# Blood sugar or HbA1C levels: routinely tested or when needed/asked? **URL:** \ **Category:** Factual Questions\ **Created:** [May 15, 2005, 1:20am UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889 "2005-05-15T01:20:49Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![WeRSauron](https://avatars.discourse-cdn.com/v4/letter/w/f19dbf/32.png) [@WeRSauron](https://boards.straightdope.com/u/WeRSauron)\ **Post date:** [May 15, 2005, 1:20am UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/1 "2005-05-15T01:20:49Z")
When people go to their doctor for a check-up, is blood sugar or HbA1C levels routinely tested or is it only done at the patient’s request or based on the patient’s health, individual health history, or family health history? WRS ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [May 15, 2005, 3:49am UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/2 "2005-05-15T03:49:08Z")
> [@WeRSauron](#): > > When people go to their doctor for a check-up, is blood sugar or HbA1C levels routinely tested or is it only done at the patient’s request or based on the patient’s health, individual health history, or family health history? > > WRS It should only be tested to determine how well a known diabetic’s blood sugar control is. The standard recommendation is every 3 months for type I diabetics and every 3 to 6 months for type II diabetics, depending on how well they’re controlled. The HbA1C is **not** a screening test to determine if one has diabetes. Many people with early diabetes will still have normal HbA1C levels. The best way to screen for diabetes is either with fasting blood sugars, or on occasion the glucose tolerance test. Frankly I favor the fasting sugars for screening myself. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [May 15, 2005, 7:08am UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/3 "2005-05-15T07:08:34Z")
As always, **QtM** is correct. I’ll add that the HbA1c level is probably diagnostic of diabetes **if** it’s elevated (i.e. it’s specific for diabetes), but a normal HbA1c level does not rule it out (i.e. it’s not a sensitive test for diabetes - just as **Dr. Qad** said). [Here’s a formal statement](http://care.diabetesjournals.org/cgi/content/full/26/11/3160) on the use of HbA1c as a screening test for diabetes: > [@](#): > > The use of HbA1c (A1C) as a diagnostic test for diabetes was not recommended. The primary reason for this decision was a lack of standardized methodology resulting in varying nondiabetic reference ranges among laboratories because of > [@](#): > > 1. A profusion of assay methods has led to different nondiabetic reference ranges because different glycated hemoglobin fractions have been measured (30). This problem has been reduced in the U.S. because of the efforts of the NGSP. Although the NGSP has succeeded in standardizing 95% of the laboratories in the U.S., with results certified as “traceable to the DCCT A1C assay,” (12) the level of precision and accuracy of the A1C test may still not be sufficient in all laboratories to allow the assay to be used to diagnose diabetes. Moreover, in many countries, A1C assays are not widely available and no A1C standardization program has even begun. Newer methods for measuring A1C by mass spectrometry, although not practical for clinical use, have the potential to provide better standardization across all A1C assays. > > 2. A chemical preparation to create uniform calibration standards has only recently been established (30). This preparation however has not yet been widely adopted. > > 3. A1C values may be affected by other conditions (e.g., hemoglobinopathy, pregnancy, uremia, blood transfusion, and hemolytic anemia), and depending on the laboratory method used, this may confound the diagnosis of diabetes. > > On balance, therefore, it seems best to continue to use the A1C test as a monitor for the effectiveness of glycemic therapy and as an indicator for when therapy needs to be modified. In conclusion, the Committee believes that it is still premature to add A1C to the group of tests used for the definitive diagnosis of diabetes. ---
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [May 15, 2005, 7:04pm UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/4 "2005-05-15T19:04:29Z")
At my routine annual physical in 1999, which was the last one I had before being diagnosed with type 2 diabetes a couple years later, they did a random blood sugar check along with all the other stuff they were checking. As I recall, it came back highlighted as “impaired glucose tolerance” but my nurse practitioner didn’t make a big deal about it. I kind of wish she had, in retrospect. I did mark on my paperwork that I had a family history of diabetes, so I don’t know if they would have included the blood sugar check anyway or not. They definitely did not do an A1C. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [May 15, 2005, 7:57pm UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/5 "2005-05-15T19:57:24Z")
> [@MsWhatsit](#): > > At my routine annual physical in 1999, which was the last one I had before being diagnosed with type 2 diabetes a couple years later, they did a random blood sugar check along with all the other stuff they were checking. As I recall, it came back highlighted as “impaired glucose tolerance” but my nurse practitioner didn’t make a big deal about it. I kind of wish she had, in retrospect. > > I did mark on my paperwork that I had a family history of diabetes, so I don’t know if they would have included the blood sugar check anyway or not. They definitely did not do an A1C. Nor should they have done the A1C. But a 2nd fasting glucose is standard when the first is in the “glucose intolerany” range. If the second is in that range too, then perhaps a glucose challenge test is needed. Someone identified as glucose intolerant should get counselled on diet and exercise routines which may stave off developing full blown diabetes (for a while at least) and be closely followed up to ensure that if the person does tip over into diabetes, it’s identified. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [May 15, 2005, 8:06pm UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/6 "2005-05-15T20:06:51Z")
Thanks for the additional input, **KarlGauss** , along with the props. But I ain’t always right, you know. I am frequently sure (even if incorrect), and I _always_ have an opinion (even if it’s uninformed), but I ain’t always on the money. 😃 ---
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [May 15, 2005, 8:18pm UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/7 "2005-05-15T20:18:14Z")
> [@Qadgop the Mercotan](#): > > Nor should they have done the A1C. But a 2nd fasting glucose is standard when the first is in the “glucose intolerany” range. If the second is in that range too, then perhaps a glucose challenge test is needed. Oh, definitely, I didn’t mean to imply that I felt they should have done an A1C at that point. However, the diet and exercise counseling you mentioned sure would have been helpful. My nurse practitioner basically just shrugged it off and said it wasn’t a big deal and I should “avoid sugary foods” and come back to get checked again in a year. ---
**Author:** ![WeRSauron](https://avatars.discourse-cdn.com/v4/letter/w/f19dbf/32.png) [@WeRSauron](https://boards.straightdope.com/u/WeRSauron)\ **Post date:** [May 16, 2005, 12:24am UTC](https://boards.straightdope.com/t/blood-sugar-or-hba1c-levels-routinely-tested-or-when-needed-asked/303889/8 "2005-05-16T00:24:07Z")
Thanks, y’all! Your answers help me lots. 🙂 I hope you will indulge me in [this thread](http://boards.straightdope.com/sdmb/showthread.php?p=6161449) now. WRS