Measurements of hemoglobin A1c (HbA1c) more accurately identify persons at risk for clinical outcomes than the commonly used measurement of fasting glucose, according to a new study. HbA1c levels accurately predict future diabetes, and they better predict stroke, heart disease and all-cause mortality as well.
Which is more accurate A1c or fasting glucose?
“While the American Diabetes Association guidelines specify that diabetes can be diagnosed based on fasting plasma glucose (FPG), the OGTT, or the A1c, our findings confirm that reliance on A1c remains the least reliable method for assessing diabetes risk.”
What is the normal range of fasting blood sugar?
- Random blood sugar test. A blood sample will be taken at a random time. ...
- Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. ...
- Oral glucose tolerance test. For this test, you fast overnight, and the fasting blood sugar level is measured. ...
What is a normal fasting glucose level?
Target levels
- HbA1c results. Prediabetes is when blood sugar levels are higher than normal levels but not high enough to indicate diabetes.
- Home testing. However, the target numbers will vary between individuals. ...
- Prediabetic range. A fasting blood sugar level of 100–125 mg/dl indicates prediabetes. ...
What is the difference between glucose and A1C?
The main difference between Glucose and A1c is that the percentage of them differs when checked in the hemoglobin level of the body. When glucose is checked in the body, it shows how much sugar is there in the body. However, A1c refers to checking for diabetes at the initial stage, which is the path to checking sugar levels over a period of time.
Is A1C test better than glucose test?
An A1C between 5.7 percent and 6.4 percent suggests prediabetes. An A1C of 6.5 or more indicates type 2 diabetes if the test is confirmed....A1C test.Type of resultsA1CEstimated average blood glucose level (mg/dL)diabetes A1C resultsabove 6.4%above 1372 more rows
Which is more accurate HbA1c or fasting glucose?
Generally, FBS was a more accurate predictor for HbA1c compared with HbA1c as a predictor of FBS. Although the optimum cutoff point of HbA1c was >6.15%, its precision was comparable with the conventional cutoff point of >6%.
Why is my fasting blood sugar high but my A1C is normal?
A1C tests measure average blood glucose over the past two to three months. You may have high fasting blood sugar, but your overall blood sugar may be normal, or vice versa. Normal fasting blood sugar levels may not eliminate the possibility of type 2 diabetes.
What is the most accurate diabetes test?
The A1C test is one of the most common because its results estimate blood sugar levels over time, and you don't have to fast before the test. The A1C test is also known as the glycated hemoglobin test....A1c test.Test resultIndicated condition5.7% to 6.4%Prediabetes6.5% or greaterDiabetes1 more row
Why is HbA1c a better diagnostic test than FBS fasting blood glucose?
The investigators concluded that HbA1c testing has a higher sensitivity for identifying patients at risk for diabetes vs FPG, and therefore may have a greater impact on the diagnoses, cost, burden, and treatment of patients with diabetes.
What is the difference between HbA1c and glucose test?
The HbA1c develops when haemoglobin, a protein within red blood cells that carries oxygen throughout your body, joins with glucose in the blood, becoming 'glycated'. For people with diabetes this is important because the higher the HbA1c, the greater risk of developing diabetes related complications.
When is A1C not accurate?
Conditions such as acute and chronic blood loss, hemolytic anemia, and splenomegaly can all cause falsely lowered A1c results. Patients with end-stage renal disease generally have falsely low A1c values. This is primarily due to the associated chronic anemia with decreased red cell survival.
Can glucose be low but A1C high?
You Have Low Thyroid Levels The number of thyroid hormones in the bloodstream can affect your A1C level. This will cause the reading to fluctuate or give you false results. For example, hypothyroidism, or a low thyroid hormone levels, can lead to an elevated level of A1C.
How can I lower my fasting blood sugar in the morning?
How can high blood sugar levels in the morning be controlled?Changing the timing or type of your diabetes medications.Eating a lighter breakfast.Increasing your morning dose of diabetes medication.If you take insulin, switching to an insulin pump and programming it to release additional insulin in the morning.
What is the gold standard for diagnosing diabetes?
HbA1c has become the gold standard for monitoring glycemic control in patients with diabetes mellitus. The use of this test has been expanded to diagnose and screen for diabetes mellitus with the endorsement of influential diabetes societies and the World Health Organization.
Which method is most accurate for blood glucose estimation?
In most hands, the glucose oxidase strip method is accurate and reliable. Since whole blood is used, the results tend to be slightly lower than simultaneous venous samples, but this is balanced by the fact that capillary blood has a higher glucose concentration than venous blood.
How do I know if my glucose meter is accurate?
Check your blood sugar level with your meter at the same time that blood is drawn for lab tests, being sure to use a fingerstick sample, not blood from the blood draw. Then compare your meter's reading with the lab results. Results that are within 15% of the lab reading are considered accurate.
A1c Fasting Blood Glucose Chart
Hemoglobin is the molecule within red blood cells.that carries oxygen to the bodys tissues.a small percentage of the hemoglobin has sugar attached to it, and this type of hemoglobin is known as hemoglobin a1c..
Fasting Is Not Needed For A1c Assessment And No Acute Perturbations Affect A1c
Plasma glucose levels are not stable but rather vary throughout the day, mainly in postprandial periods. Although it is believed that fasting glucose levels are reproducible across days, a number of acute perturbations of glucose homeostasis have been described.
