Does Injected Insulin Hold Fat in the Stomach?
I am 83 years old and have had diabetes for 48 years. I have tried for seven years to lose weight, and I lose it everywhere except my stomach. I've injected insulin in my stomach for 45 years. Is it true that the insulin I inject holds the fat in my stomach? If so, how can I get rid of the stomach fat without moving the injection site to other parts of my body? Paul Gregory, King City, California
Janis McWilliams, RN, MSN, CDE, BC-ADM, responds:
Congratulations on living well with diabetes for 48 years! No, insulin doesn't cause obesity or "generalized" deposits of abdominal fat. Insulin is absorbed and doesn't stay where it's injected. What you may be describing is called lipohypertrophy or insulin hypertrophy. It is a fatty thickening of the lipid tissue, and these soft, grapelike lumps are sometimes felt more easily than they are seen. The most likely cause is repeated injections of insulin into the same spot. Since you have been injecting insulin for a long time, you may have done this without realizing it. Generally, if you avoid using these sites for injection, the hypertrophy may decrease if not disappear. I have seen some reports of using liposuction to treat hypertrophy, but it is not a common practice.
Another key reason to avoid these areas is that when one injects into these fatty lumps, the insulin's action can be erratic, causing poor blood glucose control. These areas are also less sensitive, and they can become favorite sites, as the injection is more comfortable. This is less of an issue if you use shorter, finer needles because they cause little pain when injecting.
It is important to rotate sites when injecting insulin, but you can continue to use your stomach for injections as long as you can avoid these problem areas. You may also rotate to other sites like your buttocks, arms, or legs to give your abdomen a breather. Just be aware that different sites have different rates of insulin absorption and that you should never use a site like your leg if you are planning a walk or other activity using your limbs. Also, there is some evidence that reusing insulin needles can be a risk factor for developing lipohypertrophy, so it's best to use a new needle for each injection.
Finally, it is a good idea for insulin users to periodically schedule a visit with their diabetes educator to review technique and any changes that may have occurred in injection therapy.