NEW ORLEANS — Young and middle-aged adults who meet criteria for metabolic syndrome are at a 2.5-fold greater risk of having subclinical atherosclerosis, Kwame O. Akosah, M.D., said at the annual scientific sessions of the American Heart Association.
This is true regardless of whether they have a low Framingham risk score or a normal-range C-reactive protein (CRP) level. The risk of subclinical atherosclerosis associated with metabolic syndrome is also independent of—and even greater than—that associated with diabetes mellitus, a coronary heart disease equivalent, added Dr. Akosah of the Gundersen Lutheran Health System, La Crosse, Wisc.
“It appeared in our study that metabolic syndrome was the driving force for developing early atherosclerosis, not high-sensitivity CRP or diabetes mellitus,” he said.
Dr. Akosah reported on 253 consecutive men and women, mostly in their 40s and 50s, who were evaluated for possible coronary artery disease. All underwent carotid ultrasound assessed by blinded cardiologists for the presence of subclinical carotid atherosclerosis, a well-established marker for atherosclerosis in other vascular beds.
Subclinical carotid atherosclerosis—as defined by focal plaque and/or a mean intimal-medial thickness of 1.0 mm or more—was identified in 59% of subjects. Yet 89% of study participants had a low-risk Framingham risk score. And 37% didn't even have multiple major cardiovascular risk factors, Dr. Akosah said.
Among the 75 subjects who met criteria for metabolic syndrome, 18 had concomitant diabetes. Another 17 subjects had diabetes without metabolic syndrome. The prevalence of subclinical carotid atherosclerosis was significantly greater among participants with metabolic syndrome than in those with diabetes only or with neither condition. (See graph.)
In a multivariate logistic regression analysis, metabolic syndrome independently conferred a 2.5-fold increased risk of having subclinical atherosclerosis.
Of note, CRP was not useful in risk stratification. For example, the prevalence of subclinical atherosclerosis among 64 subjects with elevated CRP but without metabolic syndrome was 50%, yet it was 59% among 109 individuals with neither an elevated CRP nor metabolic syndrome.
Despite the increasing emphasis devoted to metabolic syndrome in medical circles since the 2001 National Cholesterol Education Program guidelines identified it as a secondary therapeutic target, 56% of subjects in the study didn't have a fasting blood glucose level taken along with their lipid measurements, making it impossible to properly assess them for the presence of metabolic syndrome.
“We cardiologists are very good at preaching what to do and talking about the things that we do,” Dr. Akosah said. “But if you go look back in our records, you'll find out that we're not doing as well as we're convincing everybody. Sure, we need to check blood pressure and lipid levels, but fasting glucose is no longer something that should be measured only at the endocrinologist's office.”
