Benign brain tumors that have previously been associated with obesity and diabetes are surprisingly less likely to emerge in patients with high blood sugar, according to new research.1

Meningioma is a type of benign brain tumor that arises from the brain and spinal cord. The tumor usually is not cancerous but it can require risky surgery and affect a patient’s quality of life. Previous research established that these slow-growing tumors are more common among people who are obese and those who have diabetes. This research team, led by Judith Schwartzbaum, PhD, of The Ohio State University, Columbus, focused on blood markers for the disease, including glucose.

The researchers compared blood tests results from a group of more than 41,000 Swedes with meningioma diagnoses 15 or fewer years later. High blood sugar, particularly in women, actually meant the person was less likely to develop a brain tumor.

“It’s so unexpected. Usually diabetes and high blood sugar raise the risk of cancer, and it’s the opposite here,” said Schwartzbaum, an associate professor of epidemiology and a researcher at OSU Comprehensive Cancer Center.

“It should lead to a better understanding of what’s causing these tumors and what can be done to prevent them.”

Schwartzbaum explained that, though meningiomas are rarely cancerous, they behave similar to cancer, which has led scientists to wonder if some relationships between possible risk factors and tumor development would be similar.

The researchers identified 296 cases of meningioma from data collected from 1985 to 2012, with more than 61% of tumors occurring in women. They found that women with the highest fasting blood sugar levels were less than half as likely as those with the lowest readings to develop a tumor. For men, the relationship between fasting blood sugar and tumor development was not statistically significant.

However, they found that that both men and women with high blood sugar had a lower likelihood of meningioma diagnosis when they compared the less-reliable non-fasting sugar readings (those taken without a period of no food or drink that could influence the results).

The risk of this tumor appeared to be decreased by a diabetes diagnosis before meningioma. Schwartzbaum noted that the data likely had incomplete information on diabetes.

“These tumors take years to develop, and an earlier diagnosis would certainly lead to better surgical outcomes,” she said. “There are so many things still to be learned, but I am glad that people are now serious about studying these so-called benign tumors.”

Approximately 7 in 100,000 US residents receive a meningioma diagnosis annually. Meningiomas can cause headaches, weakness in the limbs, seizures, vision problems and personality changes. They represent approximately one-third of all tumors that originate in the brain, according to the American Brain Tumor Association.

Reference

1. Bernardo BM, Orellana RC, Weisband YL, et al. Association between prediagnostic glucose, triglycerides, cholesterol and meningioma, and reverse causality. Br J Cancer. 2016 Jun 28. doi: 10.1038/bjc.2016.157. [Epub ahead of print]