Sodium Intake Is associated With Endothelial Damage Biomarkers and Metabolic Dysregulation.

BACKGROUND: Mounting evidence has associated high sodium (HS) intake with hypertension, cardiovascular disease, and stroke. We investigated whether HS intake modulates the parameters of endothelial damage, inflammation, and oxidative stress. METHODS: We used a cross-sectional study design including 223 Chilean subjects (6.9-65.0 years old). We measured aldosterone, renin activity, cortisol, cortisone, adiponectin, leptin, hsCRP, interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor type 1 (PAI-1), metalloproteinase (MMP)-9 and MMP-2 activity, and malondialdehyde. Sodium and creatinine were measured in 24-hour urine samples. The subjects were divided by sodium intake, high sodium (HS): ≥150 mEq/day, n = 118, and adequate sodium (AS): <150 mEq/day, n = 105. RESULTS: We observed a positive correlation between urinary sodium excretion and blood pressure (r = 0.1669, P = 0.0124 for systolic and r = 0.2416, P = 0.0003 for diastolic), glycemia (r = 0.2660, P < 0.0001), and triglycerides (r = 0.1604, P = 0.0175) and a highly significant correlation between sodium excretion and PAI-1 (r = 0.2701, P < 0.0001). An inverse correlation was observed between urinary sodium and HDL-cholesterol (r = -0.2093, P = 0.0018) and adiponectin (r = -0.2679, P < 0.0001). In a linear regression model, urinary sodium excretion remained significantly associated with PAI-1 values even after adjusting for age, gender, and BMI. The HS group had higher blood pressure, glycemia, HOMA-IR, atherogenic index of plasma, and PAI-1 values than the group with AS intake. CONCLUSIONS: HS intake is associated with endothelial damage (high PAI-1) and metabolic dysregulation. On the other hand, inflammation and oxidative stress parameters are not modified by sodium intake.

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 and Potassium Consumption in a Semi-Urban Area in Peru: Evaluation of a Population-Based 24-Hour Urine Collection.

Despite the negative effects of high sodium and low potassium consumption on cardiovascular health, their consumption has not been quantified in sites undergoing urbanization. We aimed to determine the sodium and potassium consumption in a semi-urban area in Peru with a cross-sectional study. 24-h urine samples were collected. The outcomes were mean consumption of sodium and potassium, as well as adherence to their consumption recommendation: <2 g/day and ≥3.51 g/day, respectively. Bivariate analyses were conducted to identify socio-economic and clinical variables associated with the consumption recommendations of 602 participants, complete urine samples were found in 409: mean age of participants was 45.7 (standard deviation (SD): 16.2) years and 56% were women. The mean sodium and potassium consumption was 4.4 (SD: 2.1) and 2.0 (SD: 1.2) g/day. The sodium and potassium recommendation was met by 7.1% and 13.7% of the study sample; none of the participants met both recommendations. People not adherent to the sodium recommendation had higher diastolic (73.1 mmHg vs. 68.2 mmHg, p = 0.015) and systolic (113.1 mmHg vs. 106.3 mmHg, p = 0.047) blood pressure than those who comply with the recommendation. Public health actions ought to be implemented in areas undergoing urbanization to improve sodium and potassium consumption at the population level.

Sodium excretion and associated factors in urine samples of African descendants in Alcântara, Brazil: a population based study.

In most countries, salt intake has been excessive and constitutes one of the main risk factors for disease development, especially hypertension. Factors such as age, gender, sedentary lifestyle, smoking, African descent, obesity, dietary habits and family history of hypertension may be associated with high blood pressure. Studies show a positive association between the excretion of sodium and increased blood pressure. We evaluated the urinary excretion of sodium and associated factors in isolated urine samples of African descendants from remaining Quilombos. We performed a cross-sectional, population-based study with 1162 African descendants living in remaining quilombos in Alcântara, Maranhão, Brazil. Demographic, nutritional, clinical and laboratory data were analyzed. Urinary sodium excretion was estimated using the Kawasaki equation. A multivariate linear regression model was used to identify the variables related to sodium excretion. The average age was 37.6 ± 11.8 years and 51.2% were women. The prevalence of hypertension was 21.3%. The average urinary excretion of sodium was high, especially among the hypertensive (217.9 ± 90.1 vs. 199.2 ± 83.0 mmol/d; p = .002). After an adjusted analysis, only the waist circumference (odds ratios (OR) = 1.16; confidence intervals(CI)95%: 1.03-1.30), triglyceride (OR = 1.13; CI95%: 1.05-1.22), systolic blood pressure (OR = 1.19; CI95%: 1.08-1.32) and Chronic Kidney Disease Epidemiology (CKD-EPI;OR = 1.24; CI95%: 1.15-1.35) remained related to urinary sodium excretion. African descendants had a high rate of sodium excretion, especially among those who had hypertension. Abdominal adiposity, triglyceride and systolic blood pressure levels and renal function by CKD-EPI equation were associated to urinary sodium excretion.

