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.
High blood pressure and stiff arteries contribute to the development of heart disease. T1D patients have a higher chance of developing heart disease than people without the condition since they have a chronic, lifelong condition where their pancreas doesn’t generate enough insulin to control blood sugar levels.
Children who are diagnosed with T1D are significantly more at risk for heart disease than adults who are. Hence, 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 Schäfer, 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.”
A multidisciplinary team to investigate the effects of bromocriptine and a placebo on blood pressure and aortic stiffness in Type 1 diabetic adolescents carried out this study.
A stiff aorta predisposes a patient to other health issues, such as organ dysfunction or atherosclerosis and higher stress or strain on cardiac muscle. 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.
Michal Schäfer
Bromocriptine is in a class of medications called dopamine receptor agonists. It raises dopamine levels in the brain, which increases the body’s receptivity to insulin, also known as insulin sensitivity. Bromocriptine has been FDA-approved since 2009 to treat adults with Type 2 diabetes due to its effect on insulin sensitivity.
The study included 34 participants (13 male, 21 female) ages 12 to 21 years who had been diagnosed with Type 1 diabetes for at least a year, and their HbA1c (glycosylated hemoglobin a measure of blood glucose) was 12% or less.
An HbA1c level of 6.5% or higher indicates diabetes. 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. The study was conducted in two phases.
Participants took the first treatment or placebo for 4 weeks in phase 1, then had no treatment for a 4-week “wash-out” period, followed by phase 2 with 4 weeks on the opposite treatment. In this “crossover” design, each participant served as their own control for comparison.
At the beginning of the trial and at the conclusion of each phase, blood pressure and aortic stiffness were measured. 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 study found:
- Compared to placebo, blood pressure was significantly decreased with bromocriptine. On average, bromocriptine therapy resulted in a systolic blood pressure decrease of 5 mm Hg and a diastolic blood pressure decrease of 2 mm Hg at the end of 4 weeks of treatment.
- Aortic stiffness was also reduced with bromocriptine therapy. The ascending aorta showed the greatest improvement in aortic stiffness, with a decrease in pulse wave velocity of roughly 0.4 meters/second and an increase in distensibility, or elasticity, of 8%. In the thoraco-abdominal aorta, bromocriptine was associated with a lowered pulse wave velocity of about 0.2 meters/second, with a 5% increase in distensibility.
“A stiff aorta predisposes a patient to other health issues, such as organ dysfunction or atherosclerosis and higher stress or strain on cardiac muscle,” Schäfer 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.”
The study’s small size is a limitation. The researchers point out that larger trials are needed to better understand the effects of bromocriptine on vascular health in a larger population of persons with Type 1 diabetes.
