March 28, 2011 (Anaheim, Calif.) -- Nicotine appears to be the main culprit responsible for high blood sugar levels in smokers with diabetes, according to new research presented here at the annual meeting of the American Chemical Society.
''If you have diabetes and if you are a smoker, you should be concerned about this," says Xiao-Chuan Liu, PhD, a researcher at California State Polytechnic University in Pomona, who spoke about his findings at a news conference Sunday.
In his laboratory study, he exposed human blood samples to nicotine. The nicotine raised the level of hemoglobin A1c, a measure of blood sugar control. The higher the nicotine dose, the more the A1c level rose.
For years, doctors have known that smokers who have diabetes tend to have poorer blood sugar control than nonsmokers with diabetes.
However, until Liu's study, he says, no one could say for sure which of the more than 4,000 chemicals in cigarette smoke was responsible.
About 26 million people in the U.S. have diabetes, according to the American Diabetes Association, although 7 million of those are undiagnosed.
Liu took red blood cells from people and treated them in the laboratory with glucose and nicotine at various concentrations.
To measure the effects of the nicotine on the levels of blood sugar, he used the hemoglobin A1c blood test. This test measures the average blood sugar control for the previous three months or so.
The higher the test results, the more uncontrolled the blood sugar is.
Liu used doses of nicotine comparable to what would be found in the blood of smokers. The levels of nicotine he used in the lab would correspond roughly to the exposure a smoker would get by smoking one or two packs a day, he says.
He found that the nicotine raised the HbA1c level by nearly 9% to up to 34.5%, depending on nicotine exposure.