Why You Really Do Need to Rotate Injection Sites
“Rotate your injection sites.” Most of us have heard this advice, but do we really understand why it’s important?
You may be aware that if you inject insulin into the same spots repeatedly, you’ll inevitably develop lumps of unhealthy fat under the skin. This is called lipohypertrophy, and it sounds like reason enough to take rotation seriously, but you may be surprised to learn that lipohypertrophy can result in a host of major negative consequences: more frequent hypos, rollercoastering blood sugars, increased insulin needs, and rising A1C.
And even many health care professionals don’t understand how common it is: it may affect more than half of all people injecting insulin. Even if you don’t have visible lumps on your body, you may have some measure of lipophypertrophy, and you may be suffering its insidious consequences without even knowing it.
What Is Lipohypertrophy?
To understand the problem and its scope, we spoke to Lori Berard, an expert in the subject.
Berard has been involved in diabetes research and care for over 30 years, as a registered nurse and diabetes educator. For the last ten years she has chaired the Canadian Forum for Injection Techniques, a position from which she aims to raise awareness around the problem of lipohypertrophy.
Insulin acts as a growth factor, and when it is repeatedly injected into the same area, it can result in localized fat growth. “Insulin acts basically like a steroid to increase the size of the subcutaneous tissue. The individual fat cells are being fueled,” Berard states. Repeated injections (and needle re-use) increase the trauma to the area.
The real problem comes when patients continue to inject insulin into these unhealthy fat deposits. Insulin injected directly into the lumpy fat is both less effective and less predictable. Less predictable insulin action increases glycemic variability – unexpected highs and lows – and less effective uptake prompts the patient to use more and more insulin, which itself increases the amplitude of variability. It’s a vicious cycle, and in many patients the phenomenon may be responsible for a great deal of the frustrating unpredictability that makes diabetes so difficult to manage from one day to the next.
How common is lipohypertrophy?
In 2016, the Mayo Clinic Proceedings published the results of a worldwide injection technique survey. The survey found that some 30% of insulin-injecting patients experienced lipohypertrophy. This was enough for the authors to call for major changes in the way that injection technique is taught and assessed, but Berard fears that even this number hugely understates the prevalence of this complication. In her own health center, with health care professionals specifically trained to look out for lipohypertrophy, Berard found the complication in an astonishing 80% of patients.
In short, lipohypertrophy may be far more widespread than almost anyone understands. It is only a minority of patients that exhibit the lumpy deposits that can easily be identified with the naked eye. Some deposits can only be felt under careful examination; others may only be unveiled with with ultrasound imaging.
Berard explained that lipohypertrophy was a high-profile issue generations ago, when beef and pork insulins were common. But when the world moved to human and then analog insulins,
“somehow health professionals, including endocrinologists, lost the art of examining injection sites and talking about proper rotation.”
What problems can lipohypertrophy cause?
Studies suggest that lipohypertrophy may have an outsized effect on outcomes for insulin-reliant people with diabetes. A 2013 study inDiabetes & Metabolism compared patients with and without the condition, with jaw-dropping results. Those with lipohypertrophy experienced unexplained hypoglycemia 6 times more often than those without; they also used 37% more insulin.
Berard hopes that healthcare providers can be retrained to make site inspection a more central part of their practice. If something as simple as better injection technique can meaningfully improve outcomes and reduce reliance on expensive technology, insulin and other pharmaceuticals, the savings for insurers and patients alike may be considerable.
What can you do?
The good news is that, according to the Diabetes & Metabolismstudy, good injection site rotation almost perfectly prevented the development of lipohypertrophy: “Of the patients who correctly rotated sites, only 5% had LH while, of the patients with LH, 98% either did not rotate sites or rotated incorrectly.”
The last detail is important. My endocrinologist shared an anecdote with me recently. She had asked a patient if he rotated his injection sites. “Of course I do, every time I inject.” But upon examination, she found two characteristic lumps on his abdomen. The patient had simply been alternating between two small spots, injecting again and again into unhealthy tissue.
Good injection rotation isn’t complex, but as long as diabetes experts give this vital subject short shrift, patients will find themselves casually repeating the same mistakes.