HEALTH TOPICS A TO Z

WHAT IS DIABETES?

Diabetes is a chronic disease that occurs when the pancreas does not produce enough insulin, or alternatively, 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 1 diabetes (previously known as insulin-dependent or childhood-onset) is characterized by a lack of insulin production. Without daily administration of insulin, Type 1 diabetes is rapidly fatal.
• Symptoms include excessive excretion of urine (polyuria), thirst (polydipsia), constant hunger, weight loss, vision changes and fatigue. These symptoms may occur suddenly.
• Type 2 diabetes (formerly called non-insulin-dependent or adult-onset) results from the body’s ineffective use of insulin. Type 2 diabetes comprises 90% of people with diabetes around the world, and 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, once complications have already arisen.
• Until recently, this type of diabetes was seen only in adults but it is now also occurring in obese children.
• Gestational diabetes is hyperglycaemia which is first recognized during pregnancy.
• Symptoms of gestational diabetes are similar to Type 2 diabetes. Gestational diabetes is most often diagnosed through prenatal screening, rather than reported symptoms.

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.

DIABETES FACTS

• The World Health Organization (WHO) estimates that more than 180 million people worldwide have diabetes. This number is likely to more than double by 2030.
• In 2005, an estimated 1.1 million people died from diabetes.¹
• Almost 80% of diabetes deaths occur in low and middle-income countries.
• Almost half of diabetes deaths occur in people under the age of 70 years; 55% of diabetes deaths are in women.
• WHO projects that diabetes deaths will increase by more than 50% in the next 10 years without urgent action. Most notably, diabetes deaths are projected to increase by over 80% in upper-middle income countries between 2006 and 2015.

WHAT ARE COMMON CONSEQUENCES OF DIABETES?

Over time, diabetes can damage the heart, blood vessels, eyes, kidneys, and nerves.

• 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. After 15 years of diabetes, approximately 2% of people become blind, and about 10% develop severe visual impairment.
• Diabetic neuropathy is damage to the nerves as a result of diabetes, and affects up to 50% of people with diabetes. Although many different problems can occur as a result of diabetic neuropathy, common symptoms are tingling, pain, numbness, or weakness in the feet and hands.
• Combined with reduced blood flow, neuropathy in the feet increases the chance of foot ulcers and eventual limb amputation.
• Diabetes is among the leading causes of kidney failure. 10-20% of people with diabetes die of kidney failure.
• Diabetes increases the risk of heart disease and stroke. 50% of people with diabetes die of cardiovascular disease (primarily heart disease and stroke).
• The overall risk of dying among people with diabetes is at least double the risk of their peers without diabetes.

WHAT IS THE ECONOMIC BURDEN OF DIABETES?

Diabetes and its complications impose significant economic consequences on individuals, families, health systems and countries.

WHO estimates that over the next 10 years (2006-2015), China will lose $ 558 billion in foregone national income due to heart disease, stroke and diabetes alone.

HOW CAN THE BURDEN OF DIABETES BE REDUCED?

Without urgent action, diabetes-related deaths will increase by more than 50% in the next 10 years.

To help prevent type 2 diabetes and its complications, people should:

• Achieve and maintain healthy body weight.
• Be physically active - at least 30 minutes of regular, moderate-intensity activity on most days. More activity is required for weight control.

Early diagnosis can be accomplished through relatively inexpensive blood testing.

Treatment of diabetes involves lowering blood glucose and the levels of other known risk factors that damage to blood vessels. Tobacco cessation is also important to avoid complications.

Interventions that are both cost saving and feasible in developing countries include:

• Moderate blood glucose control. People with type 1 diabetes require insulin; people with type 2 diabetes can be treated with oral medication, but may also require insulin;
• Blood pressure control;
• Foot care.

Other cost saving interventions include:

• Screening for retinopathy (which causes blindness);
• Blood lipid control (to regulate cholesterol levels);
• Screening for early signs of diabetes-related kidney disease.

These measures should be supported by a healthy diet, regular physical activity, maintaining a normal body weight and avoiding tobacco use.

WHO ACTIVITIES TO PREVENT AND CONTROL DIABETES

WHO aims to stimulate and support the adoption of effective measures for the surveillance, prevention and control of diabetes and its complications, particularly in low and middle-income countries. To this end, WHO:

• Provides scientific guidelines for diabetes prevention;
• Develops norms and standards for diabetes care;
• Builds awareness on the global epidemic of diabetes; including partnership with the International Diabetes Federation in the celebration of World Diabetes Day (14 November);
• Conducts surveillance of diabetes and its risk factors.

The WHO Global Strategy on Diet, Physical Activity and Health complements WHO's diabetes work by focusing on population-wide approaches to promote healthy diet and regular physical activity, thereby reducing the growing global problem of overweight and obesity. The Strategy calls upon all stakeholders to take action at the global, regional and local levels and aims to lead to a significant reduction in the prevalence of diabetes and other chronic diseases.

WHO's work on diabetes is integrated into the overall WHO chronic disease prevention and control framework of the Department of Chronic Diseases and Health Promotion. The strategic objectives of the Department are to raise awareness about the global epidemic of chronic diseases; create healthy environments, especially for poor and disadvantaged populations; slow and reverse trends in common chronic disease risk factors such as unhealthy diet and physical inactivity; and prevent premature deaths and avoidable disability due to major chronic diseases.

¹ This would underestimate the true burden from diabetes.Although people may live for years with diabetes, their underlying cause of death is usually recorded as heart disease or kidney failure. An alternative estimate, taking into account deaths in which diabetes was a contributory condition, suggests that approximately 2.9 million deaths per year are attributable to diabetes.