(DM) or simply diabetes, is a group of metabolic
diseases in which a person has high blood
This high blood sugar produces the symptoms of frequent
thirst, and increased
hunger. Untreated, diabetes can cause many complications.
complications include diabetic
ketoacidosis and nonketotic
hyperosmolar coma. Serious long-term complications include
failure, and damage
to the eyes.
is due to either the pancreas
not producing enough insulin,
or because cells
of the body do not respond properly to the insulin that
There are three main types of diabetes mellitus:
1 DM results from the body's failure to produce
insulin. This form was previously referred to as "insulin-dependent
diabetes mellitus" (IDDM) or "juvenile diabetes".
2 DM results from insulin
resistance, a condition in which cells fail to use
insulin properly, sometimes also with an absolute insulin
deficiency. This form was previously referred to as
non insulin-dependent diabetes mellitus (NIDDM) or "adult-onset
diabetes, is the third main form and occurs when
pregnant women without a previous diagnosis of diabetes
develop a high blood glucose level.
and treatment often involve a healthy
exercise, not using tobacco,
and being a normal
pressure control and proper foot care are also important
for people with the disease.
Type 1 diabetes must be managed with insulin
Type 2 diabetes may be treated with medications with or
Insulin and some oral medications can cause low
blood sugar, which can be dangerous. A pancreas
transplant is occasionally considered for people with
type 1 diabetes who have severe complications of their
disease, including end
stage renal disease requiring kidney
They have had limited success Gastric
bypass surgery has been successful in many with severe
type 2 DM. Gestational diabetes usually resolves after
the birth of the baby.
as of 2013, an estimated 382 million people have diabetes
worldwide, with type 2 making up about 90% of the cases.
This is equal to 3.3% of the population with equal rates
in both women and men.
In 2011 it resulted in 1.4 million deaths worldwide making
it the 8th leading cause of death.
The number of people with diabetes is expected to rise to
592 million by 2035.
of the most significant symptoms of diabetes
classic symptoms of untreated diabetes are weight loss,
(increased thirst), and polyphagia
Symptoms may develop rapidly (weeks or months) in type 1
diabetes, while they usually develop much more slowly and
may be subtle or absent in type 2 diabetes.
high blood glucose can cause glucose absorption in the lens
of the eye, which leads to changes in its shape, resulting
in vision changes. Blurred vision is a common complaint
leading to a diabetes diagnosis. A number of skin rashes
that can occur in diabetes are collectively known as diabetic
(usually with type 1 diabetes) may also experience
episodes of diabetic
ketoacidosis, a type of metabolic problems characterized
by nausea, vomiting and abdominal
pain, the smell of acetone
on the breath, deep breathing known as Kussmaul
breathing, and in severe cases a decreased level of
rare but equally severe possibility is hyperosmolar
nonketotic state, which is more common in type 2
diabetes and is mainly the result of dehydration.
forms of diabetes increase the risk of long-term complications.
These typically develop after many years (10–20), but may
be the first symptom in those who have otherwise not received
a diagnosis before that time. The major long-term complications
relate to damage to blood
vessels. Diabetes doubles the risk of cardiovascular
The main "macrovascular"
diseases (related to atherosclerosis
of larger arteries) are coronary
artery disease (angina
vascular disease. About 75% of deaths in diabetics are
due to coronary artery disease.
also damages the capillaries
retinopathy, which affects blood vessel formation in
the retina of
the eye, can lead to visual symptoms including reduced vision
and potentially blindness.
nephropathy, the impact of diabetes on the kidneys,
can lead to scarring
changes in the kidney tissue, loss of small
or progressively larger
amounts of protein in the urine, and eventually chronic
kidney disease requiring dialysis.
