Salt Intake in Adults with Diabetes and Hypertension: The Longitudinal Study of Adult Health-Brasil Study.

Background and Objective: Hypertension and type-2 diabetes are strong risk factors for cardiovascular diseases, and their management requires lifestyle changes, including a shift in dietary habits. The consumption of salt has increased in the last decades in some countries, but its association with type-2 diabetes remains unknown. Thus, we aimed to estimate the amount of salt intake among adults with and without diabetes and to assess whether concomitant hypertension and diabetes are associated with higher salt intake. Methods: Data from 11,982 adults 35-74 years of age enrolled in the baseline of the Longitudinal Study of Adult Health-Brasil study (2008-2010) were studied. A clinical and anthropometric evaluation was performed, and their daily salt intake was estimated by the overnight 12-hr urine sodium excretion. Results: Salt intake (gram per day) was higher in participants with diabetes as compared with those without diabetes, regardless of sex (men: 14.2 ± 6.4 vs. 12.4 ± 5.6, P < 0.05; women: 10.5 ± 4.8 vs. 9.1 ± 4.1, P < 0.05). However, salt intake is high in participants with fasting glucose ≥126 mg/dL or HbA1c ≥6.5%, but not in participants with blood glucose 2 hr after the glucose tolerance test ≥200 mg/dL. When hypertension and diabetes coexisted, salt consumption was higher than among people without these conditions. The prevalence of hypertension increased with increasing salt intake in women with diabetes, but not in men with this condition. Conclusions: Our findings highlight the high consumption of salt in individuals with diabetes and/or hypertension, and the need for effective strategies to reduce salt consumption in these groups of increased risk for major cardiovascular events, especially in women.

The high salt intake in adults with metabolic syndrome is related to increased waist circumference and blood pressure: the Brazilian Longitudinal Study of Adult Health study (ELSA-Brasil).

OBJECTIVES: The association between metabolic syndrome (MetS), a cluster of cardiometabolic risk factors, and salt consumption has fed intense debate in recent years, although it is yet to be fully elucidated. We aimed to evaluate whether individuals with MetS have a high salt consumption and to identify which components of the MetS diagnosis could be independently related to high salt consumption. METHODS: We analyzed data from 11 982 adults, ages 35 to 74 y, from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort study, from which clinical and anthropometric data were assessed, and a validated 12-h overnight urine collection was used to estimate salt intake. MetS was defined according to the Adult Treatment Panel III criteria. RESULTS: Salt intake was increased in individuals with MetS compared with individuals without MetS, regardless of sex (men: 14.3 ± 6.4 g/d versus 12.2 ± 5.5 g/d, P < 0.001; women: 10.6 ± 4.9 g/d versus 8.9 ± 4.0 g/d, P < 0.001) and increased progressively as the MetS criteria accumulated. The high salt intake in MetS participants, however, was observed only in the presence of elevated waist circumference and/or blood pressure and not with the other MetS criteria (reduced high-density lipoprotein, increased triglycerides, and impaired fasting blood glucose), regardless of the presence of MetS. When diabetes was incorporated as a MetS criterion, increased salt intake was observed in men but not in women. CONCLUSIONS: Salt intake should be reduced worldwide, but strategies must be more intense in people with elevated blood pressure and waist circumference, regardless of MetS diagnosis, to avoid the associated morbidity and mortality.

Assessment of 24 h Sodium and Potassium Urinary Excretion in Normotensive and Hypertensive Dominican Adults.

