Families touched by diabetes must learn to plan for every eventuality. If you are likely to be away from home past the time for a test and injection, the equipment must come, too. You have to consider traffic jams, car breakdowns and sudden changes in plans.
1. What is diabetes?
It is a disorder in which the body’s capacity to utilize sugar, fat and protein is disturbed. As poor utilization of sugar produces the most obvious symptoms and sugar is the most easily measured body fuel, it tends to receive the most attention – hence the term “sugar diabetes”. The medical name is diabetes mellitus.
The role of glucose
Like all living things, human beings require energy, and the major source of energy is glucose, a form of sugar. (Other sources of energy are fats and proteins.) Unlike plants, animals (including, of course, human beings) cannot manufacture glucose but must obtain it from the food they eat.
The glucose is absorbed in the bowel and then released into the blood. In the blood, it is carried to the cells and tissues, where it is used as a fuel to supply energy – the energy needed to keep all the bodily systems functioning as well as the energy we use in activity.
The glucose not immediately required is stored in the liver in the form of a starch called glycogen. This is released into the blood as required to provide energy between meals. Up to 150 g of glycogen can be stored in the liver. It can also be stored in the muscles, where it supplies energy for bursts of activity.
It is essential that the level of blood glucose remains within a certain range. One very important reason for this is that glucose is the brain’s sole source of energy, and if blood glucose falls and remains below a certain level, the brain is “starved” and will cease to function.
The role of insulin
Normally, the amount of glucose (or sugar) circulating in the blood is regulated by a substance called insulin, a hormone produced by the pancreas. Two important functions of insulin are to help glucose be absorbed from the blood into cells and to cause glucose to be stored in the liver and muscles in the form of glycogen. It also aids the build-up and storage of protein and fat.
One of the things that triggers the release of insulin into the blood is the amount of glucose circulating in the blood. When the level of blood glucose rises after a meal, the pancreas releases extra insulin to cause the glucose to be either used or stored, and the blood glucose level is then returned to normal. Fat and protein in the meal are also stored.
When the level of blood glucose falls, for example in starvation or after exercise, the pancreas releases less insulin, so that less glucose is removed from the blood. It also releases another hormone called glucagon, which has the function of breaking down the glycogen stored in the liver to glucose, so that this glucose can then enter the bloodstream. As a result of these two processes, the level of blood glucose rises to the normal level.
What goes wrong in diabetes?
Diabetes results when insulin fails to lower the blood sugar – either because the body does not produce enough (or even any) insulin or because the insulin does not function properly.
After a meal, diabetic people are therefore left with an excessively high level of blood glucose. Because of the lack of insulin, much of this glucose cannot reach the cells, where it is needed. The glucose is filtered through the kidneys, and the excess escapes into the urine, where its presence can be recognized by simple tests.
Unless supplied with insulin when it is grossly deficient, the body begins to draw on its reserves of fats and even proteins as a source of energy. The use of fats is dangerous in the long-term, because when fats are broken down excessively, acid substances called ketones are released.
If these accumulate in large quantity, they disturb body functions and produce a condition called acidosis (or ketoacidosis). When the body begins to use stored proteins as an energy source, this is equivalent to it feeding on itself. The muscles begin to waste and the person loses a great deal of weight and becomes very weak. Without insulin treatment in this situation, the diabetic would rapidly fall into a coma and die.
Types of diabetes
There are two types of diabetes, which have different causes, and to some extent, different symptoms.
One is juvenile onset or insulin-dependent diabetes, now called type 1 diabetes. This affects about one in six diabetics and usually starts before 30 years of age. The problem here is that the pancreas secretes little or no insulin, and without insulin injections, the person would go into a coma and die.
This type of diabetes arises suddenly, with symptoms of weight loss, thirst and frequent urination. The cause is uncertain, but there is increasing evidence that some people at least inherit a susceptibility to various factors including virus infections that cause damage to the pancreas.
The second type of diabetes is maturity onset or insulin-independent diabetes, now called type 2 diabetes. This type usually occurs in older, overweight people. There may be mild symptoms for many months or even no symptoms at all, the disorder being diagnosed by routine urine or blood sugar tests.
Correct diet is essential for insulin-independent diabetics, and often no other treatment is necessary.
The symptoms of diabetes type 1 and 2
The symptoms of juvenile onset (or type 1) diabetes usually include tiredness, excessive urination, thirst and loss of weight and may develop over several days or weeks. With the increase in blood sugar levels, the excess glucose spills into the urine. Glucose attracts water and therefore increases the volume of urine, which explains the thirst and frequent urination.
