While it is well known that smoking causes lung cancer, heavy smokers with diabetes are can be at even greater risk of death from causes other than lung cancer, according to a study by the Radiological Society of North America.
To determine the extent to which diabetes is associated with deaths from lung cancer, other cancers, and other causes among heavy smokers, researchers examined the risk for what is known as “all-cause mortality”.
“In our study, we found a statistically significant link between diabetes and all-cause deaths, non-lung cancer deaths and lung cancer deaths in women,” said Kavita Garg, M.D., professor of radiology from the University of Colorado – Denver.
For the study, Dr. Garg and colleagues looked at data from 53,454 participants in the NLST and identified 5,174 participants who reported having diabetes at screening.
They conducted an analysis of the relative risk for overall mortality, lung cancer mortality, and non-lung cancer mortality associated with diabetes, adjusting for age, gender, body mass index (BMI), and pack-years of smoking. Over the course of the study, there were 3,936 total deaths, including 1,021 from lung cancer and 826 from cancers not of the lung.
Participants with diabetes tended to be older, reported more pack-years of smoking, and had a higher BMI than those without diabetes. There were 650 deaths (12.6 percent of patients) among participants with diabetes and 3,286 deaths (6.8 percent of patients) among participants without diabetes.
“We found that diabetes doubles the risk for all-cause mortality and non-lung cancer mortality among heavy smokers,” Dr. Garg said. “We also found that women with diabetes have an increased risk of lung-cancer mortality, but did not find the same effect in men.”
The researchers continue to analyze data in an effort to better understand the underlying cause. In the meantime, Dr. Garg emphasizes the importance of taking control of diabetes and undergoing lung cancer screening if you’re a smoker.
“Patients have to take care of their diabetes to maximize the benefit of CT screening for lung cancer,” she said. “It truly makes a magnitude of difference in mortality risk.”