TeachableMedicalNews article 01172021

Teachable moment in classrooms:

  1. endocrine system chapter – insulin production by beta cells
  2. endocrine system chapter – action of hormones through receptors
  3. endocrine system chapter – action of hormones inside target cells
  4. metabolism chapter – effect of insulin on glucose utilization by body cells

The news item:  Recently a new report appeared about the diabetes treatment drug Trulicity:

FDA approves Eli Lilly’s Trulicity to reduce cardiovascular risks in type 2 diabetic patients

Eli Lilly and Co said on Friday the U.S. Food and Drug Administration has approved Trulicity for reducing cardiovascular risk factors in type 2 diabetic patients. The approval makes Trulicity the first and only type 2 diabetes drug approved to reduce heart related risks in adults with and without established cardiovascular disease, the company said in a statement.

The article states that the type 2 diabetes treatment drug was approved for reducing heart disease risk as well.

So, Why Do I Care??  About 30 million people in the US has type 2 diabetes. The disorder causes about 80,000 deaths yearly. In addition, there is a yearly $327 billion cost from lost productivity and medical cost that includes treatment for diabetic vision loss and diabetic nephropathy. Diabetes also causes heart damage. New treatments have a chance to reduce deaths and lost working hours.

Plain English, Please!!!

First, let’s talk about type 2 diabetes. Diabetes, in general, is a disorder where blood sugar (glucose) level is higher than normal for long periods of time. The continuous high blood glucose level damages small blood vessels in the eye, in the heart and in the kidneys, thus causing several diseases. In people without diabetes, when the blood glucose level is high after eating, the hormone insulin is released from the pancreas.  The insulin hormone tells the cells of our body to use up surplus glucose from the blood, so as a consequence blood glucose level returns to normal. In many type 2 diabetic patients there is a shortage of insulin, and the blood sugar remains higher than normal, because the cells don’t receive enough instruction to use glucose from blood.

Second, let’s talk about what determines just how much natural insulin is made.   Insulin is made by the special cells (beta cell) of the pancreas. Beta cells make insulin when there is high glucose level in the blood. The beta cells don’t work well in type 2 diabetes, as they don’t respond to high blood glucose level. In addition to glucose, there are other factors that stimulate beta cells. In our intestines several protein hormones are made (such as GIP and GLP-1), and those hormones instruct beta cells to make more insulin.

Third, let’s talk about how Trulicity acts. Trulicity is not insulin, so we are not directly adding insulin to the patient. However, Trulicity injection will lead to higher natural insulin production. Imagine that the beta cell is a house, and GLP-1 is a pizza delivery person. To get the attention of the people in the house the pizza delivery person pushes the doorbell, and the bell will ring inside the house. The message of GLP-1 needs to get the attention of the cell, so GLP-1 contacts the hormone receptor, which acts like a doorbell.  Once the GLP-1 contacts the receptor, chemical reactions happen inside the cell that leads to more insulin production. Trulicity is an amplifier for the doorbell. When GLP-1 tells the beta cell to make more insulin, Trulicity amplifies the activity of the receptor, and multiplies the chemical reactions inside the cell, so the beta cell will make a lot more insulin, and, therefore, the blood sugar level will be lowered.