Blood Pressure BasicsMonday, January 12, 2015
If you have diabetes, “knowing and controlling your numbers” is not just about blood glucose (blood sugar) control. It is also important to know your blood pressure numbers. This blog will explore what blood pressure is and why it is so important for someone with diabetes to have it under control. Current guidelines for recommended blood pressure values will also be discussed.
What is blood pressure?
Blood pressure values are measurements taken to determine the pressure exerted when blood flows through our arteries. Two numbers are displayed (one over another) when blood pressure readings are noted. The top number is called the systolic blood pressure. This is a measurement of the pressure in the arteries as the heart contracts or pumps. This is the higher of the two numbers. The diastolic pressure (the bottom number) is the measurement of pressure as the heart relaxes and fills with blood before it is pumped throughout the body. (1)
An example of a blood pressure could be:
120/72 mm Hg (millimeters of mercury)
Why is controlling blood pressure so important for people with diabetes?
Experts tell us that cardiovascular disease (CV) is the leading cause of death in people with diabetes. When a person has diabetes, it has been found they also have a risk factor for CV. High Blood pressure (also called hypertension) is a major risk factor for CV. The American Diabetes Association has studied and shown the effectiveness of controlling blood pressure to help prevent or slow the progression of CV. Controlling blood pressure also decreases the risk for microvascular complications. (2) Microvascular complications are damage to small blood vessels. These may include retinopathy, nephropathy, and/or neuropathy.
New 2015 recommendations and target levels for blood pressure by the American Diabetes Association
1. People with diabetes should have a blood pressure check at every medical visit. If the reading is high, a reevaluation of the pressure should occur on another day. (2)
Sometimes people do not properly prepare for having their blood pressure taken. The National Institutes of Health (NIH) recommends the following for a proper evaluation of blood pressure:
- The person should be seated in a chair with their back supported. They should rest for at least 5 minutes before their blood pressure is checked.
- Legs should not be crossed and feet on the floor should be planted on the floor
- Their arm should be supported at the level of the heart for arm measurements
- The arm should be bare.
- The person should not have their blood pressure taken immediately after exercise, or within 30 minutes of using a tobacco product or consuming a drink or food with caffeine. (3)
Other factors that may give an inaccurate blood pressure include:
- Talking or listening while getting a pressure taken
- Having a full bladder
- Using an inaccurate blood pressure cuff size (4)
Cuff size is determined by arm diameter. Arm circumference should be measured at the midpoint between the shoulder and your elbow. Blood pressure UK recommends the following cuffs for different adult upper arm circumferences:
|7.1-8.7 inches (18-22 cm)||
|8.8-12.8 inches (22-32 cm)||Medium|
|12.8-18 inches (32-45 cm)||Large|
If you are instructed to take your blood pressure at home with a cuff, bring the cuff into the doctor’s office to make sure it is calibrated correctly and that you understand the correct procedure for measuring blood pressure. If the cuff calibration is incorrect, call the manufacturer of the cuff to see if they can correct the problem. Home blood pressure cuffs have various recommendations for upper arm circumferences. Make sure your arm circumference fall into the guidelines before purchasing the cuff. If your health care provider determines you should not have pressure placed on your upper arms for health care reasons, blood pressure can be measured in other places such as the ankle. (6) Ask your healthcare team for guidance for special needs.
2. Your doctor should determine your blood pressure goals. The American Diabetes Association recommendations for people who are not pregnant with diabetes and hypertension should be treated to a systolic blood pressure (upper number) of 140 mmHg and a diastolic blood pressure of 90 mmHg. Therapy should include lifestyle changes if needed and medication. These goals may be too high if an individual is able to get to lower goals such as 130/80 without undue burden or if your doctor determines this will benefit certain conditions such as chronic kidney disease. It may also be advised for people with a long life expectancy to have lower goals. (2)
Ask your doctor if the pressure you measure is high, how high should be a concern such that you should seek immediate medical help. The American Heart Association recommends immediate action when blood pressure is over 180 mm Hg (systolic) or 110 mm Hg (diastolic) when these readings are found twice within a few minutes of each other. (7)
Lifestyle goals should be determined by your health care team. If needed, weight loss and following a meal plan such as the Dietary Approaches to Stop Hypertension (Dash) diet is sometimes recommended. This plan stresses reducing sodium (from table salt and processed foods) and increasing potassium containing foods. Your doctor and dietitian can advise you on the amounts of dietary sodium that you should consume. Increasing exercise and moderation in alcohol consumption should also be included as a lifestyle change when needed. (2)
3. For non-pregnant adults with hypertension and diabetes, the American Diabetes Association recommends medications in the angiotensin converting enzyme inhibitor (ACE) or angiotensin receptor blocker (ARB) classification as appropriate. It is not unusual for a person with diabetes and hypertension to require more than one type of blood pressure medication to achieve control. It is also recommended to take at least one antihypertensive medication at bedtime to help control blood pressure while sleeping. Ask your doctor for guidance. (2)
People with diabetes need to take special care to control their blood pressure. Ask your physician if you need help to control this very important number.