ABC News recently aired an item that discussed the tuberculosis (TB) risk in children and adolescents that may have caused alarm for children and teens living with type 1 diabetes. The July 2009 issue of The International Journal of Tuberculosis and Lung Diseases noted that nearly one in three children and adolescents with type 1 diabetes have a positive skin test for TB and are at risk of developing active tuberculosis in a TB-endemic area (Cape Town, South Africa). It was unknown if poor control of blood sugars predisposed these children to contracting TB following infection or if the poor glycemic control was secondary to tubercular disease. The authors of the study in South Africa determined the prevalence of TB among 258 children with type 1 diabetes under age 21 in TB prevalent areas. The prevalence of TB infection was nearly 30 percent and active TB was noted in 3.5 percent of the children, while 6.2 percent were previously treated for tuberculosis. According to the authors, the prevalence of TB increased from nearly 8 percent at age 5 to 12.5 percent at age 10, years after the diagnosis of diabetes. The observed prevalence of TB in children with type 1 diabetes was more than 6.8 times greater than the population prevalence. Poor control of diabetes in association with exposure to a known person with TB combined for an even higher risk for contracting TB, 1.4 percent and 2.8 percent respectively. The key to understanding the above research is to keep in mind that TB screening is even more crucial for children with type 1 diabetes living in an area with increased tuberculosis disease.
Upon review of the literature associated with diabetes and TB, I discovered that this link between diabetes and TB has been noted throughout the world. A paper (2008) by Jeon and Murray called Diabetes Mellitus Increases the Risk of Active Tuberculosis: A Systematic Review of 13 Observational Studies noted that diabetes was associated with an increased risk of TB regardless of study design and population. The systematic review demonstrated that compared to people without diabetes, people with diabetes had a three-fold increased risk of developing active tuberculosis. The authors suggested that this increased risk of TB associated with diabetes may already be responsible for greater than 10 percent of TB cases in India and China. Other studies suggest that the impact due to diabetes may vary by region and ethnicity. The important take-home message is to continue to follow general healthcare recommendations including appropriate immunizations and PPD (TB) screening to treat exposure to TB early and to avoid active tuberculosis.
In other research news, one of our new families at Children's National alerted us to study being conducted by Michael Haller, MD, at the University of Florida. In this study, cord blood that has been saved by parents after childbirth (in a specialized bank) was infused into the blood of their children with type 1 diabetes. As you may know, new parents are now given the option to either bank or discard their baby's umbilical cord blood. The cord blood contains all the typical components of blood: red and white blood cells, platelets, and serum, as well as stem cells. These stem cells may then have future uses in treatment of genetic diseases, as well as in transplants for malignancies such as leukemia. Banking cord blood is costly; however, the family has legal rights to use the blood if it is ever required. These stem cells are a perfect match for the baby.