The tiredness, weakness and weight loss are caused by a combination of factors: glucose is not reaching the tissues; proteins, especially in the muscles, are being broken down; and water and salts are being lost in the urine. When the insulin deficiency is great, the body’s stores of fat are broken down excessively, leading to the over-production of acids called ketones. If untreated, these ketones accumulate to an alarming degree and eventually lead to acidosis and coma.
Although sometimes without symptoms, maturity onset (or type 2) diabetes usually makes itself known by thirst and excessive urination.
Sometimes, stress resulting from an infection, operation or accident, or some drugs widely (and wisely) used to treat high blood pressure and heart failure, may interfere with the body’s production of insulin or the action of the insulin, and trigger diabetes in a person predisposed to its development.
At other times, the symptoms of maturity onset diabetes relate to specific organs or systems; for example, there may be vaginal itching, caused by yeast infection (which is promoted by high glucose levels); blurred vision (due to a change in the shape of the lens of the eye); numbness or sensations of pins and needles in the limbs (due to the effect of diabetes on the nerves); or double vision (due to the effects of diabetes on the nerves controlling the movements of the eyeball).
Less commonly, blood vessel complications may be the reason the person visits the doctor; for instance, narrowing of the arteries and the resulting restriction of blood flow may cause pain in the calf muscles or chest during exercise (especially in diabetics who smoke), and evidence of disease in very tiny blood vessels may be found during detailed examination of the eyes or tests for kidney function. In such cases, it is assumed that the diabetic process started some years before it was diagnosed.
The easiest way of screening people without symptoms is to test the urine for glucose. (But note that the urine sample should not be taken first thing in the morning, as this is the least likely to contain glucose; the sample is best taken two hours after a meal.)
This test can be done with tablets or with test strips that change color if glucose is present. The presence of glucose in urine does not necessarily mean that the person has diabetes. Some non-diabetic people excrete glucose in the urine, despite having low blood sugar levels. This may also happen in normal pregnancy.
Conversely, elderly people with reduced kidney function may have high blood sugar levels while their urine remains free of sugar. For this reason, blood sugar levels must be measured as well.
The blood sugar is measured twice, either after an overnight fast or two hours after a meal. If both tests show a high level of blood sugar, diabetes will be diagnosed.
Where the results are borderline, a glucose tolerance test will usually decide the matter. This involves taking a blood test every half hour for two hours after drinking a glucose solution. If the results of this test are also borderline, the person would not be diagnosed as diabetic but would be strongly advised to remain under medical supervision, as diabetes could develop in the future.
2. Diabetes and general health
The treatment of diabetes results in a certain amount of inconvenience for diabetics and their families. The quantity and type of food they can eat may be restricted; meal times must be regular; tablets and/or insulin injections must be taken regularly; regular urine and/or blood tests are necessary.
Sustained blood sugar levels above or below the normal range may result in uncomfortable symptoms for the diabetic. In long-standing diabetes, such abnormal levels may contribute to the development of various complications.
High blood sugar
In the diabetic established on a treatment program, blood sugar levels will rise if food intake, particularly carbohydrate, is increased; if tablets or insulin are reduced or omitted; if physical activity is reduced (which means less energy is being used); or if the person is affected by illness or infection, or undue emotional stress.
Prolonged periods of high blood sugar can result in the symptoms of diabetes reappearing. They also make the person more susceptible to infections, particularly of the skin, bladder and urinary tract; women and girls are prone to vaginal thrush. Diabetics who do not obtain insulin when they need it may eventually develop acidosis which can result in coma.
Low blood sugar (hypoglycemia or insulin reaction)
If a diabetic has insufficient food or too much insulin, or is more active without taking extra carbohydrate to provide the extra energy required, the blood glucose level may fall.
This rarely occurs in people who are taking tablets for the treatment of their diabetes and does not occur in those whose diabetes is controlled by diet alone. (Insulin lowers the blood sugar more dramatically than these other methods.)
Warning symptoms of an undue fall in blood sugar include sweating, weakness, nervousness and tremor, palpitations and hunger. All these symptoms disappear promptly when glucose or a readily digested and absorbed carbohydrate food is taken by mouth (for example, fruit juice or a sweet soft drink).
Diabetics readily learn to recognize these early symptoms of hypoglycemia (sometimes known as a “hypo”) and are educated to carry an appropriate form of carbohydrate with them in order to treat the condition promptly. If these early symptoms are not heeded and corrected by taking sugar, brain function is depressed and the person becomes confused, behaves oddly and may fall into a coma. This rarely occurs in well-regulated diabetics. When it does occur, it requires prompt medical intervention and is readily treated.
Some people who have had diabetes for many years undergo tissue changes that make them more likely than the normal individual to develop certain illnesses and may reduce life expectancy.