Food Sources of Sodium Intake in an Adult Mexican Population: A Sub-Analysis of the SALMEX Study.

Excessive dietary sodium intake increases blood pressure and cardiovascular risk. In Western diets, the majority of dietary sodium comes from packaged and prepared foods (≈75%); however, in Mexico there is no available data on the main food sources of dietary sodium. The main objective of this study was to identify and characterize the major food sources of dietary sodium in a sample of the Mexican Salt and Mexico (SALMEX) cohort. Adult male and female participants of the SALMEX study who provided a complete and valid three-day food record during the baseline visit were included. Overall, 950 participants (mean age 38.6 ± 10.7 years) were analyzed to determine the total sodium contributed by the main food sources of sodium identified. Mean daily sodium intake estimated by three-day food records and 24-h urinary sodium excretion was 2647.2 ± 976.9 mg/day and 3497.2 ± 1393.0, in the overall population, respectively. Processed meat was the main contributor to daily sodium intake, representing 8% of total sodium intake per capita as measured by three-day food records. When savory bread (8%) and sweet bakery goods (8%) were considered together as bread products, these were the major contributor to daily sodium intake, accounting for the 16% of total sodium intake, followed by processed meat (8%), natural cheeses (5%), and tacos (5%). These results highlight the need for public health policies focused on reducing the sodium content of processed food in Mexico.

Formula to detect high sodium excretion from spot urine in chronic kidney disease patients.

INTRODUCTION: Excessive sodium intake is related to adverse renal and cardiovascular outcomes in patients with chronic kidney disease (CKD) and assessment of sodium intake is complex and not evaluated very often in clinical practice. OBJECTIVE: To develop a new formula to estimate 24h sodium excretion from urine sample (second void) of patients with CKD. METHODS: We included 51 participants with CKD who provided 24-hour urine collection and a sample of the second urine of the day to determine the sodium excretion. A formula to estimate the 24-hour sodium excretion was developed from a multivariate regression equation coefficients. The accuracy of the formula was tested by calculating the P30 (proportion of estimates within 30% of measured sodium exection) and the ability of the formula to discriminate sodium intake higher than 3.6 g/day was evaluated by ROC curve. RESULTS: Correlation test between measured and estimated sodium was significant (r = 0.57; p < 0.001), but P30 test identified a low accuracy (61%) of the formula. Different cutoff points were tested by performance tests and a ROC curve was generated with the cutoff that showed better performance (3.6 g/day). An area under the curve of 0.69 with a sensitivity of 0.91 and specificity of 0.53 was obtained. CONCLUSION: A simple formula with high sensitivity in detecting patients with sodium consumption higher than 3.6 g/day from isolated urine sample was developed. Studies with a higher number of participants and with different populations are necessary to test formula´s validity.

Formula to detect high sodium excretion from spot urine in chronic kidney disease patients / Fórmula para detectar elevada excreção de sódio a partir de amostra isolada de urina de pacientes com doença renal crônica pré-dialítica

Abstract Introduction: Excessive sodium intake is related to adverse renal and cardiovascular outcomes in patients with chronic kidney disease (CKD) and assessment of sodium intake is complex and not evaluated very often in clinical practice. Objective: To develop a new formula to estimate 24h sodium excretion from urine sample (second void) of patients with CKD. Methods: We included 51 participants with CKD who provided 24-hour urine collection and a sample of the second urine of the day to determine the sodium excretion. A formula to estimate the 24-hour sodium excretion was developed from a multivariate regression equation coefficients. The accuracy of the formula was tested by calculating the P30 (proportion of estimates within 30% of measured sodium exection) and the ability of the formula to discriminate sodium intake higher than 3.6 g/day was evaluated by ROC curve. Results: Correlation test between measured and estimated sodium was significant (r = 0.57; p < 0.001), but P30 test identified a low accuracy (61%) of the formula. Different cutoff points were tested by performance tests and a ROC curve was generated with the cutoff that showed better performance (3.6 g/day). An area under the curve of 0.69 with a sensitivity of 0.91 and specificity of 0.53 was obtained. Conclusion: A simple formula with high sensitivity in detecting patients with sodium consumption higher than 3.6 g/day from isolated urine sample was developed. Studies with a higher number of participants and with different populations are necessary to test formula´s validity.

