Sodium Intake In Man Research Articles

Don't Take it With a Grain of Salt

Background: Currently, sodium consumption of Canadians (2760 mg/day) exceeds the 2300 mg/day tolerable upper level putting Canadians at risk for hypertension and cardiovascular disease. Voluntary sodium reformulation strategies have been implemented in Canada, the United Kingdom (UK), United States (US) to reduce sodium intake from processed foods. The potential for sodium reformulation to reduce sodium intake across socioeconomic position (SEP) is not well understood. The objective of this study was to evaluate the extent to which fully achieving sodium reformulation targets for processed foods outlined in the Canada, UK, US strategies would decrease population and social inequities in sodium intake in Canadian adults. 
 Design: A cross-sectional study was conducted using the 2015 Canadian Community Health Survey–Nutrition (n=13,519 participants aged ≥19 years, 53% females). Foods from the 24-hour dietary recall were matched to each country’s sodium reduction categories and target sodium levels were applied. Multivariable linear regressions were used to estimate mean sodium intake for the population and across SEP indicators (educational attainment, household food security, and household income adequacy quintiles). 
 Results: Achieving Canada’s targets would reduce average sodium intake by 228 mg/day (95%CI: 196,260) compared to baseline. UK’s sodium targets would achieve greater reductions, decreasing average sodium intake by 270 mg/day (95%CI: 242,299). The US sodium targets would increase average sodium intake by 98 mg/day (95%CI: 64,132). Achieving sodium reformulation targets resulted in greater reductions in sodium intake in men, and in lower SEP groups. For example, educational inequalities in sodium intake observed at baseline were reduced in men [Canada: (RD: 148 mg/day, 95%CI: -30,327); UK: (RD: 152 mg/day, 95%CI: -43,347)] and eliminated in women. 
 Conclusion: Achieving targets outlined in Canada and UK’s voluntary sodium reformulation strategies would significantly reduce mean sodium intake in Canadians. This study demonstrated the potential for reducing social inequities in sodium intake and health.

Sodium intake in Germany.

For many years, a high sodium intake has been discussed as a potential risk factor in the development of hypertension and, consequently, cardiovascular diseases. As part of the German Health Interview and Examination Survey for Adults (DEGS1), which was conducted between 2008 and 2011, sodium excretion in casual urine samples was used as a biomarker to measure sodium intake. DEGS1 observed that the median daily sodium intake of women (3.4 g) as well as men (4.0 g) exceeds the levels recommended by German and international organisations. Among other factors, men's higher sodium intake could be explained by their higher energy intake. In addition, DEGS1 demonstrates an association between women's sodium intake and age; however, no equivalent correlation was identified for men. Furthermore, although high socio-economic status is associated with lower sodium intake in men, no comparable correlation was observed among women.

Validation of nutrient intake estimates derived using a semi-quantitative FFQ against 3 day diet records in the Baltimore Longitudinal Study of Aging

To examine the relative validity of a multicultural FFQ used to derive nutrient intake estimates in a community dwelling cohort of younger and older men and women compared with those derived from 3 day (3d) diet records during the same time-frame. Cross-sectional analyses. The Baltimore Longitudinal Study of Aging (BLSA) conducted in the Baltimore, MD and District of Columbia areas. A subset (n=468, aged 26 to 95 years (y), 47% female, 65% non-Hispanic white) from the BLSA, with complete data for nutrient estimates from a FFQ and 3d diet records. Pearson’s correlation coefficients (energy adjusted and de-attenuated) for intakes of energy and 26 nutrients estimated from the FFQ and the mean of 3d diet records were calculated in a cross-sectional analysis. Rankings of individuals based on FFQ for various nutrient intakes were compared to corresponding rankings based on the average of the 3d diet records. Bland Altman plots were examined for a visual representation of agreement between both assessment methods. All analyses were stratified by sex and age (above and below 65 y). Median nutrient intake estimates tended to be higher from the FFQ compared to average 3d diet records. Energy adjusted and de-attenuated correlations between FFQ intake estimates and records ranged from 0.23 (sodium intake in men) to 0.81 (alcohol intake in women). The FFQ classified more than 70 percent of participants in either the same or adjacent quartile categories for all nutrients examined. Bland Altman plots demonstrated good agreement between the assessment methods for most nutrients. This FFQ provides reasonably valid estimates of dietary intakes of younger and older participants of the BLSA.

