International studies of salt and blood pressure.

Comparing the distributions of blood pressure in different populations it has been found that the log-normal distribution gave the best summary of the data. The geometric mean and the coefficient of variation of the underlying blood pressure distribution were the most informative statistics. Using this blood pressure distribution, a model is discussed for the change in blood pressure with age and between populations. These changes are consistent with an environmental factor, such as salt intake, affecting the position of the mean of the blood pressure distribution and with a gradient of susceptibility within a population.