Resumo Introdução: O consumo excessivo de sódio está relacionado a piores desfechos renais e cardiovasculares em pacientes com doença renal crônica (DRC), mas a avaliação deste consumo é complexa e mensurada com baixa frequência na prática clínica. Objetivo: Desenvolver uma nova fórmula para estimar a excreção de sódio de 24h a partir da concentração de sódio em amostra isolada da segunda urina do dia em pacientes com DRC pré-dialítica. Métodos: 51 participantes com DRC forneceram coleta de urina de 24h e uma amostra da segunda urina do dia para determinação da excreção de sódio. Uma fórmula para estimar a excreção de sódio de 24h foi desenvolvida a partir dos coeficientes da equação de regressão. A acurácia da fórmula foi testada por meio do cálculo do P30. A habilidade da fórmula em discriminar consumo de sódio superior a 3,6 g/dia foi avaliada pela curva ROC. Resultados: O teste de correlação entre sódio mensurado e estimado pela fórmula foi r = 0,57; p < 0,001, porém o resultado do P30 identificou baixa acurácia (61%). Diferentes pontos de corte foram testados por meio de testes de performance e uma curva ROC foi gerada com o ponto de corte de melhor performance (3,6 g/dia). Foi obtida uma área sob a curva de 0,69 com sensibilidade 0,91 e especificidade 0,53. Conclusão: Foi desenvolvida uma fórmula simples com elevada sensibilidade em detectar pacientes com consumo de sódio superior a 3,6 g/dia a partir de amostra de urina isolada. Estudos que testem a fórmula com um maior número de participantes e com outras populações são necessários.

Usefulness and Pitfalls in Sodium Intake Estimation: Comparison of Dietary Assessment and Urinary Excretion in Chilean Children and Adults.

BACKGROUND: High sodium intake has been associated with various noncommunicable disease like hypertension, cardiovascular disease, or stroke. To estimate accurately sodium intake is challenging in clinical practice. We investigate the usefulness and limitations of assessing sodium intake simultaneously by dietary assessment and urinary samples in both children and adults. METHODS: We used a cross-sectional study design inviting 298 Chilean subjects (74 children and 222 adults) aged between 9 and 66 years of both genders. Sodium intake by dietary assessment was obtained from Chilean food composition data, based on FAO tables. Sodium and creatinine excretion were measured in 24-hour urine samples, in all participants. RESULTS: Adequate urinary collection was obtained in 81% of children (59/74) and 61% of adults (135/222). The mean sodium intake by dietary assessment was similar to the sodium excretion in 24 hours (3,121±1,153mg/d vs. 3,114±1,353mg/24h, P = nonsignificant) in children but was significantly lower (3,208±1,284mg/d vs. 4,160±1,651mg/24h, P < 0.001) in adults. In both children and adults, sodium intake correlated with urinary sodium excretion (r = 0.456, P < 0.003 and r = 0.390, P < 0.001, respectively). Secondary analyses also suggested that the dietary assessment was more inaccurate in overweight adult subjects. CONCLUSIONS: Our results showed that average sodium intake was higher than recommended in both children and adults (WHO ≤2,000mg/d). The sodium intake estimated by dietary assessment correlated with urinary excretion in all subjects, but in obese adults was more inaccurate than in children. Future studies to validate the appropriate test to assess sodium intake by age and nutritional status are warranted.

