From the Guidelines
Yes, cancer can cause hyperglycemia (high blood sugar). This occurs through several mechanisms, including direct damage to insulin-producing cells, increased glucose consumption by cancer cells, and release of hormones that counteract insulin's effects, creating insulin resistance 1. Cancer treatments like glucocorticoids and some chemotherapy agents can also raise blood sugar.
Mechanisms of Hyperglycemia in Cancer
- Direct damage to insulin-producing cells, particularly in pancreatic cancer, reducing insulin production and leading to elevated blood glucose 1
- Increased glucose consumption by cancer cells, which can trigger the liver to produce more glucose, raising blood sugar levels
- Release of hormones that counteract insulin's effects, creating insulin resistance
- Cancer treatments like glucocorticoids (such as dexamethasone or prednisone) and some chemotherapy agents can also raise blood sugar
Management of Hyperglycemia in Cancer Patients
- Treating the underlying cancer while controlling blood sugar through diet modifications, oral medications like metformin (starting at 500mg daily, potentially increasing to 1000mg twice daily), or insulin therapy as needed 1
- Regular glucose monitoring is essential during cancer treatment, especially for those with pre-existing diabetes or receiving steroids as part of their treatment regimen
- Increasing the ratio of energy from fat to energy from carbohydrates in weight-losing cancer patients with insulin resistance may help reduce the glycemic load and increase the energy density of the diet 1
Importance of Glucose Monitoring
- Patients with cancer experiencing symptoms like increased thirst, frequent urination, fatigue, or blurred vision should have their blood glucose monitored
- Regular glucose monitoring can help identify hyperglycemia early, allowing for prompt treatment and reducing the risk of complications.
From the Research
Hyperglycemia and Cancer
- Hyperglycemia is a common condition in patients undergoing cancer treatment, either as a new-onset condition or as an exacerbation of existing diabetes 2, 3, 4.
- Cancer treatment can cause hyperglycemia due to various factors, including glucocorticoids, L-asparaginase, and targeted oncologic treatments such as mammalian target of rapamycin (mTOR) inhibitors and immunotherapy 4, 5.
- Hyperglycemia can increase the risk of adverse events and outcomes in patients with cancer, including infections, mortality, and symptoms 3.
Causes of Hyperglycemia in Cancer Patients
- Glucocorticoids can cause hyperglycemia by increasing insulin resistance, diminishing insulin secretion, and exaggerating hepatic glucose output 4.
- L-asparaginase can cause long-term hyperglycemia, especially in patients with hematologic malignancies treated with L-asparaginase-based regimens and total body irradiation 4.
- Targeted oncologic treatments, such as mTOR inhibitors and immunotherapy, can also cause hyperglycemia 4, 5.
Management of Hyperglycemia in Cancer Patients
- Screening strategies for hyperglycemia include random glucose testing, hemoglobin A1c testing, oral glucose loading, and fasting plasma glucose screens 4.
- Management of hyperglycemia starts with insulin or sulfonylurea, depending on the type, dose, and delivery of the glucocorticoid formulation 4.
- Proper monitoring and management of symptoms, including lifestyle changes and pharmacologic intervention, may allow patients to continue benefiting from use of anticancer agents 5.