The primary difference between insulin resistance and pre-diabetes is that the insulin resistance causes pre-diabetes. Insulin resistance is a metabolic disorder that causes an increase in blood glucose levels. Pre-diabetes is a newly named condition that is characterized by moderately high glucose levels in people who do not meet the diagnostic criteria for type 2 diabetes.
Blood Glucose Tests
The diagnosis of pre-diabetes is made from one of two different tests for elevated blood glucose. The fasting blood glucose test measures the concentration of glucose in a small sample of blood after a 12 hour fast. For the oral glucose tolerance test, blood glucose is measured after fasting and also 2 hours after drinking a beverage that contains 75 grams of glucose. This test determines whether a person has an impaired response to a rapid increase in blood glucose. Normally, after glucose is ingested cells in the pancreas secrete insulin, which rapidly decreases the amount of glucose in the blood by increasing cellular uptake. In individuals with impaired glucose tolerance, the increase in blood glucose lasts for a longer period of time, which is indicative of insulin resistance.
Pre-diabetes
The American Diabetes Association diagnostic criteria for pre-diabetes are fasting blood glucose levels between 100 and 125 mg/deciliter and/or glucose levels between 140 and 199 mg/dL after an oral glucose tolerance test. The ADA states that the reason for naming the condition of moderate hyperglycemia pre-diabetes is to increase the awareness that people with even moderately high glucose levels have a high probability of developing type 2 diabetes and are already at risk for developing cardiovascular complications. The National Diabetes Information Clearing House reported that one in four adults in the United States is pre-diabetic.
Insulin Resistance
Insulin resistance is a condition in which certain cells, including muscle, fat and liver cells in the body do not respond well to insulin. The primary function of insulin is to increase the cellular uptake of glucose. When cells do not take up glucose, glucose accumulates in the blood. To compensate, beta-cells in the pancreas produce and release more insulin to reduce blood glucose levels. Therefore people with insulin resistance also have hyperinsulinemia. The main consequences of insulin resistance are an elevation in fasting blood glucose levels and an increase in the duration of high glucose levels after consuming a meal. The main risk factor for insulin resistance is obesity. Other risk factors include genetics, race, sedentary lifestyle and poor diet.
