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Effect of Dietary Sodium Intake on Blood Pressure in Hypertensive Patients in Primary Care

This study has been completed.
Fund for Scientific Research, Flanders, Belgium
Information provided by (Responsible Party):
University Ghent Identifier:
First received: April 11, 2011
Last updated: April 20, 2012
Last verified: April 2012

There is strong evidence that our current consumption of salt is the major factor increasing blood pressure (BP). The current salt intake in most countries in the world is 9 to 12 grams per day (g/d), whil the World Health Organization's recommendation is < 5 g/d.

The aims of the present study is to determine if the overconsumption of salt influences the bp in patients with uncontrolled hypertension or frequently elevated bp.

Each study subject will complete questionnaires, and their usual dietary salt intake is estimated from food composition on 3 completed food diaries. This is also compared with a 24-hour urine sample collection.

Based on these results, the study subject receives personal advice to decrease sodium consumption and will change the diet for at least 28 days. During this diet, bp will be measured and food diaries will be completed. After the intervention, a questionnaire and a 24-hour urine sample collection will be collected.

Condition Intervention
Arterial Hypertension
Other: A 4-week diet, low in sodium.

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Effect of Dietary Sodium Intake on Blood Pressure in Hypertensive Patients in Primary Care

Resource links provided by NLM:

Further study details as provided by University Ghent:

Primary Outcome Measures:
  • Measurement of blood pressure after a 4-week diet, low in sodium. [ Time Frame: after 4 weeks ]

Secondary Outcome Measures:
  • Life style change after a 4-week diet, low in sodium. [ Time Frame: after 4 weeks ]

Enrollment: 25
Study Start Date: May 2010
Study Completion Date: April 2011
Primary Completion Date: April 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 4-week diet, low in sodium
The study subjects go on a 4-week diet, low in sodium.
Other: A 4-week diet, low in sodium.

Study subjects receive personal advice to decrease sodium consumption and will change his diet for 28 days.

Follow up is performed by measuring blood pressure, a 24-hour urine sample collection, diaries and questionnaires.


Ages Eligible for Study:   50 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • adults, 50 years of age or older with changing blood pressure (bp) with or without drugs and patients with uncontrolled bp despite drugs
  • An average systolic bp on 2 of the 3 previous visits of 140 mm Hg or more (130 mm Hg for diabetics) and an average diastolic bp of 80 to 100 mm Hg.
  • Blood analysis (fasting glycaemia, creatinin, total cholesterol, high- density lipoprotein cholesterol) in the last 6 months
  • At least 3 criteria of the following:

    • using table salt
    • 2-3/weeks consumption of prepared meals (butchery, warehouse...)
    • 2-3/weeks consumption of effervescent tablet
    • Daily consumption of cheese/cold cuts
    • Daily consumption of salted butter/margarine
    • 2-3/weeks consumption of smoked fish/meat
    • 2-3/weeks consumption of bouillon cube-soup (self-made or preserved)
    • 2-3/weeks consumption of cookies
    • 2-3/weeks consumption of vegetables preserved in jars
    • 2-3/weeks consumption of vegetable juice
    • 2-3/weeks consumption of snacks (chips, cheese, nuts...)

Exclusion Criteria:

  • heart failure
  • renal insufficiency
  • secondary hypertension
  • isolated systolic/diastolic hypertension
  • bp difference of more than 10 mm Hg between left and right arm
  • lactation or pregnancy
  • active malignancy
  • an active 'low in salt' diet
  • changing the use of antihypertensive drugs or other medication that would affect bp for the last 4 weeks
  • impaired cognitive functioning$
  • planning a smoke cessation
  Contacts and Locations
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Please refer to this study by its identifier: NCT01334138

University Ghent
Ghent, Belgium, 9000
Sponsors and Collaborators
University Ghent
Fund for Scientific Research, Flanders, Belgium
Principal Investigator: Stefaan Dehenauw, Ph.D, Professor University Ghent
  More Information

Responsible Party: University Ghent Identifier: NCT01334138     History of Changes
Other Study ID Numbers: 2010/233
Study First Received: April 11, 2011
Last Updated: April 20, 2012

Keywords provided by University Ghent:

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases processed this record on May 25, 2017