risk is diabetic
neuropathy, the impact of diabetes on the nervous
system — most commonly causing numbness, tingling, and
pain in the feet, and also increasing the risk of skin damage
due to altered sensation. Together with vascular disease
in the legs, neuropathy contributes to the risk of diabetes-related
foot problems (such as diabetic
foot ulcers) that can be difficult to treat and occasionally
diabetic neuropathy causes painful muscle
wasting and weakness.
is a link between cognitive
deficit and diabetes. Compared to those without diabetes,
those with the disease have a 1.2 to 1.5-fold greater rate
of decline in cognitive function.
the United States, there were approximately 675,000 diabetes-related
emergency department (ED) visits in 2010 that involved neurological
complications, 409,000 ED visits with kidney complications,
and 186,000 ED visits with eye complications.
of type 1 and 2 diabetes
mellitus is classified into four broad categories: type 1,
diabetes, and "other specific types".
The "other specific types" are a collection of a few dozen
The term "diabetes", without qualification, usually refers
to diabetes mellitus.
diabetes mellitus is characterized by loss of the insulin-producing
of the islets
of Langerhans in the pancreas, leading to insulin deficiency.
This type can be further classified as immune-mediated or
idiopathic. The majority of type 1 diabetes is of the
immune-mediated nature, in which a T-cell-mediated
attack leads to the loss of beta cells and thus insulin.
It causes approximately 10% of diabetes mellitus cases in
North America and Europe. Most affected people are otherwise
healthy and of a healthy weight when onset occurs. Sensitivity
and responsiveness to insulin are usually normal, especially
in the early stages. Type 1 diabetes can affect children
or adults, but was traditionally termed "juvenile diabetes"
because a majority of these diabetes cases were in children.
diabetes, also known as unstable diabetes or labile diabetes,
is a term that was traditionally used to describe the dramatic
and recurrent swings in glucose
levels, often occurring for no apparent reason in insulin-dependent
diabetes. This term, however, has no biologic basis and
should not be used.
Still, type 1 diabetes can be accompanied by irregular
and unpredictable hyperglycemia,
frequently with ketosis,
and sometimes with serious hypoglycemia.
Other complications include an impaired counterregulatory
response to hypoglycemia, infection, gastroparesis
(which leads to erratic absorption of dietary carbohydrates),
and endocrinopathies (e.g., Addison's
These phenomena are believed to occur no more frequently
than in 1% to 2% of persons with type 1 diabetes.
diabetes is partly inherited, with multiple genes, including
genotypes, known to influence the risk of diabetes.
In genetically susceptible people, the onset of diabetes
can be triggered by one or more environmental factors, such
as a viral infection or diet. There is some evidence that
suggests an association between type 1 diabetes and Coxsackie
B4 virus. Unlike type 2 diabetes, the onset of type 1
diabetes is unrelated to lifestyle.
diabetes mellitus is characterized by insulin
resistance, which may be combined with relatively reduced
The defective responsiveness of body tissues to insulin
is believed to involve the insulin
receptor. However, the specific defects are not known.
Diabetes mellitus cases due to a known defect are classified
separately. Type 2 diabetes is the most common type.
the early stage of type 2, the predominant abnormality
is reduced insulin sensitivity. At this stage, hyperglycemia
can be reversed by a variety of measures and medications
that improve insulin sensitivity or reduce glucose production
by the liver.
diabetes is due primarily to lifestyle factors and genetics.
A number of lifestyle factors are known to be important
to the development of type 2 diabetes, including obesity
(defined by a body
mass index of greater than thirty), lack of physical
activity, poor diet, stress, and urbanization.
Excess body fat is associated with 30% of cases in those
of Chinese and Japanese descent, 60-80% of cases in those
of European and African descent, and 100% of Pima Indians
and Pacific Islanders.
Those who are not obese often have a high waist–hip
factors also influence the risk of developing type 2
diabetes. Consumption of sugar-sweetened
drinks in excess is associated with an increased risk.
The type of fats in
the diet is also important, with saturated
fats and trans
fatty acids increasing the risk and polyunsaturated
fat decreasing the risk.
