carbs 2

24–28 weeks

Timeframe of gestation for initial screening procedure for gestational diabetes in women not previously diagnosed with overt diabetes

50g

Oral glucose load administered during the nonfasting Glucose Challenge Test screening

1 hour

Elapsed time before measuring blood glucose following the 50-g load in the Glucose Challenge Test

>140 mg/dL

Plasma glucose threshold 1 hour after a 50-g load indicating proceed to 100-g OGTT

7.8 mmol/L

SI unit equivalent threshold for >140 mg/dL measured 1 hour after a 50-g load

100g

Glucose load administered during Step 2 of the Two-Step OGTT

Fasting

Patient preparation status required prior to Step 2

Insulin Tolerance

Tolerance test evaluating sensitivity to insulin and anterior pituitary / adrenal cortex function

30 minutes

Elapsed time after insulin injection before oral glucose administration in Insulin Glucose Tolerance Test

Galactose Tolerance Test

Tolerance test detecting impaired glycogenolysis due to severe liver damage

Leucine Tolerance Test

Tolerance test indicated for children suffering from hypoglycemic episodes

Tolbutamide Tolerance Test

Tolerance test evaluating hypoglycemic effects caused by an insulinoma

Intravenous Glucose Tolerance Test

Tolerance test for diabetic patients with GI disorders unable to tolerate large oral carbohydrate loads

Hexokinase, Glucose Oxidase (Saifer-Gernstenfield), Glucose Oxidase (Polarographic), Glucose Dehydrogenase

Four enzymatic methods for measuring glucose

Copper Reduction and Ferric Reduction

Two chemical oxidation-reduction categories for glucose measurement

Hexokinase

Enzymatic principle serving as the Reference Method for glucose determination

G6PD

Enzyme employed in the second coupling step of the hexokinase principle

Magnesium

Ion cofactor required by G6PD in the hexokinase principle

340 nm

Measurement wavelength for the increase in absorbance of NADPH/NADH in hexokinase assay

BaSO4 and ZnSO4

Two chemical reagents used to deproteinize plasma prior to hexokinase assay

Leuconostoc mesenteroides

Bacterial source organism of G6PD used in hexokinase assay

Falsely low glucose

Interference effect of gross hemolysis on glucose values in hexokinase method

>500 mg/dL

Triglyceride concentration threshold causing falsely low glucose in hexokinase method

Phosphoglucose isomerase (PGI)

Enzyme released by hemolysis that converts G6P into fructose-6-phosphate

Ascorbic acid or uric acid

Two reducing substances that do not affect the hexokinase method

Beta-D-glucose

Specific stereoisomer form of D-glucose recognized by glucose oxidase

Mutarotase

Enzyme required to convert alpha-D-glucose to beta-D-glucose

36%

Percentage of alpha-D-glucose converted to beta-D-glucose by mutarotase

Trinder's Reaction

Common designation for the coupled colorimetric enzyme reaction in Saifer-Gernstenfield method

540 nm

Measurement wavelength for red-colored oxidized o-dianisidine

Peroxidase

Enzyme inhibited by uric acid, ascorbic acid, bilirubin, tetracycline, hemoglobin, and glutathione

Consumption of oxygen

Parameter measured to quantify glucose in polarographic glucose oxidase methods

Oxygen-sensing electrode

Sensor device used to measure oxygen consumption rate in glucometers

Catalase

Reagent enzyme inhibiting the reversible movement of hydrogen peroxide in polarographic method

Gluconolactone

Reaction product formed from glucose oxidation by glucose dehydrogenase

Shorten

Role of mutarotase added to glucose dehydrogenase reagent ______ the time necessary to reach equilibrium

Bacillus cereus

Bacterial source organism of glucose dehydrogenase

Hexokinase

Reference procedure with which glucose dehydrogenase results show close agreement

Cuprous ions

Ionic reduction product formed when glucose reacts in hot alkaline solution

Phosphomolybdate

Reagent reacting with cuprous ions in Folin-Wu method to form phosphomolybdenum blue

80-120 mg/dL

Glucose reference value range in Folin-Wu method

Arsenomolybdate

Reagent reacting with cuprous ions in Nelson-Somogyi method to form arsenomolybdenum blue

Most accurate REDOX test for glucose

Designation of Nelson-Somogyi method among chemical glucose assays

2,9 dimethyl, 1,10-phenanthroline hydrochloride

Chemical name corresponding to Neocuproine reagent

Thiosulfate

Chemical solution used to titrate excess iodine until colorless in Shaffer-Hartman-Somogyi method

Indirectly proportional

Mathematical relationship between thiosulfate volume used and glucose concentration

Yellow

Color change occurring when glucose reduces ferricyanide in hot alkaline solution ______ ferricyanide to form a colorless ferrocyanide

