DIABETES
Prevalence & Diagnosis
Ceri Jones
Diabetes Nurse Facilitator
March 2013
Learning Outcomes




Apply the WHO criteria for classification
& diagnosis
Distinguish between the different types
of diabetes
State the risk factors associated with
diabetes & how it can be prevented
Describe the steps taken to confirm
diagnosis
PREVALENCE
Country
2006
%
England 3.6
N Ireland 3.06
2012 2013
%
5.5 4.8%
3.8 4.1%
Scotland 3.4
WALES 4.1
4.3
5.0
4.6%
5.4%
Diabetes prevalence April 2013 – QOF Database
What is Diabetes

Diabetes is a complete or relative lack of
insulin.
 First noted in 1552BC
 Diabetes (Greek) – siphon of water
 Mellitus (Latin) – honeysweet
 11th Century detected by urine drinking
 19th Century pancreas noted as the cause
Why is diabetes significant?

Up to 5 per cent of NHS expenditure is spent on
diabetes, accounting for over £1 billion.

People with diabetes have a high risk of heart
disease, stroke, blindness, kidney disease and
amputations.

They are five times more likely than the general
population to suffer heart failure.

It is the leading cause of blindness in the working
age population.

Across the UK one thousand people with diabetes
start kidney dialysis every year.
Why are the numbers
increasing?

The population of the UK is ageing.

The risk of developing Type 2 diabetes
increases by up to 10 x in people with a
body mass index of more than 30.

Britain has the fastest growing rate of
obesity in the developed world.
The diabetes epidemic

366 million affected in 2011

552 million in 2030
WALES
– 2.9 million diagnosed
850,000
Undiagnosed
400
17
3
per day
per hour
every 10 minutes
IDF Diabetes Atlas
Impact of Obesity

Over half the adult population of UK is
officially overweight

One in five is clinically obese

20% children are overweight

10% children are clinically obese
LHB
DIABETES
OBESITY
%
%
Cwm Taf
5.5
11.4
Cardiff & Vale
4.4
8
Abertawe
5.8
10
Betsi Cadwalader
5.2
10.5
Hywel Dda
5.6
10.3
Powys
5.3
10.9
Aneurin Bevan
6.1
11.6
http://www.gpcontract.co.uk/browse/UK/1
1
Classification
Four revised classifications (WHO 1999)
– Type 1
– Type 2
– Gestational
– Other – drug induced / pancreatic disease /
MODY

N.B. Roman numerals removed and Arabic
used instead
TYPE 1






Beta-cell destruction, absolute insulin deficiency
Either immune mediated or idiopathic
Genetic susceptibility
Environmental trigger
Age of onset peaks
– preschool
– puberty
Autumn/winter peaks
Prevention of type 1
diabetes
Insulin
• Diabetes Prevention Trial
• Diabetes Prediction and Prevention
Project
Type 2 Diabetes

Disorders of insulin action/secretion

Predominantly insulin resistance with relative
insulin deficiency
Or

Predominantly an insulin secretory defect with
or without insulin resistance.
Those at Risk of developing
Type 2 Diabetes








Gestational Diabetes
Family History
Ethnicity
Obesity
Physical Inactivity
Age
IGT/IFG
Polycystic Ovary Syndrome
Risk factors for type 2
diabetes





Hypertension
Dyslipidaemia
Abdominal obesity
Overweight
Insulin Resistance
Metabolic Syndrome/
Syndrome X
Prevention of type 2
diabetes
Lifestyle modification
 Diabetes Prevention Program
 Finnish Diabetes Prevention Study
Prevention of Type 2
Diabetes

Type 2 diabetes can be delayed

Lifestyle modification is effective

Who do we Screen?

Opportunistic or Structured screening?

How do we Screen?
Comparisons of Type 1 & Type 2
Type 1 (5-10%)
Sudden onset
Severe symptoms
Weight loss
Lean
Ketosis
Absent C-peptides
Markers of autoimmunity
present
Family history uncommon
Onset usually in the young
Type 2 (90-95%)
Gradual onset
May be Asymptomatic
Often no weight loss
Usually obese
Not ketotic
C-peptide detectable
No markers of
autoimmunity present
Family history
Onset usually >40 years
old
Diagnosis of Diabetes
Diagnosis cannot be made from:
 Blood glucose strips read visually or by a
meter.

Urine testing

Glycosalated Haemoglobin - HbA1c
Diagnosis of Diabetes
Two pieces of evidence required
 Symptoms

Random Venous Plasma Glucose > 11.1

Fasting Venous Plasma Glucose > 7.0

2 Hour Venous Plasma Glucose > 11.1
WHO 1999
Glucose Tolerance Test
3 days of unrestricted diet and exercise
 Evening meal as normal the night before
 Overnight fast of 8-14 hours
TEST
 Fasting blood on the morning
 Drink 75g of anhydrous glucose in 250300ml water over 5 mins
 Blood sample 2 hours later
 No smoking during the test

