Blood Pressure Response to Sodium in the Diet

NCT ID: NCT01899495

Last Updated: 2016-10-18

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 400 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2005-01-31
• Study Completion Date: 2021-08-31

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.

Detailed Description

Subjects are placed on an isocaloric diet, one week with high sodium(300mEq) and one week with low sodium(10mEq), in randomized order. Twenty-four hour urine sodium and urine creatinine levels verify diet compliance. Blood pressure measurements are recorded during each diet week by automated blood pressure monitoring system. Each blood pressure is taken in the right arm 3 times while the subject is sitting quietly for 45 minutes .

Conditions

Hypertension

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

High sodium diet and low sodium diet

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

Group Type: EXPERIMENTAL

High sodium diet and low sodium diet

Intervention Type: OTHER

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

Interventions

High sodium diet and low sodium diet

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

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• hypertension
• blood pressure > 140/90 mmHg

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: collaborator

University of Virginia

OTHER

Sponsor Role: lead

Responsible Party

Robert M. Carey, MD

Professor of Medicine; Dean, Emeritus; University Professor Division of Endocrinology and Metabolism

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Robert M Carey, MD

Role: PRINCIPAL_INVESTIGATOR

University of Virginia

Locations

University of Virginia

Charlottesville, Virginia, United States

Site Status: RECRUITING

Countries

United States

Facility Contacts

Mahabuba Akhter, M.B.B.S, MS

Role: primary

SaltSensitivityStudy@email.virginia.edu

434-924-8757

References

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

Reference Type: RESULT

Other Identifiers

P01HL074940

Identifier Type: NIH

Identifier Source: secondary_id

View Link

11494

Identifier Type: -

Identifier Source: org_study_id