1. Is lipohypertrophy a painful condition?
According to our study, it’s only really painful in a minority of patients — about 20% to 30%. For about the same number, the injection is actually less painful. So it can go either way.
2. How serious can the swelling become in extreme cases of lipohypertrophy?
We’ve observed some extreme cases of lipohypertrophy. In one of those cases, we asked a surgeon to perform liposuction on a female patient. She had lipohypertrophy in the region of the umbilicus, in the thigh, and in the upper arm, because she had tried to rotate sites in order to avoid the condition, but wherever she injected she suffered lipohypertrophy. The surgeon, in this case, had to remove more than two litres of fat tissue to obtain a cosmetically satisfying result.
3. If some patients do everything right and still suffer lipohypertrophy, have patients been unfairly blamed for causing and aggravating the condition by trying to avoid painful injections?
This is a common belief, and while we found it to be true in some cases that patients would repeatedly use the same site because they found it to be less painful, they were certainly a minority. In those cases, according to our experience, it was often a lack of information or wrong advice. We had some patients who told us that they’d been informed to use only a very small area of the abdomen around the umbilicus. Under those circumstances, it’s hardly surprising that lipohypertrophy occurred.
4. Why is the abdomen particularly prone to this condition?
To my knowledge, that is not fully clear. But it is known that abdominal fat tissue responds more extensively to hormones or nutritional factors, for example. We did a study a few years ago that appeared in the Journal of Obesity in which we looked at preadipocytes (incipient fat cells) in different fat deposits and their capacity to form new fat cells. We found that the greatest capacity to create new fat tissue is in the abdomen, compared with femoral adipose tissue, for instance.
5. Apart from the appearance and inconvenience, are there any other negative effects of this disorder?
The kinetics of insulin absorption can be affected. We have observed patients in whom metabolic instability was traced to unpredictable absorption of insulin at sites of lipohypertrophy. But in my experience, this is only the case if there is some fibrotic conversion (ie. the formation of fibrous tissue). If there is only a soft swelling, there is less problem with varying absorption.