Higher salt (sodium) intake has been associated with higher blood pressure (BP). The degree of association may be influenced by factors such as age, origin, and dietary components. This study aimed to evaluate the 24 h urinary sodium (Na) and potassium (K) excretion in normotensive and hypertensive Dominican adults and estimate their salt intake. 163 volunteers (18-80 years old) participated in a cross-sectional study. The 24 h Na and K urinary excretion were measured using an ion-selective electrode technique. Na and K urinary excretion (99.4 ± 46.5 and 35.0 ± 17.5 mmol/24 h) did not correlate with BP, except in the normotensive group, in which K correlated with SBP (0.249, p = 0.019). Na and K excretion were similar in normotensive and hypertensive subjects. When considering two age groups (18-45, 46-80 years), the Na-to-K molar ratio (3.1 ± 1.3) was higher in younger subjects (p = 0.040). Na-to-K ratio was associated with DBP in the total group (r = 0.153, p = 0.052), in the hypertensive group (r = 0.395, p < 0.001), and in the older group with SBP (0.350, p = 0.002) and DBP (0.373, p < 0.001). In the older group, Na-to-K ratio and DBP correlated after controlling for subjects with hypertension controlled by treatment (r = 0.236, p = 0.041). The Na-to-K ratio correlated, when salt intake was over 5 g/day (52.2%), with SBP (rho = 0.219, p = 0.044) and DBP (rho = 0.259, p = 0.017). Determinants of BP in the total sample were age (SBP, beta: 0.6 ± 0.1, p < 0.001; DBP, beta: 0.2 ± 0.1, p < 0.002), sex (SBP, beta: 11.2 ± 3.5, p = 0.001), body mass index (BMI) (SBP, beta: 1.0 ± 0.3, p < 0.001; DBP, beta: 0.4 ± 0.2, p = 0.01), and Na-to-K ratio (SBP, beta: 3.0 ± 1.1, p = 0.008; DBP, beta: -12.3 ± 4.0, p = 0.002). Sex and BMI were determinants in the younger group. Na-to-K molar ratio was determinant in the older group (SBP, beta: 6.7 ± 2.4, p = 0.005; DBP, beta: 3.8 ± 1.1, p < 0.001). The mean Na and salt intakes (2.3 and 5.8 g/day) were slightly higher and the K intake lower (1.4 g/day) than WHO recommendations.

Dietary sodium intake remains high in Brazil: Data from the Brazilian National Dietary Surveys, 2008-2009 and 2017-2018.

Reducing salt intake is considered one of the most cost-effective interventions to decrease morbidity and mortality resulting from noncommunicable diseases. This study aimed to describe changes in sodium intake in the Brazilian population using data from the National Dietary Surveys (NDS) conducted in 2008-2009 and 2017-2018. We hypothesized that over the 10-year period evaluated, sodium intake has remained high in Brazil. Nationwide representative samples of 34,003 and 46,164 individuals (aged ≥10 years) from NDS 2008-2009 and 2017-2018, respectively, were evaluated. Food consumption data were obtained from 2 nonconsecutive food records (NDS 2008-2009) and two 24-hour food recalls (NDS 2017-2018). Trends, percentiles of distribution, and proportions of the population exceeding the age-specific tolerable upper intake level for sodium were estimated. Dietary sodium intake was also estimated as a function of energy intake (mg/1000 kcal). Overall, mean crude daily sodium intake was slightly lower in 2017-2018 than in 2008-2009 (2489 mg/d vs. 2529 mg/d). The decrease in sodium intake (mg/day) was statistically significant (P < .05) only among female adolescents and subjects in the highest income level. Additionally, an overall statistically significant increase in dietary sodium density was observed independent of age, sex, and income level for energy-adjusted data (P < .05). Our findings indicate that sodium intake has not significantly changed over time in the Brazilian population; thus, policies aimed at reducing sodium intake in Brazil are necessary.

Rapid onset sodium appetite and orofacial responses to intraoral capsaicin and hypertonic NaCl in the rat.

