Diabetes is a chronic disease that occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. Insulin is a hormone that regulates blood sugar. Hyperglycaemia, or raised blood sugar, is a common effect of uncontrolled diabetes and over time leads to serious damage to many of the body’s systems, especially the nerves and blood vessels.

Type 2 diabetes

Type 2 diabetes (formerly called non-insulin-dependent, or adult-onset) results from the body’s ineffective use of insulin. More than 95% of people with diabetes have type 2 diabetes. This type of diabetes is largely the result of excess body weight and physical inactivity.

Symptoms may be similar to those of type 1 diabetes but are often less marked. As a result, the disease may be diagnosed several years after onset, after complications have already arisen.

Until recently, this type of diabetes was seen only in adults but it is now also occurring increasingly frequently in children.

Type 1 diabetes

Type 1 diabetes (previously known as insulin-dependent, juvenile or childhood-onset) is characterized by deficient insulin production and requires daily administration of insulin. Neither its cause nor the means to prevent it are known.

Symptoms include excessive excretion of urine (polyuria), thirst (polydipsia), constant hunger, weight loss, vision changes, and fatigue. These symptoms may occur suddenly.

Gestational diabetes

Gestational diabetes is hyperglycaemia with blood glucose values above normal but below those diagnostic of diabetes. Gestational diabetes occurs during pregnancy

Women with gestational diabetes are at an increased risk of complications during pregnancy and at delivery. These women and possibly their children are also at increased risk of type 2 diabetes in the future.

Gestational diabetes is diagnosed through prenatal screening, rather than through reported symptoms.

Prediabetes (Impaired glucose tolerance and impaired fasting glycaemia)

Impaired glucose tolerance (IGT) and impaired fasting glycaemia (IFG) are intermediate conditions in the transition between normality and diabetes. People with IGT or IFG are at high risk of progressing to type 2 diabetes, although this is not inevitable.

Health impact

Over time, diabetes is a serious disease and can damage the heart, blood vessels, eyes, kidneys, and nerves.

• Adults with diabetes have a two- to three-fold increased risk of heart attacks and strokes.

• Combined with reduced blood flow, neuropathy (nerve damage) in the feet increases the chance of foot ulcers, infection and eventual need for limb amputation.

• Diabetic retinopathy is an important cause of blindness, and occurs as a result of long-term accumulated damage to the small blood vessels in the retina.

• Diabetes is among the leading causes of kidney failure.

Prevention

Simple lifestyle measures have been shown to be effective in preventing or delaying the onset of type 2 diabetes. To help prevent type 2 diabetes and its complications, people should:

• achieve and maintain a healthy weight and body mass index

• be physically active – doing at least 30 minutes of regular, moderate-intensity activity on most days. More activity is required for weight control

• eat a healthy diet, avoiding sugar, simple carbohydrates and saturated fats

• avoid tobacco use – smoking increases the risk of diabetes and cardiovascular disease

• avoid high alcohol consumption

• prevent incidence of high blood pressure

• avoid high triglyceride (fat) levels in the blood. When it exceeds 150 milligrams per deciliter (mg/dL), it is too high

• lower risk of developing cardiovascular disease by managing well cardiovascular risk factors

• prevent incidence of gestational diabetes during pregnancy

• ensure prediabetes is not left untreated

• manage carefully polycystic ovary syndrome (PCOS). PCOS is characterized by polycystic ovary development. Those suffering from PCOS, can experience irregular menstruation, excessive hair growth and obesity, and are at greater risk of developing diabetes

• people belonging to ethnic groups at greater risk for diabetes like African Americans, Native Americans, Hispanics, and Asians should take additional care to prevent diabetes

• people over 45 years old should also take more care to prevent diabetes as diabetes type 2 is highly associated with older age. At age 45, the risk of type 2 diabetes begins to rise significantly, and increases even more past the age of 65

• those who have undergone an organ transplant may also take additional care. It is common that medication is needed to be taken for the rest of a person’s life after an organ transplant, so that the body does not reject the organ. Although these drugs improve the chances of organ transplantation, some of them, such as tacrolimus (Astagraf, Prograf) or steroids, can lead to diabetes or worsen it

• An abdominal fat distribution that is above the hips and thighs, as opposed to the hips and thighs, may indicate greater risk. Type 2 diabetes is more likely to occur in men who have a waist circumference of over 40 inches (101.6 centimeters) or in women who have a circumference of over 35 inches (88.9  centimeters)

• Family history. If a parent or sibling has type 2 diabetes, there is an increased risk of developing the condition

Diagnosis

Early diagnosis can be accomplished through relatively inexpensive testing of blood sugar.

Testing should be carried out in a health care setting (such as a doctor’s office or a lab). If the doctor determines that the blood glucose (blood sugar) level is very high, or if there are classic symptoms of high blood glucose in addition to one positive test, the doctor may not require a second test to diagnose diabetes.

A1C

The A1C test measures the average blood glucose for the past two to three months. The advantages of being diagnosed this way are that there is no need to fast or drink anything.

• Diabetes is diagnosed at an A1C of greater than or equal to 6.5% 

Normal less than 5.7%

Prediabetes 5.7% to 6.4%

Diabetes 6.5% or higher

Fasting Plasma Glucose (FPG)

This test checks fasting blood glucose levels. Fasting means after not having anything to eat or drink (except water) for at least 8 hours before the test. This test is usually done first thing in the morning, before breakfast.

• Diabetes is diagnosed at fasting blood glucose of greater than or equal to 126 mg/dl

Normal less than 100 mg/dl

Prediabetes 100 mg/dl to 125 mg/dl

Diabetes 126 mg/dl or higher

Oral Glucose Tolerance Test (OGTT)

The OGTT is a two-hour test that checks blood glucose levels before and two hours after drinking a special sweet drink. It tells the doctor how the body processes sugar.

• Diabetes is diagnosed at two-hour blood glucose of greater than or equal to 200 mg/dl

Normal less than 140 mg/dl

Prediabetes 140 to 199 mg/dl

Diabetes 200 mg/dl or higher

Random (also called Casual) Plasma Glucose Test

This test is a blood check at any time of the day when there are severe diabetes symptoms.

• Diabetes is diagnosed at blood glucose of greater than or equal to 200 mg/dl

Treatment

Diabetes care and disease control involve diet and physical activity along with lowering of blood glucose and the levels of other known risk factors that damage blood vessels. Tobacco use cessation is also important to avoid complications.

Interventions that are both cost-saving and feasible include:

• blood glucose control, particularly in type 1 diabetes. People with type 1 diabetes require insulin, people with type 2 diabetes can be treated with oral medications, but may also require insulin

• blood pressure control

• foot care (patient self-care by maintaining foot hygiene; wearing appropriate footwear; seeking professional care for ulcer management; and regular examination of feet by health professionals)

• screening and treatment for retinopathy (which causes blindness)

• blood lipid control (to regulate cholesterol levels)

• screening for early signs of diabetes-related kidney disease and treatment