Introduction > Diabetes diagnosis
Diabetes diagnosis
A. Diagnosis of diabetes outside pregnancy
Diabetes diagnosis is based on measurements of blood glucose (blood sugar concentration) using venous blood (venous plasma). There are 3 ways to make the diagnosis:
1. The classic symptoms of diabetes (high thirst, frequent urination, unexplained weight loss) + a blood sugar anytime during the day ≥ 200mg/dl (11 mmol/l), regardless of time elapsed since last meal or how copious it was.
OR
2. If your blood sugar on an empty stomach in the morning, after fasting for 8 hours is ≥ 126 mg / dl (7 mmol/l) diabetes can be diagnosed. However, values close to borderline have to be confirmed within a couple of days.
OR
3. If your blood sugar on an empty stomach in the morning, after fasting for 8 hours is less than 126 mg/dl (7 mmol/l), then make a so-called glucose tolerance test. After an overnight fast (8 hours) fasting blood glucose is measured. The patient drinks 75g glucose dissolved in 300 ml water, (with lemon for taste) within five minutes and glucose is measured again after 2 hours (mean time do not eat , smoke, walk; you can drink water). If 2 hours after glucose ingestion blood glucose is ≥ 200 mg/dl (11 mmol/l) diabetes can be diagnosed.
The recent recommendations for diagnosis of diabetes based on glycosylated hemoglobin (HbA1c) with threshold ≥ 6.5% cannot be used unless the laboratory has the HPLC method with validation according to international standards.
B. Diagnosis of diabetes during pregnancy
Diagnosis of gestational diabetes underwent multiple changes in time because until recently it was not known the blood glucose values from which the pregnancy complications begin to arise. The report of a large study in this area has brought more light on diagnostic criteria.
HAPO study analyzed more than 25,000 pregnant women without previously known diabetes, who had a glucose tolerance test and were followed closely throughout the pregnancy. There was no glycemic threshold at which complications begin to appear and below which the woman is safe. Even in the normal range, a higher blood glucose is associated with a higher risk of pregnancy complications.
As a result of this new information, experts from around the world met to discuss the diagnosis of diabetes in pregnancy. The IADPSG (International Association of Diabetes and Pregnancy Study Groups) consensus was the recommendation of new criteria for diagnosis of gestational diabetes. In January 2011, the American Diabetes Association (ADA) has adopted the new standard diagnostic criteria for use in USA and included them in the 2011 diabetes guidlines. The former two variants of diagnosis (O `Sullivan test with 50/100g glucose and WHO test with75g glucose) were withdrawn from clinical use.
New diagnostic criteria require that any pregnant woman without previously known diabetes to make an oral glucose tolerance test with 75g glucose in week 24-28 of pregnancy, carrying out three blood glucose measurements:
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fasting (normal value < 92 mg/dl / 5.1 mmol/l)
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after one hour (normal value < 190 mg/dl / 10 mmol/l)
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after two hours from 75g glucose ingestion (normal value < 153 mg/dl / 8.5 mmol/l).
Gestational diabetes is diagnosed if at least one of three blood glucose is greater than or equal to the threshold of 92 mg / dl (5.1 mmol / l) for morning blood glucose on an empty stomach (fasting), 180 mg / dl (10 mmol / l ) after one hour and 153 mg / dl (8.5 mmol / l) after two hours from 75g glucose ingestion. Note that unlike any other previous methods of diagnosis it is sufficient to have one glucose measurement greater than or equal to threshold and the diagnosis of gestational diabetes is established.
Given the strong arguments behind these new diagnostic criteria it is likely to have a rapid worldwide acceptance, in the absolute benefit for concerned women.
