Doctors know that diabetics have a higher than normal risk of dying of heart attacks or strokes, but new research showed that having diabetes also ups the risk of dying from many cancers and other diseases.
The findings shed light on the potential burden of disease that will build in the future as the number of cases of diabetes is predicted to rise dramatically in coming decades.
"These findings highlight even more the need to prevent diabetes and to understand it better," said Emanuele Di Angelantonio of Britain's Cambridge University, who worked on the study as part of an international collaboration.
"They show that diabetes is not only a cardiovascular risk factor, but is linked as well to other conditions."
The research, published in the New England Journal of Medicine (NEJM), collated and analyzed data from 97 previous studies, involving more than 820,000 people worldwide.
Death risk up by 25%
It found that being a diabetic hiked the odds of dying from cancer by 25%, and also heightened the risk of death from infection, kidney and liver disease.
The risk of death was only higher in people with poorly controlled diabetes, however, as indicated by high blood sugar levels after a fast.
Diabetes is reaching epidemic levels with an estimated 280 million people, or 6.4% of the world's population, suffering from it, and numbers predicted to rise further as obesity rates also increase.
The United States Centres for Disease Control and Prevention says up to a third of US adults could have diabetes by 2050 if they continue to gain weight and shun exercise.
Undiagnosed and poorly treated
Another study published this week found that millions of people with diabetes are undiagnosed or poorly treated, raising their risk of early death from heart disease and of serious complications like blindness and chronic kidney disease.
The Cambridge-led study found that aside from cancer and vascular diseases, such as stroke, diabetes was also associated with deaths from many other causes including renal disease, liver disease, chronic obstructive pulmonary disease, mental disorders, pneumonia, other infectious diseases.
"A 50-year-old with diabetes died, on average, six years earlier than a counterpart without diabetes," said Cambridge University's John Danesh, who also worked on the study.
The study did not look at why these death rates were higher among diabetics, so the researchers could not say whether the diabetes link was simply a proxy for generally poorer health.
"Preventing diabetes becomes that much easier when we have a complete picture of the debilitating effect it has across the body and we know what steps to take to mitigate the damage," said Stephen Holgate of Britain's Medical Research Council, which part-funded the study. - (Kate Kelland and Gene Emery/Reuters Health, March 2011)