5 Things Every Family Physician Should Know in 2015

Frank J. Domino, MD

Disclosures

March 03, 2015

In This Article

Editor's Note: This article is derived from a lecture presented by Dr Domino at the American Academy of Family Physicians October 2014 conference.

Best Strategies for Treatment of Hypertension

Although much remains unknown about the best therapies for treatment of hypertension, an increasing body of evidence sheds light on some of the important questions.

Should we be treating patients with mild hypertension? A Cochrane review[1] analyzed four randomized controlled trials involving almost 9000 patients with mild hypertension (systolic blood pressure [SBP] 140-159 mm Hg and/or diastolic blood pressure [DBP] 90-99 mm Hg) and without cardiovascular disease (CVD) treated with antihypertensive therapy or placebo for an average of 4-5 years. The reviewers found no difference between treated and untreated individuals in the incidence of coronary heart disease, stroke, total cardiovascular (CV) events, and death. Furthermore, about 9% of patients treated with drugs discontinued treatment owing to adverse effects. The bottom line? Treating mild hypertension provides little prevention of CVD in the short term; use the least bothersome first-line agent as possible.

Is sodium restriction helpful? A meta-analysis[2] of 34 trials examining the effect of salt restriction on blood pressure (BP) found a mean reduction in SBP of 5.39 mm Hg and mean DBP reduction of 2.82 mm Hg. From a population viewpoint, these were deemed to be important reductions in BP and were found in both hypertensive and normotensive individuals, irrespective of sex and ethnic group. The investigators further speculated that the significant association between the reduction in 24-hour urinary sodium and the fall in SBP indicates that larger reductions in salt intake would lead to larger SBP reductions. There were small physiologic increases in renin activity, aldosterone, and noradrenaline. Renin increases the amount of angiotensinogen in the blood, which could increase BP; the release of aldosterone has the potential to increase both sodium retention and potassium secretion, which also could increase BP.

How low should sodium intake go? The 2010 Dietary Guidelines for Americans[3] recommend reducing daily sodium intake to less than 2300 mg for the general population and to 1500 mg among higher-risk groups including African Americans, adults aged 51 years and older, and those with hypertension, diabetes, or chronic kidney disease (CKD). However, a 2013 report[4] from the Institute of Medicine concluded that current evidence did not support this lower recommendation for some populations. So, at least for now, one size appears to fit all. The bottom line? Limiting the use of a salt shaker is unlikely to improve any short- or long-term outcomes. Instead, encourage patients to limit their intake of prepared foods (canned soups, store or restaurant prepared foods) that contain large amounts of hidden sodium.

Could potassium be the answer? A systematic review and meta-analysis[5] of 22 randomized controlled trials and 11 cohort studies examined the effects of potassium intake on BP, renal function, lipids, catecholamine concentrations, all-cause mortality, CVD, stroke, and coronary heart disease. Increased potassium intake reduced BP with no adverse effect on lipids, catecholamine concentrations, or renal function in adults. The highest intake of more than 4700 mg/day was associated with the largest SBP reduction. However, the average American consumes only 2640 mg/day.[6] The highest potassium concentrations are found in figs, molasses, seaweed, dates, prunes, tree nuts, avocados, bran cereal, wheat germ, and lima beans. Just one fourth of a teaspoon of Morton® salt substitute provides more potassium than such frequently cited food sources as bananas, oranges, potatoes, and spinach. The Office of Disease Prevention and Health Promotion in the Department of Health and Human Services provides an online table of foods ranked by mg of potassium per standard serving.

If you are going to treat, should you use chlorthalidone or hydrochlorothiazide? To try to better answer this question, an observational cohort study[7] of almost 30,000 individuals aged 65 years or older who had not had a hospitalization for major CV event in the previous year and were newly treated with chlorthalidone or hydrochlorothiazide was conducted in Canada. The investigators concluded that the risk for death or adverse CV events was similar and use of chlorthalidone in older adults was not associated with fewer adverse CV events or deaths compared with hydrochlorothiazide. The chlorthalidone group was, however, more likely to be hospitalized with hypokalemia (hazard ratio [HR], 3.06) or hyponatremia (HR, 1.68). And thanks to the Joint National Committee 8 (JNC 8), thiazides are not the only choice for first-line treatment.

What does JNC 8 say? In December 2013, the long-awaited adult hypertension management guidelines from JNC 8[8] were released to much fanfare and controversy. Some of the new recommendations include:

  • In patients aged 60 years or older, start treatment for SBP >150 mm Hg or DBP >90 mm Hg and treat to under those thresholds.

  • In patients aged 18-60 years, treatment initiation and goals should be 140/90 mm Hg.

  • The same goals apply to patients with diabetes or CKD.

  • In nonblack patients, initial treatment can be a thiazide-type diuretic, calcium channel blocker (CCB), angiotensin-converting-enzyme (ACE) inhibitor, or angiotensin receptor blocker (ARB).

  • For black patients, initial therapy should be a thiazide-type diuretic or CCB.

  • In patients aged 18 years or older with CKD, initial or add-on therapy should be an ACE inhibitor or ARB, regardless of race or diabetes status.

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