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Friday, June 21, 2013

Chronic Kidney Disease & High Blood Pressure

Control of hypertension is the single most important intervention to delay progression of chronic kidney disease (CKD). Extracellular fluid volume expansion is one of the most important factors leading to persistent hypertension in patients with CKD. Older individuals and black patients are more likely to be salt-sensitive and exhibit an antihypertensive response to sodium restriction or diuretic therapy.

If hypertension and proteinuria persist despite sodium restriction, the addition of a diuretic may be beneficial. Thiazide diuretics, if not used as a first-choice antihypertensive drug, are almost always indicated as an additional drug in patients with incompletely controlled hypertension, because these agents augment most other agents used as monotherapy.

Most hypertensive patients will require more than one antihypertensive drug to lower BP below target levels. The combination of diuretics with renin-angiotensin system (RAS) antagonists offers several advantages to include additive BP-lowering efficacy and enhanced reductions in urinary protein excretion. Thiazide diuretics are associated with metabolic complications that are particularly evident when used in high doses. When used in combination with RAS blockade, metabolic complications such as hypokalemia are minimized. The avoidance of hypokalemia has been linked to less thiazide-induced glucose intolerance. Patient persistence on therapy is dependent on well tolerated drug combinations.


Ardavan Mashhadian D.O.
Nephrologist
1127 Wilshire Blvd Suite 510
Los Angeles CA 90017
(213) 537-0328

Resistant Hypertension

Resistant hypertension is defined as blood pressure that remains above goal despite treatment with the optimal dosage of three antihypertensive agents, including a diuretic.

Patient characteristics more likely to be associated with resistant hypertension include:
1. Older age
2. BMI above 30
3. Higher baseline blood pressure
4. Diabetes mellitus
5. Black race.

Excessive consumption of dietary salt and alcohol contributes to resistant hypertension. Many patients with resistant hypertension have secondary hypertension caused by primary aldosteronism or renovascular hypertension, and these conditions should be excluded.

Treatment of resistant hypertension should include appropriate lifestyle modifications, discontinuation of agents that may increase blood pressure such as NSAIDs, and correction of secondary causes of hypertension. Mineralocorticoid receptor antagonists are particularly effective in treating resistant hypertension even in the absence of hyperaldosteronism. The Anglo-Scandinavian Cardiac Outcomes Trial evaluated the efficacy of spironolactone among 1411 participants with an average age of 63 years who received this medication mainly as a fourth-line antihypertensive agent for uncontrolled blood pressure. After 1 year of treatment, blood pressure in these patients decreased by approximately 21.9/9.5 mm Hg.

Ardavan Mashhadian D.O.
Nephrologist
1127 Wilshire Blvd Suite 510
Los Angeles CA 90017
(213) 537-0328

Thursday, June 20, 2013

Managing High Blood Pressure

Lifestyle modifications are recommended for all patients with hypertension, including prehypertension. The Dietary Approaches to Stop Hypertension (DASH) study showed that 8 weeks of a diet of fruits, vegetables, low-fat dairy products, whole grains, poultry, fish, and nuts, along with a reduction in fats, red meat, and sweets, caused an 11.4-mm Hg decrease in systolic pressure and a 5.5-mm Hg decrease in diastolic pressure. In addition, patients using the DASH diet who consumed less than 100 mmol/d of sodium had a systolic pressure 3 mm Hg and a diastolic pressure 1.6 mm Hg less than those who consumed high amounts of sodium.


Weight reduction in a patient whose weight is 10% above ideal body weight lowers blood pressure by an average of 5 to 7 mm Hg. Alcohol consumption should be limited to two drinks daily for men and one for women, because excess amounts of alcohol may contribute to hypertension and resistance to antihypertensive medications. Regular aerobic exercise also modestly decreases blood pressure. In addition, patients should be counseled about smoking cessation.


The goal of treatment of hypertension is to reduce cardiovascular morbidity and mortality by lowering blood pressure. Lowering blood pressure has definitively been shown to reduce stroke, myocardial infarction, heart failure, and overall cardiovascular mortality. Evidence obtained from clinical trials suggests that the goal of antihypertensive treatment is to reduce blood pressure to below 140/90 mm Hg in the general population. The American Heart Association recommends a blood pressure target of 130/80 mm Hg for those with coronary artery disease, carotid artery disease, peripheral artery disease, abdominal aortic aneurysm, and a Framingham 10-year risk score of 10% or greater. However, data clearly demonstrate a linear, progressive increased risk of ischemic heart disease and stroke in patients with blood pressures higher than 115/75 mm Hg, which suggests that these targets may be too high. Clinical trials addressing lower blood pressure targets are currently being planned.


Ardavan Mashhadian D.O.
Nephrologist
1127 Wilshire Blvd Suite 510
Los Angeles CA 90017
(213) 537-0328