Sodium appetite reverts from aversive to hedonic the orofacial responses to intraoral hypertonic NaCl in a taste reactivity test (TRT). An electrophysiological-based hypothesis suggests that aversion to salty taste results from oral nociception (e.g., like that produced by intraoral capsaicin). In the present work, we used the TRT to investigate whether sodium appetite and its sensitization produce similar effects on the orofacial responses to the intraoral infusion of either capsaicin or hypertonic NaCl. We produced rapid onset sodium appetite by subcutaneous injection of furosemide combined with a low dose of captopril (Furo/Cap) in adult rats instrumented with intraoral cannula. Then, the animals had 1-h free access to water (thirst test). Immediately after, they entered the TRT receiving a first intraoral infusion (1 ml for a total of 1 min) of (0.5 µM) capsaicin and, 20 min later, a second one of (0.3 M) NaCl. The sequence, Furo/Cap injection - thirst test - TRT, was repeated twice more every three days. The repetition of the Furo/Cap increased the frequency of hedonic responses, decreased the frequency of aversive responses, and increased the hedonic:neutral response ratio to NaCl. The repetition of Furo/Cap reduced transiently the neutral orofacial responses and ended decreasing the aversive:neutral response ratio to capsaicin. The results suggest that repeated Furo/Cap sensitizes the palatability of hypertonic NaCl. They also suggest that sensitization of sodium appetite involves increased sodium "liking". Finally yet importantly, we found that sensitization of sodium appetite can influence orofacial responses to capsaicin. Rapid onset sodium appetite and orofacial responses to intraoral capsaicin and hypertonic NaCl in the rat.

The Jamaica Salt Consumption Study Protocol: Sodium Intake; Sodium Content in Restaurant Foods; Knowledge, Attitudes, and Practices; Spot Urine Sodium Validation.

Background: Excess dietary salt consumption is a major contributor to hypertension and cardiovascular disease. Public education programs on the dangers of high salt intake, and population level interventions to reduce the salt content in foods are possible strategies to address this problem. In Jamaica, there are limited data on the levels of salt consumption and the population's knowledge and practices with regards to salt consumption. This study therefore aims to obtain baseline data on salt consumption, salt content in foods sold in restaurants, and evaluate knowledge, attitudes, and practices of Jamaicans regarding salt consumption. Methods: The study is divided into four components. Component 1 will be a secondary analysis of data on urinary sodium from spot urine samples collected as part of a national survey, the Jamaica Health and Lifestyle Survey 2016-2017. Component 2 will be a survey of chain and non-chain restaurants in Jamaica, to estimate the sodium content of foods sold in restaurants. Component 3 is another national survey, this time on a sample 1,200 individuals to obtain data on knowledge, attitudes and practices regarding salt consumption and estimation of urinary sodium excretion. Component 4 is a validation study to assess the level of agreement between spot urine sodium estimates and 24-hour urinary sodium from 120 individuals from Component 3. Discussion: This study will provide important baseline data on salt consumption in Jamaica and will fulfil the first components of the World Health Organization SHAKE Technical Package for Salt Reduction. The findings will serve as a guide to Jamaica's Ministry of Health and Wellness in the development of a national salt reduction program. Findings will also inform interventions to promote individual and population level sodium reduction strategies as the country seeks to achieve the national target of a 30% reduction in salt consumption by 2025.

Applying Customer Journey Mapping in Social Marketing to Understand Salt-Related Behaviors in Cooking. A Case Study.

Worldwide, salt consumption exceeds the World Health Organization's recommendation of a daily intake of 5 g. Customer journey mapping is a research method used in market research to understand customer behaviors and experiences and could be useful in social marketing as well. This study aimed to explore the potential of customer journey mapping to better understand salt-related behaviors performed during the preparation of household cooking. We tracked the journey of four women in their kitchens for approximately two hours to observe the preparation of lunch. Individual journey maps were created, one for each woman, that were composited into a single journey map. We found that customer journey mapping was a suitable research method to understand how food preparers made decisions around adding salt and artificial seasonings at each stage of the journey. In contrast to the interviewee' responses, it was observed that the four women added salt and artificial seasonings consistently and incrementally with little control and without any standard measure. In this study, we demonstrate the utility of customer journey mapping in a novel context and nudge social marketers to include this tool in their repertory of research methods to understand human behavior.

