diabetes, bronzeAnother name for
haemochromatosis, a rare genetic dis-
ease in which excessive amounts of iron
are deposited in tissues. It causes a
bronze skin coloration, and sufferers
often develop diabetes mellitus.
diabetes insipidusA rare condition
characterized by excessive thirst and
the passing of large quantities of dilute
urine. It usually results from a failure of
the pituitary gland to secrete ADH
(antidiuretic hormone). Diseases of the
pituitary gland can cause failure of ADH
secretion. The condition may temporar-
ily follow brain surgery. Treatment uses
a nasal spray containing ADH. A rare
form of the disease, nephrogenic dia-
betes insipidus, is due to the kidneys
not responding to ADH; treatment is by
a low-sodium diet and, paradoxically,
thiazides (see diuretic drugs).
diabetes mellitusA disorder caused
by insufficient or absent production of
the hormone insulinby the pancreas, or
because the tissues are resistant to the
effects. Insulin is responsible for the ab-
sorption of glucoseinto cells. Lack of
insulin causes high blood levels of glu-
cose, resulting in the passage of large
quantities of urine and excessive thirst.
Other symptoms are weight loss, hunger,
and fatigue. Urinary tract infections may
also occur. Lipid(fat) metabolism is
affected and small blood vessels degen-
erate. Undiagnosed diabetes can lead
to blurred vision, boils, and tingling or
numbness of the hands and feet.
There are 2 main types of diabetes
mellitus, both of which tend to run in
families. Type 1 (insulin-dependent) dia-
betes is the less common form of the
disorder and usually develops in child-
hood or adolescence. In this type of
diabetes, insulin-secreting cells in the
pancreas are destroyed, and insulin
production ceases. Type 2 (noninsulin-
dependent) diabetes generally develops
gradually, mainly in people over the age
of 40. Although insulin is still produced,
there is not enough for the body’s
needs as the tissues become relatively
resistant to its effects. Symptoms may
be present in only a 3rd of people with
this type of diabetes; it is often diag-
nosed only when complications occur.Treatment aims to keep blood glucose
as normal as possible. It involves achiev-
ing and maintaining a normal weight,
regular physical activity, dietary man-
agement, and, if necessary, treatments
with antidiabetic drugs.
People with type 1 diabetes require
regular insulin injections. Carbohydrate
intake is spread out over the day, intake
of fats should be kept low, and self-
monitoring of blood glucose levels is
important. If the glucose/insulin bal-
ance is not maintained, hyperglycaemia
or hypoglycaemiamay develop.
Treatment of type 2 diabetes usually
consists of dietary measures, weight
reduction, and antidiabetic drugs, often
hypoglycaemicdrugs such as sulphony-
lureas. Some people eventually need
insulin injections.
Complications of diabetes mellitus
include retinopathy, peripheral neuro-
pathy, and nephropathy. Ulcers on the
feet are another risk. People with dia-
betes mellitus also have a greater risk
of atherosclerosis, hypertension, other
cardiovascular disorders, and cataracts.
With modern treatment and sensible
self-monitoring, nearly all diabetics can
look forward to a normal lifespan.
diabetic pregnancyPregnancy in a wo-
man with pre-existing diabetes mellitusor
in a woman who develops diabetes dur-
ing pregnancy. The latter is known as
gestational diabetes. Women with es-
tablished diabetes mellitus can have a
normal pregnancy provided that the di-
abetes is controlled well. Poor control of
blood glucose during the pregnancy may
affect the baby’s growth or increase the
risk of complications during pregnancy.
Gestational diabetes is usually detect-
ed in the second half of pregnancy. The
mother does not produce enough
insulin to keep blood glucose levels
normal. True gestational diabetes dis-
appears with the delivery of the baby
but is associated with an increased risk
of developing type 2 diabetes in later life.
diagnosisThe process of finding the
nature of a disorder. The doctor listens
to a patient’s account of his or her illness
and a physical examination is usually
involved. Tests may be ordered after the
formation of a provisional diagnosis.DIABETES, BRONZE DIAGNOSISD