Life Insurance and test results?

I recently had my blood work done to get life insurance. When the nurse called to schedule the blood work I thought it was odd she said to fast for only 6 hours before the test. Isn't it normally a 12 hour fast when your cholesterol is tested? I feel like I've been tricked, obviously this works in their favor, they are telling me I'm going to have to pay an extra 25$ a month because my cholesterol came back in the 230 range. Can I demand a re-test? Can I have my normal family doctor do the bloodwork instead of the insurance company. I am also on Wellbutrin XL, and was told that is another reason the premium went up. Why do they do this when I'm getting help for the problem, it seems like as soon as someone hears you have depression your automatically a nut job and want to commit suicide.