Dr. Roach: This common steroid can have a big effect on blood sugar

One of the effects of cortisone is to oppose the action of insulin by raising blood sugar through several mechanisms, including causing the liver to make more sugar and preventing fat cells from taking up sugar. Steroids always make blood sugar go up, but the effect differs among people and by the dose of steroid.

When used at low doses (the equivalent of a prednisone level of less than 10 mg per day), steroids increase the risk of developing new diabetes by 80%. At doses above 30 mg daily, the risk of new diabetes is more than 1,000% greater.

There are many other side effects of steroids like prednisone. They increase blood pressure and might cause behavioral changes ranging from anxiety to psychosis. When taken over a long enough time, steroids weaken bones and can prevent the body from making its own cortisone, a life-threatening condition when the body is under stress, called an Addisonian crisis.

I seldom discuss Type 1 diabetes, an autoimmune disease in which the body attacks the insulin-producing cells of the pancreas. An insulin pump mimics the body’s regulation of blood sugar by adjusting the insulin production and is an effective treatment, especially given the increasing ability for these units to adjust their own rates of infusion by a system that monitors blood glucose automatically. Type 1 diabetes should be managed by an endocrinologist whenever possible.

Dear Dr. Roach: When Alzheimer’s disease came to medical attention decades ago, some experts thought aluminum caused the disease, and were concerned that antiperspirants containing aluminum might be dangerous. Should I be alarmed? I am also concerned that antiperspirants and deodorants might cause breast cancer. — P.G.

Answer: I also recall back in the ‘60s and ‘70s that aluminum was found in the brains of people with Alzheimer’s disease, and there was concern that drinking from aluminum cans or cooking in aluminum pots might put people at risk. Many studies have looked at this and failed to demonstrate any risk for aluminum, whether ingested (antacids contain large amounts of aluminum) or used topically (only antiperspirants contain aluminum). I don’t think aluminum is a significant factor in Alzheimer’s disease.

The role of aluminum in breast cancer is not as well studied. Several small studies have shown no risk; however, one study interviewing women who had breast cancer suggested women who shave and use deodorants more had an earlier age of diagnosis of breast cancer. There are several reasons why this might be the case without concluding that aluminum causes breast cancer. The preponderance of evidence shows no significant link between breast cancer and aluminum antiperspirants.