Can Secondhand Smoke Increase Diabetes Risk?

The relationship between secondhand smoke exposure and type 2 diabetes….

Secondhand smoke, also known as passive smoking, is the inhalation of tobacco smoke by those other than the actual (active) smoker. It is linked to many of the same diseases as actual smoking such as lung cancer, respiratory, and cardiovascular diseases. Despite evidence that shows the health benefits of smoke-free environments, these environments are not implemented in many areas of the United States as well as countries in the European Union.

Previous studies have shown that there is a direct relationship between tobacco smoking and type 2 diabetes. Tobacco smoke exposure to rats has resulted in chronic pancreatic inflammation, weight gain, and impaired glucose metabolism. Secondhand smoke in humans is associated with obesity and insulin resistance. However, there have been few studies that evaluated the relationship between secondhand smoke and type 2 diabetes.

A retrospective cohort study was performed in France in which a study population of 37,343 nonsmoking women were evaluated between 1992 and 2007 and were given questionnaires to fill and mail out back to the study center. These women also did not have type 2 diabetes, cancer, or cardiovascular disease at baseline. The study participants were asked about parental smoking during their childhood, as well as their current exposure to secondhand smoke. In this instance, they were asked if their spouse or the person they currently live with smokes, and were also asked to estimate the number of hours they were exposed to secondhand smoke during the day both inside and outside the home. The results of this study has identified 795 incident cases of type 2 diabetes, with 58% of the participants reporting exposure to parental smoking during their childhood. For adult secondhand smoke exposure, the study has shown that those who reported an exposure of > 4 hours of secondhand smoke a day had a 36% higher rate of type 2 diabetes than those who reported no secondhand exposure to smoke, deeming it to be statistically significant. However it should be noted that the association with adult secondhand exposure and type 2 diabetes appeared to be restricted to exposure outside the home.

In conclusion, type 2 diabetes rates increased with secondhand exposure to smoke in childhood as well as increased adult exposure. This study brings up the importance of smoke free environments, especially in public places. Smoking bans and increased smoke-free environments may prove to be an important approach to reducing the incidence of type 2 diabetes worldwide.

• Exposure to secondhand smoke is associated with a higher incidence of type 2 diabetes.
• Smoking cessation is paramount in reducing the incidence of many diseases including type 2 diabetes not only with smokers themselves but with nonsmokers as well. 

Diabetes/Metabolism Research & Reviews 2014. Lajous, M. et al. "Childhood and Adult Secondhand Smoke and Type 2 Diabetes in Women." Diabetes Care 36 (2014): 2720-2725