High-sensitivity C-reactive protein is associated with the presence of coronary artery calcium in subjects with normal blood pressure but not in subjects with hypertension

Background and Aims: An association has been described between high sensitivity C-reactive protein (hs-CRP) and cardiovascular disease (CVD) in some studies but not in others. This finding may be explained by a differential impact of inflammation according to the absence or presence of certain co-existing risk factors. Because hypertension may be an effect modifier of inflammation on CVD, our aim was to investigate the relationship between hs-CRP and pre-clinical atherosclerosis in subjects with normal blood pressure and hypertension. Methods: Data were analyzed from 14,584 Korean subjects. Subjects were stratified according to: a) 6030 (41.3%) patients with normal blood pressure (120/80 mmHg), b) 5630 (38.6%) patients with pre-hypertension (120-139 mmHg and 80-89 mmHg) and c) 2924 (20.0%) patients with hypertension (≥140/90 mmHg). Prevalence and odds ratio for the association between increased hs-CRP (>2 mg/L) and presence of CAC (coronary artery calcium) were calculated. Results: In both normal and pre-hypertensive groups, the prevalence of CAC >0 was higher in subjects with increased hs-CRP concentrations (>2 mg/L). Adjusting for age, sex, cerebrovascular accident, coronary heart disease and diabetes mellitus, lifestyle, obesity, fasting glucose, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol concentrations, there was a significant association between higher hs-CRP levels (>2 mg/L) and CAC score in the normal group (OR 1.55, 95% CI 1.11-2.16; p= 0.010); a borderline significant association in the pre-hypertensive group (OR 1.33, 95% CI 0.99-1.76; p= 0.054); and no association in the hypertensive group (OR 1.01, 95% CI 0.76-1.33; p= 0.94). Conclusions: Higher hs-CRP levels (>2 mg/L) are associated with pre-clinical atherosclerosis in subjects with normal blood pressure but not hypertension.