most appropriate approach to reduc-

ing the risk of using dietary supple-

ment products containing ephedrine

alkaloids.

The National Advisory Council for

the National Center for

Complementary and Alternative

Medicine, part of the National

Institutes of Health (NIH), was sched-

uled to meet on March 17 to assess the

evidence on ephedra’s safety and effec-

tiveness in order to develop a research

agenda on ephedra. FDA will give that

committee an opportunity to com-

ment on the notice, should the com-

mittee find it appropriate to do so.

Health care practitioners are being

urged to submit written comments to

the FDA or report any known adverse

events related to ephedra use to

www.fda.gov/medwatch.

Sleeping PatternImportant in Reducing SIDS

Infants accustomed to sleeping on

their backs who are then placed to

sleep on their stomachs or sides are at

an increased risk for SIDS—greater

than the increased SIDS risk of infants

always placed on their stomachs or

sides, according to a newly released

study.

The study, conducted by Kaiser

Permanente in Northern and Southern

California and supported by the

National Institute of Child Health and

Human Development (NICHD) and

the National Institute on Deafness and

Other Communications Disorders,

appears in American Journal of

Epidemiology.

The study also shows that infants

sleeping on their sides are at an

increased risk of SIDS. The researchers

think that a large part of the risk may

be due to the instability of the side

sleeping position and the tendency for

infants sleeping in this position to turn

onto their stomachs.

The study, which was conducted in

11 counties in Northern and Southern

California, is the first to examine the

relationship between infant sleeping

position and SIDS in a racially diverse

U.S. population. The incidence of

SIDS has declined over 50 percent

since 1992, when the American

Academy of Pediatrics recommended

that infants be placed on their backs to

sleep. Before the current study, evi-

dence of the link between stomach

sleeping and SIDS risk was based

largely on overseas studies, where pop-

ulations and cultural practices are dif-

ferent from those in the U.S.

The researchers also collected infor-

mation about bedding materials, type

of mattress, room- or bed-sharing,

room temperature, exposure to passive

smoking and infant sickness. The

researchers found that infants last

placed on their sides for sleep were

twice more likely to die of SIDS than

infants last placed on their backs. In

addition, the risk of SIDS was signifi-

cantly increased if infants turned from

their sides to their stomachs during

sleep. While the reason isn’t clear, the

researchers think that the instability of

the side position makes it more likely

for babies who are placed to sleep in

this position to roll over onto their

stomachs.

A pattern also emerged when the

researchers looked specifically at the

position in which an infant was last

placed to sleep, compared to their

usual sleeping position. If an infant

who was usually placed to sleep in the

low-risk position—on the back—was

then placed to sleep in a high-risk

position (the stomach or side), his or

her SIDS risk was seven to eight times

greater than that of an infant who was

always placed to sleep on his or her

back. “The message here is ‘every night

and nap time count,’” said study co-

author Dr. Marian Willinger of

NICHD. “Parents and caregivers

should place their babies on their

backs every time they go to sleep.

Consistency is the key.”

One of the strengths of this study is

that the researchers interviewed a

racially—and culturally diverse group

of mothers—White, African American,

Hispanic, and Asian/Pacific Islander,

although the small sample size limited

the researchers’ ability to examine risk

within each racial group. This study

provides results from the first study of

infant sleeping position in relation to

SIDS risk to be collected entirely after

the NICHD’s “Back to Sleep” cam-

paign is launched to inform the public

about the importance of sleep position

in preventing SIDS.

Low-Dose WarfarinPrevents Clot Recurrence

Astudy of long-term, low-dose

warfarin to prevent the recur-

rence of the blood clotting disorders

deep vein thrombosis (DVT) and pul-

monary embolism (PE) resulted in

such a high degree of benefit to the

patients—without significant adverse

106 AWHONN Lifelines Volume 7 Issue 2

effects—that the National Heart,

Lung, and Blood Institute (NHLBI)

of the National Institutes of Health,

in Bethesda, MD, stopped the study

early.

The multicenter Prevention of

Recurrent Venous Thromboembolism

(PREVENT) trial found a 64 percent

reduction in episodes of DVT and pul-

monary embolism in study partici-

pants taking low-dose warfarin com-

pared to those taking a placebo.

Furthermore, there was no evidence of

significant risks such as major hemor-

rhage or other potential side effects of

warfarin, which is an anticoagulant—a

drug that prevents blood clotting.

At the time the study was terminat-

ed, patients had been followed for up

to about four years, with an average of

about two years. All study participants

had experienced a previous episode of

either DVT or PE placing them at

greater risk of a recurrence.

PREVENT is the first study to eval-

uate the use of low-dose warfarin for

the long-term prevention of venous

thromboembolism (VTE), a term that

includes both DVT and pulmonary

embolism. The study is published in

the April 10, 2003, issue of The New

England Journal of Medicine. Due to its

importance, the journal posted the

article online on February 24.

The trial, which began in 1998, was

scheduled to run until 2005. However,

at a regularly scheduled meeting of the

study’s independent Data and Safety

Monitoring Board (DSMB) held

December 4, 2002, the interim findings

were reviewed, and based on the

strong benefit of low-dose warfarin,

the DSMB recommended halting the

study. The recommendation was

approved by the NHLBI.