Effects of gonadotropin inducible ovarian transcription factor 1 in the paraventricular nucleus on fluid intake after dehydration of ovariectomized female rats.

NEW FINDINGS: What is the central question of this study? Giot1, the gene for gonadotropin inducible ovarian transcription factor 1 (GIOT1), is upregulated in osmotically challenged rats: does Giot1 gene expression in the paraventricular nucleus have a role in controlling fluid intake following dehydration and what is the role of ovarian hormones in the modulation of GIOT1 actions? What is the main finding and its importance? GIOT1 acts to regulate water and salt intake as well as hormone secretion after dehydration. The identification of genes that participate in the hormone and behavioural responses involved with hydromineral homeostasis is essential for future exploration of novel drug targets for the treatment of metabolic disease. ABSTRACT: In order to maintain body fluid balance after dehydration, hypothalamic neurons of the paraventricular nucleus (PVN) are activated to promote secretion of vasopressin (AVP) and oxytocin (OXT) from the neurohypophysis, and to modulate the behavioural allostatic responses of thirst and salt appetite. Gonadotropin inducible transcription factor (GIOT1) is a Krüppel-type zinc finger protein induced by gonadotropins and oestradiol (E2). This transcription factor is expressed in the hypothalamus, specifically in the PVN where expression of Giot1 mRNA increases following hydromineral challenges such as water deprivation or salt loading, although its physiological role is not clear. We hypothesize that GIOT1 has a central role in the integrated homeostatic and allostatic responses to disturbances in hydromineral balance, especially in the presence of female gonadal hormones. Female rats with intact ovaries or ovariectomized rats were subjected to specific microinjection of a lentiviral vector mediating Giot1 knockdown in the PVN. Three weeks after injection, rats were subjected to 48 h water deprivation, and thereafter water and salt intake were evaluated. Giot1 knockdown in PVN reduced water and saline intake as well as AVP and OXT secretion. Furthermore, Giot1 knockdown had profound effects on gene expression in the PVN, reducing the abundance of transcripts encoded by the Avp, Oxt, Nr4a1 and Crh genes. In conclusion, the present study shows for the first time that GIOT1 in the PVN regulates both transcription and fluid intake, although any connection to ovarian hormones remains to be established.

Depletion of C1 neurons attenuates the salt-induced hypertension in unanesthetized rats.

High salt intake is able to evoke neuroendocrine and autonomic responses that include vasopressin release and sympathoexcitation resulting in increasing in the arterial blood pressure (BP). The C1 neurons are a specific population of catecholaminergic neurons located in the RVLM region and they control BP under homeostatic imbalance. Thus, here we hypothesized that the ablation of C1 neurons mitigate the high blood pressure induced by high-salt intake. To test this hypothesis, we injected anti-DßH-SAP saporin at the RVLM and monitored the BP in unanesthetized animals exposed to high salt intake of 2% NaCl solution for 7 days. The injection of anti-DßH-SAP into the RVLM depleted 80% of tyrosine hydroxylase-positive neurons (TH+ neurons) in the C1, 38% in the A5, and no significant reduction in the A1 region, when compared to control group (saline as vehicle). High salt intake elicited a significant increase in BP in the control group, while in the anti-DßH-SAP group the depletion of TH+ neurons prevents the salt-induced hypertension. Moreover, the low frequency component of systolic BP and pulse interval were increased by high-salt intake in control animals but not in anti-DßH-SAP group, which indirectly suggests that the increase in the BP is mediated by increase in sympathetic activity. In conclusion, our data show that hypertension induced by high-salt intake is dependent on C1 neurons.

The association between salt intake and arterial stiffness is influenced by a sex-specific mediating effect through blood pressure in normotensive adults: The ELSA-Brasil study.

