Sodium metabolism and insulin sensitivity: Therapeutic implications

Antihypertensive therapy needs accurate metabolic phenotyping to obtain an effective decrement of individual cardiovascular risk. Accordingly, the possible metabolic effects of each class of antihypertensive drugs have been widely studied. However, the information available on the role of changes in sodium chloride dietary intake as a non-pharmacologic approach to metabolic disturbances in hypertensive patients is scarce. Clinical and experimental data support the concept that non-obese, non-diabetic salt-sensitive hypertensives are often insulin-resistant, whereas matched salt-resistant patients seem to be "protected" against the development of the so-called "insulin-resistance syndrome". In accordance with this difference, short-term sodium chloride restriction may result in a modest but significant improvement in glucose tolerance and insulin sensitivity, a finding observed only in patients experiencing a concomitant significant decrement in blood pressure. Therefore salt-sensitivity seems to be characterized by an increased risk of developing insulin resistance and the consequent detrimental changes in cardiovascular risk. Salt-sensitive individuals are likely to show the greatest metabolic benefit from salt restriction.