Sodium and potassium intake estimated using two methods in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) / Consumo de sódio e potássio estimado por dois métodos no Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil)

ABSTRACT CONTEXT AND OBJECTIVE: Sodium and potassium intake from different food sources is an important issue regarding cardiovascular physiology. Epidemiological assessment of the intake of these electrolytes intake is done through food frequency questionnaires or urinary excretion measurements. Our aim was to compare these methods using a sample of Brazilian civil servants. DESIGN AND SETTING: Cross-sectional baseline evaluation from the Brazilian Longitudinal Study of Adult Health. METHODS: Sodium and potassium intake was obtained using two methods: a semi-quantitative questionnaire including 114 food items; and overnight 12-hour urinary excretion measurement. Sodium and potassium estimates obtained through the questionnaire were adjusted for energy intake using the residual method. Urinary excretion measurements were considered valid if they met three adequacy criteria: collection time, volume and total creatinine excretion. Mean nutrients were estimated, and Spearman correlations were calculated. Sodium and potassium intake was categorized into quintiles, and weighted kappa coefficients and percentage agreement were calculated. The significance level for all tests was 0.05. RESULTS: Data from 15,105 participants were analyzed, and significant differences between mean intakes of sodium (questionnaire: 4.5 ± 1.7 g; urine: 4.2 ± 2.1 g) and potassium (questionnaire: 4.7 ± 1.8 g; urine: 2.4 ± 1 g) were found. Weak agreement was found for sodium (K = 0.18) and potassium (K = 0.16). The percentage disagreement between methods ranged from 41.8 to 44.5%, while exact concordance ranged from 22.1% to 23.9%. CONCLUSIONS: The agreement between the food frequency questionnaire and urinary excretion measurements for assessment of sodium and potassium intakes was modest.

RESUMO CONTEXTO E OBJETIVO: O consumo de sódio e potássio de diferentes fontes alimentares é uma questão importante para a fisiologia cardiovascular. A avaliação epidemiológica do consumo desses eletrólitos é feita pelo questionário de frequência alimentar ou pela excreção urinária. O objetivo deste estudo é comparar esses métodos em uma amostra de servidores públicos brasileiros. TIPO DE ESTUDO E LOCAL: Avaliação transversal da linha de base do Estudo Longitudinal de Saúde do Adulto. MÉTODOS: O consumo de sódio e potássio foi obtido por dois métodos: questionário semi-quantitativo com 114 itens alimentares e excreção urinária de 12 horas noturnas. Estimativas de sódio e potássio obtidas pelo questionário foram ajustadas pela energia utilizando o método residual. A excreção urinária foi considerada válida se atendesse a três critérios: tempo de coleta, volume e excreção total de creatinina adequados. Foram estimadas médias dos nutrientes e calculada a correlação de Spearman. O consumo de sódio e potássio foi categorizado em quintis e foram calculados o kappa ponderado e o percentual de concordância. O nível de significância para todos os testes foi de 0,05. RESULTADOS: Foram analisados dados de 15,105 participantes e encontradas diferenças significativas entre médias de sódio (questionário: 4,5 ± 1,7 g; urina: 4,2 ± 2,1 g) e potássio (questionário: 4,7 ± 1,8 g; urina: 2,4 ± 1 g). Foi encontrada fraca concordância para sódio (K = 0,18) e potássio (K = 0,16). Percentuais de discordância entre métodos variaram de 41,8-44,5%; concordâncias exatas de 22,1-23,9%. CONCLUSÃO: A concordância entre o questionário de frequência alimentar e excreção urinária para avaliação do consumo de sódio e potássio foi modesta.

Sodium and potassium intake estimated using two methods in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

CONTEXT AND OBJECTIVE: Sodium and potassium intake from different food sources is an important issue regarding cardiovascular physiology. Epidemiological assessment of the intake of these electrolytes intake is done through food frequency questionnaires or urinary excretion measurements. Our aim was to compare these methods using a sample of Brazilian civil servants. DESIGN AND SETTING: Cross-sectional baseline evaluation from the Brazilian Longitudinal Study of Adult Health. METHODS: Sodium and potassium intake was obtained using two methods: a semi-quantitative questionnaire including 114 food items; and overnight 12-hour urinary excretion measurement. Sodium and potassium estimates obtained through the questionnaire were adjusted for energy intake using the residual method. Urinary excretion measurements were considered valid if they met three adequacy criteria: collection time, volume and total creatinine excretion. Mean nutrients were estimated, and Spearman correlations were calculated. Sodium and potassium intake was categorized into quintiles, and weighted kappa coefficients and percentage agreement were calculated. The significance level for all tests was 0.05. RESULTS: Data from 15,105 participants were analyzed, and significant differences between mean intakes of sodium (questionnaire: 4.5 ± 1.7 g; urine: 4.2 ± 2.1 g) and potassium (questionnaire: 4.7 ± 1.8 g; urine: 2.4 ± 1 g) were found. Weak agreement was found for sodium (K = 0.18) and potassium (K = 0.16). The percentage disagreement between methods ranged from 41.8 to 44.5%, while exact concordance ranged from 22.1% to 23.9%. CONCLUSIONS: The agreement between the food frequency questionnaire and urinary excretion measurements for assessment of sodium and potassium intakes was modest.

