Registration Dossier

Toxicological information

Basic toxicokinetics

Currently viewing:

Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
other: review of articles
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Original references are not available

Data source

Reference
Reference Type:
review article or handbook
Title:
Recommendations on dietary salt
Author:
Fodor, J.G.
Year:
1999
Bibliographic source:
CMAJ, May 4, 1999; 160 (9 Suppl), page S29-S34

Materials and methods

Objective of study:
other: evidence-based recommendations concerning effects of dietary salt intake on prevention and control of hypertension in adults (except pregnant women)
Principles of method if other than guideline:
A MEDLINE search was conducted for the period 1966-1996 using the terms hypertension, blood pressure, vascular resistance, sodium chloride, sodium, diet, sodium or sodium chloride dietary, sodium restricted/reducing diet, clinical trials, controlled clinical trial, randomized controlled trial and random allocation. Both trials and review articles were obtained, and other revelant evidence was obtained from the reference lists of the articles identified, from the personal files of the autors and through contacts with experts. The articles were reviewed, classified according to study design and graded according to level of evidence. In addition, a systematic review of all published randomized controlled trials relating to dietary salt intake and hypertension was conducted
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
Sodium
EC Number:
231-132-9
EC Name:
Sodium
Cas Number:
7440-23-5
IUPAC Name:
sodium
Details on test material:
- Name of test material (as cited in study report): sodium
Radiolabelling:
no

Test animals

Species:
human
Strain:
not specified
Sex:
not specified
Details on test animals or test system and environmental conditions:
STUDY SUBJECTS:
- Age at study initiation (in articles reviewed): subjects in the studies of normotensive people were generally younger (mean age 26 years) than those in the studies of hypertensive people (mean age 47 years)
- Diet: dietary salt intake was studied in the articles reviewed

Administration / exposure

Route of administration:
oral: feed
Vehicle:
not specified
Duration and frequency of treatment / exposure:
Studies of normotensive subjects tended to be short-term studies with less than 1 month of intervention. Only 3 long-term studies of normotensive subjects (lasting more than 1 year) were identified. Trials with hypertensive subjects had longer intervention periods, and 5 long-term studies were identified.
No. of animals per sex per dose / concentration:
number of subjects not specified.
Control animals:
other: normotensive population
Statistics:
A statistical analysis was performed to determine the effect of dietary interventions by correlating changes in urinary excretion of sodium with changes in blood pressure.

Results and discussion

Any other information on results incl. tables

Twenty-nine studies of normotensive subjects and 30 studies of hypertensive subjects were identified and reviewed. Studies of normotensive subjects tended to be shortterm studies with less than 1 month of intervention. Only 3 long-term studies of normotensive subjects (lasting more than 1 year) were identified. The subjects in the studies of normotensive people were generally younger (mean age 26 years) than those in the studies of hypertensive people (mean age 47 years). Trials with hypertensive subjects had longer intervention periods, and 5 long-term studies were identified. Apart from the meta-analysis, 19 additional studies were evaluated.

-Restriction of salt intake for normotensive people is not recommended at present because of insufficient evidence of hypertension (grade B recommendation)

-To avoid excessive intake of salt people should be counselled to choose foods low in salt (e.g., pre-prepared foods), to refrain from adding salt at the table and minimize the amount of salt used in cooking, and to increase their awareness of the salt content of food choices in restaurants (grade D recommendations)

-It is recommended that the salt consumption of hypertensive patients be determined by interview (grade D recommendation)

Applicant's summary and conclusion