Some researchers believe people who are
overweight but otherwise healthy don't have a higher-than-normal risk of heart
disease. But a new report suggests extra weight can be harmful alone,
regardless of whether people have a cluster of risk factors known as metabolic
Metabolic syndrome is a group of conditions
linked to heart disease. It includes a large waist circumference, high blood
pressure, high triglycerides, low "good" cholesterol and diabetes.
Although each of those conditions is
closely tied to extra weight, some researchers think metabolic syndrome and not
the weight itself is what cause heart disease.
"There's been so much about that in
the literature over the last many years, that it's only the ones with metabolic
syndrome that are at risk," Dr Børge G. Nordestgaard said.
His research suggests the picture is more
For their study, Nordestgaard and Dr Mette
Thomsen of the University of Copenhagen recruited 71 527 Danish adults without
The researchers weighed, measured and
checked participants for the five components of metabolic syndrome.
People were considered to have metabolic
syndrome if they had at least three of those conditions. 44% of the
participants had a normal weight, 40% were overweight and 16% were obese when
the study started.
Rates of metabolic syndrome ranged from one
in ten among normal-weight people to close to two-thirds of obese participants.
Over the next three to four years, 634
people in the study had a heart attack and 1 781 were diagnosed with heart
The research duo found people's chances of
developing heart problems went up as their weight went up, whether or not they
had metabolic syndrome.
Obese people without metabolic syndrome
were almost twice as likely to have a heart attack as normal-weight people
without metabolic syndrome, for instance.
The results suggest only a fraction of the
extra heart risks seen among overweight and obese people can be explained by
more of them having metabolic syndrome, the researchers write in JAMA Internal
"There could be other factors in
obesity and overweight that also contributes, like inflammation for
example," Nordestgaard told Reuters Health. But, "I'm not saying
these cardiovascular disease risk factors are not important," he said.
Blood pressure and cholesterol contribute
to a person's chance of getting heart disease, Nordestgaard said. But the label
of metabolic syndrome, which is used by some doctors as a clear dividing line,
may not be what's critical.
"Whether you call someone as having or
not having metabolic syndrome as kind of a yes/no variable, is not helpful
clinically and it doesn't make sense biologically," Dr Meir J. Stampfer
Stampfer, from the Harvard School of Public
Health, co-wrote a commentary published with the new study.The idea that people aren't at risk unless
they meet the criteria for metabolic syndrome is "really flawed", he
told Reuters health.
"It's basically just that the metabolic
syndrome is waiting to happen to those people. "Based on this study, extra
weight and metabolic problems may have a "cumulative effect" on a
person's risk of heart disease, Dr Jiang He told Reuters Health in an email.
He is the chair of the Tulane University
School of Public Health and Tropical Medicine Department of Epidemiology in New
Orleans and wasn't involved in the new study.
Researchers agreed that people should do
what they can to control their weight. "Obesity is a preventable
condition," he said.
Nordestgaard recommended that people who
are overweight think about their diet and get more exercise to avoid future
heart problems. "Any overweight or obesity puts you at increased risk of
heart disease," he said.