Treatment of hypertension in obesity

Abstract

Hypertension and obesity are common medical conditions independently associated with increased cardiovascular risk. Many large epidemiological studies have demonstrated associations between body mass index and blood pressure, and there is evidence to suggest, that obesity is a causal factor in the development of hypertension in obese subjects. Weight Reduction and maintenance is an essential first step in the treatment of obesity-associated hypertension. Weight reduction may be achieved by behavior modification, diet, and exercise or by the use of anti-obesity medication. However, the long-term outcomes of weight management programs for obesity are generally poor, and most hypertensive patients will require antihypertensive drug therapy. Obese hypertensive patients often have metabolic abnormalities known to be exacerbated by commonly used antihypertensive agents but also obesity per se is often associated with endorgan damage including left ventricular hypertrophy, glomerular hyperfiltration and microalbuminuria, congestive heart failure or sudden cardiac death. Furthermore they have revealed volume expansion, increased cardiac output, and lower total peripheral resistance than lean patients. Hypertension in obese patients appears to be related to both increased sympathetic nervous system activity and activation of the renin-angiotensin system. Where antihypertensive therapy is necessary, the aim should be to use agents based on the hemodynamic and metabolic background and that have benefits beyond blood pressure lowering and improve the conditions most commonly linked with obesity-associated hypertension, such as hyperlipidaemia, Type II diabetes, left ventricular hypertrophy, coronary artery disease, or congestive heart failure. Based on their favorable metabolic profiles, it would appear that ACE inhibitors, angiotensin receptor blockers, calcium channel blockers, moxonidine and alpha-blockers can lower blood pressure without worsening the metabolic abnormalities, that is just one aspect of the problem. Yet, most guidelines fail to provide specific advice on the pharmacological management of hypertension in obese patients. This may be due to the fact that there are currently no studies that have addressed the efficacy of specific antihypertensive agents in reducing mortality in obese-hypertensive patients. This paper reviews the theoretical reasons for the differential use of the major classes of antihypertensive agents in the pharmacological management of obesity-related hypertension and also considers the potential role of anti-obesity agents.