Blood Pressure Response to Sodium in the Diet

NCT01899495 | Unknown

• 2 other identifiers: 11494P01HL074940
• Study Type: interventional
• Target: 400
• Locations: 1 country
• Sites: 1

Brief Summary

Previous studies have demonstrated that single nucleotide polymorphisms (SNPs) of the sodium-bicarbonate co-transporter gene (SLC4A5) are associated with hypertension. We tested the hypothesis that SNPs in SLC4A5 are associated with salt sensitivity of blood pressure in 185 whites consuming an isocaloric constant diet with a randomized order of 7 days of low sodium (Na+) and 7 days of high Na+ intake. Salt sensitivity was defined as a ≥7-mm Hg increase in mean arterial pressure during a randomized transition between low and high Na+ diet. A total of 35 polymorphisms in 17 candidate genes were assayed, 25 of which were tested for association. Association analyses with salt sensitivity revealed 3 variants that associated with salt sensitivity. Of these, 2 SNPs in SLC4A5 (rs7571842 and rs10177833) demonstrated highly significant results and large effects sizes, using logistic regression. These 2 SNPs had P values of 1.0×10-4 and 3.1×10-4 with odds ratios of 0.221 and 0.221 in unadjusted regression models, respectively, with the G allele at both sites conferring protection. These SNPs remained significant after adjusting for body mass index and age (P=8.9×10-5 and 2.6×10-4 and odds ratios 0.210 and 0.286, respectively). Furthermore, the association of these SNPs with salt sensitivity was replicated in a second hypertensive population. Meta-analysis demonstrated significant associations of both SNPs with salt sensitivity (rs7571842 \[P=1.2×10-5\]; rs1017783 \[P=1.1×10-4\]). In conclusion, SLC4A5 variants are strongly associated with salt sensitivity of blood pressure in 2 separate white populations.

Conditions

Hypertension

Keywords

blood pressure; hypertension; salt sensitivity

Outcome Measures

Primary Outcomes (1)

• Blood pressure; Change in Mean Arterial Pressure from low salt diet to high salt diet

  The mean arterial pressure that will determine salt sensitivity will be assessed during the last day of the diet week. The study will be stopped for any individual during any visit if there is an average blood pressure of \>180/114 mmHg.

  Study subjects will be observed 5 times during the 2 week intervention

Secondary Outcomes (2)

• Urine sodium

  Urine chemistry analysis will be assessed from a 24-hour urine collection on the last day of each diet week.

• Genetic analysis for specified genes associated with hypertension

  During the screening visit

Study Arms (1)

High sodium diet and low sodium diet

EXPERIMENTAL

Each subject experiences both a high sodium and a low sodium diet.

Other: High sodium diet and low sodium diet

Interventions

High sodium diet and low sodium diet OTHER

Isocaloric diet with 60 mEq of potassium and 1gm protein/kg body weight with high sodium 300mEq; low sodium 10 mEq.

High sodium diet and low sodium diet

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Ages 18-70 (inclusive)
• Sex Male and female
• Race Caucasian and African-American/black
• BMI 18.-0-29.9
• BP Normal

You may not qualify if:

• hypertension
• blood pressure \> 140/90 mmHg

Sponsors & Collaborators

• University of Virginia: lead
• National Heart, Lung, and Blood Institute (NHLBI): collaborator

Study Sites (1)

University of Virginia

Charlottesville, Virginia, 22903, United States

RECRUITING

Related Publications (1)

• http://hyper.ahajournals.org/content/early/2012/09/17/HYPERTENSIONAHA.112.196071.full.pdf

  RESULT

MeSH Terms

Conditions

Hypertension

Interventions

Diet, Sodium-Restricted

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Robert M Carey, MD

  University of Virginia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Medicine; Dean, Emeritus; University Professor Division of Endocrinology and Metabolism

Study Record Dates

• First Submitted: January 22, 2013
• First Posted: July 15, 2013
• Study Start: January 1, 2005
• Primary Completion: August 1, 2021
• Study Completion: August 1, 2021
• Last Updated: October 18, 2016

Record last verified: 2016-10

Locations

US (1)