renal disease, thyroid disorders, coeliac disease, Addison’s
disease or gastroparesis. A review of the child’s injection
sites should be offered at each clinic visit.h
Infection, stress, accidental or surgical trauma, and
puberty may all increase the required insulin dose. Insulin
requirements may be decreased (and therefore susceptibility
to hypoglycaemia increased) by physical activity,
intercurrent illness, reduced food intake, and in certain
endocrine disorders, such as anterior pituitary or
adrenocortical insufficiency and hypothyroidism.
gRapid-acting insulin analogues should be supplied
for use during intercurrent illness and episodes of
hyperglycaemia.h
Risks of hypoglycaemia with insulin
gHypoglycaemia is an inevitable adverse effect of insulin
treatment, and children and their carers should be advised of
the warning signs and actions to take (for guidance on
management, see Hypoglycaemia p. 465 ).h
Impaired awareness of hypoglycaemia can occur, when the
ability to recognise usual symptoms is lost, or when the
symptoms are blunted or no longer present.gAwareness
of hypoglycaemia should be discussed and assessed with the
child and their carer approximately every 3 months.l
An increase in the frequency of hypoglycaemic episodes
may reduce the warning symptoms experienced by the child.
Impaired awareness of symptoms below 3 mmol/litre is
associated with a significantly increased risk of severe
hypoglycaemia. Beta-blockers can also blunt hypoglycaemic
awareness, by reducing warning signs such as tremor.
Loss of warning of hypoglycaemia among insulin-treated
children can be a serious hazard, especially for adolescents
who are drivers, cyclists, or in dangerous occupations.
Advice should be given in line with the Driver and Vehicle
Licensing Agency (DVLA) guidance (seeDriving, under
Diabetes p. 445 ).
gTo restore the warning signs, episodes of
hypoglycaemia must be minimised. Insulin regimens, doses
and blood-glucose targets should be reviewed and
continuous subcutaneous insulin infusion therapy and real-
time continuous glucose monitoring should be considered.
h
gChildren and their carers should receive structured
education to ensure they are following the principles of a
flexible insulin regimen correctly, with additional education
regarding avoiding and treating hypoglycaemia for those
who continue to have impaired awareness. If recurrent
severe episodes of hypoglycaemia continue despite
appropriate interventions, the child should be referred to a
specialist centre.l
Manufacturers advise any switch between brands or
formulation of insulin (including switching from animal to
human insulin) should be done under strict supervision; a
change in dose may be required.
Hypodermic equipment
gChildren and their carers should be advised on the safe
disposal of lancets, single-use syringes, and needles, and
should be provided with suitable disposal containers.
Arrangements should be made for the suitable disposal of
these containers.h
Lancets, needles, syringes, and accessories are listed under
Hypodermic Equipment in Part IXA of the Drug Tariff (Part
III of the Northern Ireland Drug Tariff, Part 3 of the Scottish
Drug Tariff). The drug Tariffs can be accessed online at:
.National Health Service Drug Tariff for England and Wales:
http://www.nhsbsa.nhs.uk/pharmacies-gp-practices-and-appliance-
contractors/drug-tariff.Health and Personal Social Services for Northern Ireland
Drug Tariff:www.hscbusiness.hscni.net/services/ 2034 .htm
.Scottish Drug Tariff:
http://www.isdscotland.org/Health-Topics/Prescribing-and-Medicines/
Scottish-Drug-TariffUseful Resources
Diabetes (type 1 and type 2 ) in children and young people:
diagnosis and management. National Institute for Health
and Care Excellence. Clinical guideline NG 18. August 2015.
http://www.nice.org.uk/guidance/ng 18Insulin 05-Jun-2017
Overview
For recommended insulin regimens see Type 1 diabetes
p. 445 and Type 2 diabetes p. 448.
Insulin is a polypeptide hormone secreted by pancreatic
beta-cells. Insulin increases glucose uptake by adipose tissue
and muscles, and suppresses hepatic glucose release. The
role of insulin is to lower blood-glucose concentrations in
order to prevent hyperglycaemia and its associated
microvascular, macrovascular and metabolic complications.
The natural profile of insulin secretion in the body consists
of basal insulin (a low and steady secretion of background
insulin that controls the glucose continuously released from
the liver) and meal-time bolus insulin (secreted in response
to glucose absorbed from food and drink).
Sources of insulin
Three types of insulin are available in the UK: human
insulin, human insulin analogues, and animal insulin.
Animal insulins are extracted and purified from animal
sources (bovine or porcine insulin). Although widely used in
the past, animal insulins are no longer initiated in people
with diabetes but may still be used by some adult patients
who cannot, or do not wish to, change to human insulins.
Human insulins are produced by recombinant DNA
technology and have the same amino acid sequence as
endogenous human insulin. Human insulin analogues are
produced in the same way as human insulins, but the insulin
is modified to produce a desired kinetic characteristic, such
as an extended duration of action or faster absorption and
onset of action.
Immunological resistance to insulin is uncommon and
true insulin allergy is rare. Human insulin and insulin
analogues are less immunogenic than animal insulins.Administration of insulin
Insulin is inactivated by gastro-intestinal enzymes and must
therefore be given by injection; the subcutaneous route is
ideal in most circumstances. Insulin should be injected into a
body area with plenty of subcutaneous fat—usually the
abdomen (fastest absorption rate) or outer thighs/buttocks
(slower absorption compared with the abdomen or inner
thighs).
Absorption from a limb site can vary considerably (by as
much as 20 – 40 %) day-to-day, particularly in children. Local
tissue reactions, changes in insulin sensitivity, injection site,
bloodflow, depth of injection, and the amount of insulin
injected can all affect the rate of absorption. Increased blood
flow around the injection site due to exercise can also
increase insulin absorption.
gLipohypertrophy can occur due to repeatedly
injecting into the same small area, and can cause erratic
absorption of insulin, and contribute to poor glycaemic
control. Patients should be advised not to use affected areas
for further injection until the skin has recovered.
Lipohypertrophy can be minimised by using different
injection sites in rotation. Injection sites should be checked
for signs of infection, swelling, bruising, and
lipohypertrophy before administration.hBNFC 2018 – 2019 Diabetes mellitus 447
Endocrine system6