Background: The use of serum high-sensitivity C-reactive protein (hs-CRP) for cardiovascular risk profiling requires knowledge of the distribution in different populations. We studied serum hs-CRP in a healthy Brazilian population, with no evidence of heart disease, relative to gender and smoking status as well as other clinical and laboratory variables.
Methods: 684 healthy Brazilian individuals, aged 14-74 years (mean 40.6 years), 295 men (43.1%) and 389 women (56.9%), were enrolled between July 1998 and July 2001. The relationship between the log-transformed hs-CRP, stratified by gender and smoking status (non-smokers, smokers), and clinical and laboratory variables were analyzed using the Spearman correlation coefficient and multiple linear regression.
Results: In a multiple linear regression model age (beta=1.0069, p=0.03), body mass index (BMI) (beta=1.0093, p<0.01), total cholesterol/HDL cholesterol ratio (TC/HDL-C) (beta=1.1015, p<0.01) and heart rate (beta=1.0139, p<0.01) were independently correlated with hs-CRP. Stratification according to gender and smoking was able to disclose different interactions between these variables and hs-CRP. Variables significantly correlated in each stratum were as follows: in smoker men, age (beta=1.0236, p=0.04) and TC/HDL-C (beta=1.2065, p<0.01); in non-smoker men, BMI (beta=1.0786, p<0.01) and TC/HDL-C (beta=1.1397, p=0.01); in smoker women, BMI (beta=1.1006, p=0.03); and in non-smoker women, BMI (beta=1.0873, p<0.01), TC/HDL-C (beta=1.1405, p=0.01) and heart rate (beta=1.0165, p=0.02).
Conclusions: The clinical and laboratory variables studied influenced the concentration of hs-CRP according to gender and smoking. In assessing the risk of cardiovascular events in relation to serum hs-CRP level, stratification by gender and smoking status is indicated.