Metabolic syndrome raises risk of heart failure

NEW YORK (Reuters Health) – The findings of a new study
suggest that the metabolic syndrome is a risk factor for heart
failure, and this relationship is seen with or without the
presence of other known heart failure risk factors, such as
previous heart attack.

Individuals with the metabolic syndrome have a cluster of
heart disease and diabetes risk factors, such as excess body
weight, high blood pressure, high blood sugar and high
cholesterol levels.

The results imply that the “metabolic syndrome provides
important risk information beyond that of established risk
factors for heart failure,” lead author Dr. Erik Ingelsson,
from Uppsala University in Sweden, and colleagues note. They
suggest that insulin resistance and higher than normal levels
of insulin in the blood may underlie this increased heart
failure risk in these patients.

The findings, which appear in the medical journal Heart,
are based on a study of 2,314 men who were 50 years of age and
free of heart failure, heart attack, and heart valve disease at
study enrollment in the early 1970s. The men were then followed
through age 70.

Ingelsson’s team used a modified version of the National
Cholesterol Education Program’s definition of metabolic
syndrome, which substituted measurement of waist circumference
with body mass index (BMI), the ratio of height to weight often
used to determine obesity. (A normal BMI is between 18.5 and
24.9 – obesity is defined as a BMI of 30 or greater.) The
primary study outcome measure was having a first
hospitalization for heart failure.

After analysis of the data, factoring in the effects of
established heart failure risk factors, the investigators found
that men with the metabolic syndrome at study entry had a 66
percent increased risk of developing heart failure during
follow-up, compared with those without the metabolic syndrome.
After accounting for heart attack during follow-up, the
increased risk rose even further to 80 percent.

If these findings are confirmed, the researchers conclude,
the metabolic syndrome may have direct effects on the heart, in
addition to an increased risk of atherosclerosis.

SOURCE: Heart, June 2006.