Yes, cortisone shots commonly cause a temporary rise in blood sugar levels, a side effect medically known as hyperglycemia. Cortisone is a synthetic glucocorticoid hormone. This temporary elevation in glucose is an expected physiological response and is often more pronounced in people who already have diabetes or pre-diabetes. While the injection is often localized, the medication is absorbed into the bloodstream, where it affects the body’s overall glucose regulation.
How Cortisone Affects Blood Sugar Levels
Cortisone is a glucocorticoid, and its presence influences how the body processes sugar. The primary way this medication raises blood sugar is by stimulating the liver to produce more glucose, a process called hepatic gluconeogenesis. Cortisone increases the activity of enzymes responsible for creating new sugar from non-carbohydrate sources like amino acids and fats, releasing this new glucose directly into the bloodstream.
This process is compounded by inducing temporary insulin resistance in peripheral tissues. Insulin resistance means that muscle and fat cells become less responsive to the action of insulin. Because the cells cannot effectively take up the glucose, and the liver is simultaneously creating more, the concentration of sugar in the blood rises significantly.
In individuals without pre-existing diabetes, the pancreas can often compensate by releasing extra insulin to overcome this resistance. However, for those with diabetes or underlying insulin resistance, the pancreatic reserve is insufficient to manage the dual challenge of increased production and reduced uptake, leading to clinically significant hyperglycemia.
The Timeline of Hyperglycemia
The blood sugar elevation following a cortisone shot follows a predictable pattern related to the steroid’s absorption and peak action. Onset of the effect typically begins six to twelve hours after the injection, as the medication is gradually released into the circulation. The blood glucose level usually reaches its peak elevation approximately 24 to 48 hours after the shot, reflecting the highest systemic concentration of the active glucocorticoid.
The duration of this hyperglycemia is temporary, but it can last anywhere from three to seven days, depending on the specific steroid compound used and the dosage. The severity of the spike is often directly linked to an individual’s pre-injection glucose control, with patients who have a higher baseline hemoglobin A1c experiencing greater and longer-lasting increases.
The location of the injection can also influence the timeline, as injections into larger joints often use a higher dose of steroid, which may lead to a more sustained effect. Monitoring blood glucose during the afternoon and evening is especially important, as the peak steroid effect often causes the highest readings during this time.
Managing Blood Glucose After the Shot
Proactive management of blood glucose is necessary, particularly for individuals with diabetes. This process begins with clear communication before the shot is administered. It is necessary to inform both the prescribing doctor and the diabetes management team about the upcoming injection. This allows the team to create a temporary adjustment plan for medications to safely manage the anticipated glucose spike.
Increased frequency of blood glucose monitoring is a cornerstone of post-injection care and should be done for at least five to seven days. Patients with diabetes are advised to check their blood sugar four times a day, focusing on the afternoon and evening readings when the steroid’s effect is strongest. Relying only on fasting morning glucose checks will likely miss the peak hyperglycemia.
The diabetes care team will recommend temporary medication adjustments, which might include increasing the dosage of existing oral medications or basal and bolus insulin. These adjustments must be guided by a physician, as the required increase in insulin can be substantial to overcome the severe insulin resistance. Supportive measures like maintaining adequate hydration and avoiding excess carbohydrate intake during the peak period can also help mitigate the severity of the spike.
Patients should contact their care team if blood sugar levels consistently exceed 180 mg/dL despite adjustments or if they experience signs of severe hyperglycemia, such as excessive thirst, frequent urination, or nausea. The goal is to keep blood sugar within a safe target range until the steroid’s effect naturally wears off.