Impaired fasting glycaemia
Encyclopedia
Impaired fasting glucose (IFG), more commonly known as pre-diabetes refers to a condition in which the fasting blood glucose level is consistently elevated above what is considered normal levels; however, it is not high enough to be diagnosed as diabetes mellitus. This pre-diabetic state is associated with insulin resistance and increased risk of cardiovascular pathology, although of lesser risk than impaired glucose tolerance
(IGT). IFG can progress to type 2 diabetes mellitus if lifestyle changes are not made. There is a 50% risk over 10 years of progressing to overt diabetes. A recent study cited the average time for progression as less than three years.
Fasting blood glucose levels are in a continuum within a given population, with higher fasting glucose levels corresponding to a higher risk for complications caused by the high glucose levels. Impaired fasting glucose is defined as a fasting glucose that is higher than the upper limit of normal, but not high enough to be classified as diabetes mellitus. Some patients with impaired fasting glucose can also be diagnosed with impaired glucose tolerance, but many have normal responses to a glucose tolerance test.
(WHO) criteria for impaired fasting glucose differ from the American Diabetes Association
(ADA) criteria, because the normal range of glucose is defined differently. Fasting glucose levels 100 mg/dL and higher have been shown to increase complication rates significantly. However, WHO opted to keep its upper limit of normal at under 110 mg/dL for fear of causing too many people to be diagnosed as having impaired fasting glucose, whereas the ADA lowered the upper limit of normal to a fasting glucose under 100 mg/dL.
are a potential risk that is elevated in diabetic individuals. This may lead to heart attack or stroke. Blindness is another concern associated with type 2 diabetes. It is cause by microvascular disease
in which high blood glucose levels damage blood vessels in the retina
by the formation of scar tissue or hemorrhage. Not only do these high levels cause vision loss, they may also cause sensory nerve damage (Neuropathy). This presents as tingling, numbness or pain and in the most severe cases requires amputation. When these elevated levels of blood glucose are chronic there is a potential that irreversible kidney damage can occur. It is important that individuals with IFG or diabetes mellitus monitor their condition and make healthy lifestyle choices to reduce the onset of these life threatening symptoms. Pre-diabetic individuals who have abdominal obesity, high blood pressure, high LDL cholesterol, low HDL cholesterol, and high levels of triglycerides in the blood have an increased risk of developing type 2 diabetes mellitus. These risk factors are known collectively as the metabolic syndrome
. Recent evidence suggests that, similar to diabetes mellitus, individuals with IFG have higher degree of periodontal inflammation.
should also be limited. Advice and guidelines about eating a nutritious, balanced meal can be found using Canada's Food Guide. Vegetables and fruit should be consumed in the largest proportions. Regular physical activity has the potential to reduce insulin resistance and help decrease elevated blood glucose levels.
Impaired glucose tolerance
Impaired glucose tolerance is a pre-diabetic state of dysglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years...
(IGT). IFG can progress to type 2 diabetes mellitus if lifestyle changes are not made. There is a 50% risk over 10 years of progressing to overt diabetes. A recent study cited the average time for progression as less than three years.
Fasting blood glucose levels are in a continuum within a given population, with higher fasting glucose levels corresponding to a higher risk for complications caused by the high glucose levels. Impaired fasting glucose is defined as a fasting glucose that is higher than the upper limit of normal, but not high enough to be classified as diabetes mellitus. Some patients with impaired fasting glucose can also be diagnosed with impaired glucose tolerance, but many have normal responses to a glucose tolerance test.
Signs and Symptoms
The World Health OrganizationWorld Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
(WHO) criteria for impaired fasting glucose differ from the American Diabetes Association
American Diabetes Association
The American Diabetes Association is a United States-based association working to fight the consequences of diabetes, and to help those affected by diabetes...
(ADA) criteria, because the normal range of glucose is defined differently. Fasting glucose levels 100 mg/dL and higher have been shown to increase complication rates significantly. However, WHO opted to keep its upper limit of normal at under 110 mg/dL for fear of causing too many people to be diagnosed as having impaired fasting glucose, whereas the ADA lowered the upper limit of normal to a fasting glucose under 100 mg/dL.
- WHO criteria: fastingFastingFasting is primarily the act of willingly abstaining from some or all food, drink, or both, for a period of time. An absolute fast is normally defined as abstinence from all food and liquid for a defined period, usually a single day , or several days. Other fasts may be only partially restrictive,...
plasma glucoseGlucoseGlucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
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).
Risk factors
IFG is a risk factor for mortality due to the serious complications of type 2 diabetes mellitus. Diabetes is a multi-factor disease and it can affect many areas of the body. The depositions of plaque in the arteries known as atherosclerosisAtherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
are a potential risk that is elevated in diabetic individuals. This may lead to heart attack or stroke. Blindness is another concern associated with type 2 diabetes. It is cause by microvascular disease
Microvascular disease
Microangiopathy is an angiopathy affecting small blood vessels in the body. It can be contrasted to macroangiopathy....
in which high blood glucose levels damage blood vessels in the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
by the formation of scar tissue or hemorrhage. Not only do these high levels cause vision loss, they may also cause sensory nerve damage (Neuropathy). This presents as tingling, numbness or pain and in the most severe cases requires amputation. When these elevated levels of blood glucose are chronic there is a potential that irreversible kidney damage can occur. It is important that individuals with IFG or diabetes mellitus monitor their condition and make healthy lifestyle choices to reduce the onset of these life threatening symptoms. Pre-diabetic individuals who have abdominal obesity, high blood pressure, high LDL cholesterol, low HDL cholesterol, and high levels of triglycerides in the blood have an increased risk of developing type 2 diabetes mellitus. These risk factors are known collectively as the metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
. Recent evidence suggests that, similar to diabetes mellitus, individuals with IFG have higher degree of periodontal inflammation.
Prevention
With proper education, eating habits, physical activity, weight management, and lifestyle the risk of developing type 2 diabetes mellitus is reduced . Blood glucose levels can managed by the healthy eating and physical activity guidelines as an individual with normal blood glucose levels, however some minor modifications may be required. These variations depend on the individual, but it may include a slight decrease in the amount of carbohydrates consumed. The consumption of alcoholAlcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
should also be limited. Advice and guidelines about eating a nutritious, balanced meal can be found using Canada's Food Guide. Vegetables and fruit should be consumed in the largest proportions. Regular physical activity has the potential to reduce insulin resistance and help decrease elevated blood glucose levels.
See also
- Diabetic dietDiabetic dietThere is much controversy regarding what diet to recommend to sufferers of diabetes mellitus. The diet most often recommended is high in dietary fiber, especially soluble fiber, but low in fat . Recommendations of the fraction of total calories to be obtained from carbohydrate intake range from 1/6...
- Low GI diet
- Impaired glucose toleranceImpaired glucose toleranceImpaired glucose tolerance is a pre-diabetic state of dysglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years...
- Glucose tolerance testGlucose tolerance testA glucose tolerance 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, insulin resistance, and sometimes reactive hypoglycemia and acromegaly, or rarer disorders of...