As you may be aware, chronic inflammation is a hot topic in the health research field, and is associated with a number of adverse health outcomes including coronary heart disease (CHD). CHD is best thought of as a condition where one or more coronary arteries have significant blockages present; this in turn often leads to heart attack. Among the more common blood markers of inflammation are white blood cell count (WBC), C-reactive protein (CRP), and albumin. The higher the WBC and CRP values, the greater the amount of inflammation present. Conversely, lower levels of albumin are associated with greater inflammation. Most studies that have examined the relationship of these inflammation markers with health outcomes such as coronary heart disease have only considered a single marker. In other words, there is limited research on whether the risk for coronary heart disease is progressively greater with a higher number of inflammation biomarkers at abnormal levels. A recent study in the American Heart Journal helped to shed much-needed light on this issue.
How the Study was Done
The authors studied 15,758 Black and White adults from 48 states who were age 45 and older and did not have a history of coronary heart disease. Baseline data was collected between 2003 and 2007. During the initial baseline exam, a health history was performed via telephone. This was followed by an in-home exam that included measurements of height, weight, resting blood pressure (BP), and electrocardiogram (ECG). Blood was drawn at this visit following a 10-hour fast and then analyzed for the inflammatory markers of WBC, CRP, and albumin. Each participant was then categorized as having 0, 1, 2, or 3 abnormal values for these biomarkers. The group was carefully followed for an average of 11.4 years, with the main variables of interest being non-fatal and fatal heart attack, as well as sudden cardiac death. Several factors that might have affected their observations were taken into account. These included age, sex, race, body mass index, resting blood pressure, blood cholesterol and glucose levels, statin or antihypertensive medication use, presence of diabetes, and smoking.
What Were the Results?
Of the 15,758 participants, 38.9% had 0, 36.6% had 1, 19.8% had 2, and 4.7% had 3 markers of abnormal inflammation.
On average, those with a higher number of abnormal markers were more likely to be older, Black, a current smoker, be obese, have higher systolic blood pressure, have a history of diabetes, and use antihypertensive medication. A total of 954 participants experienced either fatal or non-fatal heart attack, or sudden cardiac death during the follow-up. The Figure below shows the risk of these events according to the number of abnormal inflammatory markers at baseline.
As you see from the Figure, using those with 0 abnormal inflammatory markers as a reference, the risk of a CHD event was 26%, 72%, and 84% higher in those with 1, 2, or 3 abnormal inflammatory markers, respectively. Thus, the current study shows that a higher number of abnormal inflammation markers is associated with coronary heart disease events independently of traditional risk factors such as smoking, obesity, abnormal blood cholesterol levels, etc.
Since blood levels of WBC, CRP, and albumin are markers of inflammation, it is important to have these values measured. Individuals who are found to have abnormal levels for one or more of these markers should make lifestyle changes to try to improve their levels. One way to decrease inflammation is to meet current public health guidelines for physical activity, that is, accumulate at least 150 minutes each week of moderate intensity aerobic physical activity and perform resistance training at least two days each week. For individuals who are very sedentary, it may take several weeks to gradually build up to recommended physical activity levels. Individuals found to have abnormal values of these inflammatory markers should consult with their health care provider regarding additional strategies to decrease inflammation. These lifestyle strategies typically include avoiding tobacco in all forms, losing weight if overweight, and consuming a heart healthy diet such as the DASH Eating Plan or the Mediterranean Diet. From a pharmacological perspective, in addition to lowering blood LDL-cholesterol and triglyceride levels, statin drugs have also been shown to reduce inflammation.
Alinyelure, O., et al. Inflammation biomarkers and incident coronary heart disease: The Reasons for Geographic and Racial Differences in Stroke Study. American Heart Journal. Published ahead-of-print, July 2022.