured by 24-hour Sodium (Na) excretion in hypertensives and non-hypertensives were 202.56 (SD±85.45)mmol/day and 176.79 (SD±82.02)mmol/day, respectively. A 100-mmol increase in sodium was associated with an average increase of 3.1 (95percentCI 2-4.2) mmHg in systolic BP and 1.8 (95percentCI 0.89-2.6) mmHg in diastolic BP. Higher salt intake was found in managerial assistants (12.38±5.0g) compared with senior officers (10.84±4.9g). Salt intake among these administrators was alarmingly high. High salt intake was positively associated with hypertension and more prevalent in lower socioeconomic strata.

Within-country variation of salt intake assessed via urinary excretion in Japan: a multilevel analysis in all 47 prefectures.

Salt intake in Japan remains high; therefore, exploring within-country variation in salt intake and its cause is an important step in the establishment of salt reduction strategies. However, no nationwide evaluation of this variation has been conducted by urinalysis. We aimed to clarify whether within-country variation in salt intake exists in Japan after adjusting for individual characteristics. Healthy men (n=1027) and women (n=1046) aged 20-69 years were recruited from all 47 prefectures of Japan. Twenty-four-hour sodium excretion was estimated using three spot urine samples collected on three nonconsecutive days. The study area was categorized into 12 regions defined by the National Health and Nutrition Survey Japan. Within-country variation in sodium excretion was estimated as a population (region)-level variance using a multilevel model with random intercepts, with adjustment for individual biological, socioeconomic and dietary characteristics. Estimated 24 h sodium excretion was 204.8 mmol per day in men and 155.7 mmol per day in women. Sodium excretion was high in the Northeastern region. However, population-level variance was extremely small after adjusting for individual characteristics (0.8 and 2% of overall variance in men and women, respectively) compared with individual-level variance (99.2 and 98% of overall variance in men and women, respectively). Among individual characteristics, greater body mass index, living with a spouse and high miso-soup intake were associated with high sodium excretion in both sexes. Within-country variation in salt intake in Japan was extremely small compared with individual-level variation. Salt reduction strategies for Japan should be comprehensive and should not address the small within-country differences in intake.

Plasma steroid profiling and response to trophins to illustrate intra-adrenal dynamics.

The importance of corticosteroids in cardiovascular and other chronic disease is recognised. In addition, plasma steroid precursor-to-product ratios are useful and convenient indirect indicators of efficiency of key steroidogenic enzymes (aldosterone synthase, 11β-hydroxylase and 17α-hydroxylase). The use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) has enabled measurement of numerous corticosteroid compounds simultaneously. However, normal responses to trophins and variation in salt intake are not well described. This study examined these parameters in a large group of healthy volunteers. Sixty normotensive volunteers were recruited and underwent infusion of angiotensin II (AngII) and ACTH, following low- and high-salt diet. Measurement of plasma steroids at baseline and 30 min after infusion of trophin was carried out by LC-MS. As expected, plasma mineralocorticoid levels increased in response to salt restriction and were suppressed with salt loading; ACTH infusion increased all corticosteroids, while AngII increased mineralocorticoids and suppressed glucocorticoid production. ACTH increased S:F but decreased DOC:B, thus the S:F ratio is a more appropriate index of 11β-hydroxylase efficiency. The B:F ratio increased following ACTH treatment and salt restriction. A larger proportion of plasma B than generally accepted may be derived from the zona glomerulosa and this ratio may be most informative of 17α-hydroxylase activity in salt-replete subjects. Although DOC:aldosterone, B:aldosterone and 18-hydroxyB:aldosterone should provide indices of aldosterone synthase efficiency, responses of individual compounds to trophins suggest that none of them accurately reflect this. Based on these data, aldosterone synthase activity is most accurately reflected by aldosterone concentration alone.

Regulation of renin secretion and arterial pressure during prolonged baroreflex activation: influence of salt intake.