Eating lots of white
rice appears to also play a role in increasing risk.
A lack of exercise is believed to cause 7% of cases.
diabetes mellitus (GDM) resembles type 2 diabetes in
several respects, involving a combination of relatively
inadequate insulin secretion and responsiveness. It occurs
in about 2–5% of all pregnancies
and may improve or disappear after delivery. Gestational
diabetes is fully treatable, but requires careful medical
supervision throughout the pregnancy. About 20–50% of affected
women develop type 2 diabetes later in life.
it may be transient, untreated gestational diabetes can
damage the health of the fetus or mother. Risks to the baby
(high birth weight), congenital cardiac and central nervous
system anomalies, and skeletal muscle malformations. Increased
fetal insulin may inhibit fetal surfactant
production and cause respiratory
distress syndrome. Hyperbilirubinemia
may result from red blood cell destruction. In severe cases,
perinatal death may occur, most commonly as a result of
poor placental perfusion due to vascular impairment. Labor
induction may be indicated with decreased placental
function. A Caesarean
section may be performed if there is marked fetal distress
or an increased risk of injury associated with macrosomia,
such as shoulder
indicates a condition that occurs when a person's blood
glucose levels are higher than normal but not high enough
for a diagnosis of type 2 DM. Many people destined
to develop type 2 DM spend many years in a state of
autoimmune diabetes of adults (LADA) is a condition
in which type 1 DM develops in adults. Adults with
LADA are frequently initially misdiagnosed as having type 2
DM, based on age rather than etiology.
cases of diabetes are caused by the body's tissue receptors
not responding to insulin (even when insulin levels are
normal, which is what separates it from type 2 diabetes);
this form is very uncommon. Genetic mutations (autosomal
can lead to defects in beta
cell function. Abnormal insulin action may also have
been genetically determined in some cases. Any disease that
causes extensive damage to the pancreas
may lead to diabetes (for example, chronic
pancreatitis and cystic
fibrosis). Diseases associated with excessive secretion
cause diabetes (which is typically resolved once the hormone
excess is removed). Many drugs impair insulin secretion
and some toxins damage pancreatic beta cells. The ICD-10
(1992) diagnostic entity, malnutrition-related diabetes
mellitus (MRDM or MMDM, ICD-10 code E12), was deprecated
by the World
Health Organization when the current taxonomy was introduced
forms of diabetes mellitus include congenital diabetes,
which is due to genetic
defects of insulin secretion, cystic
fibrosis-related diabetes, steroid diabetes induced
by high doses of glucocorticoids,
and several forms of monogenic
following is a comprehensive list of other causes of diabetes:
fluctuation of blood sugar (red) and the sugar-lowering
(blue) in humans during the course of a day with three
meals - one of the effects of a sugar-rich
vs a starch-rich
meal is highlighted.
of insulin release in normal pancreatic beta cells
- insulin production is more or less constant within
the beta cells. Its release is triggered by food,
chiefly food containing absorbable glucose.
is the principal hormone that regulates uptake of glucose
from the blood into most cells (primarily muscle and fat
cells, but not central nervous system cells). Therefore,
deficiency of insulin or the insensitivity of its receptors
plays a central role in all forms of diabetes mellitus.
are capable of digesting some carbohydrates,
in particular those most common in food; starch, and some
disaccharides such as sucrose, are converted within a few
hours to simpler forms, most notably the monosaccharide
principal carbohydrate energy source used by the body. The
rest are passed on for processing by gut flora largely in
the colon. Insulin is released into the blood by beta cells,
found in the islets of Langerhans in the pancreas, in response
to rising levels of blood glucose, typically after eating.
