Diabetes is a common condition in which blood sugar levels are high. The reason is that the production of the hormone insulin is inadequate. Another reason is that the cells fail to respond to insulin. Diabetes is particularly common in older people and can affect up to 25% of them.

In Singapore 10% of our population have diabetes. Most Singaporeans suffer from type 2 diabetes. An important aspect of diabetes management is the control of blood sugar levels with medication or with insulin. It is important to understand the role of insulin and how the various oral medications work.

Diabetic treatment is not limited to just the control of blood sugar. Management includes the treatment of high blood pressure and elevated cholesterol, and preventing stroke, heart troubles, blindness and the amputation of limbs.

Good management must include education on dieting especially when the patient is overweight, exercise, medication and frequent monitoring of blood sugar levels. Good education should also promote an understanding of the most important complication of treatment – hypoglycaemia (low blood sugar).

The important cause of type 2 diabetes is being overweight (obesity) – eating too much and exercising too little. As such, diet control is important.

However, in many patients, diet and exercise alone are inadequate to lower blood sugar levels, in which case, medications become essential.

Oral anti-hyperglycaemic drugs are frequently used to treat patients with type 2 diabetes. These include biguanides, sulfonylureas, meglitinides, thiazolidinediones and glucosidase inhibitors.

Sometimes the doctor has to combine two or more of these oral medications.

These drugs work by stimulating the pancreas to produce more insulin. Others increase the body’s response to the insulin produced yet others block the intestine from absorbing the sugar.

Insulin for type 2 diabetes is given if oral drugs are unable to control blood sugar levels. In some countries, half of the patients with type 2 diabetes eventually require insulin.

There are four basic types of insulin in use:
 

1. Rapid-acting insulin: The fastest and shortest acting. Its maximum effect is 60 minutes and it lasts for three hours.

2. Short-acting insulin: Its maximum effect is three hours and it lasts for seven hours.

3. Intermediate-acting insulin: It starts in three hours, the maximum effect is eight hours and it works for 24 hours.

4. Long-acting insulin: It lasts for over 24 hours. The maximum effect is 18 hours.

Glargine, which is different from the other long-acting insulin, continues to have the same level of effectiveness throughout the day and has become a useful insulin.

These four types of insulin can be taken in a variety of ways and in a variety of combinations depending on the need of the individual patient. They can sometimes be combined with oral medications.

It is essential to understand that the objective of treatment is to maintain a normal level of blood sugar. It is also essential to understand that the blood sugar level would vary depending on the food eaten, on the exercise regime, on the stress level and on co-existing illnesses. All these factors may mean a variation of insulin.

Monitoring of blood sugar is essential as the blood sugar level changes by the hour. There must be a combination of diet, exercise and a record of blood sugar levels. Patients have to learn how to do that in consultation with the nurse, the health team or general practitioners. Patient education, diet and exercise are essential elements of drug therapy.

Lastly, an important danger of treatment especially with insulin is the development of hypoglycaemia (low blood level). If the blood level is too low, it is dangerous as the patient can go into coma and may even die.

Hypoglycaemia is a common complication with insulin injection. Sometimes, it occurs with sulfonylureas, especially glyburide and glipizide. Other oral medications do not usually cause hypoglycaemia.

Common symptoms include sweating, nausea, feeling warm, anxiety, shakiness, palpitations, hunger, headache, blurred or double vision, confusion and difficulty speaking, and these patients can be mistaken for taking alcohol as the symptoms are similar.

When the blood sugar level is too low, the patient may faint, develop stroke, go into coma or even die. Treatment then becomes urgent.

In conclusion, type 2 diabetes has become common. The good thing is with new oral medications and different types of insulin, most patients with diabetes can have their blood sugar under good control. The degree of control over a period of three months can be measured with a blood test known as haemoglobin A1C.

Ideally this should be at 6%, but 7% is acceptable. Any level over 8% indicates poor control.

The main objective of maintaining normal blood sugar levels is to prevent serious health complications. There is evidence that complications can be prevented and even if they develop, the progress can be slowed or even prevented from further development with proper control of blood sugar.

I wish to emphasise that one of the main problems is non-compliance – the patient does not follow the doctor’s instructions. This is mainly due to the lack of education.

One of the essential functions of the Diabetic Society of Singapore is to explain the condition to the patient and his relatives so that they have a better grasp of diabetes and its control. In this way, the patient will be more committed to controlling his own blood sugar.

We hope to build a good and strong group of educators who can function as trained nurses or lay people who are willing to volunteer to help by patiently and repeatedly explaining to patients the importance of maintaining normal blood sugar levels.

Prof Arthur Lim, MD (Hon), FRCS
Patron, Diabetic Society of Singapore