Quick Facts
- Sample: Blood draw (EDTA tube)
- Fasting: 8 hours required
- Turn-around: 3–5 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Early diabetes detection - identifies risk 5-7 years before glucose abnormalities appear
- Comprehensive pancreatic assessment - evaluates β-cell function beyond standard glucose testing
- No doctor referral needed - direct access for proactive health monitoring
- High diagnostic accuracy - 85% sensitivity and 100% specificity for detecting dysfunction
- Cardiovascular risk insight - elevated levels linked to heart disease risk
- Quick, convenient results - confidential results within 3-5 days
Who Is This Test For?
- Individuals with family history of diabetes seeking early screening
- People experiencing unexplained hypoglycemia symptoms (confusion, sweating, shakiness)
- Those with cardiovascular risk factors requiring comprehensive metabolic evaluation
- Health-conscious consumers wanting proactive diabetes risk assessment
- Patients with previous abnormal glucose test results needing further evaluation
- Anyone monitoring pancreatic β-cell function as part of preventive care
How It Works – Just 3 Steps
- Fast for 8 hours before your blood draw appointment at any partner location
- Quick blood sample collected in a special EDTA tube, then processed on ice
- Receive results within 3-5 hours via secure online portal with reference ranges
FAQ
What does this test measure? Proinsulin levels in your blood, which indicate how well your pancreatic β-cells are functioning and your diabetes risk.
How is this different from regular glucose testing? Proinsulin testing detects pancreatic dysfunction years before glucose levels become abnormal, providing earlier warning signs.
What do elevated results mean? Levels above 22 pmol/L suggest β-cell dysfunction and increased diabetes risk, requiring follow-up evaluation.
Can this test diagnose diabetes definitively? No, but it's an excellent screening tool that identifies high-risk individuals who need additional testing.
Is fasting absolutely required? Yes, an 8-hour fast is essential for accurate results, though you can drink water during this period.
Should I stop taking medications before testing? Inform the lab about all medications, especially insulin or diabetes drugs, but don't stop without consulting your healthcare provider.
More Details
What is the purpose of this test?
The proinsulin blood test measures a precursor molecule to insulin, providing critical insight into pancreatic β-cell function and diabetes risk assessment. Unlike standard glucose testing, proinsulin levels can detect metabolic dysfunction years before clinical symptoms appear (Mayo Clinic 2025). This test also helps diagnose insulin-secreting tumors and evaluate unexplained hypoglycemia episodes.
Who would benefit from this test?
People with family histories of diabetes benefit most from early screening capabilities. Individuals experiencing unexplained hypoglycemia symptoms like confusion, shakiness, or sweating should consider testing. Those with cardiovascular risk factors gain valuable insight, as elevated proinsulin levels independently predict heart disease risk (UCSD Health 2025). The test is also valuable for comprehensive metabolic evaluations in health-conscious consumers.
When should I order a Proinsulin Blood Test?
Consider ordering when assessing diabetes risk, especially after abnormal glucose results or when experiencing hypoglycemia symptoms. The test is particularly valuable as part of comprehensive metabolic evaluation for individuals with multiple risk factors. Studies show it's most effective when used proactively before glucose abnormalities develop (Journal of Diabetes Science and Technology 2017).
How do I interpret the results?
3.6–22 pmol/L
- Meaning: Normal pancreatic function
- Action: Continue routine monitoring
22–50 pmol/L
- Meaning: Mild β-cell dysfunction
- Action: Lifestyle modifications, repeat testing
Above 50 pmol/L
- Meaning: Significant dysfunction or possible insulinoma
- Action: Immediate medical evaluation required
Values above 22 pmol/L after fasting show 98% specificity for metabolic dysfunction, making this an excellent screening parameter.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
Fast for 8 hours before specimen collection (6 hours maximum for children under 2 years). Maintain normal water intake during the fasting period. Inform lab personnel about any medications you're taking, particularly insulin or oral diabetes medications. Some providers may recommend a 2-hour post-meal test for evaluating β-cell function under glucose challenge.
How often should I get tested?
- Normal results, low risk – Every 2–3 years
- Elevated results or family history – Every 6–12 months
- Active diabetes management – As directed by healthcare provider
- Cardiovascular risk factors – Annually with other metabolic panels
Why early detection matters
Elevated proinsulin levels predict type 2 diabetes development up to 5-7 years in advance, allowing time for preventive interventions (Diabetes & Metabolism 2015). Studies show all patients with impaired glucose tolerance who had elevated proinsulin levels progressed to diabetes within 5 years. Early detection enables lifestyle modifications, weight management, and medical interventions that can delay or prevent diabetes onset.
Related tests you may consider
C-peptide Test - provides complementary information about insulin production and helps differentiate between type 1 and type 2 diabetes when ordered with proinsulin.
Glucose Tolerance Test, 2-Hour - evaluates glucose processing over time and identifies highest-risk individuals when combined with proinsulin measurement.
Hemoglobin A1C - measures long-term glucose control and complements proinsulin testing by providing insight into existing glucose management.