Development of a formula for estimation of sodium intake from spot urine in people with chronic kidney disease.

BACKGROUND/AIMS: High sodium intake is associated with adverse cardiovascular and renal outcomes in people with chronic kidney disease (CKD), and simple methods to facilitate assessment of sodium intake are required. The objective of this study was to develop a new formula to estimate 24-hour urinary sodium (24hUNa) excretion from urinary Na concentration measured on an early morning urine specimen (EM UNa). METHODS: Seventy participants from a prospective cohort of patients with CKD stage 3 in primary care, the Renal Risk in Derby (RRID) study, agreed to collect an additional EM UNa on the day after completing a 24-hour urine collection. A formula to estimate 24hUNa from EM UNa and body weight was developed using the coefficients from a multivariable linear regression equation. The accuracy of the formula was tested by calculating the P30 (proportion of estimates within 30% of measured sodium exection), and the ability of the estimated 24hUNa to discriminate between measured sodium intake above or below 100 mmol/day was assessed by receiver operating characteristic (ROC) curve. A Bland-Altman plot was used to estimate the bias and limits of agreement between estimated and measured 24hUNa. Seventy-four additional paired 24hUNa and EM UNa from 50 CKD stage 3 patients in the RRID study were used to validate the formula. RESULTS: The mean difference between measured and estimated 24hUNa was 2.08 mmol/day. Measured and estimated 24hUNa were significantly correlated (r = 0.55; p < 0.001) but accuracy of estimated 24hUNa was low (P30 = 60%). Analysis of the ROC curve with a cut-off point >100 mmol/day yielded an area under the curve of 0.668, sensitivity of 0.85 and specificity of 0.52. CONCLUSIONS: We have developed a simple formula to identify people with a high sodium intake from EM UNa, suitable for use in large-cohort or population studies.

[Assessment of dietary intake and urinary excretion of sodium and potassium in adults]. / Evaluación de la ingesta dietética y excreción urinaria de sodio y potasio en adultos.

BACKGROUND: Hypertension is associated with elevated sodium and low potassium intakes. The determination of sodium and potassium intake by dietary records is inaccurate, being its measurement from 24-h urine collection the reference method. AIM: To determine urinary sodium and potassium excretion in adults. To compare dietary sodium and potassium intake and their excretion from an isolated urine sample against the reference method. MATERIAL AND METHODS: Seventy healthy adults aged 35 ± 8 years with a body mass index 25 ± 2 kg/m² (36 women) were studied. Urine was collected over 24 h, including an isolated urine sample taken in fasting conditions. Additionally, three 24-h dietary records were performed. RESULTS: Reported sodium and potassium intake was 2,720 ± 567 and 1,068 ± 433 mg/day, respectively. In turn, urinary excretion of sodium and potassium was 4,770 ± 1,532 and 1,852 ± 559 mg/day, respectively. These latter values were significantly higher than those obtained by dietary records. Furthermore, the urinary sodium and potassium excretion estimated from an isolated urine sample was 4,839 ± 1,355 and 1,845 ± 494 mg/day, respectively. These values were similar to those obtained with a 24 h urine collection. CONCLUSIONS: Dietary records underestimated electrolyte intake when compared with the reference method. Using an isolated urine sample to estimate electrolyte intake may be a reliable alternative.