DIAGNOSIS AFTER AN OGTT
Impaired
Fasting
Glucose (IFG)
Impaired
Diabetes
Glucose
Tolerance (IGT)
Fasting
Venous
Plasma
Glucose
6.1 mmol/l to
6.9 mmol/l
<7.0 mmol/l
> 7.0 mmol/l
2 hr post
< 7.8 mmo/l
>7.8 mmol/l up
to 11.1 mmol/l
>11.1 mmol/l
(WHO,2006)
Impaired Glucose Regulation

Impaired Glucose Tolerance (IGT)
- Abnormalities in glucose regulation in the postprandial state.
- More common in women

Impaired Fasting Glucose (IFG)
- Elevated fasting glucose concentrations, but lower
than those required to diagnose diabetes
- More common in men
Impaired Glucose Regulation





IFG and IGT are not interchangeable.
Both can lead to diabetes or revert to
normoglycaemia
Both are associated with an increased
risk of Cardiovascular disease
Identify & Read Code
Adhere to local guidelines regarding
follow up
HbA1c Criteria

Recently agreed by WHO & Diabetes UK
 Provides positive identification (ie specific)
- If Hba1c > 48mmol/mol, twice or once in
prescence of osmotic symptoms, and…
- if no confounding clinical problems
 Fails to rule out normality
- Hba1c <48mmol/mol does not rule out
diabetes
- glucose criteria then remain essential
 Algorithm not widely agreed. Awaiting WEDS
approval.
HbA1c > 48mmol/mol
Symptomatic
Asymptomatic
Repeat within 2 weeks
HbA1c > 48mmol/mol
Type 2 Diabetes Diagnosed
HbA1c < 47mmol/mol
Does not exclude Diabetes
Hba1c 42 –47mmol/mol
Lifestyle changes &
monitor at least annually
Symptoms present
exclude diabetes
using conventional
glucose tests
Do not use HbA1c

Under 18yrs
 Possible Type 1
 Where glucose may rise rapidly e.g.: steroids,
antipsychotics.
 Reduced red cell survival e.g. haemolytic
anaemia
 Gestational Diabetes
 Pancreatic damage/surgery
 Anaemia/Haemoglobinopathy
Use HbA1c– for patients under investigation, or annual
assessment of at risk groups including

IFG / IGT


Metabolic syndrome


PMH Gestational Diabetes or large for dates baby (>4kg)


Established Vascular disease CVA, IHD, PVD


Age > 45 plus +ve Family history


Age > 40 (or >30 if Asian or Pacific island descent) with hypertension
& BMI>30


PCOS
Do Not Use HbA1c as it is unreliable as a screening tool in
(see over):

Anyone under age 18


Possible Type 1 Diabetes, e.g. Symptoms of Diabetes for under 2 months or
clinically unwell


Situations where glucose may rise rapidly e.g. patient on atypical antipsychotics,
steroids


Patients known to have reduced red cell survival e.g. haemolytic anaemia


Gestational diabetes


Acute pancreatic damage / pancreatic surgery


Anaemia / Haemoglobinopathy
WHO recommendation
20111





HbA1c can be used as a diagnostic test for diagnosing diabetes providing
Stringent quality assurance tests are in place
Assays are standardised to criteria aligned to the international reference values
There are no conditions present which precludes its accurate measurement



An Hba1c of 48mmol/mol (6.5%) is recommended as the cut point for diagnosing Diabetes. A value
of less than 48 mmol/mol (6.5%) does not exclude diabetes, which can still be diagnosed using
glucose tests.
HbA1c is unreliable if used
alone in

















All symptomatic children and young people
Symptoms suggesting Type 1 diabetes (any age)
Short duration of diabetes symptoms
Patients at high risk of diabetes who are acutely ill
Those taking medication that may cause a rapid glucose rise e.g. steroids, antipsychotics
Acute pancreatic damage/pancreatic surgery
HbA1c reflects 2-3 month of hyperglycaemia and may not be elevated in these situations where
blood glucose has risen rapidly
Altered Haemoglobin (haemoglobinopathies)
Altered glycation (alcoholism, chronic renal failure, aspirin)
Anaemia, Erythrocyte destruction e.g. splenectomy, antiretrovirals.
Assays eg hyperbilirubinaemia, alcoholism, large doses of aspirin, chronic opiate use,
hypertriglyceridaemia.
See Annex 1 WHO report
Haemoglobinopathies may result in falsely increased or decreased HbA1c depending on assay
Different glycation rates for haemoglobin
New haemoglobin is unglycated
Interfere with some assay methods to falsely increase HbA1c

Caution: HbA1c should not be used to assess glycaemic
status 6 weeks post partum – use OGTT


HbA1c can also be elevated by:


Age. HbA1c is 4.5 mmol/mol higher at 70 than 40 years of
age,


Ethnicity. Afro-Caribbean and South Asians HbA1c is 4.5
mmol/mol higher than comparable Caucasians

NB. In above situations where HbA1c must not be used as
the sole test to diagnose Diabetes do an immediate qualityassured finger-prick capillary glucose test. If glucose is
>11.0 mmol/l seek same-day specialist diabetes advice.
For children and teenagers contact the specialist paediatric
diabetes team same day. Send same day laboratory venous
glucose, adding HbA1c to exclude stress hyperglycaemia
and/or for baseline, but do not delay seeking advice whilst
awaiting the result.