In people with Type 2 diabetes, insulin does not work as well as it should when telling the liver not to make glucose and transferring glucose into cells. This is called insulin resistance, because the particular organ is "resistant" to the action of insulin, and higher-than-normal amounts are needed to do the job.
Insulin resistance is also associated with various other diseases, such as high blood pressure, abnormal blood fats (lipids), hardening of the arteries, and obesity. Not surprisingly, these abnormalities are commonly found in people with diabetes, and may be present even before diabetes develops.
By improving (i.e. lowering) insulin resistance, glucose will move into cells easier, lowering the amount of glucose in the blood.
Insulin resistance can be improved by exercise, eating less fat, and lowering the amount of body fat.
Drugs are available to improve insulin resistance as well (see Thiazolidinediones, and Metformin). No matter how it is achieved, lowering insulin resistance will improve (lower) blood glucose, thereby helping to prevent complications. It may also directly or indirectly improve lipids, blood pressure, hardening of the arteries, and life expectancy.