Relationship of Urine Sodium Excretion to Central Blood Pressure and Aortic Pulse Wave Velocity

One interesting area is the relationship of high salt intake and central aortic blood pressure. High salt intake is associated development of hypertension and cardiovascular mortality. Central aortic pressure is better correlated with cardiovascular events and mortality. With recent advances in technology, it is possible to measure central aortic pressure noninvasively and easily. Until now there is no study to evaluate the relationship of high salt intake and aortic blood pressure.

The purpose of the present study is to evaluate the relationship of high salt intake and aortic blood pressure and aortic stiffness.

Subjects with or without hypertension will be enrolled for investigation. Subjects with hypertension should be never treated with antihypertensive medications. Subjects with secondary hypertension, diabetes, heart failure, high grade kidney disease, ischemic heart disease, and major arrhythmia will be excluded.

Sodium intake is measured by 24 hour urinary sodium excretion, with the measurement of peripheral and central aortic blood pressure, and aortic pulse wave velocity.

Salt sensitive hypertension related single nucleotide polymorphism will be analyzed to define the relationship with high salt intake and aortic pressure and pulse wave velocity.

Study Overview

• Status: Completed
• Conditions: Hypertension

Detailed Description

Measurements: should be performed for 2 days

1. 24 hour urine Na, K and Creatinine, 24 hour urine amount

   1. Calculation of urine completeness index : Cr/(21 x Bwt)
   2. Definition of complete urine collection: complete index ≥ 0.7 and loss not more than one time and 100 mL

2. Peripheral blood pressure (pBP)

   1. Microlife WatchBP Office
   2. Sitting position
   3. After 5 minutes resting
   4. Peripheral systolic BP (pSBP), Peripheral diastolic BP (pDBP),

3. Central aortic blood pressure

   1. SphygmoCor (AtCor Medical, Australia)
   2. Central systolic blood pressure
   3. Difference between peripheral SBP and central SBP (SBPp-c)

4. Pulse wave velocity

   1. VP2000 (Colin, Japan)
   2. Central pulse wave velocity: carotid-femoral Pulse Wave Velocity
   3. Measure by tape
   4. distance from suprasternal notch to carotid artery
   5. distance from suprasternal notch to femoral artery
   6. Silent environment

5. Blood chemistry and complete blood count

   1. Measure at the morning of second day after overnight fasting
   2. complete blood count, blood urea nitrogen/Creatinine, fasting blood glucose, Total cholesterol, Triglyceride, High density lipoprotein cholesterol
6. 24 hour ambulatory blood pressure measurement

Measurement protocol

1. 1st day

   1. Visit hospital before 9:00 AM after overnight fasting
   2. start 24 hour urine collection from 9:00 AM (with education for complete collection)
   3. start 24 hour ambulatory blood pressure monitoring, in parallel with 24 hour urine collection

2. 2nd day

   1. Measure central aortic blood pressure
   2. Measure blood Lab
   3. Measure Pulse Wave Velocity

Analysis of Salt sensitive gene polymorphism

1. Single Base Extension technology(SBE)
2. single nucleotide polymorphism rs2398162 and other salt sensitive hypertension related single nucleotide polymorphism

• Study Type: Observational
• Enrollment (Actual): 200

Contacts and Locations

Study Locations

• Korea, Republic of
  • Gyenggi
    • Goyang, Gyenggi, Korea, Republic of, 410-773
      • Dongguk University Ilsan Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

subjects with or without hypertension

Description

Inclusion Criteria:

• subjects without hypertension: n=100
• subjects with hypertension, not treated at least within 6months: n=100

Exclusion Criteria:

• secondary hypertension
• known diabetes (HbA1C >7.5%)
• night worker
• stage 3 hypertension
• renal artery stenosis
• primary aldosteronism
• elevated GOT and/or glutamate-pyruvate transaminase > 2 fold of normal range
• heart failure, significant arrhythmia, angina, myocardial infarction, stroke, carotid stenosis
• pregnancy
• autoimmune disease, debilitating disease
• significant liver disease; active hepatitis, liver cirrhosis
• alcoholics
• Renal disease: Cr > 1.2 and/or proteinuria
• Medication affecting blood pressure and/or vascular stiffness, including lipid lowering agents

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
normotensive subjects; subjects without hypertension, and without diabetes, ischemic heart disease, major arrhythmia, heart failure, secondary hypertension, high grade renal disease,
Hypertensive subjects; subjects with hypertension,; currently not treated at least within 6 months; without diabetes, ischemic heart disease, major arrhythmia, heart failure, secondary hypertension, high grade renal disease,

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the relationship between 24 hour ambulatory blood pressure and 24 hour urine sodium/potassium excretion	the relationship between 24 hour ambulatory blood pressure and 24 hour urine sodium/potassium excretion will be analysed. daytime, nighttime and morning BP will be analysed to 24 hour urinary sodium/potassium excretion	cross-sectional study

Secondary Outcome Measures

Outcome Measure	Time Frame
the relationship between 24 hour urinary sodium/potassium excretion and central BP and arterial stiffness	Cross-sectional study

Other Outcome Measures

Outcome Measure	Time Frame
the relationship between ambulatory BP variability and arterial stiffness	Cross-sectional study

Collaborators and Investigators

• Sponsor: DongGuk University
• Collaborators: The Korean Society of Cardiology
• Investigators: Principal Investigator: Moo-Yong Rhee, Prof,MD, PhD, Cardiovascular Center, Dongguk University Ilsan Hospital

Study record dates

Study Major Dates

• Study Start: May 1, 2010
• Primary Completion (Actual): December 1, 2011
• Study Completion (Actual): December 1, 2011

Study Registration Dates

• First Submitted: November 9, 2010
• First Submitted That Met QC Criteria: November 9, 2010
• First Posted (Estimate): November 10, 2010

Study Record Updates

• Last Update Posted (Estimate): January 23, 2013
• Last Update Submitted That Met QC Criteria: January 21, 2013
• Last Verified: January 1, 2013

More Information

Terms related to this study

• Keywords: hypertension
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: 2010-1-15