The GGT bood test looks for an enzyme, or protein, called gamma-glutamyl transpeptidase (GGT) in your blood. GGT is found in liver cells. This test helps your doctor look for possible damage to your liver or its ducts. It can also help tell the difference between liver and bone disease if your results from a different blood test called alkaline phosphatase are abnormal. Higher than normal test results could be a sign of liver damage from diseases such as hepatitis, cirrhosis, tumors, or pancreatic cancer. But a higher than normal GGT level does not tell you the specific cause of liver disease or damage.

A single fasting growth hormone (GH) level is of limited value. The secretion of GH is episodic and pulsatile. GH has a half-life of 20 to 25 minutes. Testing for growth hormone deficiency or excess is best done as part of a dynamic test involving specific stimuli (see the online Endocrine Appendices: Growth Hormone Stimulation and Growth Hormone Suppression). Insulin-like growth factor-1 can also be useful in assessing growth hormone status.

The thyroid stimulating hormone (TSH) is produced and secreted by the pituitary gland and stimulates the thyroid to produce T3 and T4. When TSH is elevated, low thyroid function may be indicated. If TSH is low it is indicative of high thyroid function. A study found that TSH was suppressed in all subjects after food, so fasting may be suggested although it is not reqired by Quest. Free T4 and Free T4 values did not change significantly after eating.

Insulin-like Growth Factor 1, also known as IGF-1, is used as a biomarker for blood levels of human growth hormone. It is a hormone produced by the liver and other tissues which affects growth-promoting activities and glucose metabolism. The blood level of IGF-1 appears to fluctuate over 24 hours and is found to be related to growth hormone secretion.

SHBG (sex hormone binding globulin) binds to testosterone and estradiol. High SHBG may decrease free testosterone and free estradiol.

The Urinalysis test panel screens for a variety of conditions including urinary tract infections ( UTI ), urinary bladder disease, kidney disease and diabetes. Tests included: Color, Appearance, Specific gravity, pH, Protein, Glucose, Occult blood, Ketones, Leukocyte esterase, Nitrite, Bilirubin, Urobilinogen, and Microscopic examination of urine sediment

Cortisol (hydrocortisone) is the most prominent glucocorticosteroid, and it is essential for the maintenance of several body functions. The most important physiological effects of cortisol are that it raises blood sugar levels (enhances gluconeogenesis, or breaks down glucose) and lowers inflammation and the immune system.

T3 or triiodothyronine is the active form of the thyroid hormone. T3 acts as a metabolic throttle for fueling all of the daily cellular functions. Free T3 is the unbound portion of T3 that is biologically active.

The serum iron test measures the amount of iron in your blood. The total iron-binding capacity (TIBC) test looks at how well the iron moves through your body.

Vitamin B-12 is an essential vitamin. Low blood levels of B12 can cause: Anemia and pernicious anemia, loss of balance , numbness or tingling in the arms and legs, and weakness

The electrolyte panel includes: Carbon dioxide, chloride, potassium, and sodium  

Ferritin is a protein that stores iron. Red blood cells need iron to form normally and carry oxygen around your body. Low levels of ferritin lead to iron deficiency anemia, which means you have too few red blood cells. High levels of ferritin can damage your joints, heart, liver, and pancreas.

B12 and folic acid blood testing help doctors diagnose central nervous system disorders, anemia, and malabsorption syndromes. B12 and folic acid also play an important role in energy level, muscle strength and memory. Because B12 and folate are derived solely from dietary intake, such as egg yolks, beef, poultry and fish, many people are deficient in these important vitamins.

Elevated levels of homocysteine in the blood, known as hyperhomocysteinemia, have been linked to an increased risk of cardiovascular disease, including heart attack and stroke. High homocysteine levels may also be associated with an increased risk of certain other health conditions, such as osteoporosis and pregnancy complications.