Characteristics of the association between salt intake and blood pressure in a sample of male working population in southern Italy.

A possible association between dietary salt intake and blood pressure was investigated in an unselected sample of 188 healthy Neapolitan men. In univariate analysis diastolic pressure was positively correlated with age, body mass index and 24-h excretion of sodium, potassium and creatinine, but not with urine volume or sodium: potassium ratio. Systolic pressure was also related to age, body mass index and 24-h sodium, but to a lesser degree. As a high level of intercorrelation was apparent, multivariate analysis was also carried out. Body mass index was shown to be the variable having the largest influence on diastolic pressure variability: nevertheless a significant independent role was still found for 24-h urinary sodium when the latter was included in a regression along with body mass index, age, urine volume and potassium excretion. These results seem to support the possibility that dietary salt has a substantial influence on blood pressure levels.