Common Laboratory (LAB) Values [ G ]

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Gastrin (serum) Glucagon (Serum) Glucose (fasting) plasma Glucose (ADA goals) Glucose-6-phosphate dehyrogenase (G6PD) Glucose tolerance test (GTT) Plasma Gamma Glutamyl Transferase, Serum(GTT) Growth Hormone (serum) GH
Lab (Specimen)	Conventional Units	SI Units
Gastrin (serum)	< 200 pg/mL (nonfasting) < 100 pg/mL (fasting)	< 200 ng/L (nonfasting) < 100 ng/L (fasting)
Glucagon (Serum)	50 - 200 pg/mL	50 - 200 ng/L
Glucose (fasting) plasma	< 110 mg/dL	< 6.1 mmol/L
Glucose (ADA goals)	Blood sample drawn from a vein (a whole-blood sample) Before meals (fasting) 80 mg/dL to 120 mg/dL Bedtime: 100 mg/dL to 140 mg/dL Blood sample drawn from a fingertip (plasma blood sample) Before meals (fasting) 90 mg/dL to 130 mg/dL Bedtime: 110 mg/dL to 150 mg/dL Less than 180 mg/dL one to two hours after meals. The ADA also recommends a hemoglobin A1c (HbA1c) target level of less than 7%.
Glucose-6-phosphate dehyrogenase (G6PD) (Blood)	5 - 13 U/g Hb	5 - 13 U/g Hb
Glucose tolerance test (GTT) Plasma	Fasting Blood Glucose From 70 to 99 mg/dL (3.9 to 5.5 mmol/L) Normal glucose tolerance From 100 to 125 mg/dL (5.6 to 6.9 mmol/L) Impaired fasting glucose (pre-diabetes) > /= 126 mg/dL (7.0 mmol/L)  on more than one testing occasion Diabetes Oral Glucose Tolerance Test (OGTT) [except pregnancy] (2 hours after a 75-gram glucose drink) Less than 140 mg/dL (7.8 mmol/L) Normal glucose tolerance From 140 to 200 mg/dL (7.8 to 11.1 mmol/L) Impaired glucose tolerance (pre-diabetes) Over 200 mg/dL (11.1 mmol/L) on more than one testing occasion Diabetes Gestational Diabetes Screening: Glucose Challenge Test (1 hour after a 50-gram glucose drink) Less than 140* mg/dL (7.8 mmol/L) Normal glucose tolerance 140* mg/dL (7.8 mmol/L) and over Abnormal, needs OGTT (see below) * Some use a cutoff of >130 mg/dL (7.2 mmol/L) because that identifies 90% of women with gestational diabetes, compared to 80% identified using the threshold of >140 mg/dL (7.8 mmol/L). Gestational Diabetes Diagnostic: OGTT (100-gram glucose drink) Fasting* 95 mg/dL (5.3 mmol/L) 1 hour after glucose load* 180 mg/dL (10.0 mmol/L) 2 hours after glucose load* 155 mg/dL (8.6 mmol/L) 3 hours after glucose load* ** 140 mg/dL (7.8 mmol/L) * If two or more values are above the criteria, gestational diabetes is diagnosed. ** A 75-gram glucose load may be used, although this method is not as well validated as the 100-gram OGTT; the 3-hour sample is not drawn if 75 grams is used.
Gamma Glutamyl Transferase, Serum  (GTT)	Male:  8-61 U/L (< 65 U/L) Female 5-36 U/L (< 45 U/L)
Growth Hormone (serum) GH	< 8 ng/mL	< 8 µg/L
Important Notes
>Unless noted, all values are for adults. >All laboratory values listed are method dependent (Methods include: immunoassay, colorimetry, electrophoresis, HPLC, etc). >Values may vary between laboratories.