THURSDAY, May 26 (HealthDay News) -- Although early research had
suggested that the nutrient niacin might raise levels of "good"
cholesterol and thwart heart attacks, a major clinical trial has
been stopped 18 months early because it has shown no such
The trial, sponsored by the U.S. National Institutes of Health
and a drug maker, enrolled patients with a history of heart disease
who had their LDL ("bad") cholesterol under control with statin
medications. The new trial hoped to use niacin (also known as
vitamin B3) to boost levels of "good" HDL cholesterol while
lowering blood levels of fats called triglycerides to help reduce
the odds of heart attack or stroke.
Unfortunately, "this study has ended 18 months early because we
have answered the primary question," Dr. Susan B. Shurin, acting
director of the U.S. National Heart, Lung, and Blood Institute
(NHLBI), said during a morning press conference Thursday. "While
high-dose niacin raised participants' HDL cholesterol and lowered
triglycerides, it did
not affect the overall rate of cardiovascular events," she
"There was also an unexplained higher incidence of stroke in the high-dose niacin group, compared to the group on statins alone," Shurin added.
It is not clear if this trend toward stroke was merely a matter
of chance, but it was a factor in the NHLBI's decision to stop the
trial, especially in the face of a lack of benefit from niacin, she
"The U.S. Food and Drug Administration is aware of the findings and is recommending no change in labeling or practice [regarding niacin], pending full analysis of the data," Shurin said.
Prior to the trial, some observational studies had shown that
low HDL cholesterol was a risk factor for heart attack and stroke,
so it was thought that any drug that could boost HDL might help
patients. In addition, some studies had shown that low HDL plus
high triglycerides boosted the odds of cardiovascular events.
In the trial, more than 3,400 patients averaging 64 years of age
were randomly assigned to high-dose niacin or a placebo. Those in
the niacin arm of the trial took Abbott Laboratories' Niaspan, a
time-released form of niacin that contains a much higher dose of
niacin than is found in over-the-counter supplements.
All of the participants also took the cholesterol-lowering
statin drug Zocor (simvastatin).
As expected, participants who took Niaspan for the 32 months of
the trial saw their blood levels of HDL cholesterol rise and their
triglycerides lower, compared with those who took a statin
But the boost in HDL failed to translate to any reduction in
heart attacks or strokes, the team said. Nor did it lower the rate
of hospitalizations for heart disease or procedures to open blocked
cardiac arteries, according to the NHLBI.
Worse, more people taking niacin had strokes than those on a
statin alone, the researchers found. In fact, 28 participants
taking Niaspan suffered strokes, compared with 12 in the placebo
group. Nine of the strokes in the Niaspan group happened to
participants who had stopped using the drug at least two months and
up to four years before their stroke.
Earlier studies had not shown any connection between high-dose
niacin and stroke risk, Shurin said. Why the uptick in strokes was
seen in this study isn't clear, she said.
Shurin cautioned people who take supplemental niacin not to stop
taking it. They might want to talk with their doctor, she said. But
this study is no reason to change what they are doing, she
All those in the study have been notified of the results and
will be scheduled for clinic visits within the next several months.
They will also be followed for 12 to 18 months.
The trial was funded by the NHLBI with support from Abbott
Laboratories, which provided the Niaspan. Drug maker Merck
Pharmaceuticals provided the Zocor.
Commenting on the decision to stop the trial, Dr. Gregg C.
Fonarow, a professor of cardiology at the University of California,
Los Angeles, said that "these findings highlight the critical
importance of basing treatment decisions on well-powered,
randomized clinical outcome trials rather than on surrogate
endpoints like changes in lipid [blood fat] levels or imaging
Statin therapy has been proven in trial after trial to reduce
fatal and not-fatal cardiovascular events in patients with -- and
at risk for -- cardiovascular events, he said.
"However, many clinicians have been led to believe that the so-called 'residual risk' of cardiovascular events that remained after statin therapy could be addressed with therapies like niacin added to statin therapy to raise HDL and lower triglycerides," Fonarow said.
But this trial has demonstrated no added reduction in
cardiovascular events with this strategy. "A prior trial, ACCORD,
showed no benefit with the addition of TriCor, which reduces
triglycerides, to statin therapy. Together these trials challenge
that concept that raising HDL and lowering triglycerides is
beneficial," Fonarow said.
Niaspan's maker looked at the results more positively.
The study results "affirmed the positive impact of Niaspan on
HDL and triglyceride lipid [blood fat] values. Previous studies
support HDL as an independent risk factor for cardiovascular
disease," Abbott said in a statement.
For more information on cholesterol, visit the
U.S. National Library of Medicine.
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