But the findings are far from definitive and not yet
ready for prime-time medical practice.
not necessarily direct clinical implications, but
the data support previous hypotheses that calcium
channel blockers may have neuroprotective effects,"
said study senior author Christoph R. Meier, a
clinical pharmacologist with University Hospital
Basel, in Switzerland. "This may stimulate
additional clinical and mainly basic research in
The findings were published in the Feb. 6 online
issue of Neurology, the medical journal of
the American Academy of Neurology.
Parkinson's disease is a chronic, degenerative
neurological disorder affecting at least one million
people in the United States and six million people
worldwide, according to the Michael J. Fox
Foundation for Parkinson's Research. The condition
involves the loss of brain cells that produce the
chemical dopamine, resulting in movement problems
Previous studies with rodents and primates had
uncovered a possible "neuroprotective effect" from
calcium channel blockers and angiotensin converting
enzyme (ACE) inhibitors, another class of blood
pressure medications, the researchers said.
The new study looked at the effect of calcium
channel blockers, ACE inhibitors, AT II antagonists
and beta blockers on the development of Parkinson's
The study involved more than 7,000 men and women
in the United Kingdom over the age of 40, half of
whom had been diagnosed with Parkinson's and half of
whom had not. Almost half the people in each group
used blood pressure medications.
Participants currently taking calcium channel
blockers lowered their risk of developing
Parkinson's by 23 percent. There was no real effect
for the other types of medications.
The strongest reduction in risk was seen in
patients who had had 30 or more prescriptions filled
and were still receiving prescriptions within 90
days prior to the diagnosis of Parkinson's, the
Women tended to have more of a risk reduction
than men but not if they had had less than 30
prescriptions filled. Individuals over the age of 80
had the most pronounced lowering of risk.
But even the study authors acknowledged that it's
not clear where to go next with the findings.
"It may be desirable that basic research
activities explore the effect of calcium channel
blockers on the central nervous system which may
lead (in theory) to new therapeutic strategies or
even new drugs to prevent or treat Parkinson's,"
Meier said. "Regarding clinical or
epidemiological/observational research, it would be
nice if other research groups analyzed their
databases and came up with their findings. They may
either confirm our observations or come to the
conclusion that our finding is isolated and that
there is no need to further pursue this issue."
Dr. Ralph Sacco, professor and chair of neurology
at the University of Miami Miller School of
Medicine, agreed. "This is a tricky one. You don't
know if there is a true association or not. There
are potential problems with this type of analysis,"
But, Sacco pointed out, there is evidence
accumulating on the relationship between
Alzheimer's, another neurodegenerative disease, and
circulatory system problems.