Hagedorn–Jensen Method

First automated glucose measurement method adopted by Technicon Auto Analyzer

420 nm

Measurement wavelength for decrease in ferricyanide color in Hagedorn-Jensen method

N-glycosylamine plus a Schiff's base

Green reaction products formed when glucose reacts with o-toluidine in hot glacial acetic acid

Most specific non-enzymatic method for glucose

Specificity designation of O-Toluidine / Dubowski method

Hydroxymethylfurfural

Compound formed from glucose in hot strongly acidic solution during Anthrone's Test

N-terminal valines of the beta-chains

Specific molecular location on hemoglobin A tetramer irreversibly glycosylated in HbA1c

Past 2-3 months

Preceding timeframe of average blood glucose level provided by HbA1c

Two times a year

Testing frequency of HbA1c for patients meeting treatment goals with stable control

Quarterly

Testing frequency of HbA1c for patients with changed therapy or not meeting goals

EDTA whole blood

Preferred non-fasting blood specimen type for HbA1c testing

Hemolysate

Required preparation step performed on EDTA whole blood before HbA1c assay

Hemoglobinopathies

Red blood cell disorder causing a false decrease in HbA1c levels

Diabetes Control and Complications Trial (DCCT) assay

Reference Method for HbA1c assay standardization

Aldamine or Schiff's base

Initial labile condensation product formed when glucose reacts with Hgb amine group

Amadori rearrangement

Chemical rearrangement converting aldamine into stable ketoamine glycosylated hemoglobin

<5.7% (<39 mmol/mol)

Normal HbA1c reference percentage range

5.7% - 6.4%

HbA1c value percentage range indicating prediabetes / risk for diabetes

>=6.5% (>=48 mmol/mol)

Diagnostic HbA1c threshold indicative of diabetes mellitus on at least two occasions

35 mg/dL

Plasma glucose concentration added per 1% change in HbA1c value

28.7 x HbA1c - 46.7

Formula for estimated average glucose (eAG) in mg/dL from HbA1c

Fructosamine

Generic chemical name for plasma protein ketoamines

Albumin

Plasma protein whose lysine residues undergo glycosylation to form fructosamine

2–3 weeks

Timeframe of short-term glycemic control reflected by fructosamine

Hemoglobinopathies and hemolytic anemias

Primary clinical indication for ordering fructosamine instead of HbA1c

<= 3.0 g/dL

Serum albumin concentration threshold below which fructosamine test cannot be performed

<285 umol/L

Normal fructosamine reference value in non-diabetic individuals

302–357 umol/L

Fructosamine value range indicating moderate glycemic control

Erythrocyte galactose-1-phosphate uridyl transferase activity

Diagnostic test verifying Galactosemia in pediatric patients

Galactose-1 phosphate uridyl transferase

Deficient enzyme in Type I Galactosemia

Galactokinase

Deficient enzyme in Type II Galactosemia

Galactose epimerase

Deficient enzyme in Type III Galactosemia

Glycogen Storage Diseases

Category of inherited metabolic disorders suggested by hypoglycemia with liver enlargement

Glucose-6-phosphatase

Deficient enzyme in Type Ia Glycogen Storage Disease (Von Gierke)

Glucose-6-phosphatase translocase

Deficient enzyme translocase in Type Ib Glycogen Storage Disease

Lysosomal 1,4-glucosidase

Deficient enzyme in Type II Glycogen Storage Disease (Pompe's)

Debranching enzyme (liver and muscle)

Deficient enzyme in Type IIIa Glycogen Storage Disease (Cori Forbes) in liver and muscle

Branching enzyme

Deficient enzyme in Type IV Glycogen Storage Disease (Andersen's Disease / Amylopectinosis)

Muscle phosphorylase

Deficient enzyme in Type V Glycogen Storage Disease (McArdle)

Glycogen phosphorylase (liver)

Deficient enzyme in Type VI Glycogen Storage Disease (Hers Disease

Phosphofructokinase

Deficient enzyme in Type VII Glycogen Storage Disease (Tarui)

Glucose Transporter 2 (GLUT)

Deficient transporter in Type XI Glycogen Storage Disease (Fanconi-Bickel Syndrome)

100-125 mg/dL

Fasting Plasma Glucose concentration range indicating Impaired Glucose

>=126 mg/dL

Fasting Plasma Glucose threshold diagnostic for Diabetes Mellitus

140-199 mg/dL

2-hr OGTT plasma glucose concentration range indicating Impaired Glucose

>=200 mg/dL

2-hr OGTT plasma glucose threshold diagnostic for Diabetes Mellitus

OGTT

Laboratory test serving as the confirmatory procedure for Diabetes Mellitus

HbA1c

Laboratory test serving as the primary monitoring assay for long-term glycemic control