Common heart drug shows promise for Huntington's disease

New Delhi (The Uttam Hindu): A common heart drug has shown promise to delay the onset of Huntington's disease -- a progressive and inherited brain disorder that causes nerve cells in the brain to break down, according to a new study. Common symptoms of Huntington's include uncontrolled movements like jerking and twitching, loss of coordination, difficulty swallowing, slurred speech, and trouble walking. Researchers from the University of Iowa in the US found that using beta-blocker drugs -- commonly used to treat heart and blood pressure issues -- can lead to a significantly later onset of Huntington's symptoms for people in the pre-symptomatic stages. Among those diagnosed, the beta-blocker also slowed the rate of worsening of the symptoms. "Given that there are no disease-modifying agents for Huntington's disease, the possibility that beta-blockers, which are cheap and have a known safety profile, may provide benefit to patients at various stages of the disease is very exciting," said lead author Jordan Schultz, assistant professor of psychiatry at the varsity.

Previous research has shown that patients with Huntington's disease seem to have a stronger "fight or flight" reflex, even when they are resting. The team targeted beta-blockers as they are known to block the action of norepinephrine -- a neurotransmitter and hormone involved in the "fight or flight" response. For the study, published in the JAMA Neurology, the team focussed on two distinct groups of Huntington's patients; those with the genetic mutation that causes the disease but who have not yet started showing significant clinical symptoms (pre-group), and patients who have already received a clinical diagnosis -- referred to as motor-manifest patients (mm group). Within each group, the team identified patients who were taking a beta-blocker for at least one year. Next, the team matched 174 pre and 149 mm beta-blocker users to the same number of similar non-beta-blocker users.The analysis showed that pre-beta-blocker users had a significantly lower yearly risk of receiving a clinical diagnosis of Huntington's. This signalled that beta-blocker use was associated with a later onset of the disease. Among the mm group, the patients taking beta-blockers had a significant slowing of the gradual worsening of motor, cognitive, and functional symptoms. Meanwhile, Schultz cautioned that the study only reports associations between beta-blocker use in Huntington's patients, "the data does not prove cause and effect".