High salt intake is known to increase blood pressure (BP) and also to be associated with carotid-femoral pulse wave velocity (cf-PWV). However, recent data showed a sex-specific pattern in the salt-induced rise of BP. Thus, we aimed to investigate whether the association between salt intake and arterial stiffness also has a sex-specific pattern. A total of 7755 normotensive participants with a validated 12-h overnight urine collection in which daily salt intake was estimated were included. cf-PWV, as well as clinical and anthropometric parameters, was measured. Salt intake positively correlated with cf-PWV, in which the linear regression was steeper in women than in men (0.0199 ± 0.0045 vs 0.0326 ± 0.0052 m/s per gram of salt, P < .05). cf-PWV increases over the salt quartiles in men and women. However, after adjustment for confounders, the association remained significant only for men. In the path analysis, the direct path (men: 0.048 P < .001, women: 0.029 P = .028) was higher in men while that mediated by SBP (men: 0.020 P < .001, women: 0.034 P < .001) was higher in women. We clearly demonstrated that high salt intake has a direct and independent effect increasing arterial stiffness regardless of sex. Also, the association between salt intake and arterial stiffness is more dependent on BP in normotensive women than it is in normotensive men. These results highlight the need for a sex-specific approach in the evaluation of cardiovascular risk associated with dietary habits.

The Science of Salt: Updating the evidence on global estimates of salt intake.

The Global Burden of Disease (GBD) 2010 study estimated national salt intake for 187 countries based on data available up to 2010. The purpose of this review was to identify studies that have measured salt intake in a nationally representative population using the 24-hour urine collection method since 2010, with a view to updating evidence on population salt intake globally. Studies published from January 2011 to September 2018 were searched for from MEDLINE, Scopus, and Embase databases using relevant terms. Studies that provided nationally representative estimates of salt intake among the healthy adult population based on the 24-hour urine collection were included. Measured salt intake was extracted and compared with the GBD estimates. Of the 115 identified studies assessed for eligibility, 13 studies were included: Four studies were from Europe, and one each from the United States, Canada, Benin, India, Samoa, Fiji, Barbados, Australia, and New Zealand. Mean daily salt intake ranged from 6.75 g/d in Barbados to 10.66 g/d in Portugal. Measured mean population salt intake in Italy, England, Canada, and Barbados was lower, and in Fiji, Samoa, and Benin was higher, in recent surveys compared to the GBD 2010 estimates. Despite global targets to reduce population salt intake, only 13 countries have published nationally representative salt intake data since the GBD 2010 study. In all countries, salt intake levels remain higher than the World Health Organization's recommendation, highlighting the need for additional global efforts to lower salt intake and monitor salt reduction strategies.

Sex-specific patterns in the association between salt intake and blood pressure: The ELSA-Brasil study.

Blood pressure (BP) is a strong cardiovascular risk factor, predicting cardiovascular mortality in the general population. High salt consumption is a major contributor of increased BP and hypertension. However, there is a controversy on whether BP response to salt intake would be sex-specific. Thus, we aimed to verify the changes in BP according to different salt intake in men and women in a large sample of adults. The present analysis refers to 12 813 participants (from 35 to 64 years) with a validated 12-hour overnight urine collection in which salt intake was estimated. A set of questionnaires, clinical examination, and laboratory tests were carried out during a single visit to one of the six investigation centers involved. Salt intake was 12.9 ± 5.9 g/d in men and 9.3 ± 4.3 g/d in women. BP increases as salt intake increases, regardless of using BP-lowering medication. The slope of increase in BP elicited by salt intake was significantly higher in women than in men. Thus, the increase in BP by salt intake was stepper in women even after controlling for confounders, regardless of using BP-lowering medication or being hypertensive. In conclusion, salt intake is elevated in this large sample of Brazilian adults in which only a few participants are compliant with the recommendation. Also, women have a higher responsiveness of BP according to salt intake than men, and it is not associated with age, BP level, or the use of BP-lowering medication.

Dietary sources of salt intake in adults and older people: a population-based study in a Brazilian town.

