BLOOD PRESSURE MANAGEMENT

Cardiovascular disease is the leading cause of death in the United States. We have known for many years that uncontrolled high blood pressure is one of two major factors (the other being atherosclerosis) that precipitate bad cardiovascular events. What we didn’t understand until the early 1990’s is that in people with diabetes high blood pressure has an even more profound impact to accelerate disease states than it does in non-diabetic individuals. The Diabetes Complications and Control Trial (DCCT) was the first of several studies that showed the importance of blood pressure control in this population. The most surprising finding for many physicians was that poorly controlled high blood pressure (HTN) actually was a stronger predictor of higher diabetic complication rates of all kinds than was poorly controlled blood sugar. And conversely, control of HTN had a greater effect at reducing diabetic complication rates than did control of high blood sugars! These findings have helped to change the way most physicians deal with HTN when seen in people with diabetes. Physicians need to be much more aggressive at controlling both the systolic (upper BP number) as well as the diastolic (lower BP number) blood pressure. The current recommendations are that ACTION needs to be taken when the BP rises above 130/80. In general, we would like to see the BP running in the range of 120/70 or less. This reduces the workload on the heart and reduces the stress on the circulation.

The causes of HTN are multiple and generally probably multi-factorial. Identifiable causes of HTN include aortic artery narrowing, kidney disease, primary hyperparathyroidism, Cushing’s syndrome, adrenal tumors, kidney tumors, and kidney artery narrowing. In most people with diabetes (> 90%), a specific singular cause is NOT present. For those individuals, it appears that multiple factors are contributing to the elevated pressure, including salt and fluid retention, excess weight, and genetic factors.

BP should be monitored at various times throughout the day. BP typically goes up when a person exercises, is stressed, angry, upset or anxious. BP tends to fall after exercise and with rest. To get a reliable range of blood pressure values, you should check your BP at different times throughout the day, even when you are stressed or upset. Under those circumstances, it’s O.K. for the BP to run somewhat higher, but not too high. If you’re going to have a cardiovascular event, it’s more likely to occur at those times, particularly if the BP is out of control.

There are many devices available on the market to check your BP. The most reliable method is with a blood pressure cuff (sphygmomanometer) and a stethoscope, listening for the change in sounds in the brachial artery as the pressure in the cuff falls. This is more difficult to learn, but these types of sphygmomanometers tend to be most accurate and rarely break down. Electronic sphygmomanometers are more popular, but more subject to error and break down. The only electronic sphygmomanometer you should purchase is one that fits over your upper arm. Electronic sphygmomanometers that fit over the wrist are significantly less reliable in measuring a correct reading. Those that fit over a finger are inaccurate and practically worthless.

Diet interventions to control HTN fall into two categories: weight loss and salt restriction. Weight loss tends to be associated with some diuresis (loss of salt and water) initially. Further weight reduction, however, will result in further drop in BP. Weight reduction diets are discussed in more detail elsewhere (see the Patient Information Section on Weight Loss). Salt restriction means reducing salt intake to generally less than 2000 mg (approximately 1 teaspoon of salt) per day. Significant salt restriction would be less than 1000 mg/day. Salt restriction is accomplished by reducing the amount of salt that you cook with, avoiding salty foods, foods preserved with salt, preserved meats, luncheon meats, canned foods, sauces and reducing the use of salt at the table. It is discussed in more detail in the Patient Information section of this web site under Low Sodium Diet. Be careful about using salt substitutes. Most of those are potassium salts instead of sodium salts. For many people on a restricted salt diet, taking too much potassium in their diet may raise the blood potassium levels above normal.

Exercise has also been shown to be helpful in reducing HTN. During exercise BP levels rise progressively. During rest after exercise BP levels fall to subnormal levels. Regular exercise seems to condition the heart to more effectively pump blood and may also help condition blood vessels to relax more when not exercising so as to lower the BP. The effect of regular exercise on lowering BP values lasts for days or weeks, but then will gradually wear off.

There are many drugs on the market for treating HTN. A list of common drugs, their trade and generic names, dosage, mechanism of action, and most common side effects is tabulated separately under “Commonly Used Medications”. Most people with HTN require more than one medication to control their BP level. Also, the need for BP medication typically increases as you get older. And, just like as is seen with diabetes control and diabetic complications, there is no sharp cut-off for risk reduction when lowering BP. For every further small incremental drop in BP there is a corresponding small decrease in the risk of adverse events. So the lower your BP the better you will be. Blood pressure medications are not cures. They are only treatment. Therefore, if you stop your BP medication, you can expect your BP to rise back up again. Some BP medications should not be stopped abruptly. That kind of action could potentially precipitate a rebound sharp rise in BP and lead to a stroke or heart attack.

Revised 8/08

 

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