Chemotherapy targets rapidly dividing cells to combat cancer. While effective, these treatments can influence the body’s metabolic processes, including blood sugar regulation. Chemotherapy can impact blood sugar levels, sometimes leading to elevated glucose, known as hyperglycemia. This side effect requires careful attention and management.
How Chemotherapy Can Influence Blood Sugar
Chemotherapy drugs can affect blood sugar through direct and indirect mechanisms. Specific agents like L-asparaginase, 5-fluorouracil (5-FU), platinum-based drugs (e.g., cisplatin), and busulfan have been linked to elevated glucose. These drugs can interfere with insulin production or cellular insulin response.
Corticosteroids, often given with chemotherapy for side effects like nausea or inflammation, are a common cause of high blood sugar. Steroids such as dexamethasone, prednisone, methylprednisolone, and hydrocortisone increase insulin resistance, stimulate liver glucose production, and reduce pancreatic insulin secretion. Blood sugar rises from corticosteroids often occur within 6 to 8 hours and can be more pronounced with higher doses. The body’s stress response to cancer and treatment also contributes to hyperglycemia by triggering hormonal changes.
Identifying High Blood Sugar During Treatment
Recognizing signs of elevated blood sugar is important during chemotherapy. Common symptoms include increased thirst and frequent urination as the body eliminates excess glucose. Other indicators are fatigue, blurred vision, unexplained weight loss, headaches, or increased irritability. More severe symptoms can involve intense hunger, nausea, abdominal pain, or a fruity breath odor.
Regular blood sugar monitoring helps identify hyperglycemia. Medical teams perform glucose tests, and home monitoring with a blood glucose meter is also beneficial. For some, especially those with type 1 diabetes or very high blood sugar, checking for ketones in blood or urine may be necessary to detect diabetic ketoacidosis. Prompt communication with the healthcare team about symptoms or concerning readings is crucial.
Managing Blood Sugar Levels During Chemotherapy
Managing elevated blood sugar during chemotherapy involves medical interventions and lifestyle adjustments, guided by the healthcare team. Medical approaches include adjusting diabetes medications or initiating insulin therapy, even for those not previously requiring it. Insulin or oral medication dosages are tailored based on hyperglycemia severity, existing diabetes status, and the chemotherapy regimen. Fast-acting insulin may address sudden spikes, while intermediate or long-acting insulin might be used for prolonged elevations, like those from corticosteroids.
Lifestyle modifications also support blood sugar management. Dietary adjustments, emphasizing balanced nutrition, help stabilize glucose levels. Staying well-hydrated is important, as high blood sugar can lead to dehydration. Gentle physical activity, if approved by the oncology team, can lower blood sugar by increasing insulin sensitivity. Managing treatment-related nausea and maintaining consistent meal patterns are key, as inconsistent eating disrupts blood sugar control.
Factors Increasing Risk
Several factors increase a person’s susceptibility to high blood sugar during chemotherapy. Individuals with pre-existing conditions like pre-diabetes or type 2 diabetes are at higher risk of chemotherapy-induced hyperglycemia or worsening glycemic control. Obesity is another predisposing factor, contributing to insulin resistance. Older age can also increase this risk.
Specific chemotherapy drugs also influence risk, with some agents more likely to cause blood sugar elevations. High-dose corticosteroids, often given with chemotherapy, contribute to hyperglycemia. Genetic predispositions and certain ethnicities may also play a role in developing diabetes or hyperglycemia. The overall stress from cancer and its treatment further contributes to elevated blood sugar levels.