The Effect of C-Reactive Protein on Metabolic Syndrome, Diabetes, and Heart Disease

Rutter M, Meigs J, Sullivan L, et al.: C-reactive protein, the metabolic syndrome, and prediction of cardiovascular events in the Framingham offspring study. Circulation 110:380–385, 2004.

What is the problem and what is known about it so far?

C-reactive protein is a substance made by the body in response to inflammation (cell injury). A person with inflammation is more likely to get heart disease.

A person with metabolic syndrome (a group of conditions including high blood pressure, high blood glucose, high blood fats, and other things) also is more likely to get heart disease, diabetes, and have a stroke.

The researchers in this study wanted to see if there is a relationship between C-reactive protein and other conditions that make up metabolic syndrome, heart disease, and type 2 diabetes. They also wanted to see whether having more C-reactive protein predicts whether a person is more likely to get heart disease.

Who was studied?

A total of 3,037 men and women were studied from January 1991 to June 1995. None of the participants studied had diabetes. The ages of the participants ranged from 26 to 82 years of age, with an average age of 54 years.

How was the study done?

Glucose, insulin, cholesterol, blood pressure, C-reactive protein, and waist size were all measured. The participants were then followed for about 7 years for signs of chest pains, deadly or non-deadly heart attack, stroke, heart failure, or other signs of heart disease.

What did the researchers find?

C-reactive protein levels were higher in participants who had metabolic syndrome or related conditions. Also, smokers and the participants with a higher insulin resistance (an inability of the body to use insulin) and body mass index (a measure of weight in relation to height) had more C-reactive protein. The more conditions a participant had that were linked to metabolic syndrome, the higher their C-reactive protein level.

What were the limitations of the study?

C-reactive protein was measured only in one blood sample. More blood samples might have given different results. Although researchers looked at metabolic syndrome, heart disease outcomes were not broken down in groups of men and women. Thirdly, the majority of the participants where white. A similar study with a more varied group may give different results.

What are the implications of the study?

C-reactive protein is strongly linked to metabolic syndrome. This relationship is stronger in women than men. A person with metabolic syndrome and a high level of C-reactive protein is at an increased risk for getting heart disease.