Previous research has suggested the possibility that having diabetes could increase an individual’s lifetime risk of also developing thyroid cancer. A new report, however, has solidified that claim, demonstrating that the association holds true for retirement-age Americans. The findings were published in the journal “Thyroid.”
The study was conducted by epidemiologists affiliated with the National Cancer Institute (NCI) and the National Institutes of Health (NIH). After analyzing the results of the study, the researchers found that patients age 50 to 71 who had been diagnosed with diabetes showed a one-quarter increase in 10-year risk of developing thyroid cancer.
The study used data from nearly 500,000 men and women who had participated in the NIH-American Association of Retired Persons (AARP) Diet and Health Study. The study was conducted in 1995 and 1996.
At the beginning of the study, the researchers collected information about the health of the participants through the use of questionnaires. Questions were related to pancreatic health, body mass index (BMI), the presence of diabetes, and other health factors.
Ten years later, the researchers conducted follow-up examinations on many of the participants. The study used data collected from the follow-up tests.
Researchers found that almost one in 10 volunteers had been diagnosed with diabetes at the time of the initial questionnaire. Upon follow-up examination, those who had diabetes at baseline were noted to develop thyroid cancer at a greater average frequency than those who had not been diagnosed with diabetes.
On average, those who had been diagnosed with diabetes were 25% more likely than non-diabetics to be diagnosed with thyroid cancer. The women in the study showed a particularly high risk of developing cancer.
Diabetic men experienced a 4% increase in their chances of developing thyroid cancer, but diabetic women saw their chances of developing thyroid cancer increase much more dramatically, by 46%.
The results are very similar to findings that were published a decade ago in the journal “Clinical Diabetes.” In an issue of the journal from 2000, endocrinologist Patricia Wu with the University of California in San Diego estimated that 6.6% of the population of the United States has some form of thyroid disease. Diabetics are more likely to experience thyroid problems; about 10.8 percent suffer with thyroid conditions, according to Dr. Wu.
The mechanisms underlying the relationship between diabetes and thyroid cancer are unclear. However, some scientists believe that the diseases are related in that they are both disorders of the endocrine system. Additionally, Thyroid Today notes that both diabetes and thyroid conditions are typically linked to increased body mass, age-related risk, and autoimmune problems.
Scientists have been somewhat baffled in recent years by thyroid cancer, specifically the rate at which is occurs. A paper published in the journal “Cancer” states that thyroid carcinomas are more common than doctors once thought. The National Cancer Institute (NCI) estimates that 11 out of every 100,000 Americans are diagnosed with thyroid cancer each year. However, the report in “Cancer” states that the figure was significantly lower until recently.
From 1988 to 1998, thyroid carcinoma diagnoses rose by an average of 3.5% every year. From 1998 to 2005, that number rose by 6.7% every year. The researchers commented that the reason behind the increase in cancer diagnoses needed to be explored.
“Reasons for this increase, including environmental, dietary and genetic causes, need to be explored. To our knowledge, there is no new evidence to suggest that the exposure of human beings to radiation, a well known environmental risk factor, has increased over time to account for the observed increase in thyroid cancer,” said the researchers.