High blood pressure sharply increases the risk of heart attack, stroke, heart failure, and kidney failure

Harvard Health Letters

Hypertension is one of the most common medical problems in the U.S.; at present, one of every American adults has high blood pressure. It's a shame since many, if not most, cases could be prevented by simple lifestyle measures such as dietary salt restriction, weight control, and moderate exercise.

Hypertension is also one of the most important medical problems in America; it sharply increases the risk of heart attack, stroke, heart failure, and kidney failure. That's also a shame, since excellent drugs are available to lower blood pressure and prevent these deadly complications.

You don't have to bring your pressure down to normal (below 120/80 millimeters of mercury) to get the benefit of treatment. Simply lowering an elevated blood pressure to modest treatment targets (below 140/90 for people without certain complicating conditions; below 130/80 for those with diabetes, kidney disease, heart failure, or atherosclerosis) can cut the risk of heart attack and stroke by about 34 percent and 21 percent, respectively.

But the biggest shame of all is that only about 44 percent of hypertensive patients reach these goals.

There are many explanations for these sorry results. A study highlights one of the most important reasons: poor adherence to medication regimes.

THE STUDY

Researchers in Italy obtained information from 400 primary care physicians to identify 18,806 patients ages 35 and older who were first diagnosed with hypertension during 2000 and 2001. None of the patients had been diagnosed with coronary artery disease, heart failure, or cerebrovascular disease when they entered the study; the scientists followed the patients for an average of 4.6 years to track the onset of these complications.

All patients in the study received prescriptions for one or more effective antihypertensive medications. Based on how often they filled their prescriptions, the patients were classified into three adherence levels: high (pills on at least 80 percent of days), medium (40 percent to 79 percent), or low (below 40 percent).

At the start of the study, only 8 percent were in the high-adherence group; by the end of the study, 19 percent achieved this level. Intermediate adherence fell from 41 percent to 32 percent, and low adherence was stubbornly high, declining only minimally from 51 percent to 49 percent.

Did adherence matter? It sure did. As compared with their low-adherence counterparts, the high-adherence patients enjoyed a 38 percent lower risk of acute cardiovascular events during the study period.

PERSPECTIVES

Although previous research has demonstrated that good adherence to medication results in lower blood pressure readings, fewer hospitalizations, and lower medical costs, the study is one of the first to document reduced cardiovascular events. Curiously, though, the study did not provide information on blood pressure readings, nor did it rate the patients according to their adherence to the lifestyle changes that can also lower blood pressure. Despite these limitations, the research serves to emphasize the importance of compliance with medication.

In randomized clinical trials of anti-hypertensive therapy, only 5 percent to 10 percent of motivated, supervised volunteers discontinue their medications over the course of a year, but in real world clinical practice, discontinuation rates can be 50 percent or higher within just six months. But why?

Doctors often blame their patients, but physicians who fail to explain the importance of continually taking medication, long-term lifestyle changes, and careful blood pressure monitoring and follow-up surely deserve some of the blame. And patients are often discouraged by complex medication schedules, expensive drugs, or both.

Above all, perhaps, medication can produce side effects; these are usually mild, and they can be reduced or eliminated by adjusting treatment -- but since most patients with newly diagnosed hypertension feel perfectly well, they may be reluctant to put up with short-term discomfort for long-term gains.

We can all do better. And this study points out the way to start: Take your pills.

Harvard Men's Health Watch

Twitter: @ihavenet

 

Available at Amazon.com:

Last Child in the Woods: Saving Our Children From Nature-Deficit Disorder

No More Digestive Problems

Nutrition at Your Fingertips

 

 

Copyright © 2011 Harvard Health Letters