Validation of Nutrient Intake Estimates Derived Using a Semi-Quantitative FFQ against 3 Day Diet Records in the Baltimore Longitudinal Study of Aging.

To examine the relative validity of a multicultural FFQ used to derive nutrient intake estimates in a community dwelling cohort of younger and older men and women compared with those derived from 3 day (3d) diet records during the same time-frame. Cross-sectional analyses. The Baltimore Longitudinal Study of Aging (BLSA) conducted in the Baltimore, MD and District of Columbia areas. A subset (n=468, aged 26 to 95 years (y), 47% female, 65% non-Hispanic white) from the BLSA, with complete data for nutrient estimates from a FFQ and 3d diet records. Pearson's correlation coefficients (energy adjusted and de-attenuated) for intakes of energy and 26 nutrients estimated from the FFQ and the mean of 3d diet records were calculated in a cross-sectional analysis. Rankings of individuals based on FFQ for various nutrient intakes were compared to corresponding rankings based on the average of the 3d diet records. Bland Altman plots were examined for a visual representation of agreement between both assessment methods. All analyses were stratified by sex and age (above and below 65 y). Median nutrient intake estimates tended to be higher from the FFQ compared to average 3d diet records. Energy adjusted and de-attenuated correlations between FFQ intake estimates and records ranged from 0.23 (sodium intake in men) to 0.81 (alcohol intake in women). The FFQ classified more than 70 percent of participants in either the same or adjacent quartile categories for all nutrients examined. Bland Altman plots demonstrated good agreement between the assessment methods for most nutrients. This FFQ provides reasonably valid estimates of dietary intakes of younger and older participants of the BLSA.

Sodium intake in men and potassium intake in women determine the prevalence of metabolic syndrome in Japanese hypertensive patients: OMEGA Study

Dietary intake affects hypertension and metabolic syndrome (MS) and their management. In Japanese hypertensive patients, little evidence exists regarding the relation between diet and MS. A self-administered lifestyle questionnaire was completed by each patient at the baseline. Three dietary scores were calculated for each patient: sodium intake, potassium intake and soybean/fish intake. The relationships between dietary scores and systolic blood pressure (SBP) and diastolic blood pressure (DBP) were analyzed by multiple regression analysis. The relation between dietary intake of sodium, potassium and soybean/fish, and the presence of MS was evaluated by the Mantel–Haenszel test. A total of 9585 hypertensive patients (mean age, 64.9 years; women, 51.4%) were included in this sub-analysis. High sodium intake was significantly related to increased SBP (P=0.0003) and DBP (P=0.0130). Low potassium intake was significantly related to increased SBP (P=0.0057) and DBP (P=0.0005). Low soybean/fish intake was significantly related to increased SBP (P=0.0133). A significantly higher prevalence of MS was found in men in the highest quartile of sodium intake compared with the lower quartiles (P=0.0026) and in women in the lowest quartile of potassium intake compared with the higher quartiles (P=0.0038). A clear relation between dietary habits and blood pressure was found in Japanese hypertensive patients using a patient-administered questionnaire. Sodium and potassium intake affect MS prevalence. Dietary changes are warranted within hypertension treatment strategies.

Estimate of total salt intake in two regions of Belgium through analysis of sodium in 24-h urine samples

To evaluate total salt intake in the adult population through an analysis of sodium in 24-h urine samples in two regions of Belgium. Urine samples were collected over 24 h from participants and they had to complete a specific questionnaire about salt intake afterwards. Sodium and creatinine concentrations were analysed in these samples. The target population comprised adults aged 45-65 years in the region of Ghent and Liege. A total of 123 and 157 volunteers from Ghent and Liege, respectively, were included in the study. The mean creatinine level in Flanders (n=114) amounted to 0.173±0.035 mmol/kg/day, whereas in the Walloon region (n=135) it amounted to 0.161±0.036 mmol/kg/day, after the exclusion of subjects with incomplete urine collection. Intake of sodium in Flanders (n=114) was 4.29±1.29 g/day, whereas in the Walloon region (n=135) it was 3.94±1.44 g/day. In both regions, sodium intake in men was higher than in women. Salt intake was more or less twice as high as the recommended intake. Salt intake as estimated from 24-h urine collections is substantially higher than that previously calculated on the basis of food consumption data. A salt reduction programme for Belgium is primordial.

