Insulin
Clinical Background:
Insulin is the principal hormone responsible for the control of glucose metabolism. It is synthesised in the β-cells of the islets of Langerhans as the precursor, proinsulin, which is processed to ...
Insulin is the principal hormone responsible for the control of glucose metabolism. It is synthesised in the β-cells of the islets of Langerhans as the precursor, proinsulin, which is processed to form c-peptide and insulin, which are secreted in equimolar amounts into the portal circulation. Secretion of insulin is mainly controlled by plasma glucose concentration and the hormone has a number of important metabolic actions. Its principal function is to control the uptake and utilisation of glucose in peripheral tissues. This and other hypoglycaemic actions, such as the inhibition of hepatic gluconeogenesis and glycogenolysis are counteracted by the hyperglycaemic hormones glucagon, adrenaline, growth hormone and cortisol. The principal clinical application of insulin measurement is in the investigation of unexplained hypoglycaemia.
Test Details
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Discipline:
Biochemistry
Biochemistry
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Specimen Container Adult:
Serum or plasma (LiHep or EDTA)
Serum or plasma (LiHep or EDTA)
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Specimen Container Paediatric:
Serum or plasma (LiHep or EDTA)
Serum or plasma (LiHep or EDTA)
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Minimum Volume Adult:
2 mL blood
2 mL blood
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Minimum Volume Paediatric:
1 mL blood
1 mL blood
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Special Requirement:
Samples should arrive in lab within 1 hour of sampling.
Fasting sample, unless part of dynamic function test, or during spontaneous hypoglycaemic episode.
Also send a sample for glucose (fluoride...Read MoreSamples should arrive in lab within 1 hour of sampling.
Fasting sample, unless part of dynamic function test, or during spontaneous hypoglycaemic episode.
Also send a sample for glucose (fluoride/oxalate). -
Sample Stability:
Unseparated: 2 hours
Separated:1 day at 4-8°C, 6 months at -20°CUnseparated: 2 hours
Separated:1 day at 4-8°C, 6 months at -20°C -
Transport Requirements:
External locations: send as frozen serum/plasma.
Internal samples: send unseparated at ambient temperature to be received within 1 hour of sampling.
External locations: send as frozen serum/plasma.
Internal samples: send unseparated at ambient temperature to be received within 1 hour of sampling.
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Interpretation:
The Mercodia Iso-insulin ELISA employs antisera with substantial cross reactivity with all commonly used insulin analogues. When used in combination with measurement of C-peptide this allows the re...
Read MoreThe Mercodia Iso-insulin ELISA employs antisera with substantial cross reactivity with all commonly used insulin analogues. When used in combination with measurement of C-peptide this allows the reliable detection of exogenous Insulin administration. When samples are taken during a hypoglycaemic episode, elevated insulin concentrations in the presence of suppressed c-peptide concentrations indicate exogenous insulin administration. Where both insulin and c-peptide are not appropriately suppressed, this indicates endogenous hyperinsulinism (e.g. due to the presence of an insulinoma or sulphonylurea administration).
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Reference Ranges:
Adult: 12 - 150pmol/L
Adult: 12 - 150pmol/L
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Factors Affecting Result:
Haemolysis in serum or plasma may result in a degradation of Insulin which could give falsely low values.
Heterophilic antibodies can interfere with immunoassays.Haemolysis in serum or plasma may result in a degradation of Insulin which could give falsely low values.
Heterophilic antibodies can interfere with immunoassays. -
Other Info:
EDTA or LiHep plasma also suitable
EDTA or LiHep plasma also suitable
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Routine Contact Name:
Duty Biochemist
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Routine Telephone:
Freeman: 0191 244 8889
RVI: 0191 282 9719
Freeman: 0191 244 8889
RVI: 0191 282 9719
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Routine Email:
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Specialist Test:
Yes
Yes
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Specialist Contact Name:
Endocrine Lab
Endocrine Lab
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Specialist Telephone:
0191 282 4025
0191 282 4025