Preventing onset of diabetes aim of VUMC study
Having a child with type 1 diabetes is challenging enough, but Ellen Gould has two children who are insulin dependant, and one who has the early signs of the disease.
Now she is hoping to enroll her youngest son, Oliver, 3, in a study of a treatment that may prevent the onset of the disease.
The Gould family is enrolled in the Vanderbilt arm of an international diabetes study network called TrialNet, and Oliver's early test results show he may be on the short list to become one of the first participants in the study of the use of oral insulin to prevent diabetes.
Type 1 diabetes can be devastating. Years of blood sugar highs and lows can lead to blindness, kidney failure, heart disease and lower limb amputations. Finding out why the body attacks its own insulin producing cells and halting that process is what the $1.14 billion, NIH-funded TrialNet project seeks to do.
Vanderbilt's Pediatric Diabetes Program — headed by William Russell, M.D., director of the Division of Pediatric Endocrinology at the Monroe Carell Jr. Children's Hospital at Vanderbilt — is one of 42 major TrialNet sites in the United States and abroad.
The Gould family was screened the first year Vanderbilt opened up what is called the TrialNet Natural History study, open to relatives of individuals with type 1 diabetes, as they are at much higher risk of developing the disease.
Of the eight children in the Gould family, Patrick, 15, and Sara, 8, are already insulin-dependant. Sam, 10, came in with the rest of the family to enroll in TrialNet and was found to have developed very early signs of abnormal blood sugar control. While he does not need regular insulin yet, it is likely he eventually will.
Parents Ellen and Dave Gould were also tested, but so far Oliver is the only member of the family at that crucial stage where he is likely to develop diabetes, but doesn't have it yet.
Early this year, Oliver's Natural History test results found he doesn't have any blood changes that alert doctors that he is developing diabetes, but he does have key antibodies in his blood that suggest he is very likely (greater than a 50 percent chance) to develop diabetes before his 10th birthday.
“It's so hard to have great blood sugar control,” Ellen Gould said. “Even with the new meters and the pumps, it's like hitting a moving target. So what will happen later in life? We do the best we can, but every day this is hanging over us.”
“What has been an important development is finding a number of blood markers that can predict, with fair accuracy, who is most likely to develop type 1 diabetes,” said Russell. “In the Natural History portion of our TrialNet studies, we take both adults and children who have no sign of diabetes and test them for antibodies that we know are commonly found in people who develop type 1 diabetes, and the presence of a gene that may protect against the disease.”
Researchers have found a particular antibody, called mIAA, is a key indicator of who might benefit most from oral insulin. When mIAA, along with at least one other antibody, is present in high levels, a person's risk of developing type 1 diabetes is considered to be 50 percent over the next five years.
The Diabetes Prevention Trial (DPT-1), in which Vanderbilt participated a few years ago, suggested oral insulin protected against the development of diabetes, or delayed it in those with high levels of the mIAA antibody.
If the last of his tests indicate he is still a candidate for the prevention trial, Oliver Gould will begin taking a capsule every day, perhaps for many years.
“Participants will take a capsule a day and come in for blood testing every six months,” said Margo Black, R.N., research coordinator for TrialNet at the Vanderbilt Eskind Pediatric Diabetes Clinic. “Unless they develop diabetes or otherwise drop out, we expect the study to last at least six years and possibly longer depending on how the results look.”
Vanderbilt is looking for more participants. With a goal of screening 50 new family members each month for their risk of developing diabetes, the research team anticipates five or six of those at greatest risk, mostly children, will enroll in the prevention trial every year.
Type 1 diabetes affects almost 2 million individuals, and typically has its onset in children or young adults. The most common ages of diagnosis are the early school-aged years and adolescence, but is can be diagnosed much later in life.
In type 1 diabetes, a person's own immune cells destroy the cells in the pancreas that produce insulin. Heredity plays a major role in the risk of developing the disease, but environment plays a role as well.
Individuals who are close relatives of someone with type 1 diabetes can be screened with a blood test for participation in the TrialNet studies. This includes parents, children, siblings, half-siblings, grandchildren, nieces, nephews and cousins.
There is no cost for participation. For more information, contact Margo Black at the Vanderbilt Eskind Diabetes TrialNet Research Office at 936-8638.