The Best Way To Screen For Prediabetes May Not Involve A Blood Test At All
Most prediabetes diagnoses happen by accident—a routine blood draw, a physical you almost skipped, a lab result that nearly got missed. For the roughly one in three US adults with elevated blood sugar who go undiagnosed, the barrier often isn't biology. It's access.
New research1 introduces a smarter first step: MEDWACS, a free AI-powered screening tool that uses seven simple measurements you can take at home to estimate your risk before you ever need a clinic visit.
About the study
MEDWACS (short for Machineborne Early Diabetic Warning And Control System) was built by feeding 30 years of US health data from over 17,000 adults into an AI model to find out which simple body measurements best predict prediabetes or diabetes risk.
The goal was a tool anyone could use at home, no blood draw required.
To make sure it worked beyond the original dataset, researchers tested it on two separate groups (one in the US and one in South Korea) and it held up in both.
Seven measurements that outperformed standard guidelines
The final MEDWACS model uses seven parameters, all of which can be measured at home with a tape measure, a blood pressure cuff, and a scale:
- Age: Risk increases with age, making it one of the strongest predictors in the model.
- Waist circumference: Closely linked to how well the body processes blood sugar and responds to insulin.
- Systolic blood pressure: The top number in a blood pressure reading; elevated levels are associated with blood sugar problems, and the two often go hand in hand.
- Gender: Biological sex influences how and where the body stores fat, affecting overall risk.
- Upper leg length: A proxy for early-life stressors, body composition, and metabolic health, reflecting the "developmental origins" hypothesis, where early-life growth patterns are linked to later insulin resistance.
- Arm circumference: An indicator of body composition beyond what BMI captures alone.
- BMI (body mass index): Calculated from height and weight as a general measure of body composition.
When tested against the two main US screening frameworks (the USPSTF and ADA guidelines), MEDWACS outperformed both.
At a 30% risk threshold, it identified five additional true positive cases per 100 people screened compared to the ADA strategy, without increasing unnecessary testing.
What the numbers are actually telling you
Of the seven measurements, age, waist circumference, and systolic blood pressure carried the most predictive weight. Waist circumference is closely tied to how well your body processes blood sugar.
Systolic blood pressure tends to climb alongside blood sugar problems, and the two often go hand in hand. The study also found that a larger arm circumference, combined with a wide waist and older age, was linked to higher risk.
Both waist circumference and blood pressure are worth tracking because they can change with lifestyle; diet, exercise, and stress management all influence them.
How to use MEDWACS as a starting point
Once you have your seven measurements, plug them into the free MEDWACS online self-assessment tool; it takes just a few minutes.
Your result appears as a risk probability score on a gauge chart. The tool also includes step-by-step instructions for measuring waist circumference, arm circumference, and upper leg length if you're unsure how to take them accurately.
The researchers recommend these cutoffs:
- Under 65: flag as higher risk at 45.3% or above
- 65 and older: flag as higher risk at 79.4% or above
If your score lands above your threshold, bring it to your doctor. From there, they can order a fasting plasma glucose test or an HbA1c test (a blood marker for average blood sugar levels) to confirm whether prediabetes or diabetes is present.
If prediabetes is confirmed, you have real options.
Lifestyle interventions have been shown to meaningfully slow or prevent progression to type 2 diabetes—21 years of data back this up, and one 20-year study points to a specific habit that can cut risk significantly.
For next steps, ask your doctor about routine bloodwork worth prioritizing at this stage.
The takeaway
MEDWACS offers a validated, no-cost way to flag your risk before a clinic visit is even on your radar. If your score comes back elevated, treat it as a prompt to get proper bloodwork done. Early detection is where the real opportunity lies.