FASTING BLOOD SUGAR 98 & 142 THE 2ND HOUR





Quick Answer
If you are not pregnant and this was a correctly performed 75-gram oral glucose tolerance test, fasting glucose of 98 mg/dL is normal and the two-hour result of 142 mg/dL is in the prediabetes range, also called impaired glucose tolerance. It is not in the diabetes range. The one-hour value of 167 mg/dL is not a standard diagnostic criterion for nonpregnant adults. If these readings followed an ordinary meal—or if you are pregnant—the interpretation is different.



QUESTION

Today I received my report. My fasting blood sugar was 98 mg/dL, the one-hour result was 167 mg/dL, and the two-hour result was 142 mg/dL.


Do these results mean I have diabetes? If there is a blood-sugar problem, what should I do?




Answer by Dr. Albana Greca, MD, MMedSc



Hello,



Your fasting result is normal, but the two-hour result may indicate prediabetes only if this was a formal oral glucose tolerance test. The diagnostic methods are explained in our guide to blood tests for diabetes.



How to Interpret the Results



For a nonpregnant adult undergoing a 75-gram oral glucose tolerance test:




  • Fasting 98 mg/dL: normal, because normal fasting plasma glucose is below 100 mg/dL;

  • One hour 167 mg/dL: not used by itself to diagnose diabetes or prediabetes in a standard nonpregnant OGTT;

  • Two hours 142 mg/dL: within the prediabetes range of 140–199 mg/dL;

  • Diabetes range: two-hour glucose of 200 mg/dL or higher, usually requiring confirmation when there is no clear glucose emergency.



This pattern is called impaired glucose tolerance. It means the body cleared the glucose drink more slowly than expected, but it does not diagnose diabetes.




The test method matters: A glucose reading taken two hours after an ordinary breakfast or lunch is not interpreted with diagnostic OGTT thresholds unless a standardized glucose test was performed.


Do Symptoms Change the Diagnosis?



No. Prediabetes often causes no obvious symptoms. Its diagnosis depends on the laboratory result and the way the test was performed—not on whether thirst or frequent urination is present.



Symptoms matter differently when a random plasma glucose is 200 mg/dL or higher. Classic symptoms together with that result can establish diabetes without waiting for another test.



Pregnancy Uses Different Cutoffs



The question does not state whether you are pregnant. Pregnancy glucose-tolerance tests use lower thresholds. During a one-step 75-gram pregnancy OGTT, gestational diabetes is diagnosed when any one value reaches or exceeds:




  • fasting 92 mg/dL;

  • one hour 180 mg/dL;

  • two hours 153 mg/dL.



Therefore, fasting glucose of 98 mg/dL could meet a gestational-diabetes threshold even though the one- and two-hour values are below their respective cutoffs. The maternity team must interpret the exact protocol. Our article on gestational diabetes treatment and monitoring explains why pregnancy targets differ.



Should the Result Be Confirmed?



Ask what test was performed, how much glucose was used and whether preparation was correct. An overnight fast and adequate carbohydrate intake beforehand are important.



Follow-up may include:




  • HbA1c;

  • a repeat fasting plasma glucose;

  • a repeat OGTT if the first test was uncertain;

  • blood pressure, cholesterol and weight assessment;

  • review of family history, pregnancy history and medicines that affect glucose.



The absence of symptoms does not make impaired glucose tolerance unimportant. You can compare these values with the ranges in our normal blood sugar level chart.



What Can You Do About Prediabetes?



Prediabetes does not mean that type 2 diabetes is inevitable. Lifestyle changes can improve glucose regulation and reduce future risk.




  • Choose mostly vegetables, whole grains, legumes, whole fruits, lean proteins, nuts and seeds.

  • Reduce sugary drinks, sweets and large portions of refined carbohydrate.

  • Aim for at least 150 minutes of moderate activity each week when medically safe.

  • If you have overweight or obesity, losing about 5–7% of starting weight can reduce risk.

  • Avoid smoking and address blood pressure, cholesterol and sleep.



These changes also support insulin resistance management, explained in what insulin resistance means.



Do You Need Medicine?



Not everyone with a two-hour result of 142 mg/dL needs medication. Lifestyle intervention and follow-up testing are often the first steps.



Metformin may be considered for selected people at higher risk, including some younger adults with substantial excess weight, higher fasting glucose or HbA1c, or previous gestational diabetes. The decision should not be based on this single result alone.




Seek prompt medical care for marked thirst, frequent large-volume urination, unexplained weight loss, vomiting, dehydration, confusion or a random glucose of 200 mg/dL or higher with symptoms.


My Advice



If this was a standard 75-gram OGTT and you are not pregnant, the results suggest impaired glucose tolerance—not diabetes. Confirm the test protocol, obtain HbA1c or repeat testing as advised, and begin practical lifestyle changes.



If you are pregnant, contact your maternity clinician because the fasting result is interpreted using lower pregnancy thresholds.



Hope this helps.



Dr. Albana Greca



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References





Educational only — not personal medical advice. Diagnosis depends on the test protocol, pregnancy status and confirmatory testing.


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