Both people with type 1 and type 2 diabetes usually gain weight when they begin therapy, either insulin or some type 2 diabetes medications. For many people with type 1, weight gain is advisable due to the loss of lean body mass often accompanying the disease prior to diagnosis and treatment. However, for people with type 2, and increasingly people with type 1 who were overweight or obese before their diagnosis, seeing the numbers on the scale rise is counterproductive. Increasing weight leads to more insulin resistance, which in addition to making diabetes harder to control, escalates cardiovascular risk.
There are a variety of reasons weight gain occurs when people start insulin. Some people with type 2 were in poor glycemic control prior to beginning insulin. These folks were seeing the energy from the food they ate end up in their urine stream instead of being stored as fat. As their control improves with insulin, the lost energy finds its way into the fat cells.
Treatment for hypoglycemia, if it happens frequently, can also be a source of added pounds when insulin is initiated. Additionally, since an exact replacement for physiological insulin secretion is almost impossible to duplicate, patients may often be taking slightly more insulin than needed over a 24-hour period. Normal circadian rhythm for insulin secretion surges from 4 am to about 7 am then drops, increases a bit around dinner time through 10 pm and declines to its lowest level until the early morning hours. Injected insulin is unable to mirror this profile.
Finally, injected insulin follows a slightly different pathway to the cells from insulin that comes from our bodies. Insulin from our bodies is directed first to the liver but insulin that is injected travels first through the blood circulation where you have injected it. Insulin also works on growth receptors called insulin-like growth factor-1 receptors (IGF-1), and if injected insulin has more affinity to these receptors, it can cause weight gain. Different insulins have different affinities.
For people with type 2, there are several lifestyle measures they can take to reduce weight gain, including portion control and exercise. In addition, choosing medications that are weight friendly should also be a consideration. As Osama Hamdy MD, Medical Director, Obesity and Inpatient Diabetes, puts it, “We are always telling our patients that they need to lose weight and then at the same time asking them to take medications that cause them to put more pounds on. In our program, Why WAIT, we are able to help patients with their lifestyle-based weight loss efforts by using the most weight-friendly medications.”
Diabetes medications can be divided into three categories: weight gaining, weight neutral and weight friendly. See the table below for details.
“Even among insulins there are differences”, says Dr. Hamdy. Research has shown that Levemir® and Apidra®(if injected immediately after meal) do not cause the same level of weight gain as Lantus®, Humalog® and Novolog®. Levemir® has a different affinity for the IGF-1 receptors than the other two.
Dr. Hamdy will often make changes to patient’s medications when they enter Why WAIT. “For example, if someone comes to us on a metformin and a sulfonylurea, we try to substitute one of the incretins for the sulfonyureas,” he said.
Dr. Hamdy’s group also suggests that those who are trying to lose weight are best served by taking their short-acting insulin immediately after meals or within 20-minutes from the start of the meal. Taking insulin after meals solves the problem of people needing to eat up to their dose. “Patients will calculate that they are going to eat 60 grams of carbohydrate and take insulin for that, but then they are full at 45 grams or they just don’t like the dish and they have to keep eating because the insulin has started working.” He said. “This way they inject just what they need based on what is actually eaten and not on what they assume to eat.”
It is not always possible to use only the weight-friendly diabetes medications or insulins. Talk with your health care provider to see if you are a candidate for medication adjustment. If you have diabetes, have a BMI under 45, are able to exercise and are interested in weight loss, call for more information or to make an appointment with the Why WAIT team. (add phone #). If you cannot join the 12-week group intervention of the Why WAIT program, you may be eligible to join the ACHIEVERS program, which is an individualized plan for weight management.