Atrial natriuretic peptide and chronic renal effects of changes in dietary protein and sodium intake in man

1. Plasma levels of atrial natriuretic peptide and several other hormones were measured and related to the renal responses to chronic changes in the dietary intake of protein and sodium, alone and in combination. Eight healthy subjects consumed four diets for 1 week: a basal diet containing 140 mmol of sodium/day and 1 g of protein day-1 kg-1, the same diet with isocaloric addition of 1 g of meat protein day-1 kg-1, the basal diet with addition of 170 mmol of sodium chloride/day and the basal diet with both additions. 2. Creatinine clearance was increased significantly both by protein and, to a smaller extent, by sodium. Plasma atrial natriuretic peptide and the urinary excretion of guanosine 3':5'-cyclic monophosphate were increased significantly by sodium but were not affected by protein. Protein induced a significant rise in plasma glucagon levels, whereas the rise in somatomedin C (insulin-like growth factor I) just failed to reach statistical significance. 3. These findings demonstrate that atrial natriuretic peptide does not mediate chronic protein-induced hyperfiltration, although it may contribute to the renal effects of sodium. Glucagon and somatomedin C (insulin-like growth factor I) may have contributed to chronic protein-induced hyperfiltration.

Kinetics of Renal Sodium Excretion During Changes in Dietary Sodium Intake in Man - An Exponential Process?

The kinetics of urinary sodium excretion was studied during sodium restriction and sodium supplementation in normal subjects. Eight were studied on a normal sodium intake (24 h urinary sodium: 133.3 + 9.6 mmol) and then during 6 days on a low sodium intake of 10 mmol/day. Six other subjects were studied after equilibration on the low sodium intake for 7 days and then during 5 days on a high sodium intake of 350 mmol/day. 24 h urinary sodium excretion during sodium restriction was consistent with a first-order exponential process with an estimated half-life of 21.8 + 2.4 hours. During sodium supplementation there were corresponding increases in urinary sodium excretion reaching the new steady-state within 3 days but the behaviour of the urinary sodium excretion during the transition period was not consistent with a mono-exponential process. These observations support the concept that the control of sodium balance, during sodium restriction at least, is consistent with a first order proportional feed-back system. This kinetic approach should provide a useful framework for further studies on the dynamics of sodium excretion.

Na+, K+-ATPase Inhibitory Activity of Fractionated Urine during Changes in Dietary Sodium Intake in Man.

Na+, K(+)-ATPase inhibitory activity in urine fractionated by HPLC was quantified in 7 normotensive male subjects during changes in dietary sodium intake. Subjects were studied on free sodium intake for 2 days, on low sodium intake (2 g/day) for 3 days, on high sodium intake (22 g/day) for 4 days and subsequently on normal sodium intake (6 g/day) for 2 days. Na+, K(+)-ATPase inhibitory activity in fraction 10 eluted with 17% acetonitrile by reverse-phase HPLC was 12.3 +/- 5.2% (mean +/- S.D.) on free sodium intake, 8.7 +/- 9.8% on the 3rd day of low sodium intake, 61.2 +/- 6.6% on the 4th day of high sodium intake, and 20.5% +/- 0.7% on the 2nd day of the normal sodium intake. Changes in Na+, K(+)-ATPase inhibitory activity of fraction 10 were closely associated with those in urinary sodium excretion. These results suggest that an endogenous Na+, K(+)-ATPase inhibitor(s) which plays a physiological role in the control of sodium and water balance may exist in this particular fraction.

Plasma immunoreactive attrial natriuretic peptide and changes in dietary sodium intake in man

Plasma levels of immunoreactive atrial natriuretic peptides (IrANP) have been measured in 8 normotensive subjects during alterations in dietary sodium intake. Subjects were studied on their normal sodium intake (2 days) then on a law sodium intake (7 days, 10 mmols Na +/day) and subsequently on a high sodium intake (14 days, 350 mmols Na +/day with the diets being given in a fixed order. Plasma levels (mean ±S.E.M.) of IrANP on a normal sodium diet were 7.3 ± 0.9 pg/ml; 4.5 ± 0.8 on the 7th day of a low sodium intake and 10.8 ± 1.3; 16.6 ± 3.3; 15.5 ± 4.2; 15.6 ± 2.3 pg/ml respectively or the 1st, 3rd, 10th and 14th day on the high sodium intake. Changes in plasma IrANP were closely associated with changes in urinary sodium excretion. These results suggest that in normal subjects the atrial natriuretic peptides may play an important role in the adaptation to increases in dietary sodium intake both on a short and on a longer term basis.