After almost four years there are still more questions than answers. So it is not uncommon for there to be some confusion about this, and not only among people living with HIV, but among health professionals as well. Lipodystrophy, in the true sense of the word, is not measured by a blood test to my knowledge. And it is these features that can be measured in blood tests. They're assessed by what one sees in the mirror and by repeated tape measurements.
Doctors can also tell if the increase in truncal size is water or fat upon physical examination.
And let's call the changes in body shape the true definition of lipodystrophy in the strictest sense. Often, but not always, the metabolic abnormalities accompany the body changes. Some people with HIV, taking the same medications, don't get any form of lipodystrophy while others do. So far there is no way to predict who will get what.