News & Research

Smoking May Be One Cause of Type 2 Diabetes Smoking and risk for diabetes incidence and mortality in Korean men and women, by Sun Ha Jee and colleagues. Diabetes Care 33:2567–2572, 2010

What is the problem and what is known about it so far?

Smoking is known to cause numerous diseases, such as cancer. Studies have also found that people who smoke are more likely to get diabetes. Because smoking causes immediate effects in the body, people who are current smokers may be at higher risk than those who are former smokers. Likewise, people who smoke more cigarettes per day may have a higher risk than those who smoke fewer cigarettes. Also, people with diabetes and who smoke have a much higher risk of dying that those who do not smoke. Despite this mounting evidence, smoking has not yet been designated as an actual cause of diabetes by authorities such as the U.S. Surgeon General. More study will be needed to make this determination.

Why did the researchers do this particular study?

The researchers wanted to find out more about the link between smoking and type 2 diabetes in Koreans.

Who was studied?

The study included 1.3 million Korean adults who were part of the Korean Cancer Prevention Study.

How was the study done?

All participants had medical exams every 2 years for 14 years through the Korean National Health Insurance Corporation. Researchers looked at the insurance corporation’s database to find out which patients had diabetes and to collect other personal and health information about them, including information about the patients’ smoking habits. The researchers also collected information about deaths from diabetes from the national statistics office. They then looked for links between smoking, diabetes, and death, while taking other factors into consideration.

What did the researchers find?

Men and women who smoked were more likely to get diabetes and to die than nonsmokers. People who smoked more cigarettes per day had higher risks than those who smoked less, but the risks were not greater for those who smoked for a longer period of years than for those who smoked for fewer years.

What were the limitations of the study?

The researchers had to rely on patients’ self-reports about smoking and alcohol use and on database information to learn which patients got diabetes. Some of this information could have been inaccurate. Also, this study did not include adolescents or young adults, who are now getting diabetes in greater numbers. The study included mostly middle-class, employed people who may have been healthier than the general Korean population. Therefore, the results may not completely ally to all people with diabetes or even to all segments of the Korean population.

What are the implications of the study?

This study adds to mounting evidence that smoking should be considered a possibly reversible cause of diabetes. It provides additional reason to try to control and limit tobacco use to promote better health throughout society.

FOR MORE INFORMATION

Diabetes and Smoking

Lowering the Risks of Type 2 Diabetes and Heart Disease

Type 2 Diabetes: Your Healthy Living Guide