[The association of high-sensitivity C-reactive protein with new-onset hypertension in different age groups]

Objective: To investigate the association between high sensitivity C-reactive protein (hsCRP) level and new-onset hypertension in different age groups. Methods: This was a prospective cohort study involving non-hypertensive population in Kailuan Group community who participated in health examination between 2006 and 2007.Follow-up was conducted every 2 years, and the time of new onset of hypertension was used as the endpoint of follow-up. The endtime of follow-up for patients without hypertension was the time of death or the last follow-up (December 31, 2017).According to the baseline hsCRP level, the participants were divided into low-risk group (hsCRP<1.0 mg/L), medium-risk group (hsCRP ≥1.0 and ≤3.0 mg/L), and high-risk group (hsCRP>3.0 mg/L), and further stratified by age. Kaplan-Meier method was used to calculate the cumulative incidence of hypertension in each group. Multivariate Cox regression model was used to analyze the association between hsCRP level and new-onset hypertension. Results: A total of 51 179 participants were included in this study, including 38 606 males (75.43%) with an average age of (48.1±12.2) years. The baseline hsCRP was 0.64 (0.25, 1.60) mg/L. The baseline hsCRP was 0.30 (0.16, 0.59), 1.57 (1.20, 2.10), 5.17 (3.80, 7.10) mg/L respectively in low-, medium- and high-risk groups. During the follow-up of (8.1±2.2) years, a total of 9 523 (18.60%) patients developed hypertension, and the cumulative incidence rates of low-, medium- and high-risk groups were 17.41%, 20.48% and 20.73%, respectively. The cumulative incidence of hypertension in low-, medium- and high-risk groups of<45, 45-54, 55-64, ≥65 years old were 13.53%, 15.82%, 16.76%; 19.27%, 22.84%, 21.62%; 21.55%, 24.19%, 24.88%;20.20%, 22.35%, 19.11%, respectively. Except for people aged ≥65 years, there were significant differences in the cumulative incidence of hypertension in low-, medium- and high-risk groups (all P<0.05).Multivariate Cox regression analysis showed that the risk of new-onset hypertension in the high risk group was 1.11 times higher than that in the low risk group (HR=1.11, 95%CI 1.05-1.18). The risk of new-onset hypertension in the high-risk group was 1.22 times (HR=1.22, 95%CI 1.08-1.38), 1.14 times (HR=1.14, 95%CI 1.04-1.26), 1.16 times (HR=1.16, 95%CI 1.04-1.30), and 1.02 times (HR=1.02, 95%CI 0.86-1.20) of the low-risk group, in the<45, 45-54, 55-64, and ≥65 years old groups, respectively. Conclusion: Higher hsCRP level is a risk factor for new-onset hypertension, and the risk of developing hypertension caused by elevated hsCRP is age-dependent.