Non-esterified fatty acids and blood pressure elevation: a mechanism for hypertension in subjects with obesity/insulin resistance?

The prevalence of hypertension in individuals with obesity or type II diabetes is substantially elevated. Increased levels of non-esterified fatty acids (NEFAs) in abdominally obese subjects were reported to contribute in the development of various disturbances related to the metabolic syndrome, such as hepatic and peripheral insulin resistance (IR), dyslipidaemia, beta-cell apoptosis, endothelial dysfunction and others. However, the involvement of NEFAs in the development of hypertension has been much less studied in comparison to other mechanisms linking IR and central obesity with blood pressure (BP) elevation. This article reviews the existing evidence on the relation between NEFA and hypertension in an attempt to shed a light on it. In vivo data from both animal and human studies support that acute plasma NEFA elevation leads to increase in BP levels, whereas epidemiological evidence suggests a link between increased NEFA levels and hypertension. Further, accumulating data indicate the existence of several pathways through which NEFAs could promote BP elevation, that is alpha(1)-adrenergic stimulation, endothelial dysfunction, increase in oxidant stress, stimulation of vascular cell's growth and others. The above data support a possible important role of NEFA in hypertension development in patients with obesity and the metabolic syndrome and raise hypotheses for future research.