Glucose is a simple sugar found in the blood. Your body not only receives glucose from carbohydrate-rich foods, but is able to make glucose during times of inadequate intake. The body uses glucose for energy, as noted in "Krause's Food, Nutrition, and Diet Therapy" by L. Kathleen Mahan and Sylvia Escott-Stump. Hyperglycemia exists when too much glucose remains in the bloodstream. Hypoglycemia is a condition that occurs when too much glucose leaves the blood, resulting in a low blood sugar reading. Both conditions may be serious and require immediate attention.
Fasting Plasma Glucose
Fasting plasma glucose tests a blood sample after an eight-hour fasting period. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a normal fasting glucose reading is between 70 and 99 mg/dL. A reading of 100 to 125 mg/dL may indicate impaired fasting glucose. A fasting plasma glucose of 126 mg/dL or higher may suggest diabetes; however, a single high fasting blood glucose does not definitively diagnose diabetes. A repeat test is necessary to confirm the diagnosis, as noted by the NIDDK.
Random Blood Glucose
A random blood glucose sample measures the amount of glucose in the blood regardless of time of day or meal intake, as reported by the NIDDK. Food intake, activity level and stress impact random blood glucose samples. A normal random blood glucose is less than 200 mg/dL. As with the fasting plasma glucose, a single high reading is not sufficient to diagnose diabetes.
Point of Care
Point of care testing, also known as fingerstick blood glucose, utilizes a glucometer to provide a quick blood glucose level. A small needle pricks a part of the body to yield enough blood for the glucometer to display the glucose level. According to the National Institutes of Health, a normal pre-meal blood glucose level is between 70 and 130 mg/dL. A two-hour post-meal reading glucose of 180 mg/dL is normal.
Oral Glucose Tolerance
An oral glucose tolerance test (OGTT) is a fasting glucose test requiring consumption of a glucose solution. Blood samples are taken prior to drinking the glucose solution and repeat samples are drawn two hours later. The NIDDK reports a lab value of 139 mg/dL or lower is normal. A reading of 140 to 199 mg/dL indicates impaired fasting glucose, while 200 mg/dL and higher implies diabetes. A repeat test is necessary to confirm the diagnosis of diabetes. A variation of this test helps diagnose gestational diabetes.
Hb A1c
The Hb A1c test measures the amount of hemoglobin or blood cells with a glucose fraction attached to the cell, as indicated by the National Institutes of Health (NIH). The sample provides the average blood sugar level over the past two to three months. The NIH reports a normal Hb A1 is less than 6 percent. A Hb A1c value of 6.5 percent is sufficient to diagnose diabetes.
Tips
Discuss your lab results with a medical professional. Limiting concentrated sweets, such as cookies, candy, soda and juice, may help reduce blood glucose levels.
References
- "Krause's Food Nutrition, and Diet Therapy"; L. Kathleen Mahan; Sylvia Escott-Stump;2004
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH: National Diabetes Information Clearing House: Diagnosis of Diabetes
- National Institutes of Health: Hb A1c
- National Institutes of Health: Blood Glucose Monitoring