Chronic electric activation of the carotid baroreflex produces sustained reductions in sympathetic activity and arterial pressure and is currently being evaluated as antihypertensive therapy for patients with resistant hypertension. However, the influence of variations in salt intake on blood pressure lowering during baroreflex activation (BA) has not yet been determined. As the sensitivity of arterial pressure to salt intake is linked to the responsiveness of renin secretion, we determined steady-state levels of arterial pressure and neurohormonal responses in 6 dogs on low, normal, and high salt intakes (5, 40, 450 mmol/d, respectively) under control conditions and during a 7-day constant level of BA. Under control conditions, there was no difference in mean arterial pressure at low (92±1) and normal (92±2 mm Hg) sodium intakes, but pressure increased 9±2 mm Hg during high salt. Plasma renin activity (2.01±0.23, 0.93±0.20, 0.01±0.01 ng angiotensin I/mL/h) and plasma aldosterone (10.3±1.9, 3.5±0.5, 1.7±0.1 ng/dL) were inversely related to salt intake, whereas there were no changes in plasma norepinephrine. Although mean arterial pressure (19-22 mm Hg) and norepinephrine (20%-40%) were lower at all salt intakes during BA, neither the changes in pressure nor the absolute values for plasma renin activity or aldosterone in response to salt were different from control conditions. These findings demonstrate that suppression of sympathetic activity by BA lowers arterial pressure without increasing renin release and indicate that changes in sympathetic activity are not primary mediators of the effect of salt on renin secretion. Consequently, blood pressure lowering during BA is independent of salt intake.

Socioeconomic inequality in salt intake in Britain 10 years after a national salt reduction programme

ObjectivesThe impact of the national salt reduction programme in the UK on social inequalities is unknown. We examined spatial and socioeconomic variations in salt intake in the 2008–2011 British National...

Too much salt inflames our body: fact or artifact?

lease cite this article in press as: C ssociation (2014), http://dx.doi.org tp://dx.doi.org/10.1016/j.jfma.201 29-6646/Copyright a 2014, Elsevier Like the majority of other living organisms on earth, humans cannot survive without salt. An ideal concentration of salt, or sodium chloride, is required for proper functioning of cells and organ systems. By adjusting the rate of excretion from the kidneys, the amount of salt in our body remains constant despite day-to-day variations in salt intake. However, salt-sensitive hypertension occurs in 30% of people with normal blood pressure and more often in people with high blood pressure, renal insufficiency, diabetes, or old age. As a result, salt restriction is widely viewed as an essential part of a healthy life style and is also the first line of treatment for newly diagnosed hypertension. The latest World Health Organization guidelines recommend adults consume <5 g of salt per day. Interestingly, recent studies indicate that excessive salt might cause more harm to our body than just hypertension.

Reference Values for Aldosterone–Renin Ratios in Normotensive Individuals and Effect of Changes in Dietary Sodium Consumption

Determination of the aldosterone-to-renin ratio (ARR) in blood is the preferred screening test for primary aldosteronism. Renin can be measured as the plasma renin activity (PRA) or the plasma renin concentration (PRC). Consequently, the ARR can be measured either based on the PRA (ARR(pra)) or based on the PRC (ARR(prc)). In contrast with the ARR(pra), the data on reference values for the ARR(prc) are limited. Moreover, whether the ARR(pra) or ARR(prc) is affected by variations in salt intake is unknown. We measured the PRA, the PRC, and serum aldosterone in 100 normotensive individuals between 20 and 70 years of age before and after a 3-day oral sodium-loading test (SLT). Participants were stratified according to age and sex. Data are presented as the median and interquartile range (IQR). Urinary sodium excretion after the SLT was ≥200 mmol/24 h in all participants. Serum aldosterone, PRA, and PRC values were significantly reduced after the SLT. PRC and PRA results were highly correlated [Spearman rank correlation r(s) = 0.80 and 0.74 before and after SLT, respectively; P < 0.001 for both]. The central 95% reference intervals for ARR(pra) before and after SLT were 0.07-1.45 h(-1) and 0.06-1.84 h(-1), respectively. The corresponding reference intervals for ARR(prc) were 4.1-81.3 pmol/ng and 3.9-74.8 pmol/ng. The median ARR(prc) decreased after the SLT from 19.5 pmol/ng (IQR, 13.0-29.4 pmol/ng) to 18.6 pmol/ng (IQR, 9.4-27.1 pmol/ng) (P = 0.005), whereas the median ARR(pra) did not change (P = 0.12). Both the ARR(prc) and ARR(pra) at baseline were higher in women than in men, whereas no sex difference was observed after sodium loading. We present reference values for the ARR(prc) for healthy individuals. The ARR is affected to a variable degree by sex and sodium intake.

