Prediabetes is a stage or period of glucose intolerance in body that exists before the development of frank diabetes. In normal metabolic state, body cells use glucose as main source of energy which is derived from whatever food is consumed. Whatever amount of glucose is produced after food digestion, body utilizes that as source of energy and also stores the surplus glucose in a way that glucose levels in blood are maintained in normal range. This is defined as “Normal Glucose Tolerance”(NGT). Normal glucose tolerance in body is maintained by a hormone called “insulin” produced by beta cells of pancreas (an organ in body), which is key regulator of glucose metabolism.

Once there is predisposition to development of type 2 diabetes, body cells develop resistance to the regulatory actions of insulin(Insulin Resistance) on one hand and on the other there begins a progressive decline in beta cell production of insulin leading to insulin deficiency in body. As a result blood glucose levels start rising marking the onset “impaired glucose intolerance”(prediabetes) which gradually progresses to “glucose intolerance” or type 2 diabetes.

Blood glucose levels are measured as plasma glucose levels in the labs. Normal venous plasma glucose levels are as under –

Fasting = less than 100mg/dl
PP(postprandial/ 1.5 to 2 hrs after meal) = less than 140 mg/dl
A1c = less than 5.7%

Diabetes is said to be present when glucose levels are –
Fasting = more than 126 mg/dl
PP(postprandial/ 1.5 to 2 hrs after meal) = more than 200 mg/dl
Random = more than 200mg/dl
A1c = more than 6.5%

Prediabetes is said to be present when glucose levels are –
Fasting = 100-126mg/dl
PP(postprandial/ 1.5 to 2 hrs after meal) = 140-200mg/dl
A1c = 5.7-6.4%

Prediabetes is basically a long period of glucose intolerance that precedes the development of type 2 diabetes. Screening tests during this period can identify persons at risk of development of type 2 diabetes. Untreated individuals with prediabetes are at increased risk for diabetes as well as for microvascular(kidneys, eyes, nerves) and macrovascular(heart, brain) complications of diabetes. People who are overweight or obese, have sedentary lifestyle, high blood pressure, lipid abnormalities, or have family history of diabetes, are at high risk of developing prediabetes and type 2 diabetes.

It is very important to diagnose prediabetes as intervening at this stage can prevent diabetes and also help modify/control other risk factors such as obesity, high blood pressure, and lipid abnormalities. The same blood pressure and lipid goals are suggested for prediabetes and diabetes. Intensive lifestyle management is the cornerstone of all prevention efforts; pharmacotherapy(medications) targeted at glucose may be considered in high-risk patients.

Obese is possibly the most common predisposing factor for development of prediabetes and diabetes. Studies have shown that even modest weight reduction(5-7%) can help is preventing type 2 diabetes and also in restoring normal glucose tolerance in individuals with prediabetes. Therefore, weight management in an important component of prediabetes management and prevention of type 2 diabetes.