Sodium intake and blood pressure in healthy individuals

To investigate further the relationships between blood pressure and sodium intake, which have been claimed to exist, but have not been clearly established, in epidemiological studies.

A 2-year follow up study of a cohort of 296 healthy volunteers working in the same company.

Consistent with previously reported findings, covariance analysis in the entire population, including multivariate analysis to examine the potential influence of confounding variables, failed to identify a significant relationship between blood pressure and sodium intake or between their respective changes within 2 years. To test the hypothesis of a heterogeneous distribution of salt sensitivity, we calculated the statistical dependence between blood pressure and sodium intake using the coefficient analysis that quantifies the prevalence of a statistical link between two variables. A significant dependence (P < 0.05) between diastolic (DBP) or systolic (SBP) blood pressure and sodium intake was found in 16 and 5% of the participants, respectively. The analysis of the 2-year changes in blood pressure and sodium intake reinforced our findings. Our finding of a relationship between blood pressure and sodium intake in only a few individuals may explain the lack of a global relationship between these two variables investigated by the covariance analysis in our study.(Rho)

Our results suggest that 5-16% of healthy individuals have a 'salt-dependent blood pressure' and might benefit from a reduction in dietary salt intake.