C-reactive protein levels linked to health problems

Metabolic syndrome, a cluster of health problems that includes high blood pressure, high cholesterol levels, high blood sugar, and obesity, is a common condition that medical experts believe is caused by a combination of genes, lack of physical activity, and overeating. Now researchers at Harvard-affiliated Brigham and Women’s Hospital (BWH) have shown that even people with these risk factors may benefit by having their C-reactive protein (CRP) levels checked.

Their findings appear in the January issue of Circulation: Journal of the American Heart Association.

It is estimated that more than 50 million people in the United States have at least three of the five medical problems that result in a diagnosis of metabolic syndrome. In the BWH study, 14,719 female participants in the Women’s Health Study were followed for eight years. Among those followed, 3,597 women were diagnosed with metabolic syndrome upon entering the study.

Women in the study with metabolic syndrome who had the highest levels of CRP were over two times more likely to have a cardiovascular event than those who only had metabolic syndrome. Previous studies have linked high CRP levels to increased risk of heart attack, stroke, and type 2 diabetes.

“We showed that even for these women with metabolic syndrome, CRP testing was useful in showing who was at low, moderate, and high risk,” said the study’s lead author, Harvard Medical School’s Associate Professor of Medicine Paul Ridker. “Thus, CRP is picking up many components of the metabolic syndrome we have been otherwise unable to measure in daily clinic practice.”

In a recent study previously published in the New England Journal of Medicine, Ridker and his research team showed that CRP – a protein produced by the liver when arteries become inflamed – can improve risk prediction when added to cholesterol testing.

“This research demonstrates that inflammation is a critical link between the metabolic syndrome, diabetes, and heart disease,” said Ridker. “Our new data suggest that CRP also adds prognostic information among those with metabolic syndrome.”

Ridker did caution, however, that the best way to reduce the likelihood of cardiovascular problems and diabetes is to exercise and maintain a healthy diet. He also noted that it has not yet been proven that lowering CRP levels reduces cardiovascular risk.

Ridker’s next study will examine whether or not statin therapies can be used to reduce cardiovascular risk in people who have normal cholesterol levels, but high CRP – a group that currently lacks generally accepted treatment options.

In the same issue of circulation guidelines from the American Heart Association and the Centers for Disease Control (CDC) appear which state that “measurement of CRP is an independent marker of risk and, in those judged at intermediate risk by global risk assessment at the discretion of the physician, may help direct further evaluation and therapy and primary prevention of cardiovascular disease.”