P43 Dietary salt intake in Irish adults

ObjectivesTo estimate dietary salt intakes in the Irish population, including variation by age, sex, and measures of obesity.DesignTwo cross-sectional studies.Settings and Participants(i) A nationally representative household sample of 10 364...

P1-124 The effects on fetal fluid and electrolyte balance and renal function of variation in salt intake in ewes with renal insufficiency

To be able to raise larger litters, the influences of alternative rearing strategies on piglets are currently assessed. This study compared the predominant Gram type of the adherent intestinal microbiota between conventionally and artificially reared piglets and quantified their major mucosal immune cell populations. In addition, the potential influence of the piglets' birth weights was examined. To this purpose, 40 neonatal piglets consisting of 20 normal birth weight (NBW) and 20 low birth weight (LBW) piglets suckled the sow for three days after which 20 piglets (10 NBW and 10 LBW) continued to suckle the sow and 20 piglets (10 NBW and 10 LBW) were transferred to brooders and raised on milk formula. At the age of 10 or 28 days, five piglets of each group (birth weight×rearing strategy) were euthanized and the jejunum was sampled. The presence of adherent Gram+ and Gram− bacteria was scored and the volume densities of CD8+ cells, CD4+ cells and CD172a+ myloid cells were determined. Irrespective of birth weight, sow-fed piglets possessed a predominant Gram+ microbiome at 10 days of age, whereas formula-fed animals had more Gram- microbiota. With increasing age, however, Gram+ microbiota took the upper hand in these animals. The volume densities of CD8+ and CD4+ cells rose with increasing age and were consistently lower in LBW piglets. Both rearing strategies had a similar influence on the volume densities of these cell populations. In contrast, the volume densities of CD172a+ myloid cells did not differ significantly between the birth weight, rearing strategy and age groups. Three observations allow to conclude that artificial rearing could be a valuable alternative for suckling the sow. First, within each birth weight category, the mean weight of the 28-day-old piglets was similar for both rearing groups. Secondly, the effect of milk formula on the composition of the intestinal microbiome was only temporary since formula-fed piglets restored the more beneficial Gram+ microbiome by the end of the artificial rearing period. Finally, artificial rearing did not influence, either positively or negatively, the volume densities of CD8+, CD4+ and CD172a+ immune cells when compared to conventional rearing.

Oxidant Stress and Blood Pressure Responses to Angiotensin II Administration in Rats Fed Varying Salt Diets

To examine the hypothesis that NAD(P)H oxidase (Nox)-derived superoxide generation is involved in the development of angiotensin II (ANG II)-induced hypertension, we evaluated the responses to ANG II infusion (65 ng/min; osmotic mini-pump) for 2 weeks in rats treated with or without apocynin (APO) (inhibitor of Nox subunits assembly) in drinking water (12 mmol/L). Rats were grouped according to their diets with varying salt content (normal salt [NS], 0.4%; high salt [HS], 8%; low salt [LS], 0.03%) given during the 2-week experimental period. The variation in salt intake did not alter mean arterial pressure (MAP, recorded via pre-implanted arterial catheter) but showed proportionate levels in urinary excretion rate of Isoprostaglandin(2alpha) (U(ISO)V; NS, 179 +/- 26; HS, 294 +/- 38; LS, 125 +/- 7 ng/kg/24 h). Treatment with ANG II increased MAP proportional to salt intake (NS, 126 +/- 3 to 160 +/- 5; HS, 116 +/- 4 to 184 +/- 5; LS, 125 +/- 1 to 154 +/- 5 mm Hg). However, ANG II increased U(ISO)V only in NS rats (250 +/- 19 ng/kg/24 h) but not in HS or LS rats. In response to ANG II, Nox subunits protein expression increased in HS but not in the NS or LS rats. Apocynin treatment partially ameliorated these changes in Nox proteins in HS rats but did not alter ANG II-induced increases in MAP or U(ISO)V. These data suggest that Nox activation may not be the sole factor or alternatively, that a constitutively active isoform of Nox is involved in oxidative stress mechanism that is associated with dietary salt or ANG II-induced hypertension.

