For years cardiologists and other specialists have disagreed over the condition known as metabolic syndrome, a complex confluence of factors such as abdominal obesity, low HDL, or “good” cholesterol and hypertension.
Physicians and academics have disputed the syndrome’s existence and whether it predicts cardiovascular danger. The central question of this debate has been whether the gathering of these conditions in a single person conveys a risk of heart disease greater than that conveyed by each of the components. In other words, is the whole greater than the sum of its parts? The current best evidence now shows that metabolic syndrome represents an increased risk of cardiovascular disease and death, especially in women, according to a new study in the January 30, 2007, issue of the Journal of the American College of Cardiology.
The research was conducted at the Mayo Clinic College of Medicine in Rochester, Minn. Lead researcher Apoor S. Gami, M.D., assistant professor of medicine in the division of cardiovascular diseases and internal medicine at the college, said the goal of the study was to collate and compare all the differing studies on metabolic syndrome and the risk of cardiovascular disease,.
“What was fascinating to us was the fact that all this controversy in the field existed despite the prior publication and continuing publication of countless studies on the topic,” said Dr. Gami. “We decided to use the tools of meta-analysis to best assimilate the available data and to identify relationships that might not have been clear in individual studies. In this way we could highlight important associations regarding metabolic syndrome and cardiovascular disease.”
Metabolic syndrome is a constellation of conditions, each of which individually is known to increase the risk of heart disease. Depending on the source, metabolic syndrome can include hyperglycemia, abdominal obesity, low HDL cholesterol (good cholesterol), increased triglycerides, dyslipidemia and hypertension. The condition has been attributed to the combined effects of a sedentary lifestyle, poor diet and genetic factors.
This meta-analysis provides evidence that the constellation of findings do constitute a syndrome when occurring in a single patient. It also lends some suggestive support that truncal obesity may be basic to the occurrence of other conditions (perhaps through insulin resistance) which markedly increase risk, particularly in females.
Over the years numerous agencies and individual researchers have attempted to either discount or define the syndrome. In 2005, the American Diabetes Association and their European counterpart raised many uncertainties regarding the syndrome, including its effect on cardiovascular disease risk and whether the syndrome itself was worthy of a diagnosis. In the same year, the American Heart Association and the National Heart, Lung, and Blood Institute issued a report stating that the aggregation of the factors making metabolic syndrome increases heart risk and should be aggressively targeted for medical intervention.
“There had not yet been a systematic qualitative or quantitative approach to understanding the data as a whole,” Dr. Gami said. “Our review of the best available evidence showed that in over 37 studies published since 1998, which included 43 groups of patients and over 170,000 individuals, metabolic syndrome, no matter how it is specifically defined, does increase the risk of new cardiovascular disease and death, with even greater risk in women.”