While 458 sounds higher than the normal range of less than 150, it's not uncommon to find people in your range and in fact my last test came back a 399 last week. Your doctor could prescribe something like Tricor which helps increase the enzymes necessary to break down fats in your blood. Having said that, it's not uncommon to see numbers in the thousands either before most doctors start getting concerned. You should express your concern to you doctor for clarification and good luck!
Hello~Well, to me, that is high, but I guess everyone has different opinions. To lower them, I would start taking a good, fish oil supplement, a high potency B complex and Vitamin C. Also, cut way back on your sugar intake. Make sure you get exercise as well. After a few months on this regime your numbers should start improving.