Insulin is used by about two-thirds of the body's cells
to absorb glucose from the blood for use as fuel, for conversion
to other needed molecules, or for storage.
is also the principal control signal for conversion of glucose
for internal storage in liver and muscle cells. Lowered
glucose levels result both in the reduced release of insulin
from the beta-cells and in the reverse conversion of glycogen
to glucose when glucose levels fall. This is mainly controlled
by the hormone glucagon,
which acts in the opposite manner to insulin. Glucose thus
forcibly produced from internal liver cell stores (as glycogen)
re-enters the bloodstream; muscle cells lack the necessary
export mechanism. Normally, liver cells do this when the
level of insulin is low (which normally correlates with
low levels of blood glucose).
insulin levels increase some anabolic
("building up") processes, such as cell growth and duplication,
synthesis, and fat
storage. Insulin (or its lack) is the principal signal in
converting many of the bidirectional processes of metabolism
from a catabolic
to an anabolic direction, and vice versa. In particular,
a low insulin level is the trigger for entering or leaving
ketosis (the fat-burning metabolic phase).
the amount of insulin available is insufficient, if cells
respond poorly to the effects of insulin (insulin insensitivity
or resistance), or if the insulin itself is defective, then
glucose will not have its usual effect, so it will not be
absorbed properly by those body cells that require it, nor
will it be stored appropriately in the liver and muscles.
The net effect is persistent high levels of blood glucose,
poor protein synthesis, and other metabolic derangements,
such as acidosis.
the glucose concentration in the blood is raised to about
9-10 mmol/L (except certain conditions, such as pregnancy),
beyond its renal
threshold (i.e. when glucose level surpasses the transport
maximum of glucose reabsorption), reabsorption
of glucose in the proximal
renal tubuli is incomplete, and part of the glucose
remains in the urine
This increases the osmotic
pressure of the urine and inhibits reabsorption of water
by the kidney, resulting in increased urine production (polyuria)
and increased fluid loss. Lost blood volume will be replaced
osmotically from water held in body cells and other body
compartments, causing dehydration
and increased thirst.
diabetes diagnostic criteria
6.1(>=110) & <7.0(<126)
mellitus is characterized by recurrent or persistent hyperglycemia,
and is diagnosed by demonstrating any one of the following:
plasma glucose level greater than or equal to 7.0 mmol/l
glucose greater than or equal to 11.1 mmol/l
(200 mg/dL) two hours after a 75 g oral glucose
load as in a glucose
of hyperglycemia and casual plasma glucose greater than
or equal to 11.1 mmol/l (200 mg/dl)
hemoglobin (Hb A1C) greater than or equal to 6.5%.
positive result, in the absence of unequivocal hyperglycemia,
should be confirmed by a repeat of any of the above methods
on a different day. It is preferable to measure a fasting
glucose level because of the ease of measurement and the
considerable time commitment of formal glucose tolerance
testing, which takes two hours to complete and offers no
prognostic advantage over the fasting test.
According to the current definition, two fasting glucose
measurements above 126 mg/dl (7.0 mmol/l) is considered
diagnostic for diabetes mellitus.
Health Organization people with fasting glucose levels
from 6.1 to 6.9 mmol/l (110 to 125 mg/dl) are
considered to have impaired
people with plasma glucose at or above 7.8 mmol/L (140 mg/dL),
but not over 11.1 mmol/L (200 mg/dL), two hours
after a 75 g oral glucose load are considered to have
glucose tolerance. Of these two prediabetic states,
the latter in particular is a major risk factor for progression
to full-blown diabetes mellitus, as well as cardiovascular
Diabetes Association since 2003 uses a slightly different
range for impaired fasting glucose of 5.6 to 6.9 mmol/l
(100 to 125 mg/dl).
is better than fasting
glucose for determining risks of cardiovascular disease
and death from any cause.
rare disease diabetes
insipidus has similar symptoms to diabetes mellitus,
but without disturbances in the sugar metabolism (insipidus
means "without taste" in Latin) and does not involve the
same disease mechanisms.
is no known preventive measure for type 1 diabetes.
