When stroke patients have high blood sugar levels in the two days after emergency brain surgery to remove a blood clot, they’re more likely to have poor recovery and serious complications. Researchers studied 693 stroke patients who underwent a special procedure to remove blockages in major brain blood vessels. They found that patients whose blood sugar stayed elevated after the procedure were less likely to regain independence and had higher risks of brain bleeding and death. This suggests that keeping blood sugar controlled right after this type of stroke treatment might be important for better outcomes.

The Quick Take

  • What they studied: Whether blood sugar levels measured in the first two days after emergency stroke surgery affect how well patients recover
  • Who participated: 693 stroke patients from multiple hospitals who had emergency surgery to remove blood clots from major brain arteries within 24 hours of their stroke
  • Key finding: Patients with high blood sugar after surgery (above 7.6 mmol/L) were significantly less likely to recover independence and had nearly double the risk of serious brain bleeding and 71% higher risk of death within 90 days
  • What it means for you: If you or a loved one has this type of stroke surgery, doctors may need to pay close attention to blood sugar control during recovery. However, this is observational research, so it shows a connection but doesn’t prove high blood sugar causes the problems—more research is needed to confirm this relationship.

The Research Details

This was a multicenter cohort study, meaning researchers followed a group of patients across multiple hospitals and tracked what happened to them over time. They included 693 patients who had a specific type of emergency stroke treatment called endovascular therapy (EVT), which is a minimally invasive procedure where doctors thread a catheter through blood vessels to remove blood clots blocking major arteries in the brain.

The researchers measured blood sugar levels in the first 48 hours after the procedure, focusing on measurements taken before meals (when blood sugar is most stable). They then looked at whether these blood sugar measurements were connected to how well patients recovered 90 days later. They used statistical methods to account for other factors that might affect recovery, like stroke severity.

The study defined high blood sugar (hyperglycemia) as any blood sugar reading of 7.6 mmol/L or higher in the first two days after surgery. This threshold was determined by analyzing the data to find the point where outcomes started getting worse.

Previous research showed that high blood sugar at hospital admission predicted poor stroke outcomes, but nobody had carefully studied what happens with blood sugar after the emergency procedure itself. This study fills that gap by looking at the critical recovery period right after surgery, when patients’ normal eating patterns and body rhythms are disrupted by their severe illness. Understanding this timing matters because it might identify a window where doctors could intervene to improve outcomes.

This study has several strengths: it included a reasonably large number of patients (693) from multiple hospitals, which makes the findings more generalizable; it used statistical methods to account for other factors affecting recovery; and it looked at a clearly defined outcome (functional independence at 90 days). However, as an observational study, it can only show that high blood sugar is associated with worse outcomes—it cannot prove that high blood sugar causes the problems. The study was also limited to patients who survived the initial procedure and had blood sugar measurements recorded, which might exclude some patients. Additionally, the journal impact factor is not provided, so we cannot assess the publication venue’s prestige.

What the Results Show

The main finding was that for every unit decrease in average blood sugar after the procedure, patients were significantly more likely to achieve functional independence (the ability to perform daily activities without major help). When researchers compared patients with high blood sugar (hyperglycemia) to those with normal blood sugar, the high blood sugar group had only about half the odds of becoming functionally independent.

The study also found that high blood sugar after surgery was associated with a more than doubled risk of symptomatic intracranial hemorrhage—a serious complication where bleeding occurs inside the skull. Additionally, patients with high blood sugar had a 71% increased risk of death within 90 days.

When the researchers looked specifically at patients with severe strokes (those with very high initial stroke severity scores), the connection between high blood sugar and poor outcomes became even stronger. This suggests that high blood sugar may be particularly harmful for patients with the most serious strokes.