Evaluación de la ingesta dietética y excreción urinaria de sodio y potasio en adultos / Assessment of dietary intake and urinary excretion of sodium and potassium in adults

Background: Hypertension is associated with elevated sodium and low potassium intakes. The determination of sodium and potassium intake by dietary records is inaccurate, being its measurement from 24-h urine collection the reference method. Aim: To determine urinary sodium and potassium excretion in adults. To compare dietary sodium and potassium intake and their excretion from an isolated urine sample against the reference method. Material and Methods: Seventy healthy adults aged 35 ± 8 years with a body mass index 25 ± 2 kg/m² (36 women) were studied. Urine was collected over 24 h, including an isolated urine sample taken in fasting conditions. Additionally, three 24-h dietary records were performed. Results: Reported sodium and potassium intake was 2,720 ± 567 and 1,068 ± 433 mg/day, respectively. In turn, urinary excretion of sodium and potassium was 4,770 ± 1,532 and 1,852 ± 559 mg/day, respectively. These latter values were significantly higher than those obtained by dietary records. Furthermore, the urinary sodium and potassium excretion estimated from an isolated urine sample was 4,839 ± 1,355 and 1,845 ± 494 mg/day, respectively. These values were similar to those obtained with a 24 h urine collection. Conclusions: Dietary records underestimated electrolyte intake when compared with the reference method. Using an isolated urine sample to estimate electrolyte intake may be a reliable alternative.

High sodium intake is associated with increased glucocorticoid production, insulin resistance and metabolic syndrome.

OBJECTIVE: High sodium (HS) diet is associated with hypertension (HT) and insulin resistance (IR). We evaluated whether HS diet was associated with a dysregulation of cortisol production and metabolic syndrome (MetS). PATIENTS AND MEASUREMENTS: We recruited 370 adults (18-85 years, BMI 29·3 ± 4·4 kg/m(2) , 70% women, 72% HT, 61% MetS). HS diet (urinary sodium >150 mEq/day) was observed in 70% of subjects. We measured plasma hormones, lipid profile, urinary free cortisol (UFC) and cortisol tetrahydrometabolites (THM). RESULTS: Urinary sodium was correlated with UFC (r = +0·45, P < 0·001), cortisol THM (r = +0·41, P < 0·001) and inversely with adiponectin, HDL and aldosterone, after adjusting by age, gender and BMI. Subjects with high, compared with adequate sodium intake (50-149 mEq/day) had higher UFC (P < 0·001), THM (P < 0·001), HOMA-IR (P = 0·04), HT (81% vs 50%, P < 0·001), MetS (69% vs 41%, P < 0·001) and lower adiponectin (P = 0·003). A multivariate predictive model adjusted by confounders showed a high discriminative capacity for MetS (ROC curve 0·878) using four clinical variables: HS intake [OR = 5·6 (CI 2·3-15·3)], HOMA-IR [OR 1·7 (1·3-2·2)] cortisol THM [OR 1·2 (1·1-1·4)] and adiponectin [OR = 0·9 (0·8-0·9)], the latter had a protective effect. CONCLUSIONS: High sodium diet was associated with increased urinary cortisol and its metabolites. Also, HS diet was associated with HT, insulin resistance, dyslipidaemia and hypoadiponectinaemia, even when adjusting by confounding variables. Further, we observed that high salt intake, IR and higher cortisol metabolites, alone or combined in a clinical simple model, accurately predicted MetS status, suggesting an additive mechanism in obesity-related metabolic disorders.

Projected impact of a sodium consumption reduction initiative in Argentina: an analysis from the CVD policy model--Argentina.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in adults in Argentina. Sodium reduction policies targeting processed foods were implemented in 2011 in Argentina, but the impact has not been evaluated. The aims of this study are to use Argentina-specific data on sodium excretion and project the impact of Argentina's sodium reduction policies under two scenarios - the 2-year intervention currently being undertaken or a more persistent 10 year sodium reduction strategy. METHODS: We used Argentina-specific data on sodium excretion by sex and projected the impact of the current strategy on sodium consumption and blood pressure decrease. We assessed the projected impact of sodium reduction policies on CVD using the Cardiovascular Disease (CVD) Policy Model, adapted to Argentina, modeling two alternative policy scenarios over the next decade. RESULTS: Our study finds that the initiative to reduce sodium consumption currently in place in Argentina will have substantial impact on CVD over the next 10 years. Under the current proposed policy of 2-year sodium reduction, the mean sodium consumption is projected to decrease by 319-387 mg/day. This decrease is expected to translate into an absolute reduction of systolic blood pressure from 0.93 mmHg to 1.81 mmHg. This would avert about 19,000 all-cause mortality, 13,000 total myocardial infarctions, and 10,000 total strokes over the next decade. A more persistent sodium reduction strategy would yield even greater CVD benefits. CONCLUSION: The impact of the Argentinean initiative would be effective in substantially reducing mortality and morbidity from CVD. This paper provides evidence-based support to continue implementing strategies to reduce sodium consumption at a population level.