OBJECTIVE: To assess salt intake and its dietary sources using biochemical and self-report methods and to characterize salt intake according to sociodemographic and disease-related variables in a sample of the Brazilian population. DESIGN: Population-based cross-sectional survey. SETTING: Salt intake was assessed by biochemical (24 h urinary Na excretion) and self-report methods (sodium FFQ, 24 h dietary recall, seasoned-salt questionnaire, discretionary-salt questionnaire and total reported salt intake).ParticipantsAdults and older people (n 517) aged 20-80 years, living in Artur Nogueira, São Paulo, Brazil. RESULTS: Mean salt intake based on 24 h urinary Na excretion and total reported salt intake was 10·5 and 11·0 g/d, respectively; both measures were significantly correlated. Discretionary salt and seasoned salt were the most important sources of salt intake (68·2 %). Men in the study consumed more salt than women as estimated by 24 h urinary Na excretion (11·7 v. 9·6 g salt/d; P<0·0001). Participants known to be hypertensive added more salt to their meals but consumed less salty ultra-processed foods. Waist circumference in both sexes and BMI were positively correlated with salt intake estimated by 24 h urinary Na excretion. In addition, regression analysis revealed that being a young male or having a high waist circumference was a predictor of higher salt intake. CONCLUSIONS: Salt intake in this population was well above the recommended amount. The main source of salt intake came from salt added during cooking. Salt intake varied according to sex and waist circumference.

Role of the Carotid Bodies in the Hypertensive and Natriuretic Responses to NaCl Load in Conscious Rats.

Hyperosmotic challenges trigger a hypertensive response and natriuresis mediated by central and peripheral sensors. Here, we evaluated the importance of the carotid bodies for the hypertensive and natriuretic responses to acute and sub-chronic NaCl load in conscious rats. Male Wistar rats (250-330 g) submitted to bilateral carotid body removal (CBX) or sham surgery were used. One day after the surgery, the changes in arterial blood pressure (n = 6-7/group) and renal sodium excretion (n = 10/group) to intravenous infusion of 3 M NaCl (1.8 mL/kg b.w. during 1 min) were evaluated in non-anesthetized rats. Another cohort of sham (n = 8) and CBX rats (n = 6) had access to 0.3 M NaCl as the only source of fluid to drink for 7 days while ingestion and renal excretion were monitored daily. The sodium balance was calculated as the difference between sodium infused/ingested and excreted. CBX reduced the hypertensive (8 ± 2 mmHg, vs. sham rats: 19 ± 2 mmHg; p < 0.05) and natriuretic responses (1.33 ± 0.13 mmol/90 min, vs. sham: 1.81 ± 0.11 mmol/90 min; p < 0.05) to acute intravenous infusion of 3 M NaCl, leading to an increase of sodium balance (0.38 ± 0.11 mmol/90 min, vs. sham: -0.06 ± 0.10 mmol/90 min; p < 0.05). In CBX rats, sub-chronic NaCl load with 0.3 M NaCl to drink for 7 days increased sodium balance (18.13 ± 4.45 mmol, vs. sham: 5.58 ± 1.71 mmol; p < 0.05) and plasma sodium concentration (164 ± 5 mmol/L, vs. sham: 140 ± 7 mmol/L; p < 0.05), without changing arterial pressure (121 ± 9 mmHg, vs. sham: 116 ± 2 mmHg). These results suggest that carotid bodies are important for the maintenance of the hypertensive response to acute hypertonic challenges and for sodium excretion to both acute and chronic NaCl load.

Contemporary Dietary Intake: Too Much Sodium, Not Enough Potassium, yet Sufficient Iodine: The SALMEX Cohort Results.

