Welcome back to our weekly diabetes advice column, Ask D'Mine — with your host veteran type 1, diabetes author and educator Wil Dubois. This week, Wil takes on a question about how insulin pump infusion sets can sometimes cause particularly fatty spots on the skin. Read on to find out what might help...


Carol, type 1 from Montana, writes: I am trying to find out more about lipohypertrophy. I am a 62-year-old female who's had type 1 for 31+ years. I'm on the pump, have no complications, and go swimming three times a week. I also have what I call my "insulin island," fat across my midsection that doesn't seem to be connected to any other areas of fat (I am not overweight but have some pudge like most women my age). I have been trying to find out how many others with long-term diabetes have the same problem, and is it being addressed at all by the medical community? So far all I get is: 'Oh well, you should rotate your site more.' From what I have read, liposuction seems to be the only remedy. What I want to know is: is anyone lobbying for this, especially with insurance companies? I am not vain, as one doctor suggested (I've had grey hair for over 20 years) but am really feeling uncomfortable with my insulin island. Any answers or suggestions?

Wil@Ask D'Mine answers: Your wish is my command. Here's my short course on lipohypertrophy, pronounced LIP-oh-hy-PER-truh-fee. Lipohypertrophy is simply a lump of fat under the skin that's made up of adipose tissue, the kind of fat used to store calories for times of famine. You can recognize lipolumps by touch. They feel "firmer" than the surrounding tissue because the fat lump itself is firmer than the rest of your jiggles, assuming you have any, of course.

Where do they come from? From insulin injections. Well, more specifically, from taking too many injections in one location. How does this happen? Well, hold on to your butts, we're going to dive into some deep science here to explain this: Insulin exerts a hypertrophic effect on adipose cells stimulating lipogenesis through a lipogenic effect. (I told you to hang on.) It gets worse, as it involves little-known interactions between insulin and things like acetyl-CoA, acetyl-CoA carboxylase, and malonyl-CoA.

Well, that's what I heard, anyway.

But in the vernacular, insulin is fertilizer for fat. Insulin causes fat to grow, and the more insulin, the more growth of fat. So it makes sense that injecting in the same spot every day, day after day, week after week, month after month could cause a ball of fat to grow. Picture it like watering one part of your lawn more than the rest: The grass will grow higher and greener there. Other hormones can cause fat to grow too, but insulin takes the prize as the number one hormonal accelerator when it comes to fat growth.

Lipohypertrophy is one of the rare cases where you ladies come out on top, 'cause it's more common in males than females. It's also more likely in heavier people than in thinner people, and more likely in those who use larger doses of insulin than smaller doses. The last two could be related, as heavier people generally need higher doses because insulin resistance closely correlates to body mass. I couldn't find much on the subject (and neither could our own AmyT a while back), but I had to wonder if pumpers are more likely to develop lipohypertrophy than shooters. After all, the garden hose stays in exactly the same place for three to four days with an insulin pump while even someone in the habit of injecting in the same zone won't hit the exact same spot each time.lipohypertrophy tummy

Right. One more crappy thing to worry about. But I digress...

Generally speaking, these lipolumps are small—rarely larger than one inch in diameter—so at first I thought your "insulin island" couldn't be lipohypertrophy. But then I saw this image of a poor man who has a spare butt on his stomach from decades of only injecting in two places on either side of his belly button. (And then I spent the next week staring at my own middle-aged paunch in the bathroom mirror fretting about my site-rotation technique.) So your island could be supersized lipohypertrophy, or it could just be garden-variety postmenopausal body shape.

Either way, my proudly grey-haired fox, it's bugging you, so it has to go. So what are your options? First let's assume for a moment that your island is a form of lipohypertrophy. Why are your docs so unconcerned? Because left alone, normal lipolumps go away in 2-3 months. That makes them more of an acute injury from improperly executed therapy in the eyes of the white coats, than a genuinely worrisome complication of diabetes. And they're harping on site rotation, because this really is one of those cases where an ounce of prevention avoids a pound of fat. Or something like that. In theory, you can completely avoid lipohypertrophy by good site rotation technique.

Oh, and to answer your questions about what is the medical community doing about this: Nothing. Because they view it as largely preventable, and if not prevented easily fixable by doing nothing and letting the body work it out. As to how many people are affected I don't think we really know. It's often called "common" in medical literature, and one study found it in almost a third of a small sample of type 1s. Of depressing interest, half of those T1s developed lipohypertrophy within two years of diagnosis, so you don't need to be someone with "long-term" diabetes to have lipohypertrophy.

Beyond the cosmetic issue of LTS (lumpy tummy syndrome), lipolumps can actually pose a genuine health risk, as—even though they are created by insulin—they ironically do a piss-poor job of absorbing insulin and moving it on into the rest of the body. Injecting into a lipohypertrophy is almost guaranteed to reduce the effectiveness of the shot, so you need to ramp up the volume of insulin to compensate, thus throwing more fuel on the fire as more insulin begets more lipogenesis. And the fun doesn't stop there. If you then inject these high volumes of insulin into an area free and clear of lipohypertrophy, you can have a spectacular hypo.

You'd think your health insurance would want to keep you healthy by removing all these risks, but you'd be mistaken. First off, they know that most lipolumps will go away, if left unmolested. Plus, as the typical lump is only an inch across, and since the typical American waistline is 38.8 inches, there are plenty of other places for patients to take a shot. So there's generally no medical necessity to justify the cost of the fix, which as you noted, is liposuction.

And that's the rub. Well, the second rub. Liposuction is classified strictly as a cosmetic surgery, and cosmetic surgery isn't covered in most cases by health plans. (Unless you are a member of Congress.) However, there might be a wrinkle in your case. As you wear a pump and your primary pump sites are blocked by the fat, a very creative letter of medical necessity might be able to convince an insurance company to pay. But don't hold your breath.

And of course, you could always pay out of pocket. One cosmetic surgery center had these helpful words of encouragement on their website: "Don't give up. Many people find that lipo can be surprisingly affordable. Convenient payment plans are often available as well..."

Alrighty then. Moving on...

If, on the other hand, your island isn't lipohypertrophy, but a postmenopausal "muffin top," out-of-pocket or convenient-payment-plan liposuction will still work, but you might also be able to get rid

of at least some of your island with some tummy-targeted exercises and diet changes.

As to any sort of movement to lobby for change on this whole subject, I'm not aware of one. Maybe you should start a little revolution. I'm sure our AmyT would join you, as she suffers from it too, and has written about the lipohypertrophy topic before.

But before I run out of time and space today, I want to quickly touch on the flip side of lipohypertrophy, which is a nasty complication of insulin injections called lipoatrophy. Instead of a lump, you get a hole, a "dissolving" of tissue around frequent injection sites. Luckily we almost never see this anymore as it's an adverse immunological side effect much more common with old-school animal insulins. The modern analog insulins seem to have largely put an end to it.

See? Sometimes diabetes does get better. Now all we need to do is help you swim away from that island of yours!