Type 2 diabetes can often be prevented by a person
being a normal
body weight and physical exercise.
mellitus is a chronic
disease, for which there is no known cure except in
very specific situations. Management concentrates on keeping
blood sugar levels as close to normal ("euglycemia") as
possible, without causing hypoglycemia. This can usually
be accomplished with diet, exercise, and use of appropriate
medications (insulin in the case of type 1 diabetes;
oral medications, as well as possibly insulin, in type 2
about the disease and actively participating in the treatment
is vital for people with diabetes, since the complications
of diabetes are far less common and less severe in people
who have well-managed blood sugar levels.
The goal of treatment is an HbA1C level of 6.5%, but should
not be lower than that, and may be set higher.
Attention is also paid to other health problems that may
accelerate the deleterious effects of diabetes. These include
cholesterol levels, obesity,
pressure, and lack of regular exercise.
footwear is widely used to reduce the risk of ulceration,
or re-ulceration, in at-risk diabetic feet. Evidence for
the efficacy of this remains equivocal, however.
with diabetes can benefit from education about the disease
and treatment, good nutrition
to achieve a normal body weight, and sensible exercise,
with the goal of keeping both short-term and long-term blood
glucose levels within
acceptable bounds. In addition, given the associated
higher risks of cardiovascular disease, lifestyle modifications
are recommended to control blood pressure.
is generally recommended as a first line treatment for type 2
diabetes, as there is good evidence that it decreases mortality.
Routine use of aspirin,
however, has not been found to improve outcomes in uncomplicated
converting enzyme inhibitors (ACEIs) improve outcomes
in those with DM while the similar medications angiotensin
receptor blockers (ARBs) do not.
diabetes is typically treated with a combinations of regular
and NPH insulin,
or synthetic insulin
analogs. When insulin is used in type 2 diabetes,
a long-acting formulation is usually added initially, while
continuing oral medications.
Doses of insulin are then increased to effect.
countries using a general
practitioner system, such as the United
Kingdom, care may take place mainly outside hospitals,
with hospital-based specialist care used only in case of
complications, difficult blood sugar control, or research
projects. In other circumstances, general practitioners
and specialists share care in a team approach. Home telehealth
support can be an effective management technique.
of diabetes worldwide in 2000 (per 1,000 inhabitants)
- world average was 2.8%.
for diabetes mellitus per 100,000 inhabitants in
as of 2010,
an estimated 227 to 285 million people had diabetes,
with type 2 making up about 90% of the cases.
This is equal to 3.3% of the population with equal rates
in both women and men.
In 2011 it resulted in 1.4 million deaths worldwide making
it the 8th leading cause of death.
This is an increase from 1 million deaths in 2000.
rate has increased, and by 2030, this number is estimated
to almost double.
Diabetes mellitus occurs throughout the world, but is more
common (especially type 2) in more developed countries.
The greatest increase in rates is, however, expected to
occur in Asia and Africa, where most people with diabetes
will probably be found by 2030.
The increase in rates in developing countries follows the
trend of urbanization and lifestyle changes, perhaps most
importantly a "Western-style" diet. This has suggested an
environmental (i.e., dietary) effect, but there is little
understanding of the mechanism(s) at present, though there
is much speculation, some of it most compellingly presented.
was one of the first diseases described,
with an Egyptian manuscript from c.
mentioning "too great emptying of the urine".
The first described cases are believed to be of type 1
Indian physicians around the same time identified the disease
and classified it as madhumeha or "honey urine",
noting the urine would attract ants.
The term "diabetes" or "to pass through" was first used
in 230 BCE by the Greek Appollonius
The disease was considered rare during the time of the Roman
empire, with Galen
commenting he had only seen two cases during his career.
