In Canada, about one in three adults has high blood pressure, also known as hypertension (HTN). People who have diabetes have a greater risk of developing it. Once HTN develops, it usually lasts a lifetime. However, you can prevent and control it by taking action.
Definition of high blood pressure
Blood pressure is the measure of the force of blood as it pushes against the walls of the arteries. The arteries are the blood vessels that carry blood full of oxygen away from the heart. When the heart contracts to pump out blood, the pressure in the arteries is the highest. This is systolic blood pressure (SBP). After pumping, the heart relaxes and the pressure drops to its lowest point just before a new beat. This is diastolic pressure (DBP).
Blood pressure is measured in millimetres of mercury (mm Hg). It is recorded as two numbers. The first number is the systolic blood pressure, and the second number is the diastolic blood pressure. As an example, a systolic pressure of 120 mm Hg, and a diastolic pressure of 80 mm Hg is written as 120/80. Normal blood pressure ranges from 100 to 139 systolic, and from 70 to 89 diastolic.
Before HTN is diagnosed, several measurements are taken over a period of time. High blood pressure cannot be diagnosed based on a single reading. For someone who does not have diabetes, high blood pressure is defined as systolic blood pressure greater than or equal to 140 mm Hg, or a diastolic blood pressure greater than or equal to 90 mm Hg. However, people who have diabetes should set an even lower blood pressure target of less than 130/80.
HTN is often called a silent disease. There are usually no symptoms to alert people that their blood pressure is high. High blood pressure does not make you feel sick. This is why regular visits to your health care provider are recommended in order to have your blood pressure checked.
Another way to monitor your blood pressure is to have a blood pressure machine at home. Home blood pressure units are easy to use and help avoid 'white coat' syndrome often seen at the doctor’s office. (This is when your anxiety from being at the doctor’s office causes your blood pressure to rise.)
If your high blood pressure remains undiagnosed, untreated or uncontrolled, you are at risk of complications. The high pressure is very hard on your blood vessels. This may put you at risk for some or all of the following.
This condition is mainly caused by fat deposits or cholesterol in the lining of the arteries (atherosclerosis). When these deposits (or plaques) of fat and blood cells build up, they cause blockages in blood flow in the arteries that supply the heart muscle with blood. This can lead to a heart attack. A stroke can occur when plaque breaks off in a blood vessel and travels to the brain. There it forms blockages in blood flow in the brain. An aneurysm is due to weakening or bulges in blood vessels, which can eventually burst. .
Diabetic nephropathy (kidneys)
Diabetic nephropathy is caused by narrowed or weakened blood vessels in the kidneys. It results in a slow and progressive loss of kidney function. It may also cause the loss of protein into the urine (proteinuria). This decrease in kidney function is referred to as chronic renal disease (CRD).
CRD is also thought of as a silent disease because it often goes undetected, with no warning signs. Only regular lab tests that check the urine for serum creatinine, urea, potassium and albumin can help your doctor assess your level of risk for this disease. If the kidney function declines to complete kidney failure, dialysis or kidney transplant is then required.
A group of blood pressure medications called ACE and ARBs inhibitors (see Table 1) can slow the progress of diabetic nephropathy and decrease the leaking of protein into urine. For this reason, people who have diabetes are encouraged to take these medications even if their blood pressure is normal.
Diabetic retinopathy is caused by the weakening, bulging and blocking of blood vessels in the eyes. The long-term effects can lead to damage of the retina, glaucoma and blindness.
Diabetic neuropathy (nerves)
Diabetic neuropathy is a complication of diabetes that causes temporary or permanent nerve damage. Symptoms can begin mildly with tingling, numbness or a burning sensation in the extremities – the legs, feet, arms and hands. This is known as peripheral neuropathy.
When the nerves that control your body systems are affected, this is known as autonomic neuropathy. This type of nerve damage can affect your bladder, stomach, intestines, heart, and sex organs. As a result, symptoms like incontinence, nausea, diarrhea, poor body temperature control, bloating, and vaginal dryness in women and problems with erections in men are all common. There are medications to treat symptoms of neuropathy. Ask your doctor or pharmacist for more details.
What can you do to try to avoid these complications? Keeping your blood glucose level and blood pressure within the target ranges recommended by your doctor or diabetes educator can help you delay or prevent most of these complications.
Optimal (tight) control of blood pressure reduces the risk of long-term complications. A major clinical research study (called UKPDS) was done with over 5000 people who had diabetes. It showed that people whose blood pressure and blood glucose were tightly controlled dramatically reduced their risk of suffering from heart disease, stroke, kidney disease, eye damage and death. This study also showed that half of people who were newly diagnosed with diabetes already showed signs of complications. But with optimal control over five years, people were able to maintain significant risk reduction in preventing these complications.
Therapy for high blood pressure
The safest way to control your blood pressure is to have a healthy lifestyle.
If these measures are not successful in achieving a target blood pressure of less than 130/80 mm Hg, medication may be needed. Sometimes, drug therapy may begin right when you are diagnosed if your blood pressure is very high or if complications are already present.
Many types of medications are available to reduce high blood pressure (see table on page 11). Each works in a different area of the body to lower blood pressure. This helps to individualize your medication therapy. If your blood pressure does not respond to a certain medication, using more than one medication may be required to meet your blood pressure goals.
Mechanism of Action
||Also called water pills, diuretics work by increasing the amount of water and salt lost in urine passed by the kidneys.||
|Angiotensin Converting Enzyme (ACE) Inhibitors||
||Ace inhibitors relax and widen the blood vessels by blocking the formation of angiotensin II, a hormone that causes blood vessels to narrow.||
|Angiotensin II Receptor Blockers (ARB)||
||Like the ACE inhibitors, this medication relaxes and widens blood vessels by blocking the formation of angiotensin II, a hormone that causes blood vessels to narrow.||
||Beta blockers reduce nerve impulses to the heart and blood vessels, making the heart beat slower and lowering the workload on the heart.||
||This medication relaxes blood vessels and reduces tension in the heart by keeping calcium from entering the vessels and muscle cells of the heart and blood vessels.||
||Alpha blockers reduce the workload on the heart by blocking nerve impulses to blood vessels.||
For people who have diabetes, control of high blood pressure is key in preventing complications. Unfortunately, survey research shows that up to one-third of people with diabetes do not know that they have high blood pressure. Another study shows that of people with high blood pressure, only half were taking drug therapy for the condition. Of those taking drug therapy, only about 60 per cent were within target levels.
It is extremely important to take action to control your blood pressure. The following suggestions can help you stay healthy and active.
Talk with your Sobeys / Safeway pharmacist about purchasing a blood pressure unit that best suits you.