Relationship between nutrient intake and vitamin D status in osteoporotic women.

Vitamin D is essential for maintaining calcium homeostasis and optimizing bone health. Its inadequacy is related to many factors including dietary intake. The aim of the present study was to evaluate serum 25(OH)D and its relationship with nutrient intakes in postmenopausal Brazilian women with osteoporosis. This cross-sectional study comprised 45 free-living and assisted elderly at São Paulo Hospital. Three-day dietary records were used to assess dietary intakes. Bone mineral density was measured with a dual-energy X-ray absorptiometer (DXA). Blood and urine sample were collected for analysis of biochemical markers of bone and mineral metabolism. Insufficiency of vitamin D was observed in 24.4% of the women and optimal levels (> or = 50 nmol/L) were observed in 75.6%. Parathyroid hormone was above the reference range in 51% of the participants. The mean calcium (724 mg/day) and vitamin D (4.2 microg/day) intakes were lower than the value proposed by The Food and Nutrition Board and sodium intake was more than two-fold above the recommendation. Higher levels of serum 25(OH)D were inversely associated with sodium intake. Dietary strategies to improve serum vitamin D must focus on increasing vitamin D intake and should take a reduction of sodium intake into consideration.

A randomized trial on sodium reduction in two developing countries.

Hypertension remains the most common cardiovascular risk factor in developing countries, yet the majority of patients have no access to pharmacological therapy. Population-wide preventive strategies, such as salt restriction, are an attractive alternative, but experience in resource-poor settings is limited. To address this question, we conducted a randomized crossover study of salt restriction in adults living in Nigeria and Jamaica in order to estimate the mean blood pressure (BP) response. After a 4-week run-in period to determine willingness to adhere to a low-salt diet, 56 Jamaicans and 58 Nigerians completed an 8-week crossover study of low-salt and high-salt intake. Baseline BPs were in the normotensive range (systolic=125 mmHg in Jamaica, 114 mmHg in Nigeria). Baseline urinary sodium excretion was 86.8 and 125.6 mEq/day in Nigeria and Jamaica, respectively. The mean difference between urinary sodium excretion at baseline and at the end of the 3-week low-sodium phase was 33.6 mEq/day in Nigeria and 57.5 mEq/day in Jamaica. During the high-sodium phase, mean change in urinary sodium excretion from baseline to week 3 was 35.0 and 5.5 mEq/day in Nigeria and Jamaica, respectively. The mean change in systolic BP ('high' vs 'low' sodium phase) was approximately 5 mmHg in both groups. This study suggests that the efficacy of sodium reduction in developing countries equals those noted in more affluent cultures. If promoted on a wide scale, sodium reduction could be used to treat persons with established hypertension, and more importantly, to prevent age-related increases in BP in poor communities.

Chronic activation of central alpha2-adrenoceptors prevents hypertension in DOCA-salt rats.

The effects of chronic intracerebroventricular (i.c.v.) injections of the alpha2-adrenoceptor agonist, xylazine, on blood pressure were examined in DOCA-salt rats. Acute studies also examined the renal sympathetic nerve activity (RSNA) and renal excretory responses produced by i.c.v. xylazine in rats with established DOCA-salt hypertension. Rats implanted with a chronic i.c.v. cannula for drug injection were used. In chronic studies, four groups were investigated: control rats treated with s.c. soybean oil and i.c.v. saline; DOCA-salt rats (s.c. deoxycorticosterone acetate) receiving i.c.v. saline, xylazine or the alpha2-adrenoceptor antagonist, yohimbine. During vehicle or DOCA-salt treatment, xylazine (0.2 ng/microg) or yohimbine (10O microg/kg) was injected i.c.v. daily (three times). In DOCA-salt rats receiving i.c.v. saline, resting mean arterial pressure (MAP) was elevated on days 15 and 30 (135 +/- 5 and 160 +/- 6 mmHg, respectively). Chronic i.c.v. xylazine significantly attenuated the rise in MAP produced by DOCA-salt (day 15, 118 +/- 5 mmHg; day 30, 121 +/- 4 mmHg). Alternatively, chronic i.c.v. yohimbine shortened the onset (day 15, 152 +/- 7 mmHg) and augmented the hypertension in DOCA-salt rats (0 survival by day 30). In acute studies, i.c.v. xylazine elicited a profound natriuresis and diuresis as well as a reduction in RSNA without altering MAP. This study demonstrates that the ongoing (tonic) activity of central alpha2-adrenoceptor mechanisms are critically involved in regulating blood pressure in the DOCA-salt treated rat. In this manner, an enhanced activity of central alpha2-adrenoceptor systems acts to protect against a rise in blood pressure. In contrast, the attenuation of central alpha2-adrenoceptor stimulation evokes hypertension. The central action of xylazine to prevent hypertension may be associated with the inhibition of sympathetic outflow to the kidneys and evokes an enhanced natriuresis. By inhibiting the avid sodium retention elicited by DOCA-salt treatment, the central activation of alpha2-adrenoceptors delays the onset and the severity of hypertension in this pathological model.

