The relationship between C-reactive protein and atherosclerosis differs on the basis of body mass index: the Dallas
Nitin K Gupta1, James A de Lemos, Colby R Ayers
1Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Insights
C-reactive protein (CRP) is linked to atherosclerosis, but obesity (high body mass index) weakens this association. This suggests CRP may be less effective in predicting cardiovascular disease in obese individuals.
Area of Science:
- Cardiovascular disease research
- Inflammation and atherosclerosis
- Obesity and metabolic health
Background:
- C-reactive protein (CRP) is an inflammatory marker associated with cardiovascular disease.
- Obesity is known to affect CRP levels.
- The impact of obesity on the relationship between CRP and atherosclerosis is not well understood.
Purpose of the Study:
- To investigate whether body mass index (BMI) modifies the association between C-reactive protein (CRP) and atherosclerosis.
- To compare the predictive value of CRP for atherosclerosis in individuals with normal weight, overweight, and obesity.
Main Methods:
- Cross-sectional study of 2,685 adults aged 30-65 from the Dallas Heart Study.
- Measured CRP and atherosclerosis phenotypes: coronary artery calcification (CAC), aortic wall thickness (AWT), and aortic plaque burden (APB).
- Analyzed associations of CRP with atherosclerosis across BMI categories (normal, overweight, obese) in sex-stratified analyses.
Main Results:
- The association between CRP and CAC was significant in normal weight and overweight individuals but not in obese individuals.
- Correlations between CRP and AWT/APB diminished with increasing BMI and were nonsignificant in obese individuals.
- Interaction tests confirmed that obesity significantly modifies the CRP-atherosclerosis relationship in both sexes.
Conclusions:
- The association between CRP and multiple measures of atherosclerosis is diminished in obese individuals.
- CRP's utility in predicting cardiovascular outcomes may be reduced in obese populations.
- Further research is needed to clarify the role of CRP in cardiovascular risk assessment for obese individuals.
Objectives:
This study sought to evaluate whether the relationship between C-reactive protein (CRP) and atherosclerosis is modified by body mass index (BMI).
Background:
CRP levels are affected by obesity, and it is unknown whether the associations between CRP and cardiovascular (CV) disease differ between obese and nonobese individuals.
Methods:
We measured CRP and multiple atherosclerosis phenotypes, including coronary artery calcification (CAC) (n = 2,685), aortic wall thickness (AWT) (n = 2,238), and aortic plaque burden (APB) (n = 2,224), in subjects ages 30 to 65 years from the Dallas Heart Study. The associations of CRP with CAC, AWT, and APB were compared across categories of BMI (normal, 18.5 to <25 kg/m(2); overweight, 25 to <30 kg/m(2); obese, ≥30 kg/m(2)) in sex-stratified analyses.
Results:
The overall prevalence of obesity was 38% in men and 53% in women. Increasing CRP levels (<1 mg/l, 1 to 3 mg/l, >3 mg/l) were associated with increased CAC prevalence in normal and overweight men and in normal weight women (p < 0.01), but not in obese subjects of either sex. Likewise, the correlations between CRP and AWT and APB diminished with increasing BMI and were nonsignificant in obese individuals (p < 0.05 in nonobese, p > 0.1 in obese). Interaction tests between CRP and obesity were significant for all atherosclerosis measures in men and for AWT and ABP in women (p interaction <0.05 each). In both sexes, the c-statistics of CRP for all 3 atherosclerosis measures were greater for normal weight than obese individuals.
Conclusions:
In a large, population-based study, the association between CRP and multiple measures of atherosclerosis is diminished in obese individuals. The role of CRP for predicting CV outcomes in obese subjects requires further evaluation.
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