Many reference intervals or standard reference ranges differ for pediatrics and adults, and some even differ for various stages of childhood development. Therefore, many ranges are not interchangeable between adults and children.
Blood chemistry ranges for infants, pediatrics, and oftentimes adolescents can be different from those for adults. Growth, development, and maturity of organ systems are some of the variables that affect blood chemistry reference ranges for children (Coffin 2018).
For example, alkaline phosphatase will be highest in children and adolescents due to new bone growth, with levels decreasing and leveling off in early adulthood. Persistently elevated alkaline phosphatase into adulthood should be investigated for potential bone, liver, or gallbladder dysfunction, as well as metastatic disease (Pagana 2021).
Evaluation of complete blood count data from 804,623 subjects ranging in age from 3 to 99 years noted that RBCs, WBCs, and platelets increase with age in childhood and then decrease in adulthood. However, neutrophils were found to be lowest in early childhood increasing thereafter, while lymphocytes peaked in early childhood and declined thereafter.
Regarding evaluation of type 1 diabetes, some biomarker ranges will vary between pediatrics and adults. Though reference intervals/ranges can vary from lab to lab, standard (not necessarily optimal) guidelines include (Pagana 2021):
Fasting Glucose
- Premature infant: 20-60 mg/ dL or 1.1-3.3 mmol/ L
- Neonate: 30-60 mg/ dL or 1.7-3.3 mmol/ L
- Infant: 40-90 mg/ dL or 2.2-5 mmol/ L
- Child < 2 years: 60-100 mg/ dL or 3.3-5.5 mmol/ L
- Child > 2 years to adult:
- Fasting: 70-110 mg/ dL or < 6.1 mmol/ L (Fasting is defined as no caloric intake for at least 8 hours.)
- Casual: ≤ 200 mg/ dL (< 11.1 mmol/ L) (Casual is defined as any time of day regardless of food intake.)
- Adult: 74-106 mg/ dL or 4.1-5.9 mmol/ L
- Possible critical values
- Newborn: < 30 and > 300 mg/ dL (1.67 and 16.65 mmol/L)
- Infant: < 40 mg/ dL (2.22 mmol/L)
- Adult: < 50 and > 400 mg/ dL (2.77 and 22.2 mmol/L)
Insulin
- Newborn: 3-20 μU/ mL
- General: 6-26 μU/ mL or 43-186 pmol/ L (SI units)
- Possible critical values > 30 μU/ mL
C-Peptide (low or absent with type 1 diabetes)
- General:
- Fasting: 0.78-1.89 ng/ mL or 0.26-0.62 nmol/ L (SI units)
- 1 hour after glucose load: 5-12 ng/ mL
Hemoglobin A1C
- Nondiabetic adult or child: 4% to 5.9%
- Good diabetic control: < 7%
- Fair diabetic control: 8% to 9%
- Poor diabetic control: > 9%
Type 1 diabetes will also be characterized by decreased or absent secretion of insulin and C-peptide and may be accompanied by diabetic ketoacidosis. Diagnosis should include an evaluation of the 3 stages of its development including the following: (Chiang 2018):
Stage 1:Autoimmunity, normoglycemia, presymptomatic, autoantibodies, no dyglycemia (impaired glucose tolerance or impaired fasting glucose)
Stage 2: Autoimmunity, dysglycemia, presymptomatic, autoantibodies, dysglycemia:
-
- Fasting plasma glucose 100-125 mg/dL (5.6–6.9 mmol/L)
- 2-h PG 140–199 mg/dL (7.8–11.0 mmol/L)
- A1C 5.7–6.4% (39–47 mmol/mol) or ≥10% increase in A1C
Stage 3: New-onset hyperglycemia, symptomatic, meets standard criteria for diabetes diagnosis
References
Chiang, Jane L et al. “Type 1 Diabetes in Children and Adolescents: A Position Statement by the American Diabetes Association.” Diabetes care vol. 41,9 (2018): 2026-2044. doi:10.2337/dci18-0023
Coffin, Cheryl M et al. “Pediatric laboratory medicine: current challenges and future opportunities.” American journal of clinical pathology vol. 117,5 (2002): 683-90. doi:10.1309/NYA1-V9KQ-NVF8-MA8M
Nah, Eun Hee et al. “Complete Blood Count Reference Intervals and Patterns of Changes Across Pediatric, Adult, and Geriatric Ages in Korea.” Annals of laboratory medicine vol. 38,6 (2018): 503-511. doi:10.3343/alm.2018.38.6.503
Pagana, Kathleen Deska, et al. Mosby's Diagnostic and Laboratory Test Reference. 15th ed., Mosby, 2021.