Effect of chronic salt loading on kidney function in early and established diabetes mellitus in rats

Glomerular hyperfiltration and renal hypertrophy are among the events that characterize the early course of diabetes mellitus in rats and human patients. Previous studies from this laboratory demonstrated that salt restriction paradoxically reduces total renal vascular resistance (RVR) and increases glomerular filtration rate (GFR) in diabetic rats (J Am Soc Nephrol 1995;5: 1761-7). In the present study we examined the converse condition by testing the effects of chronic salt loading on kidney function in moderately hyperglycemic insulin-treated rats with early and restablished streptozotocin diabetes. Salt loading was accomplished by adding 1% NaCl to the drinking water 1 day or 35 days after diabetes was induced. The high-salt diet appropriately increased salt excretion in diabetic rats and nondiabetic controls. GFR and renal plasma flow were determined by inulin and para-amino hippuric acid (PAH) clearance 7 days after salt loading was started. Diabetic rats receiving tap water exhibited hyperfiltration with no change in renal blood flow (RBF). In nondiabetic rats, salt loading caused a reduction in total RVR and proportional increases in RBF, GFR, and kidney weight (KW). Salt loading in early diabetes did not affect RVR, RBF, or KW and caused a paradoxical reduction in GFR. In established diabetes, salt loading reduced RVR and increased RBF, similar to results in nondiabetic rats, but as in rats with early diabetes, it did not increase GFR or KW. In summary, although the response in RVR and RBF to chronic salt loading depends on the duration of diabetes, the increase in GFR and KW as seen in nondiabetic rats is blunted in the early and established state of insulin-treated diabetes in rats. These findings further support the notion that the renal response to variation in salt intake is altered in insulin-treated diabetes in rats.

Sodium depletion and maternal separation in the suckling rat increase its salt intake when adult

To establish whether neonatal sodium depletion increases the adult's avidity for NaCl, 12-day-old suckling pups were injected with the natriuresic-diuretic furosemide (1 mg) while with their dams. The injections surged plasma aldosterone, and when the rats were adult (70 days), their spontaneous intake of 3% NaCl was increased. Additional experiments investigated whether maternal separation has a similar effect and could thus be a source of individual variation in salt intake of the adult. Fifteen-day-old pups were separated from their dams for 24 h in an incubator. When adult, their intake of 3% NaCl was increased. Availability of saline during maternal separation obviated the effect. The increase in adult intake of 3% NaCl was specific insofar as drinking of water was not increased similarly. The results show that the adult rat's avidity for sodium can be increased by postnatal natriuresis and possibly stress. The implications of the findings are discussed.

Regulation of salt intake by nymphs of Locusta migratoria

Fifth-instar nymphs of Locusta migratoria exhibited regulatory feeding for salt by defending an “intake target” for salt vs non-mineràl nutrients when challenged with a range of choices of artificial foods varying in salt content. When provided with no choice of food, however, nymphs did not regulate salt intake, due to the greater strength of regulatory mechanisms for protein and carbohydrate. Instead, they tolerated a 12-fold variation in salt intake and kept intake of non-mineral nutrients constant. Performance was reduced when dietary salt levels were less than 0.64% dry weight of Wesson's mixture. The intake target level was 1.8% in a food containing 20% protein and 10% digestible carbohydrate. This falls within the range of concentration of salts found in plant tissues. Possible regulatory mechanisms are discussed and results are interpreted within the new geometric framework for insect nutrition.

Effect of changes in sodium intake on atrial natriuretic factor (ANF) and peptides derived from the N terminus of the ANF prohormone in the rat.

