Corticosteroids and blood glucose

#KYJ - Corticosteroids &  why Blood Glucose goes crazy.

In this episode of knowing your jargon (#KYJ), we look at why steroids muck with blood sugar levels.
At a recent #RustyPills conference I was asked "why is it that when my patients take prednisone (steroids) their blood glucose goes out of control ;particularly diabetics?"

It is a great question and has a fairly straightforward answer.

Let's start with the main hormone in your body that regulates blood sugar.  Insulin : secreted from your beta cells in the pancreas reduces blood sugar levels by allowing the channels in cell membranes open so glucose can flush into the cell, where it is used to produce energy. You learned about this energy back in first year; it's called  ATP. Insulin function is dependent on many factors, and the ability for insulin to facilitate glucose transport into cells, is adversely affected by hormones that are secreted from the adrenal gland.  Particularly cortisol, but the other hormones that we often associate with sex characteristics also play a role .  In pregnancy, many of the circulating hormones that support a healthy pregnancy also produce a similar effect to an abundance of cortisol. This affect produces an insulin resistance in cells, meaning that when a patient secretes insulin, their own insulin is not as effective because, under the influence of higher circulating hormone levels,  including cortisol, cells become insulin resistant.  This causes a reduction in the ability to shift sugar (glucose) from the blood into the cell.  Its accumulation therefore, results in hyperglycaemia.

Now let's give the patient a drug that mimics cortisol.  Often used as anti-inflammatories, drugs like  hydrocortisone, dexamethasone prednisone, prednisolone and many of the inhaled corticosteroids that asthmatics and COPD patient use;  all these drugs are analogues of naturally occurring cortisol.  Thus, insulin resistance and high BSL is common as a side effect of steroid drugs.
This complicates BSL control when somebody has blood sugar level issues, such as diabetics.

One last issue to consider -
A side question might be : if our body secretes cortisol what's its purpose? Well in short, it regulates inflammation, reducing the inflammatory process when secreted.  In stress, along with adrenaline which stimulates fat cells to convert fat to glucose, cortisol is abundantly secreted, giving rise to poor BSL control in diabetics at times of stress or infection.

Remember steroids make you insulin resistant, so you secrete more insulin to try and compensate.  This causes hunger, and over eating at times of stress.

I think I need chocolate!