Diagnosis and initial evaluation of diabetes

Diagnosis and initial evaluation of type 1 and type 2 Diabetes Mellitus

1. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Welcome to the Diabetes e-Learning Suite.
Module 2:
Diagnosis, Initial Evaluation
and GlycaemicTargets
1

2. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Learning Objectives
After completing this module, you should be
able to:
List out the signs and symptoms of diabetes mellitus
Outline the different diagnostic tests used in the
evaluation of people with diabetes and their
criteria
Describe the initial evaluation of people with
diabetes
Summarise the glycaemic targets for different
populations
2

3. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Symptoms of Diabetes
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4. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Signs and Symptoms of Diabetes
4
Increased thirst
(polydipsia)
Increased appetite
(polyphagia)
Frequent urination
(polyuria)
Extreme fatigue
Blurry vision Cuts and bruises that take
longer to heal
Weight loss in patients with
T1DM
Numbness and tingling
sensation in the extremities
and pain in the feet in
patients with T2DM

5. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Tests for Diabetes
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6. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Signs and Symptoms of Diabetes
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• Presence of hyperglycaemia is the primary indicator for establishing the diagnosis of diabetes
• WHO recommends the use of venous plasma glucose as a standard method for measuring
glucose
1
Diagnostic Tests for the Measurement of Blood Glucose Levels
2,3
FPG, fasting plasma glucose; HbA1c,
glycated haemoglobin; OGTT, oral glucose
tolerance test; PPG, post-prandial plasma
glucose; RPG, random plasma glucose.
HbA1c
test
FPG
test
PPG
test
OGTT
RPG
test

7. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Glycated Haemoglobin Test
7
Used for the diagnosis of T2DMand prediabetes but not for T1DMand
GDM
1
HbA1c is a measure of the degree to which haemoglobin is
glycosylated in erythrocytes
2
Expressed as a percentage of total haemoglobin concentration
2
Indicates an individual’s blood glucose levels over the past three
months
2
GDM, gestational diabetes mellitus; HbA1c, glycated haemoglobin.
Normal
1
•HbA1c levels <5.7%
Prediabetes
1
•HbA1c levels between
5.7% and 6.4%
•Needs to be retested
after one year
Diabetes
1
•HbA1c levels ≥6.5% on
two separate tests

8. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Glycated Haemoglobin Test (Cont’d)
8
Advantages
Gives a measure of an individual’s
long-term glucose concentration
Prevents day-to-day variability in
glucose levels due to stress or illness
Convenient for people
Limitations
Lower sensitivity in determining slight
variations in the blood glucose levels
Any slight interference during the test
can show a false increase or
decrease in the result
Not recommended for rapidly
progressing diabetes
ADA recommendations
• Biannually in all people with diabetes
• Quarterly in people with diabetes whose therapy has been changed or
who are not meeting the treatment goals
ADA, American Diabetes Association; HbA1c, glycated haemoglobin.

9. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Fasting Plasma Glucose Test
• Most common test used to detect diabetes and prediabetes
• More routinely used as it is more convenient and less expensive than OGTT
• Gives more reliable data in the morning, performed after the person has fasted
overnight for at least eight hours
1
9
FPG, fasting plasma glucose; OGTT, oral glucose tolerance test.
Normal
1
•FPG levels <100 mg/dL
or 5.5 mmol/L
Prediabetes
1
•FPG levels between 100
and 125 mg/dL or 6.1-
6.9 mmol/L
Diabetes
1
•FPG levels ≥126 mg/dL
or 6.9 mmol/L
Limitations
2
• Measurement of single-point blood glucose level
• Shows fluctuations with slight modifications in the lifestyle such as stress or any illness
• Less convenient
• Less associated with diabetic complications
• Shows diurnal variations
• High within-patient variability

10. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Postprandial Plasma Glucose Test
10
Assessment of an individual’s postprandial hyperglycaemia
Measured two hours after the ingestion of meal
Indicates an individual’s ability to utilise glucose over a period of time
Elevated PPG levels contribute to suboptimal glycaemic control and is one of
the earliest indicators of defect in glucose homeostasis
Normal
• PPG levels <140 mg/dL or 7.8 mmol/L
Diabetes
• PPG levels ≥200 mg/dL or 11.1 mmol/L on
twoseparate tests
PPG, post-prandial plasma glucose.

11. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Oral Glucose Tolerance Test
• Gold standard for the diagnosis of diabetes, prediabetes or IGT and GDM
• An indicator of the body’s ability to break down glucose
1
11
GDM, gestational diabetes mellitus.
The person is
required to ingest
a minimum of
150 g of
carbohydrates
per day, three
days prior to the
test
accompanied by
the usual
physical activity
Before the test,
the person
should fast for 8-
14 hours
Baseline blood
glucose level is
measured
The person is
asked to drink 75
g of glucose
solution over the
course of five
minutes
Blood glucose
levels are
measured two
hours after the
glucose load
1
IGT –140-199 mg/dL or 7.8-11.0 mmol/L
Diabetes –≥200 mg/dL or 11.1 mmol/L on two separate tests
• Fluctuations in reading due to changes in lifestyle, stress, illness or medications
• Inconvenient for patients
• Expensive
• High within-patient variability
Limitations
2

12. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Random Plasma Glucose Test
Used to diagnose diabetes
Sampling can be done any time of the day
Fasting is not required
The person may be diagnosed with diabetes if
- ≥200 mg/dL or 11.1 mmol/L
- Classical symptoms of diabetes such as polyuria, polydipsia and
unexplained weight loss are observed
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RPG, random plasma glucose.

13. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Tests for Gestational Diabetes
Mellitus
13
Standard test for diagnosing GDM is OGTT
First pre-natal visit or between 24-28 weeks of pregnancy
depending on their risk factors and symptoms identified using
OGTT
Women with a history of GDM should undergo follow-up 6-12
weeks post-partum to test for type 2 diabetes or prediabetes
Recommended to perform the blood glucose tests instead of
HbA1c test within 12 weeks of delivery
GDM, gestational diabetes mellitus; HbA1c, glycated haemoglobin; OGTT, oral glucose tolerance test.

14. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Tests for Gestational Diabetes
Mellitus (Cont’d)
14
1-Step Strategy
• Perform a 75 gOGTT with basal glucose
measurement during fasting and at one and
two hours, at 24-48 weeks of gestation in all
pregnant women not known to have prior
diabetes
• Anticipated to increase the incidence of
GDM as only one abnormal value was
sufficient to confirm the diagnosis instead of
two values
2-Step Strategy
•Step 1: Perform a 50 gGLT with plasma
glucose measurement at one hour in all
pregnant women not known to have prior
diabetes
• The screening with a 50 gGLT does not
require fasting
•Step 2: If the plasma glucose level
measured after one hour is ≥140 mg/dL or
7.8 mmol/L, proceed with the three-hour
100 gOGTTfor which the person is
required to fast
GDM, gestational diabetes mellitus; GLT, glucose load test; OGTT, oral glucose tolerance test.

15. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Criteria for the Diagnosis of Diabetes
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16. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Criteria for Prediabetes
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17. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Criteria for Diabetes Mellitus
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A1c, glycated haemoglobin; DCCT, Diabetes Control and Complications Trial; FPG, fasting plasma glucose; NGSP, National Glycohemoglobin
Standardization Program; OGTT, oral glucose tolerance test; PG, plasma glucose; WHO, World Health Organization.

18. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Diagnostic Criteria for GDM
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GDM, gestational diabetes mellitus; GLT, glucose load test; OGTT, oral glucose tolerance test.

19. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Screening in Asymptomatic Patients
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20. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Screening in Asymptomatic Adults
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A1c, glycated haemoglobin; BMI, body mass index; CVD, cardiovascular disease; GDM, gestational diabetes mellitus; HDL, high density
lipoprotein; IFG, impaired fasting glucose; IGT, impaired glucose tolerance; OGTT, oral glucose tolerance test.

21. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Screening in Asymptomatic Children
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BMI, body mass index; GDM, gestational diabetes mellitus.

22. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Initial Evaluation of a Person with Diabetes
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23. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Components of the Initial Evaluation
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24. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Components of the Initial Evaluation
(Cont’d)
24

25. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Glycaemic Targets in Different Populations
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26. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Individualising Blood Glucose Targets
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Individualisation of Glycaemic Target
Duration of diabetes
Age or life expectancy
Other comorbid conditions
Known cardiovascular diseases or advanced microvascular
complication
Unawareness of hypoglycaemic status
Individual considerations

27. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Paediatric Age Groups
27
• Children younger than six years are unable to recognise the signs of
hypoglycaemia
• Special consideration should be given when establishing individualised
glycaemic goals

28. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Pregnant Women
Glycaemic Targets for GDM are Based on Recommendations from the Fifth
International Workshop-Conference on GDM
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Optimal Glycaemic Goals in Women with Pre-existing Type 1 Diabetes or
Type 2 Diabetes who become Pregnant
Preprandial ≤95 mg/dL (5.3 mmol/L)
One-hour post meal ≤140 mg/dL (7.8 mmol/L) or
Two-hour post meal ≤120 mg/dL (6.7 mmol/L)
Pre-meal, bedtime and
overnight glucose 60-99
mg/dL (3.3-5.4 mmol/L)
Peak PPG levels 100-129
mg/dL (5.4–7.1 mmol/L)
HbA1c levels <6.0%

29. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Older Adults
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30. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Key Points
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The diagnostic tests recommended for the measurement of blood glucose levels
include:
HbA1c test
FPG test
PPG test
OGTT
RPG test
The OGTT is the standard test for diagnosing GDM
Pregnant women can be tested at their first prenatal visit or between 24 and 28 weeks
of pregnancy depending on their risk factors and symptoms using OGTT
The 75 g one- and two-hour OGTT or one-step strategy or the 50 g one-hour GLT
followed by the 100 g three-hour OGTT or two-step strategy is used to diagnose GDM
in pregnant women
The purpose of screening is to identify asymptomatic individuals who are likely to
have diabetes
FPG: fasting plasma glucose; GDM: gestational diabetes mellitus; GLT: glucose load test; HbA1c: glycated haemoglobin; OGTT: oral glucose tolerance test; PPG:
postprandial plasma glucose; RPG: random plasma glucose; WHO: World Health Organization.

31. PCPs & GPs Course: Module 2
Diagnosis, Initial Evaluation and Glycaemic Targets
www.idfdiabeteschool.org
Key Points
31
Screening should be considered in asymptomatic children and adults after
considering their age and the risk factors presented
A comprehensive initial evaluation helps the healthcare provider to provide optimal
management for diabetes
The components of the initial evaluation in people with diabetes include medical
history, physical examination, laboratory evaluations and referrals
Blood glucose targets are individualised based on various factors such as the
Duration of diabetes
Age or life expectancy
Other comorbid conditions
Known cardiovascular diseases or advanced microvascular complications
Unawareness of hypoglycaemia
Individual considerations