Diabetes Health Talk

New evidence discovered by researchers at The University of Texas School of Public Health Brownsville Regional Campus shows that patients with Type 2 diabetes may be at increased risk of contracting tuberculosis because of a compromised immune system, resulting in life-threatening lung infections that are more difficult to treat.

The World Health Organization estimates that 180 million people in the world have diabetes, and that number is expected to double by 2030. Also, according to the WHO, each person with active, untreated TB infects on average 10 to 15 people per year. “You do the math and it adds up to a major public health threat,” McCormick said. “If you have Type 2 diabetes in an area with high rates of TB, your chances of getting TB goes up. In countries where a third of the population is infected with TB, this becomes a real issue.”

In a recently published study in linical Infectious Diseases, researchers reported that the immune systems of patients with Type 2 diabetes and tuberculosis respond differently compared with patients with TB alone. “This immune impairment may be what makes patients with diabetes so susceptible to TB,” said Fisher-Hoch, whose career as a scientist was recently honored with a Hall of Fame Award from Women In Technology International.

Restrepo and her colleagues found that innate and type 1 cytokine responses were significantly higher in patients with tuberculosis who had diabetes than in the control group of patients with TB and no diabetes. The effect was consistently and significantly more marked in diabetic patients with chronic hyperglycemia, or uncontrolled high blood sugar. Diabetes results in the body’s ineffective use of insulin. If left uncontrolled, the chronic high sugar in the bloodstream can affect the critical immune system and damage the body’s systems, especially the nerves, the retina of the eyes and blood vessels.

“These findings are the opposite of what we were expecting,” Restrepo said. “These innate and type 1 cytokines are typically associated with TB protection, but in patients with diabetes, it appears the cytokines are not effective. Diabetics may have more advanced TB with more bacteria, and hence, more stimulation for secretion of type 1 cytokines.”

The researchers wrote, “More detailed knowledge of the underlying mechanisms should focus on the effect of chronic hyperglycemia on the immune response to help in understanding the enhanced susceptibility of diabetic patients with tuberculosis.”