The problems that occur most frequently are:
- hardening and narrowing of the large arteries (atherosclerosis), leading to heart disease, and sometimes, gangrene of the lower limbs.
- changes to very small blood vessels in the eyes, which can lead to impairment of vision – a condition known as retinopathy.
- a form of nephritis or kidney damage, where changes in very small blood vessels of the kidney cause loss of kidney function.
- a form of neuritis or nerve damage, which results in loss of nerve function in the affected area. (The danger here is that, with loss of sensation, injuries such as burns can be sustained without the person realizing it.)
These complications are currently thought to be the result of abnormal blood sugar levels and associated metabolic changes. Diabetic treatment is aimed at normalizing blood sugar levels so as to avoid such complications.
The aims of a diabetic diet are:
- To achieve the best possible nutrition in all age groups. This means that normal growth and development take place in childhood and adolescence; the unborn child and the breastfed infant develop satisfactorily; adults maintain desirable body weight.
- To prevent diabetic ketoacidosis and coma, which result from uncontrolled sugar and fat metabolism.
- To reduce the chronic complications that mainly affect the small and large arteries by controlling carbohydrate (sugar and starch) metabolism, fat metabolism and weight.
In general, dietary guidelines for diabetics are the same as those now recommended for all people. In 1979, an Australian working party of dietitians, doctors, nutrition scientists, educators, consumers and representatives of the food industry and government recommended the following dietary guidelines:
- Eat a variety of foods each day.
- Encourage breastfeeding.
- Prevent and control obesity.
- Decrease total fat intake.
- Decrease consumption of sucrose (refined sugar).
- Limit alcohol consumption.
- Increase consumption of breads, cereals, fruits and vegetables.
- Reduce sodium (salt) intake.
- Encourage water intake.
3. Special needs for diabetic patients
What is important for diabetics is that they be consistent from day-to-day as to when and how much they eat, the type of food they eat at particular mealtimes and how active they are. This makes insulin treatment more effective.
It does not mean that the same foods need to be eaten each day, for many foods contain similar nutrients.
Just over half the energy (calorie) intake of food should be obtained from carbohydrate. Carbohydrate foods containing dietary fiber – whole grain cereals, fruits and vegetables – are recommended. Such foods are generally rich in essential nutrients. Approximately one-fifth should be obtained from proteins, and the remainder will be derived from fats.
To keep blood sugar levels consistent, carbohydrate should be distributed throughout the day, taking into account the action of the insulin or tablets used, the pattern of physical activity and the individual’s food preferences. Individuals will be advised by their doctor.
Diabetics and alcohol
Diabetics may drink alcohol but it can lead to weight gain. The sugar content must also be taken into account; for example, liqueurs, sweet wines and beer have a high sugar content, which makes them unsuitable for diabetics.
It is better not to use artificial sweeteners (saccharin and cyclamate) and to develop instead a taste for savory foods. If artificial sweeteners are used, it should be noted that sorbitol is a nutritive sweetener (that is, it has calories and yields energy), while saccharin and cyclamate are non-nutritive (and so do not contribute to the energy intake).
A variety of diet charts is available for diabetics. It is best to discuss these with a doctor, dietitian or nurse familiar with the individual case.
The tablets used to control diabetes are called oral hypoglycemic agents and are taken by mouth. They are useful for people who make some insulin but not enough to control the blood sugar level by diet alone – most commonly the middle-aged and elderly. The tablets are not given in place of diet but are an additional treatment.
Some people with diabetes do not produce enough insulin from the pancreas. These are generally young, thin people. These people need insulin therapy all their lives, in order to replace directly what the body cannot produce. Diet alone or a combination of diet, and tablets will not control their blood sugar.
How insulin is used
A special syringe is used to draw up a measured dose and to inject the insulin. This comes with a very fine, short needle, since the insulin should be injected just underneath the skin (in other words, subcutaneously).
The injection is given just before a meal. Many people need only one injection of delayed-action insulin per day given before breakfast. Some need an injection both before breakfast and before the evening meal to control their diabetes properly over a full 24 hours.
The technique for drawing up and injecting insulin is best learned from a nurse educator or doctor, and it should then be practiced under supervision. It can be mastered surprisingly readily at all ages, even by children.
Urine tests: The glucose in urine can be detected by test strips or by tablets These react with glucose in the urine and change color according to the amount of sugar present.
Blood glucose tests: Chemically treated indicator papers have been developed to measure the glucose level in a drop of blood. The blood is obtained from the finger by a needle prick. The change in color that occurs on contact indicates the blood sugar level and is measured either by a meter or by comparing it with a color chart.
This test is easily done at home by diabetics themselves.
NOTE: In general, diabetics should not be limited in their daily activities. Practically all things are possible with a little care and planning.