What is this test?
Diabetes screening tests help detect prediabetes and
diabetes early, allowing for timely intervention and management. Here are the
primary tests used for diabetes screening:
1. Fasting Plasma Glucose (FPG) Test
● Purpose: Measures blood
glucose levels after fasting for at least 8 hours.
● Procedure: Blood sample
taken after overnight fasting.
2. Hemoglobin A1c (HbA1c) Test
● Purpose: Measures the
average blood glucose levels over the past 2-3 months.
● Procedure: Blood sample
taken at any time; no fasting required.
3. Oral Glucose Tolerance Test (OGTT)
● Purpose: Measures blood
glucose levels before and after consuming a sugary drink.
● Procedure:
○ Fasting
blood sample taken first.
○ Drink a
glucose solution.
○ Blood
samples taken at intervals (usually at 1 and 2 hours after drinking).
4. Random Plasma Glucose Test
● Purpose: Measures blood
glucose levels at any time, regardless of when you last ate.
● Procedure: Blood sample
taken at any time.
How is it done?
All the diabetes
screening tests involve healthcare professionals who will draw a blood sample
from a vein in your arm. Just the process before the blood is drawn differs,
for some tests fasting is required while for other fasting is not required or
blood is taken after some fixed interval of time after eating.
When should it be done?
The frequency of
diabetes screening tests depends on individual risk factors, age, and health
conditions. Here are general guidelines for different groups:
General Population:
●
Adults Aged 45 and Older:
○
Frequency: Every 3 years if the results are normal.
○
More
Frequent Screening: If initial screening results indicate prediabetes, annual
screening is recommended.
Children and Adolescents:
●
Overweight (BMI > 85th percentile) and
have additional risk factors:
○
Frequency: Every 2 years starting at age 10 or puberty onset,
whichever occurs earlier.
Pregnant Women:
●
Screening for Gestational Diabetes:
○
Frequency: Between 24 and 28 weeks of gestation. Earlier screening
may be recommended for women with high-risk factors.
Individuals with Prediabetes:
●
Annual Screening: If diagnosed with prediabetes (HbA1c of
5.7% to 6.4%, FPG of 100-125 mg/dL, or OGTT of 140-199 mg/dL), screening should
be done annually.
Individuals with Diagnosed Diabetes:
●
Regular Monitoring: Once diagnosed with diabetes, regular
monitoring of blood glucose levels as recommended by your healthcare provider
is essential. This includes HbA1c tests typically every 3 to 6 months to assess
how well blood sugar levels are being managed.
What do the results indicate or eliminate?
1. Fasting Plasma Glucose (FPG) Test
●
Normal: Less than 100 mg/dL.
●
Prediabetes: 100-125 mg/dL.
● Diabetes: 126 mg/dL or higher on two separate tests.
2. Hemoglobin A1c (HbA1c) Test
●
Normal: Below 5.7%.
●
Prediabetes: 5.7% to 6.4%.
● Diabetes: 6.5% or higher on two separate tests.
3. Oral Glucose Tolerance Test (OGTT)
●
Normal: Less than 140 mg/dL at 2 hours.
●
Prediabetes: 140-199 mg/dL at 2 hours.
● Diabetes: 200 mg/dL or higher at 2 hours.
4. Random Plasma Glucose Test
●
Diabetes: 200 mg/dL or higher, along with symptoms of diabetes
(e.g., increased thirst, frequent urination).