Hypoglycemia laboratory findings: Difference between revisions
| Line 15: | Line 15: | ||
The strategy is to seek [[Whipple's triad]] under conditions in which hypoglycemia would be expected: | The strategy is to seek [[Whipple's triad]] under conditions in which hypoglycemia would be expected: | ||
* If the symptoms occur in the [[Fasting plasma glucose|fasting state]], that evaluation should be performed during fasting. | * If the symptoms occur in the [[Fasting plasma glucose|fasting state]], that evaluation should be performed during fasting. | ||
* If there is a compelling history of postprandial symptoms, it is reasonable to seek [[Whipple's triad]] with frequent, timed plasma [[Blood glucose monitoring|glucose measurements]] and recording of any symptoms after a mixed meal. | * If there is a compelling history of [[postprandial]] symptoms, it is reasonable to seek [[Whipple's triad]] with frequent, timed plasma [[Blood glucose monitoring|glucose measurements]] and recording of any symptoms after a mixed meal. | ||
* All of the following should be measured: | * All of the following should be measured: | ||
**[[Glucose]]: plasma glucose is usually <55-70 mg/dL. | **[[Glucose]]: plasma glucose is usually <55-70 mg/dL. | ||
Revision as of 17:49, 20 October 2017
|
Hypoglycemia Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Hypoglycemia laboratory findings On the Web |
|
American Roentgen Ray Society Images of Hypoglycemia laboratory findings |
|
Risk calculators and risk factors for Hypoglycemia laboratory findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Mohammed Abdelwahed M.D[2]
Overview
Laboratory investigations of hypoglycemia depend on many tests: plasma glucose is usually <55-70 mg/dL, insulin, c-peptide, proinsulin, sulfonylurea screen, beta-hydroxybutyrate, 24-hour fasting glucose level and identifying the cause after that.
Laboratory Findings
Defining Hypoglycemia
Hypoglycemia can't be diagnosed only by measuring blood glucose level because it is misleading maneuver with high false positive results. The measurement should be repeated using a collection tube that contains an inhibitor of glycolysis and processing should not be delayed.
So, the following 3 characteristics should be present to diagnose hypoglycemia, which is called Whipple's triad and includes:[1]
- Symptoms of hypoglycemia
- A low plasma glucose concentration correlated with symptoms
- Correction of glucose level relieves symptoms
The strategy is to seek Whipple's triad under conditions in which hypoglycemia would be expected:
- If the symptoms occur in the fasting state, that evaluation should be performed during fasting.
- If there is a compelling history of postprandial symptoms, it is reasonable to seek Whipple's triad with frequent, timed plasma glucose measurements and recording of any symptoms after a mixed meal.
- All of the following should be measured:
- Glucose: plasma glucose is usually <55-70 mg/dL.
- Insulin
- C-peptide
- Proinsulin
- Sulfonylurea and meglitinide screen
- Beta-hydroxybutyrate[2]
| Fasting evaluation[3][4] | Mixed-meal evaluation[5] |
|---|---|
|
|
24-hour fasting
- Increased release of glucagon, epinephrine, and cortisol is the most important factors that keep blood glucose concentrations from falling during fasting.
- Gluconeogenesis is the most important factor of glucose production after a prolonged fast.[7]
- If there is a high level of insulin, gluconeogenesis will be inhibited causing hypoglycemia during fasting.[8]
- The fasting is ended when: [9]
- Seventy-two hours have passed
- Plasma glucose concentration is ≤45 mg/dL
- Patient has symptoms or signs of hypoglycemia
- The precise level of glucose considered low enough to define hypoglycemia is dependent on:[10][11]
- Measurement method
- Age of the person
- Presence or absence of effects
- The purpose of the definition
Identifying the cause
After confirmation of hypoglycemia. Physicians should have history, signs and laboratory results sufficient to help them to identify the cause of hypoglycemia:
| Plasma insulin[12] | C-peptide[12] | proinsulin | Sulfonylurea in plasma | insulin or insulin receptor antibodies | Postprandial symptoms | Fasting symptoms | |
|---|---|---|---|---|---|---|---|
| Insulinoma | high | high | high | - | - | - | + |
| Oral hypoglycemics[13] | high | high | high | + | - | - | - |
| Autoimmune hypoglycemia[14] | high | high | high | - | + | - | - |
| NIPHS* | high | high | high | - | - | + | - |
| Exogenous insulin | high | low | low | - | - | - | - |
| Non-islet cell tumors | low | low | low | - | - | - | - |
*(NIPHS) non-insulinoma pancreatogenous hypoglycemia syndrome
Neonatal hypoglycemia:
Most of the neonatal hypoglycemias are transient but suspected cases as following should be investigated for metabolic diseases:
- Hypoglycemia that requires prolonged high rates of dextrose infusion
- Persistent hypoglycemia
- Neurologic symptoms
- History or physical findings suggestive of metabolic disease
What to measure?
