What is diabetes?

Diabetes is a condition that occurs when the levels of glucose (sugar) in the body are too high, either because the body doesn’t produce enough insulin or the body doesn’t use the insulin it produces, effectively Insulin is a hormone necessary to carry glucose from the bloodstream into the cells where it is used for energy. If there is too little insulin or resistance to insulin, blood glucose levels continue to rise, because glucose is not removed from the bloodstream. There are 3 main types of Diabetes:
  • Type 1 (insulin-dependent), usually affects younger people
  • Type 2 (also known as maturity-onset or non-insulin-dependent diabetes), tends to develop gradually in adults and is much more common
  • Gestational Diabetes,  is high glucose levels only during pregnancy. This type of diabetes can be resolved after giving birth, but can also increase the risks of Type 2 diabetes developing later in life
You are more likely to develop diabetes if you have one or more of the following risk factors:
  • Overweight or obese
  • Physical inactivity
  • Unhealthy diet
  • Family history of diabetes
  • Previous diabetes in pregnancy (gestational diabetes)
It has been estimated that there are about 1 in 10 South Africans with diabetes, but roughly 1 in 2 of these individuals don’t know it because it has not been diagnosed!

How does diabetes affect your heart?

Heart disease and strokes are the leading cause of death in people living with diabetes. The constant high blood sugar causes damage and narrowing of the blood vessels, increased blood triglycerides (a type of fat), decreased levels of “good” HDL cholesterol, high blood pressure and increased risk of a heart attack or stroke. People living with diabetes are also more prone to the development of atherosclerosis and blood clots. Diabetes also accelerates the damage done by smoking, high blood pressure and high cholesterol. Diabetes can even affect the heart muscle itself, making it a less efficient pump. As diabetes can affect the nerves to the heart, symptoms of angina may not be felt in the usual way and may be passed off as indigestion or an upset stomach. This leads to delays and difficulties in diagnosing angina and heart attacks. As you can see, diabetes increases the risk of stroke and heart disease, especially if other risk factors are already present. The risks multiply! The good news is that there are many things that you can do to control your diabetes, reduce your risks and stay healthy.

A screening or finger prick blood test can be done at a clinic or pharmacy to give you a snapshot of how high your blood sugar level is. However, a formal diagnosis requires a blood test and sometimes this will need to be repeated twice.

Fasting blood glucose test

Ideally a blood glucose test should be done in the morning after not eating or drinking anything but water since the previous evening. This is called a fasting blood glucose test. A fasting blood glucose level:

  • < 5.6 mmol/l – normal and rules out diabetes.
  • ≥ 7 mmol/l confirmed by 2 tests repeated on separate days within a two-week period – can diagnose diabetes.
  • 6 – 6.9 mmol/L – impaired fasting glucose, which means the person is at risk for future diabetes.

Random blood glucose test

A random blood glucose test is a test conducted at any time of the day in a non-fasting state. This can be used to diagnose diabetes if the blood glucose value is over 11.1 mmo/L and there are other symptoms of diabetes present. A random blood glucose test on its own cannot rule out diabetes unless your blood glucose level is <5.6mmol/l.

Oral glucose tolerance test

Often one blood test is insufficient to confirm a diagnosis of diabetes, and the test may need to be repeated again or a doctor or nurse may request an oral glucose tolerance test, which involves drinking a sugary liquid and monitoring how blood glucose levels change over the next few hours.


A blood test for HbA1c levels can also be used to diagnose diabetes, and a level of 6.5% or above can confirm diabetes.

Although there is no cure for diabetes, with careful monitoring and healthful lifestyle changes, people living with diabetes can avoid complications and enjoy a long, productive life. To reduce your risk of cardiovascular disease, learn all you can about the condition.

A healthy diet is one of the best ways to control blood sugar and reduce the risk of developing complications. Remember that a person living with diabetes doesn’t need special products, and that choosing available healthy foods is the best approach.

