Skip Ribbon Commands
Skip to main content

Diabetes Mellitus

​Diabetes Mellitus: What is it

Diabetes mellitus, usually simply called ‘diabetes’, is a condition of abnormally high blood glucose. If levels are sufficiently high, the glucose begins to filter through the kidneys and appears in the urine. Urine-attracting ants may be the first sign that something is wrong. In fact ‘mellitus’ is a Latin word denoting sweet urine.

At least 11 percent of Singaporeans have diabetes. Singapore has been found to have fourth highest diabetic rate in the world. With rising affluence, this is a trend in Asian countries.

What is glucose ?

Glucose, the type of sugar that exists in our blood, is the chief source of fuel for energy for our body cells. It is derived from carbohydrates such as rice, bread, noodles and table sugar (sucrose). Insulin, a hormone produced by the pancreas, is needed to transport glucose into cells from the blood.

What is a normal level?

Normally, glucose levels are maintained within narrow limits 4-5.5 mmol/L before food and up to 7 mmol/L two hours after eating. In diabetes mellitus, this control of blood glucose levels is lost, resulting in many undesirable effects on the body.

How does diabetes mellitus (DM) develop?

There are two distinct types of DM.

Type 1

In Type I, the pancreas is damaged by abnormal antibodies and cannot make insulin. Without insulin, glucose cannot be brought into cells and remains at a high level in the blood. The affected person, starved of energy, rapidly loses weight. As sugar holds water and brings it along into the kidneys and bladder, the patient passes large quantities of urine and consequently has excessive thirst and dehydration.

Type 1 DM patients require lifelong insulin injections. This type of DM is rare in Singapore but may be seen in Caucasian populations. It can occur suddenly at any age, even childhood.

Type 2

Almost all DM in Singapore is Type 2 DM. Here, there is sufficient insulin, but cells have developed a resistance to insulin due to long-standing dietary excesses causing more and more demand for insulin. Excessive fat also makes insulin act poorly.

Type 2 patients may not have the typical diabetic symptoms at all as they still have insulin. As such, diabetes may be present for years and cause damage to organ systems before it is ever detected by a blood test. In Singapore, 50 percent of patients have already some organ damage at the point of diagnosis.

Type 2 diabetes’ incidence increases with age, and those with a family history are more likely to develop it. Although associated with older people, with today’s consumption patterns, there is an alarming trend for patients to start developing it in their 20’s and 30’s or even earlier.

Consequences of uncontrolled diabetes

Many infections such as abscesses, chest and urine infections as well as fungal infections can be caused by uncontrolled diabetes. Many patients are diagnosed at the point when they seek medical attention for a severe infection.

Blindness can result from damage to the retina of the eyes. Cataracts form at a faster rate. High blood glucose also damages the kidneys. In Singapore, diabetes is the leading cause of kidney failure.

Atherosclerosis, which blocks off blood vessels, is caused by diabetes, together with high blood pressure, high cholesterol and smoking, (the four big villains). Heart attacks result when heart arteries are blocked; strokes when brain arteries are blocked; gangrene of feet when arteries to the legs are blocked. One or more amputations are carried out per day from diabetes In Singapore.

Poor wound healing, caused by poor blood supply due to narrowed blood vessels caused by advanced diabetes. One may hear someone saying ‘I am OK as my wounds heal well’. However, by the time poor wound healing occurs it may be too late. The ability to heal cannot be used as an indication whether diabetes is present or under control. Blood testing is still the required method to establish the status.

Diagnosis of Diabetes Mellitus

In Type 1 DM, severe symptoms drive the patient to the doctor. In Type 2 diabetes, the only sure way for diagnosis is by a blood glucose test.

Blood glucose above 7 mmol/L after an eight hour fast or 11.1mmol/L after a meal on two occasions indicates diabetes. Intermediate levels like fasting level of 6.1-6.9mmol/L or 7.8- 11.1 after meals indicates a likelihood of developing it in the future, a condition called prediabetes.

To ensure that the sugar levels have been ideal on a daily basis and not only on the day of the doctor’s visit, another blood test, HbA1C is done which reflects the average control over three months. A well-controlled diabetic must have an ideal level of HbA1C, as protection of organs from damage can only be possible if blood sugars are maintained consistently everyday and not on and off.

Managing diabetes

The cornerstone of diabetic management is:

  • Dietary control
  • Restricting carbohydrates
  • Calories
  • Meal sizes
  • Getting enough fibre

Various diabetic tablets may be prescribed for Type 2 diabetes. Insulin may be required in advanced cases of Type 2 diabetes. It is advantageous for diabetics to invest in a home blood glucose meter to monitor themselves.

Glucose levels in diabetics can also fall too low (hypoglycaemia) for example if a person takes their medication and then did not have their meal. Sugar needs to be consumed immediately in such an emergency.

How to avoid diabetes and its complications

  • Going for a blood test annually can determine if you have developed diabetes or prediabetes. The earlier the diagnosis, the better the outcome.
  • A balanced diet modest in carbohydrates, regular exercise and weight management can prevent diabetes altogether or prediabetes from developing into diabetes.
  • For the established diabetic, excellent control can prevent the tragic complications of heart attacks, strokes, foot gangrene, blindness and kidney failure. Good medical care includes surveillance for all these conditions besides blood glucose monitoring.

Please consult your Family Doctor if you have any concerns about your health.

Specialist services available at the following SingHealth institutions:

Singapore General Hospital
Tel: 6321 4377