Fasting Glucose Vs A1c
Hello, I’ve never been concerned about diabetes before as my fasting blood glucose levels have always been under 100.However, my last fasting glucose test as well as my husband’s were both high .The doctor had us return for A1c tests which were in the normal range .Based on that, the doctor assumed we had eaten something before the fasting test and said, ‘see you in 3 months’.But we didn’t eat anything.
What Blood Sugar Markers Are Reliable
Testing accurately for blood sugar is like putting pieces of a puzzle together. Fasting blood glucose, A1c and post-meal blood sugar are all pieces of the puzzle.
What Does This Mean For People Wondering About Their Diabetes Risk
For individuals who havent received a diagnosis of diabetes, Dr. Villacreses says, one important lesson from these fidings is that ”you should not feel 100% reassured if your A1c number is less than 6.5% that you are do not have diabetes.
Recruitment And Data Collection
Detailed study procedures have been previously reported. All adults aged 18 years and above who were usually residents in either of the study sites were eligible to participate in the parent study. All households were approached consecutively, and all residents aged 18 years were recruited.
What Are Normal Blood Sugar Levels
You might want to measure your blood sugar before meals to get a baseline, and then two hours after your meal to measure your normal blood sugar level. Your doctor might also suggest measuring blood sugar before bed to be sure you have been eating well throughout the day and can go to sleep with peace of mind.
FACTORS CONTRIBUTING TO VARIATION IN RESULTS
Before addressing glucose and A1C, it is important to consider the factors that impact the results of any blood test. While laboratory medicine journals have devoted some discussion to the sources of variability in results of blood tests, this topic has received little attention in the clinical literature.
GLUCOSE MEASUREMENT
Measurement of glucose in plasma of fasting subjects is widely accepted as a diagnostic criterion for diabetes ( 1, 2 ). Advantages include inexpensive assays on automated instruments that are available in most laboratories worldwide ( Table 1 ). Nevertheless, FPG is subject to some limitations.
A1C MEASUREMENT
A1C is formed by the nonenzymatic attachment of glucose to the N -terminal valine of the β-chain of hemoglobin ( 24 ). The life span of erythrocytes is ∼120 days, and consequently A1C reflects long-term glycemic exposure, representing the average glucose concentration over the preceding 8–12 weeks ( 31, 32 ).
PERSPECTIVE
Notwithstanding the use of glucose (FPG and/or the OGTT) as the “gold standard” for the diagnosis of diabetes for many years, glucose testing suffers from several deficiencies. The requirement that the subject be fasting at the time the blood is drawn is a considerable inconvenience.
Article Information
No potential conflicts of interest relevant to this article were reported.
RESEARCH DESIGN AND METHODS
NHANES 1999–2000, 2001–2002, 2003–2004, and 2005–2006 are serial cross-sectional surveys including nationally representative samples of the noninstitutionalized civilian U.S. population identified through a stratified, multistage probability sampling design. Methods for pooling these datasets have been published ( 5 ).
RESULTS
Among U.S. adults, the prevalence of undiagnosed diabetes was 2.3% using A1C and 3.6% using fasting glucose. Moderate agreement existed for A1C and fasting glucose diagnoses (κ = 0.60; 95% CI 0.55–0.64).
CONCLUSIONS
The results of the current study indicate the new recommendation by the International Expert Committee to use A1C to diagnose diabetes would result in the same classification as fasting glucose for 97.7% of U.S. adults. For those with discordant results, 0.5% of U.S.
Acknowledgments
No potential conflicts of interest relevant to this article were reported.
Study Limitations
Participants were all of Asian (Vietnamese) descent and from a highly urban population, thereby limiting the generalizability of results globally.
Reference
Ho-Pham LT, Nguyen UDT, Tran TX, Nguyen TV. Discordance in the diagnosis of diabetes: comparison between HbA1c and fasting plasma [published online August 17, 2017]. PLOS ONE. doi:10.1371/journal.pone.0182192
Is fasting glucose enough to diagnose diabetes?
The standard diagnosis of diabetes is made when two separate blood tests show that your fasting blood glucose level is greater than or equal to 126 mg/dL.
Can you have a normal fasting blood sugar and still be diabetic?
A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it’s 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes.
What diabetes test is most accurate?
The FPG blood test measures your blood glucose level at a single point in time. For the most reliable results, it is best to have this test in the morning, after you fast for at least 8 hours. Fasting means having nothing to eat or drink except sips of water.
What is considered pre diabetic?
A blood sugar level less than 140 mg/dL (7.8 mmol/L ) is considered normal. A blood sugar level from 140 to 199 mg/dL (7.8 to 11.0 mmol/L ) is considered prediabetes. This is sometimes referred to as impaired glucose tolerance. A blood sugar level of 200 mg/dL (11.1 mmol/L ) or higher indicates type 2 diabetes.
Does routine blood work show diabetes?
Type 2 diabetes can be detected easily during a routine screening exam and blood test. However, it frequently can go undiagnosed for years unless a physician draws a blood sample to check the blood glucose.
Can prediabetes go away?
Yes, prediabetes can be reversed. The most effective way to reverse prediabetes, or return to normal blood sugar levels, is to focus on exercise, healthy eating, and losing weight. Some medications may also work to stop prediabetes becoming diabetes, but none have been approved by the FDA.
Is fasting glucose or A1C more accurate?
Measurements of hemoglobin A1c (HbA1c) more accurately identify persons at risk for clinical outcomes than the commonly used measurement of fasting glucose, according to a new study. HbA1c levels accurately predict future diabetes, and they better predict stroke, heart disease and all-cause mortality as well.