This is possibly due the diet and life-style of the ancient
people, or because the clinical symptoms were observed during
the advanced stage of the disease. Galen named the disease
"diarrhea of the urine" (diarrhea urinosa). The earliest
surviving work with a detailed reference to diabetes is
that of Aretaeus
of Cappadocia (2nd or early 3rd century CE). He described
the symptoms and the course of the disease, which he attributed
to the moisture and coldness, reflecting the beliefs of
the "Pneumatic School". He hypothesized a correlation of
diabetes with other diseases and he discussed differential
diagnosis from the snakebite which also provokes excessive
thirst. His work remained unknown in the West until the
middle of the 16th century when, in 1552, the first Latin
edition was published in Venice.
and type 2 diabetes were identified as separate conditions
for the first time by the Indian physicians Sushruta and
Charaka in 400-500 CE with type 1 associated with
youth and type 2 with being overweight.
The term "mellitus" or "from honey" was added by the Briton
John Rolle in the late 1700s to separate the condition from
insipidus, which is also associated with frequent urination.
Effective treatment was not developed until the early part
of the 20th century, when Canadians Frederick
Banting and Charles
Herbert Best isolated and purified insulin in 1921 and
This was followed by the development of the long-acting
insulin NPH in the 1940s.
word diabetes comes from Latin,
which in turn comes from Ancient
Greek which literally means "a passer through; a siphon."
of Cappadocia (fl.
1st century CE)
used that word, with the intended meaning "excessive discharge
of urine", as the name for the disease.
Ultimately, the word comes from Greek, meaning "to pass
which is composed of a word meaning "through" and bainein,
meaning "to go".
The word "diabetes" is first recorded in English, in the
form diabete, in a medical text written around 1425.
comes from the classical Latin word, meaning "mellite"
(i.e. sweetened with honey;
The Latin word comes from mell-, which comes from
mel, meaning "honey";
and the suffix,
whose meaning is the same as that of the English suffix
It was Thomas
Willis who in 1675 added "mellitus" to the word "diabetes"
as a designation for the disease, when he noticed the urine
of a diabetic had a sweet taste (glycosuria).
This sweet taste had been noticed in urine by the ancient
Greeks, Chinese, Egyptians, Indians, and Persians.
was the result of international efforts to improve the care
accorded to those with diabetes. Doing so is important not
only in terms of quality of life and life expectancy, but
also economically—expenses due to diabetes have been shown
to be a major drain on health—and productivity-related resources
for healthcare systems and governments.
countries established more and less successful national
diabetes programmes to improve treatment of the disease.
with diabetes who have neuropathic symptoms such as numbness
or tingling in feet or hands are twice as likely to be unemployed
as those without the symptoms.
2010, diabetes-related emergency department (ED) visit rates
in the United States were higher among people from the lowest
income communities (526 per 10,000 population) than from
the highest income communities (236 per 10,000 population).
Approximately 9.4% of diabetes-related ED visits were for
term "type 1 diabetes" has replaced several former
terms, including childhood-onset diabetes, juvenile diabetes,
and insulin-dependent diabetes mellitus (IDDM). Likewise,
the term "type 2 diabetes" has replaced several former
terms, including adult-onset diabetes, obesity-related diabetes,
and noninsulin-dependent diabetes mellitus (NIDDM). Beyond
these two types, there is no agreed-upon standard nomenclature.
animals, diabetes is most commonly encountered in dogs and
cats. Middle-aged animals are most commonly affected. Female
dogs are twice as likely to be affected as males, while
according to some sources, male cats are also more prone
than females. In both species, all breeds may be affected,
but some small dog breeds are particularly likely to develop
diabetes, such as Miniature
The symptoms may relate to fluid loss and polyuria, but
the course may also be insidious. Diabetic animals are more
prone to infections. The long-term complications recognised
in humans are much rarer in animals. The principles of treatment
(weight loss, oral antidiabetics, subcutaneous insulin)
and management of emergencies (e.g. ketoacidosis) are similar
to those in humans.
insulin has been developed.
It was however withdraw due to side effects.
There has been further efforts to develop further versions
which may soon be FDA approved.