- Measure plasma insulin, plasma C-peptide and beta-hydroxybutyrate
- Blood pH, bicarbonate, and lactate
- Free fatty acids, acylcarnitine profile, plasma free and total carnitine levels
Surveys of healthy children and adults show that plasma glucose below 60 mg/dL or above 100 mg/dL are found in less than 5% of samples after an overnight fast.[15]
In infants and young children, up to 10% have been found to be below 60 mg/dL after an overnight fast. As the duration of fasting is extended, plasma glucose levels can fall further, even in healthy people.
In other words, many healthy people can occasionally have glucose levels in the hypoglycemic range without symptoms or disease.
References
- ↑ Guettier JM, Gorden P (2006). "Hypoglycemia". Endocrinol Metab Clin North Am. 35 (4): 753–66, viii–ix. doi:10.1016/j.ecl.2006.09.005. PMID 17127144.
- ↑ Service FJ, O'Brien PC (2005). "Increasing serum betahydroxybutyrate concentrations during the 72-hour fast: evidence against hyperinsulinemic hypoglycemia". J Clin Endocrinol Metab. 90 (8): 4555–8. doi:10.1210/jc.2005-0033. PMID 15886243.
- ↑ Cryer PE, Axelrod L, Grossman AB, Heller SR, Montori VM, Seaquist ER; et al. (2009). "Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline". J Clin Endocrinol Metab. 94 (3): 709–28. doi:10.1210/jc.2008-1410. PMID 19088155.
- ↑ Service FJ, Natt N (2000). "The prolonged fast". J Clin Endocrinol Metab. 85 (11): 3973–4. doi:10.1210/jcem.85.11.6934. PMID 11095416.
- ↑ Seaquist ER, Anderson J, Childs B, Cryer P, Dagogo-Jack S, Fish L; et al. (2013). "Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society". Diabetes Care. 36 (5): 1384–95. doi:10.2337/dc12-2480. PMC 3631867. PMID 23589542.
- ↑ Service FJ (1999). "Diagnostic approach to adults with hypoglycemic disorders". Endocrinol Metab Clin North Am. 28 (3): 519–32, vi. PMID 10500929.
- ↑ Landau BR, Wahren J, Chandramouli V, Schumann WC, Ekberg K, Kalhan SC (1996). "Contributions of gluconeogenesis to glucose production in the fasted state". J Clin Invest. 98 (2): 378–85. doi:10.1172/JCI118803. PMC 507441. PMID 8755648.
- ↑ Hogan MJ, Service FJ, Sharbrough FW, Gerich JE (1983). "Oral glucose tolerance test compared with a mixed meal in the diagnosis of reactive hypoglycemia. A caveat on stimulation". Mayo Clin Proc. 58 (8): 491–6. PMID 6876881.
- ↑ Service FJ (1999). "Diagnostic approach to adults with hypoglycemic disorders". Endocrinol Metab Clin North Am. 28 (3): 519–32, vi. PMID 10500929.
- ↑ Cornblath M, Schwartz R, Aynsley-Green A, Lloyd JK (1990). "Hypoglycemia in infancy: the need for a rational definition. A Ciba Foundation discussion meeting". Pediatrics. 85 (5): 834–7. PMID 2330247.
- ↑ Cornblath M, Hawdon JM, Williams AF, Aynsley-Green A, Ward-Platt MP, Schwartz R, Kalhan SC (2000). "Controversies regarding definition of neonatal hypoglycemia: suggested operational thresholds". Pediatrics. 105 (5): 1141–5. PMID 10790476.
- ↑ 12.0 12.1 Vezzosi D, Bennet A, Fauvel J, Caron P (2007). "Insulin, C-peptide and proinsulin for the biochemical diagnosis of hypoglycaemia related to endogenous hyperinsulinism". Eur J Endocrinol. 157 (1): 75–83. doi:10.1530/EJE-07-0109. PMID 17609405.
- ↑ Perros P, Henderson AK, Carter DC, Toft AD (1997). "Lesson of the week. Are spontaneous hypoglycaemia, raised plasma insulin and C peptide concentrations, and abnormal pancreatic images enough to diagnose insulinoma?". BMJ. 314 (7079): 496–7. PMC 2125998. PMID 9056803.
- ↑ Lupsa BC, Chong AY, Cochran EK, Soos MA, Semple RK, Gorden P (2009). "Autoimmune forms of hypoglycemia". Medicine (Baltimore). 88 (3): 141–53. doi:10.1097/MD.0b013e3181a5b42e. PMID 19440117.
- ↑ Samuel Meites, editor-in-chief; contributing editors, Gregory J. Buffone... [et al.] (1989). Pediatric clinical chemistry: reference (normal) values. Washington, D.C: AACC Press. ISBN 0-915274-47-7.