(from the WHO website, www. who.int)
Fact Sheet N° 138
Reviewed November 1999
Recently compiled data show that
between 120 and 140 million people suffer from diabetes mellitus worldwide, and
that this number may well double by the year 2025. Much of this increase will occur in
developing countries and will be due to population ageing , unhealthy diets,
obesity and a sedentary lifestyle.
By 2025, while most people with diabetes in developed
countries will be aged 65 years or more, in developing countries most will be in the 45-64
year age range and affected in their most productive years
Diabetes mellitus is a chronic disease caused by
inherited and/or acquired deficiency in production of insulin by the pancreas, or by
ineffectiveness of the insulin produced. Such a deficiency results in increased
concentrations of glucose in blood which in turn leads to damage of many of the body's
systems, especially the blood vessels and nerves.
There are two principal forms of diabetes: Type 1, formerly
known as insulin-dependent, and Type 2, formerly named non-insulin dependent. In Type 1
diabetes, the pancreas fails to produce the insulin which is essential for survival. This
form develops most frequently in children and adolescents, but is being increasingly noted
later in life.
Type 2 diabetes is much more common and accounts for about
90-95% of all diabetes cases worldwide. This form of diabetes occurs almost entirely in
adults and results from the body's inability to respond properly to the action of insulin
produced by the pancreas.
Diabetes mellitus is a hereditary disease. Certain
genetic markers are known to increase the risk of developing insulin-dependent diabetes.
Such markers have not been described for non-insulin dependent diabetes, though this form
is strongly familial.
Symptoms: The symptoms of diabetes may be pronounced
or subdued. In Type 1 diabetes, the classic symptoms are excessive secretion of urine
(polyuria), thirst (polydipsia), weight loss and a feeling of lassitude. These symptoms
may be less marked in Type 2 diabetes. In this form, it can also happen that no early
symptoms appear and the disease is only diagnosed several years after its onset, when
complications are already present.
Diagnosis: Diabetes may be diagnosed on the basis of a
fasting blood glucose value, or the blood sugar level taken two hours after a 75g
challenge of glucose taken orally.
Insulin: It was discovered by Frederick Banting and
Charles Best in 1921 in Canada. This discovery revolutionized treatment of diabetes and
prevention of its complications. It transformed Type 1 diabetes from a fatal to a
treatable disease. Oral hypoglycaemic agents, diet and physical exercise are other
important components of treatment.
People with Type 1 diabetes are usually totally dependent
on insulin injections. Such people require daily administration of insulin. For them
insulin is a lifesaving medication. The majority of people suffering from diabetes have
the non-insulin-dependent form. However, up to 30% of them may use insulin injections
some, or all, of the time to control their condition.
Insulin is a costly medication and is unavailable or
unaffordable in many poor countries, despite being listed by WHO as an essential drug.
The price of insulin (without syringes and necessary
equipment for monitoring blood glucose levels) varies widely from country to country,
ranging from less than US$3 to US$22 a vial. The mean cost of a vial of insulin is lowest
in the Middle East (US$2.70) and Southeast Asia (US$2.80) with Africa (US$9.20) and South
and Central America (US$12.20) in the middle range. However, in many African countries the
cost of a vial of insulin may be the equivalent of a month's salary.
Complications: Recent research provides clear evidence
of the potential for adequate treatment to delay or even prevent the long term
complications of diabetes, which include blindness, kidney failure, heart attacks and even
gangrene and amputation of the limbs.
DIABETIC RETINOPATHY is the leading cause of
blindness and visual disability in adults in economically developed societies.
Findings, consistent from study to study, make it possible to suggest that, after 15 years
of diabetes, approximately 2% of people become blind while about 10% develop severe
Diabetes mellitus is associated with damage to the
small blood vessels in the retina, resulting in loss of vision.
Loss of vision due to certain types of glaucoma and
cataract may also be more common in people with diabetes than in those without the
Loss of vision and blindness in persons with diabetes can
be prevented by early detection and treatment of vision-threatening retinopathy: regular
eye examinations and timely intervention with laser treatment, or through surgery in cases
of advanced retinopathy. A recent study has demonstrated that good metabolic control can
also delay the onset and progression of diabetic retinopathy.
There is evidence that, even in developed countries, a
large proportion of those in need is not receiving such care due to lack of public and
professional awareness. In developing countries, in many of which diabetes is now common,
such care is inaccessible to the majority of the population.
Diabetes is a leading cause of RENAL FAILURE, but
its frequency varies between populations and is also related to the severity and duration
of the disease. Several measures to slow down the progress of renal damage have been
identified. They include control of hyperglycaemia, control of hypertension and
restriction of dietary protein. Screening and early detection of diabetic kidney disease
are an important means of prevention.
HEART DISEASE accounts for 75 % of all deaths among
people with diabetes in industrialized countries. Risk factors for heart disease in people
with diabetes include cigarette smoking, hypertension, hypercholesterolaemia and obesity.
Diabetes negates the protection from heart disease which pre-menopausal women, without
diabetes, experience. Recognition and management of these conditions may delay or prevent
heart disease in people with diabetes.
DIABETIC NEUROPATHY is probably the most common
complication of diabetes. Studies suggest that 50%, or more, of people with diabetes are
affected to some degree. Major risk factors of this condition are the level and duration
of hyperglycaemia. Neuropathy can lead to sensory loss and damage to the limbs. It is also
a major cause of impotence in diabetic men. This fact is often under-recognized. Foot care
is an important means of reducing the impact of diabetic neuropathy.
DIABETIC FOOT DISEASE ULCERATION FREQUENTLY LEADING TO
AMPUTATION is one of the most costly complications of diabetes, especially in
communities with inadequate footwear. It is a result of both vascular and neurological
disease processes. Diabetes is the commonest cause of non-traumatic amputation of the
lower limb, which may be prevented by regular inspection and good care of the foot.
Diabetes in pregnancy may give rise to several
adverse outcomes, including congenital malformations, increased birth weight and an
elevated risk of prenatal mortality. Strict metabolic control may reduce these risks to
the level of those of non-diabetic expectant mothers.
Diabetes is a serious disease which
is becoming increasingly common, especially in developing countries.
However, there are many ways of preventing
it and/or of controlling its progress. Early diagnosis and treatment are key factors.
Public and professional awareness of the
risk factors for, and symptoms of, diabetes are an important step towards its prevention