by Carole Bartoo

The Wittenburg brothers make for a tight group. Meet Samuel, 19 months; Isaiah, 8; Isaac, 12; David, 14; and Jacob, 18. They share a brotherly bond that literally is thicker than blood.

Samuel, Isaiah, Isaac and Jacob recently had their blood drawn in a sign of solidarity for their brother, David, who has type 1 diabetes. The blood samples will be used in a study called TrialNet that aims to one day discover how to delay or prevent the onset of type 1 diabetes, previously known as juvenile diabetes. Type 1 diabetes affects about every 400 to 600 children and adolescents under the age of 20.

For an 8-year-old and a 12-year-old especially, a needle-stick blood draw is a big deal, but then again, these boys would do anything for their brother, David.

"I had all the boys with me for David's October visit with Dr. [Bill] Russell," said Angela Wittenberg, the boys' mother. "The research nurse came in and told us there was an opportunity for a new study called TrialNet."

The Vanderbilt Eskind Diabetes Clinic was selected in fall 2006 to become one of eight major affiliate sites for the type 1 diabetes TrialNet studies. Russell, director of the Division of Pediatric Endocrinology and the Vanderbilt Pediatric Diabetes Clinic, was selected as the principal investigator. The TrialNet studies, sponsored by the National Institutes of Health, seek to hone predictions about who will develop the disease and then to test promising treatments to delay or prevent the onset of type I diabetes.

The Wittenbergs said it was an answer to a prayer. In more than 12 years of bringing David to see Russell, they say it had become their habit to pray for researchers to come up with a cure for the disease.

That day in the clinic David's younger brothers, Isaac and Isaiah, were taken into a side waiting area by their parents to talk about what joining TrialNet would mean.

"We explained that it was probably not going to help David, but it might be able to help someone like David in the future," Angela said. "It was hard for us, because my husband and I immediately wanted them to join the study, but we knew with the exception of Samuel, who was too young to decide on his own, that the boys had to make this decision for themselves."

Russell had spent years explaining to families why the very tests being offered in TrialNet were not worth getting. Powerful tests have been available for a few years to predict, with 50 percent accuracy, if someone is likely to develop type 1 diabetes in the next five years.

"We had to explain to parents that when one child has type 1 diabetes, that other children, and even adults, are at higher risk for developing it too. But testing didn't pay off," Russell said. "In contrast to type 2 diabetes, where lifestyle changes in the areas of weight loss and exercise are very helpful and can reverse the development of diabetes, there are no effective ways to prevent type 1 diabetes. So knowing you are at risk does you little good until the disease begins to show itself."

But TrialNet changes the advice.

"We know, from a huge study we participated in called the Diabetes Prevention Trial (DPT-1) which wrapped up in 2003, that about 3 percent of the close family members of our patients will actually test at risk for diabetes without having developed it yet," Russell said. "Now the Natural History portion of the TrialNet studies will take a close look at who is in the 3 percent, and provide long-term follow up for those at highest risk."

Just the ability to know who in her household is at risk is important to Angela. With David, there was no family history, no early warning - just rapidly progressing symptoms that signaled diabetes was in full bloom.

"He was 2 and had been flooding the bed at night and complaining of not feeling well - just not acting himself. Within days he was admitted to the critical care unit at Vanderbilt Children's," Angela said. "I spent that night looking at the ceiling, knowing this was life threatening and trying not to panic."

Now, 12 years later, type 1 diabetes is simply a way of life for David and the whole family. But Angela says TrialNet changes things up a bit. "We have raised thousands of dollars over the years, participating in fund raising and walks for diabetes, but this was an opportunity to participate more directly in the research."

"A part of me really wanted to know … to have these tests performed on all the boys. It was really hard to lay that down and let them decide, but we decided we would not overrule them. After all, it meant drawing blood when they are healthy, and for no benefit to themselves."

Back in the clinic waiting room, Isaac, the "adventure boy" of the family with a love of the outdoors and a penchant for baking, was the first to agree to the testing.

"He's very analytical and was so focused on David, that we had to explain clearly that this was not likely to end up in a cure for David," Angela recalled. "He got real quiet and while we were talking with Isaiah, he took a deep breath and matter-of-factly said 'OK, I'll do it.'"

Isaiah was much more skittish about the blood draw after recent hospital treatment for a busted lip resulting from a fall. He is apparently the jokester of the family because he really tricked his mom that day in the clinic.

"I assured him he didn't have to do it, and left him alone to talk to the nurse, so when he came back, with his head hung low and said, 'Are you disappointed?' I assured him that - no - it was his choice; then he smiled and said, 'Well I did it!' I was so surprised."

All the boys, including the eldest, Jacob, and the youngest, Samuel, are enrolled, as is Angela. Carl Wittenberg, the boys' father and Angela's husband, is the only member of the immediate family who didn't qualify for the Natural History Trial because he's just over the age cut-off of 46.

"It amplified some whispers I had in my head, how much they were willing to do something for their brother they didn't have to do," Angela said. "We know this isn't something that can help David, and it may not even help any of us directly, but we are all excited it may offer something to the next generation of people who may face type 1 diabetes. Still, there's no doubt, we're all doing this for David."