Initiatives to reduce sodium intake are encouraged globally, yet there is concern about compromised iodine intake supplied through salt. The aim of the present study was to determine baseline sodium, potassium, and iodine intake in a sample of workers from our Institution in Mexico City (SALMEX Cohort). Methods. From a cohort of 1009 workers, appropriate 24-h urine and three-day dietary recall was collected in a sample of 727 adult subjects for assessment of urinary sodium, potassium, and iodine concentrations. Median urinary iodine excretion (UIE) was compared across categories of sodium intake of <2, 2⁻3.6, and ≥3.6 g/day. Results. Average sodium intake was 3.49 ± 1.38 g/day; higher in men than women (4.14 vs. 3.11 g/day, p ≤0.001). Only 10.6% of the population had sodium intake within the recommended range (<2 g/day); 45.4% had high (2⁻3.6 g/day) and 44% had excessive intake (>3.6 g/day). Average urinary Na/K ratio was 3.15 ± 1.22 (ideal < 1), higher in men (3.42 vs. 3.0, p ≤ 0.001). The multivariate analysis showed that sodium intake was associated with age (p = 0.03), male sex (p < 0.001), caloric intake (p = 0.002), UKE (p < 0.001) and BMI (p < 0.001). Median iodine intake was 286.7 µg/day (IQR 215⁻370 µg/day). Less than 2% of subjects had iodine intake lower than recommended for adults (95 µg/day); 1.3% of subjects in the recommended range of salt intake had low iodine intake. There is a direct relationship between iodine and sodium urinary excretion (r = 0.57, p < 0.0001). Conclusions. In the studied population, there was an excessive sodium intake and an imbalance between sodium and potassium intake. Only 10.6% of the population had sodium intake within the recommended values, but iodine intake in this group appears to be adequate.

Sodium Intake and Blood Pressure in Patients with Chronic Kidney Disease: A Salty Relationship.

BACKGROUND: Hypertension affects almost all chronic kidney disease patients and is related to poor outcomes. Sodium intake is closely related to blood pressure (BP) levels in this population and decreasing its intake consistently improves the BP control particularly in short-term controlled trials. However, most patients struggle in following a controlled diet on sodium according to the guidelines recommendation due to several factors and barriers discussed in this article. SUMMARY: This review article summarizes the current knowledge related to the associations between sodium consumption, BP, and the risk of cardiovascular disease and chronic kidney disease (CKD); it also provides recommendations of how to achieve sodium intake lowering. Key Messages: Evidences support the benefits in decreasing sodium intake on markers of cardiovascular and renal outcomes in CKD. Trials had shorter follow-up and to maintain long-term sodium intake control is a major challenge. Larger studies with longer follow-up looking at hard endpoints will be important to drive future recommendations.

Coping with Salt Water Habitats: Metabolic and Oxidative Responses to Salt Intake in the Rufous-Collared Sparrow.

Many physiological adjustments occur in response to salt intake in several marine taxa, which manifest at different scales from changes in the concentration of individual molecules to physical traits of whole organisms. Little is known about the influence of salinity on the distribution, physiological performance, and ecology of passerines; specifically, the impact of drinking water salinity on the oxidative status of birds has been largely ignored. In this study, we evaluated whether experimental variations in the salt intake of a widely-distributed passerine (Zontotrichia capensis) could generate differences in basal (BMR) and maximum metabolic rates (Msum), as well as affect metabolic enzyme activity and oxidative status. We measured rates of energy expenditure of birds after 30-d acclimation to drink salt (SW) or tap (fresh) water (TW) and assessed changes in the activity of mitochondrial enzymes (cytochrome c oxidase and citrate synthase) in skeletal muscle, heart, and kidney. Finally, we evaluated the oxidative status of bird tissues by means of total antioxidant capacity (TAC) and superoxide dismutase activities and lipid oxidative damage (Malondialdehyde, MDA). The results revealed a significant increase in BMR but not Msum, which resulted in a reduction in factorial aerobic scope in SW- vs. TW-acclimated birds. These changes were paralleled with increased kidney and intestine masses and catabolic activities in tissues, especially in pectoralis muscle. We also found that TAC and MDA concentrations were ~120 and ~400% higher, respectively in the liver of animals acclimated to the SW- vs. TW-treatment. Our study is the first to document changes in the oxidative status in birds that persistently drink saltwater, and shows that they undergo several physiological adjustments that range that range in scale from biochemical capacities (e.g., TAC and MDA) to whole organism traits (e.g., metabolic rates). We propose that the physiological changes observed in Z. capensis acclimated to saltwater could be common phenomena in birds and likely explain selection of prey containing little salt and habitats associated with low salinity.

