Hyperosmolar Hyperglycemic Syndrome: How Is It Different From DKA

Hyperosmolar Hyperglycemic Syndrome

Hyperosmolar hyperglycemic syndrome (HHS) is similar to diabetic ketoacidosis (DKA), but there are several differences we will review in this article.

Who Is Prone to HHS?

Patients with type 2 diabetes are at risk of HHS. Physicians must remember:

• The emergency complication of type 2 diabetes is HHS.
• The emergency complication of type 1 diabetes is DKA.

Key Differences between DKA and HHS

There are little to no ketone bodies in the blood in HHS since patients with type 2 diabetes have insulin in their bodies to protect against lipolysis. Lipolysis, or the breakdown of fat, leads to the build-up of ketone bodies present in DKA.

A hallmark DKA symptom is the presence of ketone bodies. A type 1 diabetic does not produce insulin to bring glucose into the cells. Therefore, the cells do not have glucose available as an energy source, so the body breaks down fats instead via lipolysis.

The extracellular fluid (ECF) of the vascular space with an HHS patient is extremely hyperosmolar due to elevated blood glucose. Osmolality (or colloid osmotic pressure) is created by albumin, glucose, sodium, and other components in the vascular space. 

Due to the hyperosmolar ECF, the body tries to dilute the blood to rid itself of the extra glucose. When glucose is removed through the urine, water follows. Therefore, patients with HHS are at risk of extreme dehydration due to water loss.

Blood contains components such as albumin (protein), glucose, and sodium that contribute to the osmotic pressure of the blood.

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Fatal Complications of HHS

The main concern with HHS is hypovolemia. Fluid replacement is crucial because osmotic diuresis is very severe in these patients. The polyuria from hyperglycemia causes osmotic diuresis. 

To compare HHS and DKA:

• Hypovolemia is the main concern with HHS.
• Hypokalemia is the main concern with DKA.

Patients with HHS are constantly urinating and thirsty. They may become dehydrated.

Related Video – What is Hyperosmolar Hyperglycemic Syndrome (HHS)?

Elevated Blood Glucose and HHS

An HHS diagnosis indicates a blood glucose of over 600 mg/dL, whereas the diagnosis of DKA is a blood glucose of over 250 mg/dL. 

Patients with type 2 diabetes often get HHS. It frequently goes undiagnosed for years until the one day they wake up lethargic and dehydrated, indicating undiagnosed HHS and diabetes.

Sometimes people who present with HHS actually have undiagnosed type 2 diabetes.

Type 1 diabetics are typically diagnosed at a very early age. They know how to monitor their sugar levels and when to seek treatment. But, if the patient is unaware of their diabetes, they may put off seeking treatment. 

Additionally, the appearance of the “3 Ps” which go with hyperglycemia are much more subtle with HHS patients than those with DKA. Sometimes, these patients may have a blood glucose 1200 mg/dL or higher.

Summary

HHS is a complication of type 2 diabetes, while DKA is a complication of type 1 diabetes. Blood glucose levels in HHS patients will be very elevated compared to the levels of DKA patients. Hypovolemia is the main concern with HHS, while hypokalemia is the main concern with DKA.