Diagnosis of diabetes

Diabetes is diagnosed as follows: 3

1. If symptomatic (at least two of polydipsia, polyuria, frequent skin infections or frequent genital thrush).

o fasting venous plasma glucose (VPG) > 7.0 mmol/L o random VPG (at least 2 hours after last eating) > 11.1 mmol/L

2. If asymptomatic:

At least 2 separate elevated values, either fasting, 2 or more hours postprandial, or the 2 values from an oral glucose tolerance test (OGTT).

Note: If random or fasting VPG lies in uncertain range (5.5-11.0 mmol/L) in either a symptomatic patient or a patient with risk factors (over 50 years, overweight, blood relative with NIDDM or high blood pressure)

perform an OGTT. The cut-off point for further testing has now been reduced to 5.5 mmol/L. 4

The OGTT should be reserved for true borderline cases and for gestational diabetes. A screening test at

26-30 weeks gestation is recommended.

The diagnostic criteria after a 75 g load of glucose are:

Venous plasma glucose


2 hours later


< 5.5

< 7.0

Impaired tolerance


> 7.0-11.1


> 7.0

> 11.1

Gestational diabetes

> 5.5

> 7.0

Urinalysis is unreliable in diagnosis since glycosuria occurs at different plasma glucose values in patients with different renal thresholds.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

Get My Free Ebook

Post a comment