Diabetes is an illness that decreases the body's ability to break down sugar for fuel. The body requires a chemical called insulin to metabolize sugars that are ingested. In type I diabetes, the body may fail to make insulin at all. Type II diabetics make insulin, but the body is not able to use it properly. If not treated, both of these conditions lead to high blood glucose levels, which can be dangerous and life-threatening.
Symptoms
Symptoms of diabetes include increased thirst, frequent urination, increased vulnerability to cuts and bruises, and tingling of the extremities. Diabetes is often difficult to diagnose because its symptoms resemble those found in many other conditions. Sometimes there may be no symptoms present at all, making a blood test necessary to provide a proper diagnosis.
A1c
The A1c test serves the dual purpose of diagnosing diabetes and evaluating diabetes management as the disease is treated. MayoClinic.com indicates that the A1c test gives an average blood glucose level over a two to three month period. This is accomplished by measuring the percentage of the patient's hemoglobin that is coated with sugar. High levels of sugar-coated hemoglobin signify that blood glucose is not being controlled properly. The test is administered several times per year to monitor blood glucose levels. Normal A1c levels range from 4 to 6 percent.
Fasting Plasma Glucose
The fasting plasma glucose test requires that blood be drawn after a patient has not eaten for eight hours. Physicians often prefer this exam for diabetes diagnosis due to its low cost and ease of administration. Normal levels are below 100 mg/dL. Levels of 100 to 125 mg/dL indicate pre-diabetes. Diabetes is diagnosed when levels exceed 126 mg/dL, according to the National Diabetes Information Clearinghouse.
C-peptide
C-peptide is a byproduct of insulin production. The C-peptide test measures the amount of this protein in the blood. The measurement of C-peptide indicates the amount of insulin produced by the body versus the amount of synthetic insulin injected. The National Diabetes Information Clearinghouse says that normal C-peptide levels range from ½ to two ng/ml. Normal values indicate that the body is producing its own insulin. Low values show that the body is not producing adequate amounts of insulin.
Blood Glucose Maintenance
Each of the blood glucose tests provides a way for physicians to diagnose diabetes and pre-diabetes. These tests also serve as a mechanism to monitor disease progression. The tests are performed at regular intervals to be sure that normal blood sugar levels are maintained. Regular testing alerts physicians of the need to change diet, exercise and medication regimens to ensure the patient's best health.
