A postprandial glucose (PPG) test is a
blood glucose test that determines the amount of
glucose
Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...
in the
plasma after a meal.
The diagnosis is typically restricted to ''postprandial hyperglycemia'' due to lack of strong evidence of co-relation with a diagnosis of
diabetes
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...
''.
''
The
American Diabetes Association
The American Diabetes Association (ADA) is a United States-based nonprofit that seeks to educate the public about diabetes and to help those affected by it through funding research to manage, cure and prevent diabetes, including type 1 diabetes ...
does not recommend a PPG test for determining diabetes, but it notes that postprandial hyperglycemia does contribute to elevated
glycated hemoglobin levels (a primary factor behind diabetes) and recommends testing and management of PPG levels for those patients who maintain optimum pre-prandial blood glucose levels but have high A1C values.
Carbohydrates
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ma ...
in the form of glucose are one of the main constituents of foods, and
assimilation starts within about 10 minutes.
The subsequent rate of absorption of carbohydrates in conjunction with the resultant rates of secretion of
insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (''INS)'' gene. It is the main Anabolism, anabolic hormone of the body. It regulates the metabol ...
and
glucagon
Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises the concentration of glucose and fatty acids in the bloodstream and is considered to be the main catabolic hormone of the body. It is also used as a Glucagon (medic ...
secretion affects the time-weighed PPG profile.
In non-diabetic individuals, levels peak at about an hour after the start of a meal, rarely exceed 140 mg/
dl, and return to preprandial levels within 2–3 hours.
These time-profiles are heavily altered in diabetic patients.
Typically, PPG levels are measured about 2 hours after the start of the meal, which corresponds to the time-span in which peak values are typically located, in case of diabetic patients.
In 2011, the
International Diabetes Federation noted elevated PPG levels to be an independent risk factor for
macrovascular disease; this had been since challenged on previous grounds and that PPG might be simply a marker or a surrogate of a complex series of metabolic events occurring in the postprandial period, that is already better reflected through other parameters. A detailed 2001 review by the
American Diabetes Association
The American Diabetes Association (ADA) is a United States-based nonprofit that seeks to educate the public about diabetes and to help those affected by it through funding research to manage, cure and prevent diabetes, including type 1 diabetes ...
had earlier noted that correlations of PPG values with other diabetics parameters were often understudied and widely variant, whilst chronic diabetes-related complications have been demonstrated over a too-broad range of PPG values, to be independently attributed to; the 2018 Standards of Medical Care in Diabetes follows the same theme roughly.''
'' A 2019 review in
Obesity Reviews was similar and noted inconclusive data as to the importance of PPG as a standalone parameter in diabetes diagnosis and management; it went on to propose a hyperglycemia-diabetes-CVD continuum and also criticized the lack of rigid standardization of a PPG test.
Reference works have recommended a peak postprandial glucose level of 140 mg/dl for any adult below 50 years of age, whilst raising it to 150 mg/dl and 160 mg/dl for patients aged between 50 and 60 years and more than sixty years, respectively.
See also
*
OGTT
*
Postprandial dip
*
Oxyhyperglycemia
*
postcibalome
References
External links
*
{{Diabetes
Diabetes-related tests