Effects of Salt on Serum Osmolarity and Hemodynamics Parameters

NCT ID: NCT03314727

Last Updated: 2018-02-09

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-09-01
• Study Completion Date: 2017-11-30

Brief Summary

Diets containing excessive salt (>12 g/day) have negative effects on kidney and cardiovascular system. Considering this known fact, the investigators aimed to study if the amount of the water taken with excessive salt had any part on these negative effects by testing the blood pressure, serum osmolality, endothelial functions, cardiac function, inflammatory parameters and sympathetic nervous system.

Excessive dietary salt raises the serum osmolality, which triggers the protection mechanisms of the body. The first mechanism is the secretion of vasopressin from posterior pituitary and the second one is the polyol mediated aldose reductase enzyme activation in renal tubules. In the beginning, water and a little amount of salt is reabsorbed from the kidneys for keeping the serum osmolality in normal ranges by the elevation of vasopressin. Besides the high levels of vasopressin for long durations may have a role in both developments of hypertension and the progression/development of chronic kidney disease. Polyol mediated aldose reductase enzyme turns glucose into sorbitol, which is turned to fructose by sorbitol dehydrogenase activity. Fructose is degraded by fructokinase activity into toxic substances. With this pathway, the acute energy need is satisfied, yet uric acid, local oxidative stress, and inflammatory mediators rise while nitric oxide levels decreasing. These facts are independent risk factors for both kidney disease progression and hypertension. In addition, excessive salt intake may elevate the transforming growth factor beta-1 (TGF-B1) levels, which activates the sympathetic system, inflammation, and endothelial dysfunction.

According to these data, the investigators speculate that if they increase the amount of water intake while eating the high salt diet they may decrease the toxic effect of salt with less increase in serum osmolarity. To test this hypothesis, by regulating the salt and water amount in healthy people's diets, the investigators aimed to evaluate the following these parameters; biochemical parameters that could affect the blood and urine osmolality, blood pressure, vascular endothelial functions with the non-invasive flow-mediated dilatation technique and arterial stiffness, systolic and diastolic functions of the heart by transthoracic echocardiography. In addition, it was planned to evaluate the hormonal effects of arginine vasopressin, a long peptide with 39 amino acids, which is longer and easier to measure than vasopressin levels in serum by measuring the pituitary hormone-derived copeptin.

Although, decreasing the salt intake is the first step of the treatment in hypertension, and kidney diseases, the compliance rate to less sodium intake is very low (<20%). The investigators aim is to evaluate the effects of water, which is taken acutely with the excessive salt intake on cardiovascular system and kidney. The findings of the study will important for public health. If the investigators prove their hypothesis, they may recommend increasing high water intake before feeling thirst of which may contribute to decreasing the prevalence of hypertension and kidney disease.

Conditions

Hypertension; Sodium Excess; Oxidative Stress; Inflammation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Control group

Drink 200 ml soup with no added salt

Group Type: NO_INTERVENTION

No interventions assigned to this group

High salt (NaCl) intake

Group 2: Drink 200 ml soup with 3 g added salt Group 3: Drink 200 ml soup with 3 g added salt plus 500 ml water Group 4: Drink 200 ml soup with 3 g added salt plus 750 ml water

Group Type: EXPERIMENTAL

High salt (NaCl) intake

Intervention Type: OTHER

Participants are asked to consume two high sodium-containing soups while monitoring their serum osmolarity levels

Interventions

High salt (NaCl) intake

Participants are asked to consume two high sodium-containing soups while monitoring their serum osmolarity levels

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Healthy, no smoker, no obese >30 BMI, no drug use in the previous month

Exclusion Criteria

• Any systemic disease, no past history of any cardiovascular disease

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Koç University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Mehmet Kanbay, MD

Role: PRINCIPAL_INVESTIGATOR

Koc University Sch. Med. Dept. Internal Med. Nephrology

Locations

Koc University Hospital

Istanbul, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

2015.097.IRB2.037

Identifier Type: -

Identifier Source: org_study_id