Researchers at Myongji Hospital have discovered that patients who use sleeping pills have a 30 percent higher risk of cancer, the hospital said Tuesday.
The research team, led by Professor Kim Hong-bae of the department of family medicine at the hospital, analyzed six sleep and cancer risk epidemiology studies conducted around the world for 10 years from 2005,
The study involved 1.8 million participants (202,629 sleeping pill users and 1.6 million non-users) and compared the cancer occurrences between the two groups.
As a result, patients who took sleeping pills showed a 29 percent increase in the risk of cancer risk compared to those who did not take them. The data became significant when the team divided the participants into subgroups by study design, study area, and the qualitative level of the research.
Regarding the type of cancer, esophageal cancer showed the highest risk with an increase of 57 percent, followed by liver cancer, kidney cancer, pancreatic cancer, lung cancer, prostate cancer and stomach cancer. Although the data did not show statistical significance, the team also found a correlation between breast cancer and brain tumors risks for taking sleeping pills.
However, cervical cancer, ovarian cancer, bladder cancer, colorectal cancer and oral cancer did not show any specific relations with hypnotic agents.
As to the type of sleeping pills, the zolpidem group increased the risk of cancer most by 1.34 times, while the benzodiazepine family raised the risk by 1.15 times
Professor Kim also found that the relationship between sleep aids and cancer risks differed by race. The research showed that Europeans had an increased cancer risk of 13 percent, while Asians showed an increased cancer risk of 48 percent.
“The mechanism by which sleeping pills can cause cancer is that it can cause infections,” Professor Kim said. “Such increased levels of infection may not be irrelevant in the development of cancer, and sleeping pills may also cause inflammation leading to cancer.”
The fact that people exposed to the risk of cancer may also be taking more sleeping medication than people who are not can also be a reason, Kim added.