The current standard treatment for

DVT and pulmonary embolism not

associated with surgery or another

specific cause is 5 to 10 days of intra-

venous or subcutaneous heparin fol-

lowed by three to six months of full-

April | May 2003 AWHONN Lifelines 107

Levels of a type of adult stem

cell in the bloodstream may

indicate a person’s risk of develop-

ing cardiovascular disease, according

to a study supported by the NHLBI.

The study looked at the blood

level of endothelial progenitor cells,

which are made in the bone marrow

and may help the body repair dam-

age to blood vessels. Scientists from

NHLBI and Emory University

Hospital in Atlanta, GA, found that

cardiovascular disease risk was high-

er in persons with fewer endothelial

progenitor cells. The cells of those at

higher risk also aged faster than

those at lower risk, as determined by

the Framingham Heart Study risk

factor score, a standard measure-

ment of cardiovascular risk.

Additionally, the study found that

blood vessels were much less likely

to dilate and relax appropriately in

persons with low levels of the cells.

Results of the study, which

involved 45 healthy men aged 21

and older, some of whom had stan-

dard cardiovascular risk factors,

appeared in the February 13, 2003,

issue of The New England Journal of

Medicine.

Researchers wrote that they

believe that these endothelial pro-

genitor cells patch damaged sites in

blood vessel walls. When the cells

start to run out, cardiovascular dis-

ease worsens. “We don’t yet know

what causes their depletion but it

may be related to the fact that the

risk of cardiovascular disease

increases as people age. For instance,

the cells may be used up repairing

damage done by other risk factors

or those risk factors could directly

affect the survival of the endothelial

cells themselves.” They noted that

some day it may be possible to test a

person’s risk of cardiovascular dis-

ease by taking a blood sample and

measuring these cells. If the level is

too low, an injection of endothelial

cells might boost the body’s ability

to repair itself and prevent more

blood vessel damage.

NNeeww HHeeaarrtt DDiisseeaassee RRiisskk IInnddiiccaattoorr DDiissccoovveerreedd

dose warfarin. Therapy typically stops

after the initial treatment period

because long-term use of full-dose

warfarin is associated with a substan-

tial risk of major bleeding. After the

initial therapy is completed, recurrent

blood clots occur in 6 to 9 percent of

patients each year. The new data

demonstrate that these recurrent

blood clots can be avoided using an

inexpensive and safe therapy.

If DVT is not treated, it can lead to

pulmonary embolism in which the

clots detach and travel through the

bloodstream to the lungs, where they

may enter a pulmonary artery. Large

clots that completely block the pul-

monary artery can be fatal. Symptoms

of pulmonary embolism include sud-

den shortness of breath, sharp chest

pain, a cough with bloody sputum,

excessive sweating, rapid pulse and

lightheadedness. Acute DVT can also

lead to complications like chronic

venous insufficiency, which is charac-

terized by pooling of blood, chronic

leg swelling and increased pressure on

the skin.

There are a number of risk factors

for DVT and pulmonary embolism,

including long periods of inactivity,

which decrease blood flow. People who

are immobile after surgery or serious

injuries and travelers on long trips are

at increased risk of blood clots.

In addition, the hormone estrogen

found in birth control pills has been

shown to increase the risk of blood

clots. The results of the Women’s

Health Initiative study, reported last

July, found significant increases in

pulmonary embolism in healthy

women taking combined estrogen and

progestin.

Genes Linked to Severe Lupus

Agenetic “signature” may be the

key to understanding why some

Lupus sufferers have such severe

symptoms, say a team of scientists

supported by the National Institute of

Arthritis and Musculoskeletal and

Skin Diseases. This genetic “signature”

is present in some patients with sys-

temic lupus erythematosus (SLE) who

develop such life-threatening compli-

cations as blood disorders, central

nervous system damage and kidney

failure.

Using DNA microarrays—small sil-

icon chips that contain tiny amounts

of thousands of known genes—to

carry out a technique called gene

expression profiling, researchers ana-

lyzed thousands of genes in the

peripheral blood cells of 48 lupus

patients and 42 healthy controls.

Surprisingly, 14 of the thousands of

genes studied were linked to a subset

of SLE patients with severe disease. In

addition, 161 of the genes studied

showed different expression patterns

in SLE patients compared with healthy

controls.

The 14 genes, referred to collective-

ly as the IFN (interferon) expression

signature, are turned on by the activity

of interferon, a complex family of pro-

teins involved in the regulation of

immune responses. The data,

researchers say, provide strong support

for developing new therapies to block

IFN pathways in patients with severe

lupus, and the pattern of gene expres-

sion in blood cells may be useful in

identifying patients most likely to ben-

efit from these new therapies. Gene

expression profiling in blood cells may

also be useful in identifying disease

pathways in other autoimmune and

inflammatory disorders.

SLE, or lupus, is a chronic, inflam-

matory, autoimmune disease. Its

symptoms range from unexplained

fever, swollen joints and skin rashes to

severe organ damage of the kidneys,

lungs or central nervous system. Lupus

is difficult to diagnose because it’s dif-

ferent for every person who has it, and

it affects women nine times more

often than men.

MRI for Diagnosing Heart Attacks

Advanced magnetic resonance

imaging (MRI) technology can

detect heart attack in emergency room

patients with chest pain more accu-

rately and faster than traditional meth-

ods, according to a new study support-

ed by the NHLBI.

Published in the February 4 issue of

Circulation: Journal of the American

Heart Association, the findings suggest

108 AWHONN Lifelines Volume 7 Issue 2