- βCGM detected high blood sugar in nearly all patient groups, including those considered well-controlled by HbA1c
- βPoorly controlled diabetes patients spent 60% of pre-op time with dangerously high glucose levels
- βStudy supports individualized CGM-based monitoring to reduce post-surgical complications
| Journal | Journal of clinical & translational endocrinology |
| Year | 2026 |
| Authors | Driessens, Woldring, Nijkamp |
| PMID | 41458099 |
What Was Studied and Why It Matters
People scheduled for pancreatic surgery face a double challenge: pancreatic tumors themselves can trigger diabetes or worsen existing blood sugar control, and poorly managed glucose levels before and during surgery significantly raises the risk of complications afterward. Researchers at a single center ran a pilot study from 2023 to 2025 to find out just how common hidden high blood sugar really is in these patients β and whether continuous glucose monitors (CGMs) could catch what standard lab tests miss.
What the Researchers Did
Fifteen patients with either Type 2 diabetes or newly diagnosed diabetes wore a blinded CGM device β meaning neither the patient nor the care team saw the readings in real time β for two weeks before surgery and two weeks around the time of the operation. The main measurement was "time above range," or how many hours per day blood sugar climbed above 180 mg/dL, a threshold linked to worse healing and infection risk.
What They Found
The results were striking across all three patient groups:
- Poorly controlled diabetes: These patients spent nearly 60% of their monitored time with blood sugar above 180 mg/dL before surgery β far higher than safe targets.
- Well-controlled diabetes: Even patients whose HbA1c suggested good control spent about 27% of their perioperative time above range, a surprising finding that standard lab work alone would have missed.
- Newly diagnosed diabetes: This group fluctuated considerably, spending about 17% of pre-op time above range but dropping to under 5% around surgery β possibly due to stress-response changes or medical adjustments.
One of the most important takeaways was the wide individual variation. Two patients with identical HbA1c scores could have very different day-to-day glucose patterns, something only a CGM can reveal.
What This Means for Real Patients
If you or a loved one has diabetes and is facing pancreatic surgery, this research is a strong argument for asking your surgical team about CGM monitoring in the weeks leading up to your procedure. A single HbA1c blood draw gives a three-month average β it cannot show dangerous overnight spikes or post-meal surges that may increase surgical risk.
For patients already using CGM devices at home, this study reinforces how valuable that real-time data truly is. Keeping your CGM sensors and supplies stocked and consistent in the weeks before any major procedure could make a meaningful difference. MDS Diabetes offers a wide range of CGM supplies and accessories to help patients stay equipped without interruption.
Bottom Line
This small but important pilot study confirms that hidden high blood sugar is common β even in diabetes patients who appear well-controlled on paper β before and during pancreatic surgery. Continuous glucose monitoring uncovered patterns that a standard HbA1c test simply cannot detect. The authors call for more individualized glucose management strategies before major surgery, and the evidence strongly supports giving CGM a central role in that plan. Larger studies are needed, but the direction is clear: better monitoring before the operating room likely means fewer complications after it.