High Dietary Sodium Intake and the Risk of Hypertension

The Association between High Dietary Sodium Intake and the Risk of Hypertension

Name

Institution

Date

Statement of the Problem

High sodium intake can be associated with high blood pressure that in many occasions results into high risk of stroke and cardiac vascular diseases. A substantial reduction of sodium intake can effectively reduce cardiac vascular problems and also reduce medical costs. Calls have been made both locally and internationally for the reduction of sodium intake for the prevention and reduction of non-communicable diseases. In the whole world, hypertension is the major cardiac contributor that account to an average of 30% of the total health care cost and has been associated with high mortality rates in different countries. In China for example, the National Nutrition and Health Survey shows that over 80% of the Chinese adults exceeded the salt intake of 6g/day in 2002.

Methods of measuring sodium intake are; dietary recall or records from twenty four to ninety six hours, 24 hour urine collection, and food frequency questionnaire methods. However, accurate estimation of sodium intake is difficult to come by due to the amount of sodium added during cooking and at the table. It is also difficult to quantify the amount of sodium remaining on the serving plate and its content bin food and drinking water. Therefore, 24-hour urine collection is the most reliable method of evaluating sodium intake in an individual.

Physiology of Sodium and Hypertension

The physiology of sodium intake and high blood pressure is complex to relate and understand. Notably, sodium (obtained from NaCl) is one of the main competent of the extracellular body fluids, whose primary function is maintaining body fluid balance. The kidney is charged with the responsibility of regulating the amount of water and sodium in the body through homoeostasis biological process. However, the renal conservation and excretion is solely responsible for regulating sodium composition in the body. Sodium is critical for the proper and active function of the body organs since it plays a fundamental role in maintaining acid-base balance, creation of oncotic pressure, and extracellular fluid regulation. In addition, sodium has an active role to play in ensuring nerve and muscle function activities. Sodium is also responsible for the generation of trans-membrane gradients, hence permitting nutrients uptake by the renal tubules and intestinal mucosa cells. A rise in the volume of extracellular fluid results to high blood pressure following the swelling of the plasma volume. On the contrary, a decrease in the volume of the extracellular fluids lowers the blood pressure.

Hypertensive Mechanisms

Although the salt intake physiology with respect to hypertension or high blood pressure is relatively complex, studies on animal specimens have indicated that as the dietary salt intake increases, the blood pressure equally increases. The association of between BP and salt intake is attributed to the fact the kidney lacks the ability and capacity to exhaustively get rid of excess sodium and salts contents in the body. A combination of potassium deficits and excess sodium in the body impact on the vascular smooth muscle cells (VSMCs) with low-potassium/high-sodium diets increases the chances of BP. The BP increase is irreversible in a number of animal specimen models implies that the BP and hypertension are possibly underestimated. In addition to demonstrating the association between adverse cardiovascular complications following high intake of sodium rich diets, these animal models indicate that high sodium intake results to cardiac and vascular damages.

Findings

Dietary sodium intake in young Korean adults and its relationship with eating frequency and taste preference

A total of 71 men and 157 women were sampled to access the association of sodium intake with blood pressure, dietary habits, and taste preference. The results indicate a partial correlation coefficient between dietary sodium intake and blood pressure adjusted for age, alcohol, BMI, smoking and drinking. There was a substantial and positive relationship between dietary sodium and salt blood pressure (SBP) in all the groups while sodium intake versus BMI was only noted in men. In all the groups, sodium intake was positively associated with snacking frequency that’s leads to hypertension in all the groups.

Association of Dietary Sodium Intake and Blood Pressure in the German Population

Out of 4,030 individuals who participated in the GeNuS study, only four decline to give information relating to their sodium intake and diastolic blood pressure. A total of 415 men and 509 women were excluded from the sample for further analysis because of unknown hypertension and use of anti-hypertension medication. The final data had 1,539 men (49.8%) and 1,553b women (50.2%) in the sample. From 86.6% selected sample, 93.5% men and 79.8% women had a SPB above 115mmHg or DBP above 75mmHg or both. The result for SBP quartiles was similar to that of DBP. Men differed significantly in BMI and DBP across all quartiles and their BMI and DBP increased substantially from the lowest to the highest SBP quartiles. Sex, BMI, alcohol consumption, smoking, and sport activities were substantially associated with blood pressure at various levels.

Dietary Sodium Intake Deleteriously Affects Blood Pressure in A Normotensive Population

A total number of 421 characteristics participated in the sample and after stratification by age, there was a significant gender and age effects in the analysis. DSI was found to be lower in women than men more so the men in the age bracket of 31-50 years. The regression analysis indicated a substantial correlation between BP parameter and DSI.

Estimation of Salt Intake by Urinary Sodium Excretion in a Portuguese Adult Population and its Relationship to Arterial Stiffness

A sample size of 426 having an average weight of 50± 22 years was evaluated in the study. It was established that their BMI was 27.9 ± 5.1, PWV 10.4 ± 2.2 m/s, and BP 159/92 mmHg. With respect to population’s daily salt intake, it was revealed that their daily sodium/salt intake averaged at 12.3g with the lowest and the highest daily intakes being 5.2g and 24.8g respectively.

Estimation of salt intake by 24-hour urinary sodium excretion: a cross-sectional study in

Yantai, China

An average of 1442 volume of urine was used ant the average urine creatinine excretion was 9.4(SD 2.6) Ml/d. The urine creatinine excretion was higher in men than women. The mean potassium: sodium ratio was 46.8 ml/d and the salt intake from weighed condiments was 10.1g/d compared with11.8 g/d from the urinary. Analyzing for sex, age, and BMI, the linear regression found that sodium excretion can be positively associated with systolic BP. However, adjusting for age, sex, and BMI, there were no correlation between urinary sodium and diastolic BP.