Salt overload does not modify plasma atrial natriuretic peptide or vasopressin during pregnancy in rats.

The present study was carried out to determine whether the increased salt intake induce by increased specific sodium appetite in pregnant rats modifies water-salt homeostasis throughout pregnancy. Two groups of pregnant rats were used, one fed ad libitum with a normal sodium (NS) diet consisting of standard rat chow and distilled water, and the other fed with a high-sodium (HS) diet with free access to chow, distilled water plus saline solution (1.5% NaCl). Virgin rats in dioestrus were also studied as non-pregnant controls. Pregnant animals were studied on days 4, 9, 14, 20 and 21 of gestation at which time body weight, water and saline intake, sodium excretion, plasma atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) concentrations, as well as plasma osmolality were determined. Data showed that water intake was higher in the NS group, but total fluid intake (water plus saline) was higher in the HS group throughout pregnancy. Dietary sodium intake was the same for both groups but total sodium intake (chow plus saline) was 60-98% higher in the HS rats. Pregnant HS rats excreted more fluid (35-50%) and sodium (up to 100%) compared with NS rats, indicating that the animals could change their renal excretion in response to a 2.5-fold higher dietary sodium intake compared with the control level. Salt satiety during pregnancy did not modify plasma ANP concentration. In both groups of pregnant rats ANP levels increased 3-fold on day 14 without significant alteration in sodium excretion, suggesting that the natriuretic action of ANP is attenuated at least after the second week of pregnancy. High sodium intake did not change plasma AVP concentration or osmolality and both groups showed the same gradual decrease in plasma osmolality (approximately 8 mosmol kg-1) at the end of pregnancy that was not accompanied by decreased plasma AVP concentration. The present data show that rats maintain the special homeostatic equilibrium that occurs in normal pregnancy even when they are allowed to increase sodium intake to satisfy their salt appetite during this period of the reproductive cycle.

Left ventricular hypertrophy is more marked in salt-sensitive than in salt-resistant hypertensive patients.

Besides the duration and severity of hypertension, several other factors have been shown to be related to left ventricular hypertrophy (LVH) in essential hypertension. The present study was conducted to examine the influence of salt sensitivity on LVH. Fifteen essential hypertensive ambulatory patients were submitted to a low-salt (30 mEq of Na/day for 7 days) and a high-salt (200 mEq of Na/day for 7 days) diet after 12 weeks on placebo. Daily urine collection was obtained during the whole study. After the placebo period, all patients were submitted to a complete clinical and laboratory investigation that included an echocardiogram (M-mode and two-dimensional). Five patients were salt-sensitive (mean blood pressure (BP) increase from the seventh day of the low- to the seventh day of the high-salt diet greater than 10%). No differences in weight, sex ratio, and duration of hypertension were obtained between salt-sensitive and -resistant patients. The initial BP was higher in the salt-sensitive patients. However, the difference was small and without statistical significance. The left ventricular weight was higher in the salt-sensitive than in salt-resistant patients (148 +/- 51 vs. 109 +/- 32 g/m2, p less than 0.05). The left ventricular end-diastolic diameter was also higher in the salt-sensitive patients (50 +/- 10 vs. 43 +/- 6 mm, p less than 0.05). The interventricular septum and posterior wall thicknesses were higher in salt-sensitive patients, although they did not reach statistical significance. In conclusion, salt-sensitive essential hypertensive patients are at a higher risk to develop LVH.