The purpose of the present study was to determine whether variations in salt intake would alter the plasma concentrations of atrial natriuretic factor and the N-terminal atrial natriuretic factor prohormone peptides proANF 1-98 and proANF 31-67. Two groups of rats were placed on different salt intakes for 1 week. The low salt group of rats was fed a diet providing less than 0.1 mM NaCl/day and given deionized water to drink. The normal salt group of rats was fed regular rat chow with deionized water to drink, providing them with approximately 2 mM NaCl/day. Plasma atrial natriuretic factor was 204 +/- 60 pg/ml (mean +/- SE) in normal salt rats and was significantly lower in the low salt group (44 +/- 13 pg/ml, P less than 0.01). ProANF 1-98 was also significantly higher in the normal salt group (635 +/- 47 pg/ml) compared with the low salt group (353 +/- 33 pg/ml, P less than 0.01). ProANF 31-67 was 123 +/- 21 pg/ml in the normal salt group and 59 +/- 12 pg/ml in the low salt group (P less than 0.05). Plasma renin activity in ng angiotensin l/ml/hr averaged 1.80 +/- 0.15 in the normal salt group of rats and was significantly higher in the low salt group of rats (5.66 +/- 1.07, P less than 0.05). These results suggest that atrial natriuretic factor and the atrial natriuretic factor prohormones may play a role in the physiological adjustments to low salt intake.

Regulation of glomerular angiotensin II receptors in hypertensive salt-sensitive Dahl rats: absence of response to variations in salt intake.

Acta Physiologica ScandinavicaVolume 137, Issue 2 p. 321-322 Regulation of glornerular angiotensin II receptors in hypertensive salt-sensitive Dahl rats: absence of response to variations in salt intake B. SAHLGREN, Corresponding Author B. SAHLGREN Department of Pediatrics, St Göran's Children's Hospital, Karolinska Institute, Stockholm, SwedenDepartment of Pediatrics, St Gtiran's Children's Hospital, Box 12500, S-112 81 Stockholm. Sweden.Search for more papers by this author B. SAHLGREN, Corresponding Author B. SAHLGREN Department of Pediatrics, St Göran's Children's Hospital, Karolinska Institute, Stockholm, SwedenDepartment of Pediatrics, St Gtiran's Children's Hospital, Box 12500, S-112 81 Stockholm. Sweden.Search for more papers by this author First published: October 1989 https://doi.org/10.1111/j.1748-1716.1989.tb08758.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume137, Issue2October 1989Pages 321-322 RelatedInformation

Regulation of glomerular angiotensin II receptors in renovascular hypertension: absence of response to variations in salt intake.

Etude de la regulation des recepteurs glomerulaires de l'angiotensine II dans l'hypertension renale chez le rat. Aucune modification de la densite de ces recepteurs n'etait observee selon les teneurs en sel des regimes prealablement fournis aux animaux

Control of plasma renin activity in heat-stressed baboons on varied salt intake.

The characteristics and control of the increase in plasma renin activity (PRA) during environmental heating (EH) were determined in 12 unanesthetized, chronically catheterized baboons. Each EH experiment consisted of a 1.5- to 4-h exposure to an ambient temperature of 39-44 degrees C until core temperature (Tc) reached 39.5-40.0 degrees C. These EH experiments were done on the baboon in an unblocked state and during beta-adrenergic receptor blockade produced by propranolol when on normal-to-high salt intake (NHSI) and on low-salt intake (LSI). PRA rose linearly with Tc during EH, but the increase in PRA was considerably larger when the baboon was on LSI. The PRA-Tc linear regression coefficients were 2.32 and 5.98 ng angiotensin I X ml-1 X h-1 X degrees C-1 in NHSI and LSI states, respectively. This rise in PRA during EH was completely eliminated during beta-blockade in both NHSI and LSI states. It is concluded that heat stress activates the sympathetic nervous system to stimulate beta-receptor-mediated renin secretion by the kidney, this activation is controlled primarily by internal thermoreceptors, and variations in salt intake alters only the magnitude of the increase in PRA during heat stress, not the mechanisms that produce it.

A comparison of the effects of angiotensin II infusion and variations in salt intake on plasma aldosterone levels in normal subjects, patients with essential hypertension and patients with hyperaldosteronism

Infusion of angiotensin II into a patient with dexamethasone-suppressible hyperaldosteronism caused a brisk increase in plasma aldosterone concentration. In this behaviour, the patient resembled those patients with idiopathic hyperaldosteronism rather than those with tumorous primary hyperaldosteronism. Sodium depletion of a small group of patients with mild essential hypertension elicited a spectrum of increases in plasma aldosterone levels ranging from zero to normal. Angiotensin II infusion in both sodium replete and deplete states also caused variable aldosterone responses. These results suggest that the derangement of adrenal function in this condition varies continuously in severity.