It’s well-documented that smoking cigarettes raises the risk of heart disease and many cancers. Now, findings show type 2 diabetes may soon join this list of smoking-related illnesses too, the Daily Times Monitor reports. Type 2 diabetes is a metabolic disease that occurs when the body is unable to use insulin properly to keep blood sugar at normal levels.

For the study, researchers at Harvard University teamed up with scientists at Huazong University of Science and Technology in China to analyze the results of 88 smoking studies that followed nearly 6 million people. Findings showed that those who smoked raised their risk of diabetes by 37 percent when compared to those who never smoked. What’s more, scientists noted that even folks who inhaled secondhand smoke from cigarettes and cigars—known as passive smoking—upped their risk of diabetes by 22 percent.

Researchers also found that new ex-smokers raised their risk of diabetes by 54 percent over the first five years. After five years these former smokers’ risk of diabetes fell to 18 percent and 11 percent after 10 years. The study also estimated that nearly 27.8 million diabetes cases worldwide could be attributed to smoking. Scientists said the findings help support the opinions of some doctors who feel warnings to the public about the serious effects of smoking on their health should name diabetes as a potential harm in addition to alerts about cardiovascular disease and cancer.