High Blood Sugar Linked to Cancer Risk

Women with high blood sugar may be more likely to develop
cancer, even if they don't have diabetes, a Swedish study shows.

High blood sugar (hyperglycemia) wasn't tied to men's overall cancer
risk.

But when researchers looked at specific types of cancer, they found that
both men and women with the highest blood sugar levels were more likely to have
pancreatic cancer, urinary tract cancer, and malignant melanoma (the most
deadly type of skin cancer) than those with the lowest blood sugar levels.

Keeping blood sugar levels within the normal range "may reduce cancer
risk," write the researchers, who included Par Stattin, MD, PhD, of
Sweden's Umea University Hospital.

For the study, Stattin's team invited all residents of a county in northern
Sweden to sign up for the study when they were 40, 50, or 60 years old.

Nearly 64,600 people accepted the offer. All were nonsmokers without
diabetes or a history of cancer (except for 1,435 people who had had
nonmelanoma skin cancer).

Upon enrolling in the study, participants took a blood test after fasting,
and another after drinking a sugary drink.

Most participants had normal results in both tests. The data show normal
blood sugar results for at least 85% of the group after fasting and at least
92% after the sugary drink.

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Study's Results

The researchers followed participants for eight years, on average.

Overall, women with the highest blood sugar levels upon joining the study
were more likely to be diagnosed with cancer before its end, compared with
women with the lowest blood sugar levels.

Also, cancer of the lining of the uterus (endometrial cancer) was more
common in women with the highest blood sugar levels, compared with those with
the lowest blood sugar levels.

Breast cancer was more common for women younger than 49 with high blood
sugar levels, compared with those with the lowest blood sugar levels, the study
also shows.

The results held when researchers considered other factors, such as
participants' weight and age.

Their study appears in the March edition of Diabetes Care.

Study's Limits

The study doesn't prove that high blood sugar levels cause cancer or that
normal blood sugar levels prevent it.

Doctors often can't explain exactly why one person develops cancer and
another doesn't. A complex mix of genetic and lifestyle factors may affect
cancer risk.

Also, the study didn't track all possible cancer influences. For instance,
researchers didn't know the participants' diet, exercise habits, or family
history of cancer.

They also didn't check participants' blood sugar over time.

More research is needed, but meanwhile, there's no reason not to get blood
sugar under control.

Doing so may help prevent diabetes and heart disease, besides possibly
making cancer less likely, Stattin's team notes.

Don't know your blood sugar level? Your doctor can run a quick blood test
and -- if necessary -- provide pointers for getting blood sugar into the normal
range.

By Miranda Hitti
Reviewed by Louise Chang
B)2005-2006 WebMD, Inc. All rights reserved