Study Aims to Protect Adolescents with Type 1 Diabetes from Kidney and Heart Complications

JDRF and the Canadian government are boosting the Adolescent Type 1 Diabetes Cardio-Renal (heart and kidney) Intervention Trial (AdDIT) by adding one additional clinical site at the Charles H. Best Diabetes Centre in southern Ontario, Canada. The expansion will serve to accelerate the recruitment of adolescents with type 1 diabetes (T1D) and microalbuminuria, a condition in which a common protein called albumin leaks into the urine—a sign of early kidney disease and a risk factor for developing heart disease later in life.

The international trial, which has multiple sites in the United Kingdom (22), Canada (5) and Australia (8), will help guide clinicians on how to best manage, treat, and prevent these serious and expensive-to-treat complications. In addition, the study will be used to identify adolescents who go on to develop complications and those who do not, and better understand what sets the two groups apart.

Nearly all adolescents with T1D are tested for microalbuminuria, and 12 to 16 percent of adolescents are diagnosed with the condition. However, it is rarely treated before 18 years of age because there are no guidelines for treating microalbuminuria in children and adolescents. Yet, it has been shown in one study in Diabetes Care that adolescents with microalbuminuria experience damage to their kidneys and blood vessels during puberty, a finding that warrants early intervention to protect and prevent adolescents from long-term complications. More high-quality evidence is needed to support clinical approaches to protect those with T1D from such complications.

“Everybody is screening adolescents for microalbuminuria, but nobody knows what to do with the results,” says David B. Dunger, M.D., professor of pediatrics at Cambridge University, England, and a principal investigator of AdDIT. “This study should have an important impact on future recommendations for managing T1D during adolescence.”

The AdDIT trial will screen adolescents with T1D, ages 10 to 16, for microalbuminuria and categorize them in one of three tertiles—low, medium, or high—depending on how much albumin is in their urine. Those in the highest tertile will be given currently approved drugs or placebo controls (cholesterol-lowering statins, blood pressure–regulating ACE inhibitors, or a combination of the two) to see if they can reduce the amount of albumin in the urine and prevent further kidney damage. Those in the two lower tertiles will be observed for three to four years, without receiving drug treatment.

Since the study began in 2008, more than 3,000 adolescents with T1D have been screened for microalbuminuria in the United Kingdom, Australia, and Canada. With the additional site in Canada, which is being led by Farid Mahmud, M.D., an endocrinologist at The Hospital for Sick Children, investigators hope to screen another 500 to 1,000 adolescents
with T1D.

The AdDIT study is now part of the JDRF Canadian Clinical Trials Network, a new clinical consortium that currently operates nine clinical trials and two projects that focus on T1D.

In addition to the human cost of developing kidney disease, there is also a financial cost associated with the disease, explains Marie Nierras, Ph.D., JDRF’s senior director of international partnerships and cure therapeutics. Some people who develop kidney problems may go on to require dialysis or take medicine for the rest of their lives. “If we can prevent these complications, we can not only help improve the quality of lives of people living with T1D, but also lessen the burden of this disease on our health care system—making a difference at the individual and global level in how we manage this disease.”