Impaired fasting glucose is a type of

prediabetes Prediabetes is a component of the metabolic syndrome and is characterized by elevated blood sugar levels that fall below the threshold to diagnose diabetes mellitus. It usually does not cause symptoms but people with prediabetes often have obesit ...

, in which a person's

blood sugar Glycaemia, also known as blood sugar level, blood sugar concentration, or blood glucose level is the measure of glucose concentrated in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the blo ...

levels during

fasting Fasting is the abstention from eating and sometimes drinking. From a purely physiological context, "fasting" may refer to the metabolic status of a person who has not eaten overnight (see " Breakfast"), or to the metabolic state achieved after ...

are consistently above the normal range, but below the diagnostic cut-off for a formal diagnosis of

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

. Together with

impaired glucose tolerance Prediabetes is a component of the metabolic syndrome and is characterized by elevated blood sugar levels that fall below the threshold to diagnose diabetes mellitus. It usually does not cause symptoms but people with prediabetes often have obesit ...

, it is a sign of insulin resistance. In this manner, it is also one of the conditions associated with metabolic syndrome. Those with impaired fasting glucose are at an increased risk of vascular complications of diabetes, though to a lesser extent. The risks are cumulative, with both higher blood glucose levels, and the total amount of time it spends elevated, increasing the overall complication rate. IFG can eventually progress to

type 2 diabetes mellitus Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urinatio ...

without intervention, which typically involves lifestyle modification. Those with impaired fasting glucose have a 1.5 fold increased risk of developing clinical diabetes within 10 years, when compared to the general population. Some studies suggest that without lifestyle changes, IFG will progress to clinically diagnosable diabetes in just under 3 years, on average. Impaired fasting glucose is often, though not always, associated with

, though it may occur in isolation, with such persons having a normal response to a

glucose tolerance test The glucose tolerance test (GTT, not to be confused with GGT test) is a medical test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood. The test is usually used to test for diabetes, ...

Signs and symptoms

Impaired fasting glucose is often without any signs or symptoms, other than higher than normal glucose levels being detected in an individual's fasting blood sample. There may be signs and symptoms associated with elevated blood glucose, though these are likely to be minor, with significant symptoms suggestive of complete progression to type 2 diabetes. Such symptoms include: * Increased thirst * Increased urination, especially waking up in the night to urinate * Tiredness and fatigue * Blurred vision * Slow healing of wounds * Altered sensation, such as numbness or tingling, particularly of the hands and feet * Recurrent, and difficult to clear infections, particularly of the urinary tract

Risk factors

As impaired fasting glucose is considered a precursor condition for type 2 diabetes, it shares the same environmental and genetic

risk factors In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection. Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often use ...

Diagnosis

Different organisations use slightly differing levels before classifying a person's fasting blood glucose as "impaired", with the American Diabetes Association using a lower cutoff in its criteria than the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...

. The upper limits remain the same, as fasting levels above this are almost universally accepted as indicative of full diabetes: * WHO criteria:

plasma

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

level from 6.1 mmol/L (110 mg/dL) to 6.9 mmol/L (125 mg/dL).. * ADA criteria: fasting plasma glucose level from 5.6 mmol/L (100 mg/dL) to 6.9 mmol/L (125 mg/dL).

Prevention

The guidelines for preventing impaired fasting glucose are the same as those given for preventing type 2 diabetes in general. If these are adhered to, the progression to clinical diabetes can be slowed or halted. In some cases, a complete reversal of IFG can be achieved. Certain risk factors, such as being of Afro-Caribbean or South Asian ethnicity, as well as increasing age, are unavoidable, and such individuals may be advised to follow these guidelines, as well as monitor their blood glucose levels, more closely.

Management

References

External links

{{Diabetes Disorders of endocrine pancreas