Relationship between Salt Intake, Salt-Taste Threshold and Blood Pressure in Nigerians

Forty subjects were included for the study that comprise of 14 men and 26 women. The study indicated that that the hypertensive subjects had a higher systolic blood pressure and urinary potassium compared to the normotensive subjects. The group with high salt threshold has a higher signs of potential development of blood pressure.

Salt intake and blood pressure in the university of Asuncion- Paraguay youths: A preliminary study

The study has 72 subjects that comprises of 37 men and 35 women and the age range was 22-30 years and a mean of 25.3 years old. 76.5% of the students had a hypertension family back ground and only 15.6% were found to actively engage in physical activity. The MBP was 91.18mmHg and the mean 24 hour urine sodium excretion was 161.57 g/d. 93% of the population studied was found to be consuming more than recommended maximum of 5g of salt per day with a further 10% found to be consuming extreme qualities up to 14g of salt per day.

Among the individuals with SBP between 120-139mmHg, their daily intake was found to be less than 6% of the 5gm salt intake per day and none of the individuals with over 140 SBP consumed less than 5gm of sodium per day. Females were found to have lower MBP group compared to their male counterparts.

Salt and High Blood Pressure

The worldwide link report indicates that there is a high link between salt intake and hypertension. 24hour urinary sodium was associated with BP and a further study shows that population with low average daily salt intake had lower BP with minimum increase in BP in the old age. Interestingly, population studies shows that individuals that migrated from areas with lower salt intake to higher ones have increased level of BP. the study suggest that decrease salt intake reduces the BP and help in preventing cardiac related diseases.

Diet, Nutrition and the Prevention of Hypertension and Cardiovascular Diseases

Evidence from the study conducted within the population across the entire globe indicates that several nutrients, food groups and dietary food pattern are associated with increased risk of hypertension. The dietary fats have been associated with increased level of CHD and at the same time increased sodium intake can result into higher blood pressure.

Blood Pressure, Cardiovascular Outcomes and Sodium Intake, a Critical Review of the Evidence

Among the 52 INTERSALT centre, the 24 hour urinary sodium excretion range from 0.2-242.1mmHg and when the correlation between blood pressure and salt intake were access ,the adjustment for age and sex applied for positive correspondent between the salt intake and hypertension. Further adjustments indicated that body mass index, potassium excretion, and alcohol consumption could be positively associated with hypertension on the affected individuals.

Evidence Summary

From all the studied conducted, all the researchers have given a positive correlation between sodium intake and high blood pressure. Most of the individuals who take more than 5 grams of salt per day are more likely to become high blood pressure. The required amount of salt intake per day for healthy individuals should be five grams or low per day. The studies further indicate that the spread and prevalence of high blood pressure has been significantly contributed by individual dietary pattern and should people change their and style of eating then this disease can be effectively controlled. Researchers have recommended adequate exercise; reduce consumption of alcohol and fatty foods, and not taking more than 5gm of salt per day.

Conclusion

The relationship between high blood pressure and salt intake is casual, with higher sodium intake responsible for the rising cases of hypertension globally. At the moment, it has been established that sodium consumption is generally above the recommended level both in developed and developing countries. This excessive salt consumption has resulted in higher cases of cardiovascular diseases and HBP that would have been prevented if recommended salt consumption was observed. Reducing sodium intake related burden calls for a collaborative effort by all the stakeholders including the government and the participants drawn from the nutrition and food industry. Although the World Health Organization recommends a maximum salt intake of not more than 5g/day, realizing this level is still a challenge to many. The reduction in salt intake to the 5g per day would be fundamental in reducing hypertension and cardiovascular related health complications because it is characterized by a downward shift in the blood pressure distribution.

Reflection Paper

Reading these research articles has enriched my understanding and knowledge on the relationship between salt/sodium intake and hypertension or high blood pressure. As established by these findings, excessive salt intake is harmful to our health given that salt is associated with HBP. From this research experience, it has been established that healthy diet is critical in reducing HBP and hypertension related diseases. Therefore, dietary is the key to reducing the risks associated with excessive intake of sodium or salt. This research experience is helpful to dietitians and nutrition professionals since it provides recommendations on the desired daily salt intake at 5g. There is no doubt that this research experience is, therefore, significant in improving the population’s health through nutrition and dietary behavior.

References

Anja, S., Gert, B. M., Mensink, Nanette, S., Roll, S, Willich, N. & Tinnemann, P. (2012). Association of dietary sodium intake and blood pressure in the German population. J Public Health, 20:621–630.

Azinge, E. C., Sofola, O.A. & Silva, B.O. (2011). Relationship between Salt Intake, Salt-Taste Threshold and Blood Pressure in Nigerians. WAJM, 30(5): 373–376.

Chateau-Degat, A., Ferland, S. & Dewailly, E. (2012). Dietary sodium intake deleteriously affects blood pressure in a normotensive population. European Journal of Clinical Nutrition, 66, 533–535.

Eugene, S., Ha-Jung, R., Jinah, H., Soo Yeon, K., & Eun-Jung, C. (2013). Dietary sodium intake in young Korean adults and its relationship with eating frequency and taste preference. Nutrition Research and Practice (Nutr Res Pract) 7(3):192-198.

Jianwei Xu., et al. (2014). Estimation of salt intake by 24-hour urinary sodium excretion: a cross-sectional study in Yantai, China. Xu et al. BMC Public Health, 14:136.