 |
|
|
Assay method |
Enzymatic, colorimetric assay. |
|
Analyzer |
Hitachi 917 or on open system following the assay procedure described in the directional insert. |
|
Specimen collection and storage |
4 µL serum or EDTA plasma. (for Hitachi 917)
Specimens are stable at room temperature or 2-8c for up to one week. Freezing is recommended for longer storage. (Freeze/thaw cycles up to three times) |
|
Intra- and inter assay imprecision range |
1.3–3.8% and 0.8–3.8% respectively. |
|
Kit storage and stability |
GlycoMark is stable at refrigerated temperature (2-8c) until the expiration date noted on the outer box. Once-opened vials are stable for 30 days. (at 2-8c) |
Expected Values
A
study was done with a presumptively normal population in order to
determine GlycoMark reference ranges for 1,5AG. The study included
serum samples from 82 males between the ages of 18 and 39, 82 females
between the ages of 18 and 39, and 30 males and 30 females of age 40 or
greater, for a total of 224 individuals. Ethnic backgrounds included
African Americans, Caucasians, Asians, and Hispanics. The data did not
demonstrate differences in ages, but there were gender differences. The
following table provides the male and female ranges, based on
non-parametric 5th-95th percentiles.
GlycoMark Reference Ranges
|
GlycoMark Reference Ranges |
Mean (SD) µg/mL 1,5AG |
Reference Interval µg/mL 1,5AG |
|
Males |
22.5 (5.8) |
10.7-32.0 |
|
Females |
17.7 (6.2) |
6.8-29.3 |
These ranges are provided only as guidelines. Each laboratory should establish their own reference ranges .
The following is a general guidance for interpretation of 1,5AG level and glycemic status suggested in Japan. For informational purposes only. Each laboratory should establish its own reference range.
|
GlycoMark (µg/mL) |
Assessment of Diabetes |
Blood Glucose (BG) Level |
|
14.0 or higher |
Normal (healthy) |
Under 160 mg/dL throughout |
|
10.0 – 13.9 |
Well controlled glycemia |
Under 200 mg/dL throughout |
|
6.0 – 9.9 |
Moderately controlled glycemia |
Day time BG 200-300 mg/dL |
|
2.0 – 5.9 |
Poorly controlled glycemia |
|
|
1.9 or lower |
Very-poorly controlled glycemia |
|
(An excerpt from lecture by Dr. Toshikazu Yamanouchi, University of Teikyo, Japan, 2004)
Limitations
- Persistently
positive urinary glucose levels or oxyhyperglycemia after gastrectomy,
may result in a low 1,5AG value. Low values have also been observed in
pregnancy, terminal stage renal failure, dialysis patients, advanced
cirrhosis, and prolonged incapability of oral ingestion of food. Abnormal values have also been noted in individuals with abnormal glomerular filtration rates.
- For
some patients with severe hyperglycemia, the internal pool of 1,5AG may
tend to remain depleted as a result of persistent glucosuria. In
these cases, measurements of 1,5AG may be less indicative of initial
recovery following initiation of anti-diabetic treatment.
- Values
may be increased during intravenous hyperalimentation. 1,5AG values may
be lower in patients undergoing therapy with steroids.
Test Availability
The laboratory service for GlycoMark test (order code: ES500609) is currently available at LabCorp (Phone: 800-762-4344 or www.labcorp.com/) and Esoterix Inc. (Phone: 800-444-9111 or www.esoterix.com)
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