  • Eat a healthy, balanced diet with small, regular meals, which will help to regulate your blood sugar levels.
  • Eat high fibre foods. High fibre starches will help to control your blood sugar levels. Increase daily dietary fibre intake by choosing high fibre whole-grain options, eating at least 5 fruit and vegetables daily and including a wide variety of legumes such as beans, peas, lentils and soya.
  • Limit added sugars such as sweets, chocolates, sweetened soft drinks, fruit juices, flavoured water and milky drinks, especially if your blood triglycerides are high. Artificial sweeteners can be used instead of sugar, and are safe when used in moderate amounts.
  • Cut down on sodium and salt. A high salt intake is linked to high blood pressure. Reduce your salt intake to no more than 5g (1 level teaspoon) of salt, from all sources, a day:
    • Reduce the salt added to your food during cooking and at the table.
    • Make use of fresh and dried herbs, spices, garlic or lemon juice to add flavour to your food, without adding extra salt or salty seasoning like chicken or BBQ spice.
    • Foods like packet soups, stock cubes, gravies, cheese, many breakfast cereals, breads, salty snacks, processed meats and fast foods are very high in salt, so should be used sparingly.
  • Choose healthier fats:
    • Cut down on unhealthy fats like saturated and trans fats which can raise blood cholesterol levels. These can be found in foods such as fatty and processed meats, chicken skin, butter, ghee, cream and hard cheeses, pies, pastries, biscuits, crackers, fast foods and deep-fried potato or slap chips.
    • Replace these with healthier fats such as mono- and polyunsaturated fats found in sunflower, canola or olive oil, soft tub margarines, peanut butter, nuts and seeds, avocado and fish.
    • Choose foods high in omega 3 fats which are good for your heart and can help to improve cholesterol levels. Including fish, especially naturally oily fish such as sardines, pilchards, mackerel and salmon, which should be eaten at least twice a week.
  • Drink alcohol carefully. Alcohol can affect blood sugar levels, so it is recommended that it is consumed with food to prevent hypoglycaemia. For those who choose to drink alcohol should do so in moderation. Moderation equates to no more than one drink a day for women and two for men.
  • Portion with caution. Try to portion your plate according to the ‘Plate Model’ where:
    • ½ of your plate consists of non-starchy vegetables such as broccoli, cabbage, tomatoes, cucumber, carrots etc.
    • ¼ of your plate consists of high fibre starches such as brown rice, whole-wheat pasta, sweet potato, butternut.
    • ¼ of your plate consists of lean protein such as grilled skinless chicken, fish, lean mince, ostrich meat, soya.

For more advice, contact the Heart and Stroke Foundation SA on 021 422 1586 or email heart@heartfoundation.co.za

  • A healthy diet and medication, if necessary, is essential for control of blood sugar.
  • Monitor and check your blood glucose levels regularly, especially if you are taking insulin. Blood glucose levels should be between 4-7 mmol/l in a fasting state. A health care professional can provide an individual target for ideal blood glucose levels two hours after a meal.
  • Be smoke-free. Quit smoking and avoid second-hand smoke.
  • Check your blood pressure regularly and keep it below 140/90 mmHg. If you already have high blood pressure your doctor may recommend an individual blood pressure target for you.
  • Check and manage your cholesterol levels. Your goal should be:
    • Total cholesterol under 4.5mmol/l
    • LDL cholesterol of less than 1.80mmol/l
    • HDL cholesterol of over 1.2mmol/l in women and over 1.0 mmol/L in men
    • Triglyceride of less than 1.7 mmol/l
  • Achieve and maintain a healthy weight. Aim for a BMI of less than 25, and a waist measurement of less than 80cm for women, and under 94cm for men. If you are overweight, even losing 5 to 10% of body weight can improve blood sugar control, blood cholesterol and blood pressure.
  • Get active. Be physically active for at least 150 minutes a week e.g. 30 minutes five times a week, by doing moderate- to vigorous-intensity aerobic physical activity.
  • Manage stress. Stress is a normal part of life but too much may be bad for your blood pressure. Find healthy ways to cope with your stress such as exercising, doing something you enjoy such as having a warm bath, socialise or speak to a friend. Avoid unhealthy ways of coping with stress such as smoking, poor food choices or alcohol abuse.
  • Look after your feet. Report any cuts or problems to your doctor or nurse as soon as possible.
  • Have an annual check-up with your doctor to check your long-term glucose control, blood pressure, cholesterol, weight, general circulation and that you are not developing any of the common complications of diabetes.

Symptoms are a result of having too much glucose (sugar) in the blood and not enough in the cells of the body. Symptoms vary from individual to individual and elderly people may not present any symptoms. Some of the symptoms may include:

  • Constant thirst
  • Passing more urine than normal
  • Tiredness
  • Unexplained weight loss
  • Blurred vision
  • Regular episodes of thrush

In uncontrolled diabetes, high levels of glucose over many years can damage many different parts of the body:

  • Aggravates atherosclerosis in the heart and blood vessels (hardening and narrowing of blood vessels by fatty deposits), causing coronary artery disease, stroke and blood circulation problems.
  • Eye damage, causing reduced vision which may lead to blindness
  • Kidney disease and kidney failure
  • Ulcers, infections, or gangrene in the feet
  • Nerve damage causing loss of sensation, especially in the feet and legs; pins and needles; and impotence