High blood pressure

High blood pressure: an introduction

High blood pressure or hypertension is common in people who have diabetes, affecting almost three-quarters of people with the disease.1 What’s more, people with hypertension are two and a half times as likely as those with normal blood pressure to develop diabetes sometime in the near future (within 5 years). What this means for you if you have type 2 diabetes is that by controlling your high blood pressure, you can reduce your risk for cardiovascular disease and a range of negative health outcomes (such as heart disease and stroke) linked to elevated blood pressure.2

For this reason, guidelines from the American Diabetes Association (ADA) and the American Heart Association (AHA) outlining care for people with diabetes who also have hypertension recommend maintaining good control of blood pressure. You have quite a few powerful tools for helping you achieve this goal of controlling your blood pressure, including healthy lifestyle changes (a healthy eating plan, regular physical activity, and weight loss) and blood pressure medication, as needed.3

What is high blood pressure?

High blood pressure is defined as the force or pressure exerted against the walls of arteries by blood as it is pumped by the heart throughout the body. When we measure blood pressure, we take two readings, one while the heart muscle is contracting (this is called systolic blood pressure [SBP]) and the other when the heart is at rest, between beats or contractions (this is called diastolic blood pressure [DBP]). Blood pressure readings are shown with the SBP first (the upper number), followed by the DBP (the lower number), and given in millimeters (mm) of mercury (Hg), or mmHg, a standard measure of pressure (for example 120/80 mmHg).4,5

  • Normal blood pressure: less than 120/80 mmHg
  • Early high blood pressure: 120/80 mmHg to 139/89 mmHg
  • Hypertension:
  • Stage 1: /90 mmHg to 159/99 mmHg
  • Stage 2: 160/100 mmHg or greater

What causes hypertension?

Although we don’t have a clear understanding of the precise cause or causes of hypertension (where it does not result from some primary cause, such as a medication or health condition), a number of factors that contribute to hypertension have been identified. These include changes in the part of the nervous system that controls the tone and contractility of blood vessels, changes in levels of hormones and other chemicals in the bloodstream that control blood pressure, genetic factors, and kidney function.4

In people with diabetes, several factors that contribute to the development of hypertension have been identified. These include6:

  • Kidney disease
  • Being overweight or obese
  • Taking too much insulin
  • Expansion of fluid in the body and retention of sodium, which may be caused by high blood sugar and insulin
  • Stiffness of arteries

We do know that certain factors increase you risk for hypertension. These include:

Hypertension is associated with a range of health problems

If you don’t get your hypertension under control, it can contribute to the development of long-term complications, including kidney disease, heart disease, and vision problems4,6

Hypertension is also often accompanied by atherosclerosis or hardening of the arteries, in which fatty deposits called plaques form on the interior walls of the arteries and other changes take place in the arteries causing them to become thickened, narrowed, and less resilient. It is recognized that high blood pressure can contribute to the development of atherosclerosis.4,6

What are the symptoms of hypertension?

What makes uncontrolled high blood pressure so dangerous is that it is often a “silent” condition. That is, it often occurs without any symptoms.

How high should my blood pressure be?

People with diabetes (who do not have kidney complications) should maintain blood pressure below 140/80 mmHg. Blood pressure below 130/80 mmHg may be appropriate for certain patient groups. Talk to your doctor about what your blood pressure target should be.5

What treatment options are there for helping me lower my blood pressure?

There are several effective treatment options for helping you lower your blood pressure and achieve your healthy blood pressure target.

Lifestyle changes. There are several lifestyle changes that you can make to counteract the factors that contribute to high blood pressure. These include2,7:

  • Decrease the amount of sodium you eat and drink (salt, which contains 40% sodium and 60% chloride is our main source of dietary sodium
  • Losing weight and keep it off (if you are overweight or obese)
  • Quitting smoking
  • Getting regular exercise of moderate intensity (at least 30 minutes a day, most days of the week)
  • – If you drink alcohol, don’t drink to excess: for men, more than 2 drinks per day (2 12 oz beers, 10 oz wine, or 3 oz 80-proof whiskey), and for women and lighter-weight men, more than 1 drink per day

Lifestyle modifications for lowering high blood pressure

Lifestyle change

Recommendation

Potential systolic BP reduction

Weight loss Achieve normal body weight (body mass index [BMI] 18.5-24.9 kg/m2) 5-20 mmHg/10 kg
DASH eating plan Eat diet rich in fruits, vegetables, low-fat dairy products 8-14 mmHg
Reduced dietary salt Decrease intake to no more than 2.4 grams sodium or 6 grams sodium chlorides 2-8 mmHg
Regular exercise Get regular aerobic exercise (any physical activity that increases your heart rate and breathing rate) for 30 min per day, most days of the week 4-9 mmHg
Moderate alcohol consumption Limit alcohol consumption to no more than 2 drinks (eg, 24 oz beer, 10 oz wine, or 3 oz 80-proof whiskey) per day in most men and 1 drink per day in women and lighter weight persons 2-4 mmHg

DASH=Dietary Approaches to Stop Hypertension.

Adapted from Chobanian AV, Bakris GL, Black HR
et al. Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206-52.

Medication. If lifestyle changes alone do not help you achieve your target blood pressure, there are medications (called antihypertensives) that are effective at reducing blood pressure. Antihypertensive that are commonly used lower blood pressure include four different classes or types of medications:

  • Diuretics
  • Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs)
  • Calcium channel blockers
  • Beta blockers

Your doctor will help determine which of these medications (or which combination of them) is most appropriate for you.

Written by: Jonathan Simmons | Last reviewed: May 2014.
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