Is insulin resistance caused by beta cell impairment? is there a way to prevent beta cell deterioration?

Yes: Weight reduction, some medications help with Insulin resistance (actos, metformin), correction of exacerbating factors - thyroid disorder, adrenal dysfunction. For most people the key is weight reduction.

No and Yes: Beta cell impairment does not cause Insulin resistance. Having a genetic predisposition and being overweight (especially in the abdomen) causes Insulin resistance. Once the beta cell starts to fail, it is a slowly progessive process, but weight loss, exercise, and medications that decrease Insulin resistance (metformin, pioglitazone) can slow the deterioration.

Insulin: Not due to beta-cell impairment, it is a condition in which cells fail to respond to normal actions of insulin. Cells become resistant to insulin, are unable to use it as effectively, leading to hyperglycemia. Beta cells in the pancreas subsequently increase their production of insulin, further contributing to hyperinsulinemia. This is a major factor in type 2 diabetes.