Assessment of Sodium and Potassium Intake by 24 h Urinary Excretion in a Healthy Mexican Cohort.

BACKGROUND AND AIMS: A high dietary sodium intake and a low potassium intake are associated with adverse cardiovascular health. Data on these nutrients consumption in Mexico is limited. The aim of this study was to assess sodium and potassium intake by 24 h urinary excretion in a clinically healthy Mexican population. We additionally explored their association with blood pressure. METHODS: 711 clinically healthy participants aged 20-50 years old recruited in the Tlalpan 2020 cohort from September 2014-December 2015, were included in this cross-sectional analysis. All participants provided a 24 h urine sample and underwent anthropometric, biochemical, and blood pressure evaluations. Univariate and multivariate linear regression analyses were used to assess the association of urinary sodium, potassium, and Na/K ratio with blood pressure. RESULTS: Mean (95% confidence interval [CI]) urinary sodium and potassium in the overall population was 3150.1 (3054.2-3246.0) mg/d and 1909.5 (1859.3-1959.6) mg/d, respectively. Overall, only 121 (17%) met the WHO recommendation for sodium intake (<2000 mg/d) and 16 (2.3%) met the goal for potassium intake (≥3510 mg/d). Urinary sodium (ß coefficient 1.3, 95% CI: 0.7, 1.8, p <0.001) and potassium (ß coefficient 2.1, 95% CI: 1.0, 3.2, p <0.001) were found to be associated with systolic blood pressure in the univariate analysis but not in the multivariate analysis. CONCLUSIONS: Sodium intake was higher and potassium intake was lower than the WHO recommendations in this healthy Mexican population. Sodium and potassium intakes were not associated with blood pressure at the mean levels of intake observed in this population, after adjusting for key variables.

Concerted regulation of renal plasma flow and glomerular filtration rate by renal dopamine and NOS I in rats on high salt intake.

Under high sodium intake renal dopamine (DA) increases while NOS I expression in macula densa cells (MD) decreases. To explore whether renal DA and NOS I, linked to natriuresis and to the stability of the tubuloglomerular feedback, respectively, act in concert to regulate renal plasma flow (RPF) and glomerular filtration rate (GFR). Male Wistar rats were studied under a normal sodium intake (NS, NaCl 0.24%) or a high sodium intake (HS, NaCl 1% in drinking water) during the 5 days of the study. For the last two days, the specific D1-like receptor antagonist SCH 23390 (1 mg kg bwt-1 day-1, sc) or a vehicle was administered. HS intake increased natriuresis, diuresis, and urinary DA while it decreased cortical NOS I expression (P < 0.05 vs. NS), Nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity in MD (P < 0.001 vs. NS) and cortical nitrates+nitrites (NOx) production (NS 2.04 ± 0.22 vs. HS 1.28 ± 0.10 nmol mg protein-1, P < 0.01). Treatment with SCH 23390 to rats on HS sharply decreased hydroelectrolyte excretion (P < 0.001 vs. HS) while NOS I expression, NADPH-d activity and NOx production increased (P < 0.05 vs. HS for NOS I and P < 0.001 vs. HS for NADPH-d and NOx). SCH 23390 increased RPF and GFR in HS rats (P < 0.01 HS+SCH vs. HS). It did not cause variations in NS rats. Results indicate that when NS intake is shifted to a prolonged high sodium intake, renal DA through the D1R, and NOS I in MD cells act in concert to regulate RPF and GFR to stabilize the delivery of NaCl to the distal nephron.