Lung Cancer Screening Reveals How Deadly Smoking Is for Those With Diabetes

Three years after a CDC report explored the links between diabetes and smoking, a new study shows just how deadly the habit can be for those with the chronic condition.

A study being presented next week at the Radiological Society of North America annual meeting in Chicago has found that smoking can double the risk of all-cause mortality among those with diabetes.

Researchers made this finding by examining data among more than 53,000 people taking part in the National Lung Screening Trial (NLST), a giant, multicenter study that led to a US Preventive Health Services Task Force recommendation for annual screenings for certain current and former long-term smokers age 55 to 80.

Of the participants, researchers identified 5174 who reported having diabetes at the time of screening. This would be about 9.6% of the study population; the CDC reports that 9.3% of the overall adult population has diabetes, with that share rising to 16.2% among those age 45 to 64. It is estimated that 27.8% of those who have diabetes are not diagnosed.

Researchers led by Kavita Garg, MD, professor of radiology at the University of Colorado at Denver, analyzed the relative risk of overall mortality, lung cancer mortality, and non-lung cancer mortality associated with diabetes, after adjusting for age, gender, body mass index, and pack-years of smoking. During the NLST, there were 3936 total deaths, including 1021 from lung cancer and 826 from other cancers.

Garg said the findings revealed a significant link between diabetes and all-cause deaths, non-cancer deaths, and lung cancer deaths in women. The NLST participants who reported having diabetes were older, had more pack-years of smoking, and had a higher BMI than others in the trial. Researchers found there were 650 deaths, or 12.6% of patients, among those with diabetes, compared with 3286 deaths, or 6.8% among those without diabetes.

"We found that diabetes doubles the risk for all-cause mortality and non-lung cancer mortality among heavy smokers," Garg said in a statement from RSNA. "We also found that women with diabetes have an increased risk of lung-cancer mortality, but did not find the same effect in men."