Joint effect of blood pressure and C-reactive protein and the risk of sudden cardiac death : a prospective cohort study

Background Both blood pressure and C-reactive protein (CRP) are each independently related to mortality risk. However, the combined effect of systolic blood pressure (SBP) and CRP on sudden cardiac death (SCD) risk has not been studied. Patients and methods We studied the joint impact of SBP and CRP and the risk of SCD in the Kuopio Ischemic Heart Disease prospective cohort study of 1953 men aged 42–61 years with no history of ischemic heart disease. Baseline investigations were conducted between March 1984 and December 1989. SBP and CRP were measured. SBP was divided based on median values to low and high (median cutoffs 132 mmHg) and CRP as low and high (median cut-off 1.30 mg/L). Hazard ratios (HRs) with confidence intervals (CIs) were calculated after multivariate adjustment. Results Subjects were followed-up for 23.2 years, and 137 SCDs occurred. In this study, elevated SBP (>132 mmHg) combined with elevated (CRP >1.30 mg/L) were associated with SCD risk. Adjustment for age, examination year, alcohol consumption, BMI, energy expenditure during exercise, total cholesterol, HDL-cholesterol, type 2 diabetes, smoking, antihypertension medication and aspirin use, the risk of SCD remained statistically significant (HR, 2,73, 95% CI, 1.62–4.60, p < .001). Further adjustment for socio-economic status, years of education and history of cardiovascular disease in a family the results were only slightly changed (HR, 2.65, 95% CI, 1.57–4.49, p < .001). Conclusions In our male cohort study, the joint effect of high SBP together with increased CRP levels is a risk predictor of SCD compared with low SBP and CRP.