Aim: To review human and animal data describing the complex interrelation between obesity hypertension, salt-sensitivity and insulin resistance.
Data synthesis: The first part of the article reviews the information available in the literature defining obesity hypertension as a salt sensitive form of hypertension and that links obesity hypertension to the presence of insulin. The second part reviews the four factors frequently cited as possible causes for this sodium retention: insulin resistance, alteration in the renin-angiotensin system, altered vascular responsiveness and alterations in the sympathetic nervous system. Special emphasis is given in an attempt to explain how each of these four factors can change pressure-natriuresis.
Conclusions: There is clearly a strong relationship between obesity hypertension, sodium sensitivity and insulin resistance. The exact mechanism responsible for linking these three conditions is still unknown. However, there is ample evidence to suggest that insulin resistance, altered vascular responsiveness, altered function of the renin-angiotensin aldosterone system and altered function of the sympathetic nervous system are important in these three conditions. Further investigation is warranted to completely elucidate the complex relationship between insulin resistance, obesity hypertension and sodium sensitivity.