Odded Leon May 19, 2011:

You need to mix both answers... It's עודף כילומיקרונים בדם. the suffix emia says that we're talking about the blood so the word has to be there. It also means there's too much of them so עודף and not הצטברות which doesn't convey any negative meaning.
Most words that come with the emia suffix are usually translated as "בדם X יתר", but X is usually an element and since chylomicrons are countable (in theory) I think עודף is better in this case.