The study found that the relationship between blood sugar and outcomes held true even after accounting for other important factors like age, stroke severity at admission, and other medical conditions. The researchers used a statistical technique called restricted cubic spline regression to determine the exact blood sugar threshold (7.6 mmol/L) where outcomes started getting noticeably worse. This suggests there may be a specific target blood sugar range that doctors should aim for during recovery from this type of stroke treatment.

This research builds on earlier studies showing that high blood sugar at hospital admission predicts poor stroke outcomes. However, it extends that knowledge by examining blood sugar control during the critical recovery period immediately after emergency stroke surgery. Previous research had largely ignored this post-procedure period, so this study provides new information about an important but understudied timeframe. The findings align with general medical knowledge that high blood sugar can impair healing and increase infection risk, but this is the first detailed look at this relationship specifically in stroke patients undergoing emergency clot removal.

This study has several important limitations. First, it’s observational, meaning researchers watched what happened naturally rather than randomly assigning patients to different blood sugar control strategies. This means we can’t be certain that high blood sugar causes poor outcomes—there could be other factors involved. Second, the study only included patients who had blood sugar measurements recorded in the first 48 hours, which might exclude some patients and could bias the results. Third, the study didn’t look at what caused the high blood sugar or whether doctors tried to treat it, so we don’t know if controlling blood sugar would actually improve outcomes. Finally, the study was conducted in real-world hospital settings where blood sugar management practices may vary, which could affect the results.

The Bottom Line

Based on this research, doctors should consider monitoring blood sugar levels carefully in the first 48 hours after emergency stroke surgery and may want to work to keep blood sugar below 7.6 mmol/L if possible. However, this is a moderate-strength recommendation based on observational evidence—it’s not yet proven that actively controlling blood sugar will improve outcomes. Patients and families should discuss blood sugar management with their stroke care team. This is especially important for patients with severe strokes, where the risks appear higher.

This research is most relevant to people who have had or are at risk for large vessel occlusion strokes (strokes caused by major blood clots in the brain) and their families. It’s also important for stroke specialists, emergency room doctors, and intensive care doctors who care for these patients. People with diabetes or prediabetes should be particularly aware, as they may be at higher risk for both strokes and high blood sugar complications. However, this research doesn’t apply to people who haven’t had this type of stroke or emergency procedure.

The study measured outcomes at 90 days after the procedure, which is the standard timeframe for assessing stroke recovery. Most functional improvement after stroke occurs in the first three months, so this is an appropriate timeframe. If blood sugar control strategies are implemented, benefits would likely be seen within this 90-day window, though some patients may continue improving beyond this period.

Want to Apply This Research?

  • For stroke survivors or those at risk, track fasting blood sugar levels daily (if you have diabetes or prediabetes) and record any symptoms of high blood sugar like increased thirst, frequent urination, or fatigue. If you’ve had this type of stroke procedure, work with your doctor to establish target blood sugar ranges and log readings during the critical first 48 hours after treatment.
  • If you’re recovering from this type of stroke, work with your medical team to maintain stable blood sugar through consistent meal timing, appropriate carbohydrate choices, and any prescribed medications. For those at risk of stroke, maintaining healthy blood sugar through diet and exercise may help prevent strokes and improve outcomes if one occurs. Use the app to set reminders for blood sugar checks and medication timing during recovery.
  • Establish a long-term blood sugar monitoring routine if you have diabetes or are at stroke risk. Track patterns over weeks and months to identify trends. Share this data with your doctor at regular appointments. If you’ve had this type of stroke procedure, maintain close follow-up with your stroke care team for at least 90 days, with special attention to blood sugar control in the first two days after treatment.

This research shows an association between high blood sugar after emergency stroke surgery and worse outcomes, but does not prove that high blood sugar causes these problems. This information is for educational purposes and should not replace professional medical advice. If you have had or are at risk for stroke, discuss blood sugar management and stroke prevention strategies with your doctor. Do not attempt to change blood sugar management on your own without medical supervision, as this can be dangerous. Always consult with your healthcare team before making changes to diabetes management or stroke prevention plans.