What causes hyperglycemia after postoperative prostatectomy?

Causes of Hyperglycemia After Post-Operative Prostatectomy

The primary cause of hyperglycemia after prostatectomy is surgical stress-induced insulin resistance, which leads to increased glucose production and decreased glucose utilization. 1

Pathophysiological Mechanisms

• Surgical stress response triggers the release of stress hormones (glucagon, cortisol, catecholamines) and inflammatory mediators (interleukin 1 and 6) that directly induce insulin resistance 1
• Peripheral insulin resistance is the main mechanism responsible for perioperative stress hyperglycemia and can last for several days after surgery 1
• Increased endogenous glucose production occurs alongside decreased glucose clearance, contributing to elevated blood glucose levels 1
• Enhanced renal reabsorption of glucose further exacerbates hyperglycemia in the post-operative period 1

Risk Factors That Worsen Post-Prostatectomy Hyperglycemia

• Pre-existing diabetes mellitus (diagnosed or undiagnosed) significantly increases the risk and severity of post-operative hyperglycemia 1
• Catecholamine infusion during and after surgery can worsen hyperglycemia 1
• Corticosteroid use for post-operative pain or inflammation management 1
• Obesity increases baseline insulin resistance 1
• Advanced age is associated with impaired glucose metabolism 1
• Prolonged surgical duration correlates with more severe hyperglycemia 1
• Prolonged immobilization affects glucose metabolism in skeletal muscles 1
• Extended perioperative fasting depletes hepatic glycogen and increases gluconeogenesis 1

Clinical Categories of Post-Prostatectomy Hyperglycemia

1. Stress Hyperglycemia

• Defined as transient hyperglycemia (≥10 mmol/L or 180 mg/dL) in previously non-diabetic patients 1
• Blood glucose returns to normal (<7 mmol/L or 126 mg/dL) after recovery from surgical stress 1
• Characterized by HbA1c <6.5% 1
• Requires monitoring as 60% of these patients may develop diabetes within one year 1

2. Previously Undiagnosed Diabetes

• Approximately 500,000 patients have undiagnosed T2D in France alone, with high prevalence among surgical patients 1
• Can be distinguished from stress hyperglycemia by HbA1c ≥6.5% 1
• These patients require follow-up and management after discharge 1

3. Known Diabetes with Poor Perioperative Control

• Patients with established diabetes often experience worsening glycemic control after surgery 1
• May require adjustment of previous antidiabetic regimen during hospitalization and after discharge 1

Consequences of Post-Prostatectomy Hyperglycemia

• Impaired wound healing due to increased protein catabolism 1
• Increased risk of surgical site infections due to impaired leukocyte function 2
• Endothelial dysfunction contributing to poor tissue perfusion 1
• Decreased phagocytic activity of polymorphonuclear neutrophils 1
• Abolished ischemic preconditioning increasing risk of ischemic complications 1

Management Approach

• Regular monitoring of blood glucose levels should be continued postoperatively to detect hyperglycemia 1
• For hyperglycemia >16.5 mmol/L (3 g/L) in patients with diabetes, check for ketosis and administer insulin as needed 1
• For stress hyperglycemia, insulin should be gradually decreased as glucose levels normalize 1
• For newly diagnosed diabetes, consultation with a diabetologist is recommended before discharge 1

Prevention Strategies

• Preoperative screening for hyperglycemia in patients at risk can identify undiagnosed diabetes 3
• Perioperative glycemic control with target range of 80–180 mg/dL (4.4–10.0 mmol/L) 1
• Avoiding prolonged fasting when possible to reduce insulin resistance 1
• Appropriate management of diabetogenic medications in the perioperative period 1

Remember that monitoring for both hyperglycemia and hypoglycemia is essential in the post-operative period, as overcorrection can lead to dangerous hypoglycemic episodes 1.