Blood Pressure Control in People with Type 2 Diabetes Mellitus: Recommendations from the American College of Physicians

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The summary below is from the full reports titled "The Evidence Base for Tight Blood Pressure Control in the Management of Type 2 Diabetes Mellitus" and "Treatment of Hypertension in Type 2 Diabetes Mellitus: Blood Pressure Goals, Choice of Agents, and Setting Priorities in Diabetes Care." They are in the 1 April 2003 issue of Annals of Internal Medicine (volume 138, pages 587-592 and pages 593-602). The first article was written by V. Snow, K.B. Weiss, and C. Mottur-Pilson for the Clinical Efficacy Assessment Subcommittee of the American College of Physicians; the second article was written by S. Vijan and R.A. Hayward.

Who developed these guidelines?

The American College of Physicians developed these recommendations. The College is the second largest medical association in the United States. College members are internists, specialists in the care of adults.

What is the problem and what is known about it so far?

Diabetes mellitus is a common disease that interferes with the body's ability to store energy from food. The pancreas makes a substance called insulin that helps to store energy from food. In type 2 diabetes mellitus (also called adult-onset diabetes), the body makes plenty of insulin but is unable to use it normally. The result is high blood sugar levels that, over time, can lead to complications that include blindness, kidney failure, nerve damage, and heart disease. Fortunately, good care to keep blood sugar under control can prevent the development of these complications. The control of blood pressure also is extremely important in preventing diabetes complications and death.

How did the College develop these recommendations?

The authors reviewed studies about blood pressure and cardiovascular complications and death in people with type 2 diabetes. They used these studies to identify the benefits of blood pressure control, the ideal blood pressure levels, and the most effective blood pressure drugs in people with this disease.

What did the authors find?

Three high-quality studies about the benefits of blood pressure control in type 2 diabetes showed that controlling blood pressure decreases heart disease, stroke, and early death. Another two studies showed that people with type 2 diabetes do best if their diastolic blood pressure (the second number in blood pressure readings) is less than 80 mm Hg. Systolic blood pressure (the first number in blood pressure readings) was less well studied. However, the studies suggested that doctors should aim for systolic blood pressure less than 135 mm Hg. The studies that evaluated the various blood pressure drugs showed that people with type 2 diabetes and high blood pressure do best when they take angiotensin-converting enzyme (ACE) inhibitors and thiazide diuretics. Angiotensin-receptor blockers are a good option in patients who do not tolerate ACE inhibitors. In one large study, patients who self-reported their ethnicity as "black" did better with thiazide diuretics. Other types of blood pressure drugs include calcium-channel blockers and ß-blockers. The studies underscored the fact that most patients with type 2 diabetes need more than one drug to control blood pressure.

What does the College suggest that patients and doctors do?

Doctors and patients should be aware that treating high blood pressure in patients with type 2 diabetes dramatically decreases patients' risk for heart disease, stroke, and early death. Patients with type 2 diabetes should aim for blood pressure levels less than 135/80 mm Hg. Angiotensin-converting enzyme inhibitors and thiazide diuretics should be the first drugs that doctors prescribe to control blood pressure in patients with type 2 diabetes.

What are the cautions related to these recommendations?

Even in the best-designed studies, most patients did not reach target blood pressure levels with just one drug. It is important for patients to understand that they will probably need to take more than one medication to adequately control their blood pressure.