Obesity and hypertension: from pathophysiology to treatment

Abstract

While the prevalence of hypertension is clearly increased among the overweight persons, the pathophysiological mechanisms underlying this frequent association of obesity and hypertension are still poorly understood. The expansion of extracellular volume, inducing hypervolaemia and increased cardiac output, represents the characteristic haemodynamic feature of the obesity-related hypertension. The maintenance of hypervolemia in the face of elevated blood pressure, indicates a resetting of pressor natriuresis toward higher blood pressure. The development of hypertension also indicates an increase in peripheral vascular resistance, thus the lack of physiological adaptation of peripheral resistance to increased cardiac output. The mechanisms underlying these changes in renal function and vascular reactivity can no longer be attributed to hyperinsulinaemia as such, but might be related to insulin resistance responsible for the enhancement in pressor activity of noradrenaline and angiotensin II. This increased reactivity to pressor factors may be due to an inadequate nitric oxide generation by vascular endothelium and to increased sodium and calcium concentration in vascular smooth muscle cells. The role of increased neuropeptide Y (NPY) activity, may also be involved. As to enhancement of tubular sodium reabsorption, it could be related to histological changes within the renal medulla, leading to compression of tubules and vasa recta, hence a more ef®cient sodium reabsorption. As to the therapeutic approach, the low-energy sodium-restricted diet associated with increased physical activity, represents the cornerstones of treatment for the obesity-related hypertension. If this approach fails, the pharmacological treatment becomes necessary, and the use of the converting enzyme inhibitors seems to be the most appropriate choice of drug therapy for hypertensive obese patients.

Blood pressure in relation to relative weight at birth through childhood and youth in obese and non-obese adult men

“…3 Blood pressure decreases during weight loss and increases during weight gain. 1,4 The mechanism behind the association between weight and blood pressure is not understood 5 and is probably complex since both current weight and change in weight in the preceding period seem to have an effect independent of each other. 6,7 In the Swedish Obese Subjects Intervention Study blood pressure after an initial decrease had regained 8 y after gastric surgery even though a weight loss of 16% was maintained.…”

Leptin Induces Endothelin-1 in Endothelial Cells In Vitro

“…A lthough the association of obesity and hypertension is well established, 1 there is, however, scarce information about the underlying pathomechanisms. Recently, the adipocyte gained more attention, serving not only as a passive energy storage pool but also as an important source of endocrine-active peptides, thus leading to a novel concept of adipocyte function.…”

The association between body mass index and incident hypertension in rural women in China

“…The specific biological mechanisms by which higher BMI increases the risk of developing hypertension remain unclear. Several metabolic and neurohormonal pathways likely have complex interactions underlying the development of hypertension among the overweight and obese, including alterations in insulin resistance, the renin-angiotensin-aldosterone system and sympathetic tone (Tuck et al, 1981;Hsueh and Buchanan, 1994;Ikeda et al, 1996;Kolanowski, 1999). Weight loss among obese individuals has been associated with improvements in insulin resistance, as well as decreases in norepinephrine, plasma rennin activity and aldosterone levels (Tuck et al, 1981;Ikeda et al, 1996).…”