Hypertension in obesity.

AIM: To review various topics regarding the relationship between obesity and hypertension. DATA
SUMMARY: Obesity is a widespread and increasingly prevalent condition associated with a large number of comorbid diseases, one of the most important of which is obesity-induced hypertension (HTN). The association between obesity and HTN has been well documented in most racial, ethnic and socio-economic groups, although the relationship between body mass index (BMI) and blood pressure values depends on age, gender, type of obesity and race differences. Obesity-induced HTN has some unique characteristics that differ from those observed in lean hypertensive patients. The hemodynamic profile of obese subjects is characterised by high cardiac output, high plasma and total blood volume, and inappropriately normal to total peripheral resistance. Clinically, hypertensive obese subjects are more likely to develop left ventricular hypertrophy and kidney damage than their lean counterparts. Various common factors are involved in establishing sodium retention and vascular resistance and may be critically influenced by the neurobiological/genetic mechanisms leading to obesity, in which insulin, leptin and the adrenergic system play major roles. Obesity is one of the main causes of therapeutic failure, and a number of studies have demonstrated that obese subjects need more antihypertensive drugs than sex and age-matched lean hypertensives. Long-term dietary treatment, consisting of a moderate restriction of energy and salt intake, is the most effective and safe treatment for obesity-associated HTN. The use of treatments other than calorie restriction should be considered with caution. Drugs that increase energy expenditure or reduce appetite may variably increase blood pressure (BP) and are unsuitable for hypertensive subjects. There do not seem to be any clear differences in the efficacy of the various antihypertensive drug classes. The clustering of cardiovascular risk factors other than HTN needs to be taken into account when choosing antihypertensive treatment for obese subjects.
CONCLUSIONS: Obesity is a highly prevalent condition that causes or exacerbates many health problems including HTN. Combined interventions at different levels can help in losing weight and therefore reduce the cardiovascular risk, morbidity and mortality associated with obesity.