Can Diabetes Cause Cancer?

Diabetes has now been associated with other complications like cancer that are unrelated to blood vessels. The exact reason behind the development of cancers in diabetes is not yet clear - whether these cancers are associated directly with increased blood sugar levels, or indirectly with insulin resistance or increased insulin levels (which are a part of diabetes as well), or due to common risk factors like obesity, or a combination of the above factors. 

A group of researchers tried to find the extent to which diabetes or increase in blood sugar levels is related to risk of death from cancer or other nonvascular conditions (conditions where the blood vessels are not affected). Their study was recently published in the New England Journal of Medicine.

The researchers studied data from previously published studies from various medical journals which described the cause of death in diabetes patients.They found that besides vascular disease, deaths in diabetes patients occurred due to cancer ( of the liver, pancreas, ovary, colorectum or bowel, lung, bladder and breast) as well as other diseases like kidney and liver disease, lung disease (pneumonia, chronic obstructive pulmonary disease), other infectious diseases, digestive diseases (besides those affecting the liver), external causes, mental disorders, intentional self-harm and nervous system disorders.

They also found that fasting blood glucose levels more than 100 mg per deciliter was associated with increased deaths. On an average, adults at 50 years of age with diabetes without known vascular disease are about 6 years younger at the time of their death compared to adults without diabetes. About 40% of the years of life lost from diabetes are due to nonvascular causes, out of which 10% are due to cancer deaths.

Further studies are required to better understand the role of diabetes in these nonvascular deaths and to find ways to prevent them.