Blood pressure versus Salt; inter-population data

Description

Median blood pressure, as a fuction of salt intake, for each of 52 human populations.

Usage

intersalt

Format

A data frame with 52 observations on the following 4 variables.

b

a numeric vector

bp

mean diastolic blood pressure (mm Hg)

na

mean sodium excretion (mmol/24h)

country

a character vector

Details

For each population took a sample of 25 males and 25 females from each decade in the age range 20 - 50, i.e. 200 individuals in all.

Source

Intersalt Cooperative Research Group. 1988. Intersalt: an international study of electrolyte excretion and blood pressure: results for 24 hour urinary sodium and potassium excretion. British Medical Journal 297: 319-328.

References

Maindonald, J.H. The Design of Research Studies ? A Statistical Perspective, viii + 109pp. Graduate School Occasional Paper 00/2, Australian National University 2000.

Examples

data(intersalt)
plot(bp ~ na, data=intersalt, xlab="Median sodium excretion (mmol/24h)",
     ylab="Median diatoluc blood pressure (mm Hg)")