Insulin also plays a key role in:
- The liver. Insulin stimulates the creation and storage of glycogen from glucose. High insulin levels cause the liver to get saturated with glycogen. When this happens, the liver resists further storage. Glucose is used instead to create fatty acids that are converted into lipoproteins and released into the bloodstream. These break down into free fatty acids and are used in other tissues. Some tissues use these to create triglycerides.
- Fat cells. Insulin stops the breakdown of fat and prevents the breakdown of triglycerides into fatty acids. When glucose enters these cells, it can be used to create a compound called glycerol. Glycerol can be combined with the excess free fatty acids from the liver to make triglycerides. This can cause triglycerides to build up in the fat cells.