TeachableMedicalNews article 10312021

Teachable moment in classrooms:

  1. chemical basis of life chapter – cholesterol is a steroid type lipid
  2. cellular basis of life chapter – cholesterol is needed to stabilize plasma membranes of our cells
  3. digestive system chapter – liver synthesizes cholesterol
  4. cardiovascular system chapter – coronary artery disease starts with cholesterol buildup in the arteries

The news item:  Recently a report appeared about lowering our blood cholesterol level:

 

FDA approves drug that lowers cholesterol in a new way

Nexletol was approved for people genetically predisposed to have sky-high cholesterol and people who have heart disease and need to further lower their bad cholesterol.

The article stated that high LDL levels are connected with risk of heart attacks, and that this new drug blocks the cholesterol making enzyme in the liver. This new drug, Nexletol, acts differently from the statin drugs that also lower blood cholesterol.

So, Why Do I Care??  In the USA over 1 million people die yearly from heart attacks and strokes, and those deaths are at least partially caused by high blood cholesterol causing blockage inside the blood vessels. While there are life style modifications and drugs we can use to lower blood cholesterol, new pharmaceuticals may increase the success of lowering blood cholesterol.

Plain English, Please!!!   First, let’s talk about what cholesterol is and how it causes cardiovascular disease. Cholesterol is an organic molecule classified as a steroid type lipid. Cholesterol makes cell membranes sturdy, so all cells need it, and cholesterol transporting trucks, called LDL (low density lipoprotein), bring cholesterol to the cells.  When there is too much cholesterol (and LDL) in the blood, the surplus cholesterol piles up inside the cells.  This makes cell to swell up, and they deform the inside of blood vessels. The result is a fatty mass that obstructs blood flow in blood vessels.

Second, let’s talk about where cholesterol is coming from. We consume cholesterol when we eat oils and fats, meat, dairy products, and eggs. On top of that dietary cholesterol, our liver is making cholesterol from scratch. It is the liver that loads cholesterol into the LDL trucks. When a low-cholesterol diet doesn’t help patients to lower their blood cholesterol, then pharmaceuticals are used to force the liver to make less cholesterol.

Third, let’s talk about this new drug can lower blood cholesterol. Cholesterol is made on an assembly line inside the hepatocytes, the cells of the liver. On the assembly line in a car factory a trained worker takes the car frame and attaches doors, the next worker puts in the engine, the next worker puts in place the windshield, and so on, all the while the partially finished car moves from one worker to the next. At the end, a car rolls off the assembly line. On the cholesterol assembly line the workers are enzymes, and the unfinished cholesterol moves from enzyme to enzyme until the cholesterol molecule is completed. The drug Nexletol inactivates one of the first enzymes on the cholesterol assembly line, just like if we would tie up that worker in duct tape. The partially finished cholesterol can not move to the next enzyme, so the entire assembly line is shut down. When the liver’s cholesterol assembly lines are shut down, cholesterol production slows, there will be less cholesterol loaded in the LDL trucks, and the blood cholesterol and LD levels will decrease.