Study: Parkinson’s treatment reduced blood pressure in adolescents with Type 1 diabetes

According to a small study published today in Hypertension, a journal of the American Heart Association, teens with Type 1 diabetes (T1D) who took bromocriptine, a drug used to treat Parkinson’s disease and Type 2 diabetes, had lower blood pressure and less stiff arteries after one month of treatment compared to those who did not take the medication.

Heart disease is facilitated by stiff arteries and high blood pressure. T1D patients have a higher chance of getting heart disease than people without the illness since they have a chronic, lifelong condition where their pancreas doesn’t generate enough insulin to manage blood sugar levels.

Children who are diagnosed with T1D are significantly more at risk for heart disease than adults who are. Therefore, scientists are looking for strategies to delay the onset of vascular damage in kids with T1D.

“We know that abnormalities in the large vessels around the heart, the aorta and its primary branches, begin to develop in early childhood in people with Type 1 diabetes,” said lead study author Michal Schafer, Ph.D., a researcher and fourth-year medical student at the University of Colorado School of Medicine in Aurora, Colorado. “We found that bromocriptine has the potential to slow down the development of those abnormalities and decrease the risk for cardiovascular disease in this population.”

This study was carried out by a multidisciplinary team to investigate the effects of bromocriptine and a placebo on blood pressure and aortic stiffness in Type 1 diabetic adolescents. The drug bromocriptine belongs to the group of drugs known as dopamine receptor agonists. It raises dopamine levels in the brain, which enhances the body’s receptivity to insulin, also known as insulin sensitivity. Due to its impact on insulin sensitivity, bromocriptine has been FDA-approved since 2009 to treat people with Type 2 diabetes.

34 individuals (13 men and 21 women) with Type 1 diabetes who were 12 to 21 years old and whose HbA1c (glycosylated haemoglobin, a marker of blood glucose) was 12% or below participated in the study. When the HbA1c is 6.5% or greater, diabetes is present. One group of 17 received bromocriptine quick-release treatment, while the other received a placebo once daily. They were randomly split into two groups of 17. There were two phases to the study’s execution. In phase 1, participants received the initial therapy or a placebo for 4 weeks. After a 4-week “wash-out” period without treatment, participants received the opposite treatment for 4 weeks in phase 2.

Each participant acted as their own control for comparison in this “crossover” approach.
At the beginning of the trial and at the conclusion of each phase, blood pressure and aortic stiffness were assessed. Aortic stiffness was assessed using cardiovascular magnetic resonance imaging (MRI) of the major arteries and a measurement of the pulse wave velocity of the blood pressure pulse.

The research revealed that bromocriptine dramatically lowered blood pressure when compared to a placebo. At the conclusion of 4 weeks of treatment, bromocriptine medication typically reduced systolic blood pressure by 5 mm Hg and diastolic blood pressure by 2 mm Hg. Bromocriptine treatment also decreased aortic stiffness.

The ascending aorta showed the greatest improvement in aortic stiffness, with a decrease in pulse wave velocity of roughly 0.4 m/s and an increase in distensibility, or elasticity, of 8%. Bromocriptine was linked to a 5% increase in distensibility and a 0.2 m/s decrease in pulse wave velocity in the thoraco-abdominal aorta. “A stiff aorta predisposes a patient to other health issues, such as organ dysfunction or atherosclerosis and higher stress or strain on cardiac muscle,” Schafer said. “We were able to take it a notch further and show, using more sophisticated metrics, that these central large arteries are impaired, and impairment among adolescents and young adults with Type 1 diabetes may be decelerated with this drug.”