Resistant hypertension and the neglected antihypertensive: sodium restriction
Nephrology Dialysis Transplantation, 08/17/2012
Agarwal R – Sodium restriction can lower blood pressure and among patients with proteinuria can even enhance the anti–proteinuric effects of drugs that block the renin–angiotensin system. Sodium restriction is therefore a valuable but a neglected antihypertensive.
- Resistant hypertension is defined as blood pressure (BP) that remains above goal (such as 140/90 mmHg or more) in spite of the concurrent use of three antihypertensive agents of different classes.
- Ideally, one of the three agents should be a diuretic and all agents should be prescribed at optimal dose amounts.
- Prevalent among 15% of the treated hypertensives, the risk factors for resistant hypertension include older age, chronic kidney disease (CKD), obesity and diabetes mellitus.
- Causes of resistant hypertension can be classified into four groups: poor adherence, biological–behavioral factors, CKD and secondary causes, and drugs or exogenous substances.
- However, before labeling the diagnosis of resistant hypertension, it is important to exclude pseudo–resistant hypertension using home BP monitoring in most patients and ambulatory BP monitoring in a few.
- Before thinking about the next antihypertensive drug, it is important to restrict dietary sodium.
- Educating the patient on how to interpret the food label and providing feedback by assessing sodium intake with 24 h urine collection are effective sodium restriction strategies.