1 Hour Glucose Tolerance

What Is a 1 Hour Glucose Tolerance Test?

A 1 hour glucose tolerance test, also commonly known as the glucose challenge test or oral glucose tolerance test, is a well-utilized medical test carried out during pregnancy to measure the patient's response to sugar. It is a vital test that helps determine whether or not the pregnant patient has developed gestational diabetes. The test can also be used as a screening tool for type 2 diabetes, as it highlights any abnormalities in how the patient's body processes glucose.

This straightforward test is broken down into two steps. Firstly the patient is asked to consume a high glucose drink, and then one hour later, blood sugar levels are taken. Should the blood sugar levels fall above or below the recommended parameters, gestational diabetes may be present, and further intervention such as a 3-hour glucose tolerance test, may be needed to help determine if the patient has developed the condition. 

Completed between the 24 to 28-week mark of pregnancy, this is an important step in pregnancy care to help identify and reduce the risk of symptoms such as preeclampsia. Having an easy and downloadable recording chart like the one offered by Carepatron's extensive template library is a no-brainer for your medical practice.

How Does It Work?

Step One: Gather your Resources

An easy-to-access and user-friendly chart for recording and analyzing the 1-hour glucose tolerance test results is key in any healthcare practice. Ensure you have your free printable 1-hour glucose tolerance test on hand by simply clicking the “Download Template” button or keyword search “1-hour glucose tolerance test” on the extensive database in Carepatrons template library.

Step Two: Collate Essential Information and Conduct Test

Fill in the patient's key details and relevant medical history as well as symptoms or gestational period that may have led to the request for a 1 hour glucose tolerance test.

The patient is required to consume a glucose drink that contains 1.8 ounces (50 grams) of sugar and to abstain from all other food and drink for one hour. After this time period, a blood sample needs to be drawn and returned to a hematology outlet for testing.

Once results are released, in the appropriate sections, fill in the results for glucose levels. For clear cross-analysis of the recommended parameters ensure these levels are in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

Step Three: Compare Results and Identify Imbalances

Once the chart is filled out in its entirety, a clear picture will be able to be formed of the status of the pregnant patient's glucose tolerance. By comparing the results to the easily accessed parameters a distinction can be made between low, normal, or high levels of blood sugar.

The interpretation of the results is key for highlighting the need for intervention moving forward. Conveniently store notes on the further steps taken within the same chart or on Carepatron's centralized workspace.

Step Four: Store the Template Securely

After reviewing the results and hosting a consultation with your patient, you need to secure the glucose tolerance test results so that access is only granted to relevant parties. Ensure this by utilizing Carepatrons HIPAA-compliant free patient records software. Here, all relevant medical records can be safely stored and collated for ease and security.

When Would You Use This Test?

The 1 hour glucose tolerance test is a valuable tool for healthcare professionals to use in the monitoring of glycemic control in pregnant patients and offers quick results with relatively low intrusive medical intervention. Here are some key scenarios and patient medical factors in which this test can be appropriately used:

Patients In the Second Trimester

Within the second trimester of your patient's pregnancy, this 1 hour glucose tolerance test is an invaluable way to reduce the risk of pregnancy issues such as life-threatening preeclampsia.

High-Risk Populations

Patients with an ethnic background of Asian American, American Indian, Black, or Hispanic also have an increased risk of gestational diabetes and should have early glucose tolerance testing.

Patients over the age of 35 are also considered a high-risk group for gestational diabetes. If the pregnant patient has carried previous children and the birth weight exceeded 9 pounds, the risk of the development of gestational diabetes is increased.

Diabetes Management and Associated Medical Conditions

Patients who have pre-existing medical conditions such as metabolic syndrome or polycystic ovary syndrome should have early glucose tolerance testing as these conditions have been linked to the development of diabetes outside of pregnancy.

Patients who have reduced physical activity and a body mass index of 30 or higher are also at greater risk of developing gestational diabetes and early intervention is desirable.

What Do the Results Mean?

1 hour glucose tolerance test results provide valuable insights into a patient's glycolic control, making them a crucial tool in gestational diabetes management and diagnosis.

Typically, the results are reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L) and can vary depending on lifestyle factors and current medical conditions. Here's what common 1 hour glucose tolerance test results typically mean:

Standard Blood Sugar Levels

A result below 140 mg/dL indicates a normal blood sugar level and glycolic control is not a cause for concern. Please note that different institutions and countries have varying parameters for standard blood sugar levels. Some labs consider 130 mg/dL to be the lower threshold.

High Blood Sugar Levels

A result that sits at 140 mg/dL to less than 190 mg/dL is evidence of low blood sugar levels and indicates the need for further intervention, such as a three-hour glucose test to help determine if gestational diabetes has been developed.

A result that sits at or above 190 mg/dL indicates high blood sugar levels and the presence of gestational diabetes. With a high-level result like this, further monitoring is essential and at-home blood sugar testing before breakfast and after meals is encouraged to help manage the condition and the risks involved.

Research & Evidence

The 1 hour glucose tolerance test, also commonly known as the glucose challenge test or oral glucose tolerance test, was created in response to the discovery that pregnancy has clear and measurable effects on the body's ability to metabolize carbohydrates. The criteria for diagnosing gestational diabetes came out of a study performed on 752 pregnant patients in 1964 but has since been elaborated on to not only test patients with pre-existing risk factors such as age, ethnicity, and current medical conditions but to run this test on all pregnant patients (O’Sullivan & Mahan, 1964). 

Regular testing of glucose levels is proven to help in the treatment and management of temporary diabetes in the prenatal stages and with the global rates of gestational diabetes rising, clear and accessible testing and charting tools are a must. The oral glucose tolerance test has been in place for years yet recent studies are questioning whether or not we can provide better and more accurate results for this growing population of at-risk clients (Bogdanet et al., 2020). There are both short-term and long-term detrimental costs for both mother and child should gestational diabetes go undetected so ensuring that testing is viable and trustworthy is a must for the delivery of dignified and well-rounded care. 

A call for a universal standard on the parameters when interpreting blood sugar levels in pregnant patients is made, and work is being done on finding new biomarkers that can also identify gestational diabetes. Results are yet to be validated, and the 1 hour glucose tolerance test still remains favorable and well-used in many healthcare practices (Bogdanet et al., 2020). 

Clinical guidelines and expert recommendations have been established, endorsing its application in particular clinical situations. It has evolved into an indispensable component of prenatal healthcare, assisting medical professionals in customizing treatment strategies and determining the need for medical interventions by assessing recent glycemic control.

References

Bogdanet, D., O’Shea, P., Lyons, C., Shafat, A., & Dunne, F. (2020). The Oral Glucose Tolerance Test—Is It Time for a Change?—A Literature Review with an Emphasis on Pregnancy. Journal of Clinical Medicine, 9(11), 3451. https://doi.org/10.3390/jcm9113451

Mayo Clinic. (n.d.). Glucose challenge test - Mayo Clinic. Www.mayoclinic.org. https://www.mayoclinic.org/tests-procedures/glucose-challenge-test/about/pac-20394277#:~:text=Overview

Mishra, S., Rao, C. R., & Shetty, A. (2016). Trends in the Diagnosis of Gestational Diabetes Mellitus. Scientifica, 2016, 1–7. https://doi.org/10.1155/2016/5489015

O’Sullivan, J. B., & Mahan, C. M. (1964). CRITERIA FOR THE ORAL GLUCOSE TOLERANCE TEST IN PREGNANCY. PubMed, 13, 278–285.