Prognostic value of C-reactive protein predicting all-cause and cause-specific mortality: a prospective cohort study in Shanghai, China.

OBJECTIVES

To investigate the role of C-reactive protein (CRP) in predicting all-cause and cause-specific mortality in a community-based Chinese cohort.

DESIGN

A community-based prospective cohort study.

SETTING

34 communities in Pudong New Area, Shanghai, China.

PARTICIPANTS

A total of 9360 permanent residents from 34 randomly selected communities were enrolled in 2013. Follow-up began at baseline and continued until death or 30 September 2023, whichever occurred first.

MAIN OUTCOME MEASURES

The primary outcome of this study was death, as recorded in the Vital Registry of Pudong New Area, Shanghai, China. Associations between CRP and risks of all-cause and cause-specific mortality were studied. Cox proportional hazards models were applied to estimate HR and 95% CI. Adjustments were made for age, sex, area, marriage status, education, current smoking, alcohol consumption, physical activity, body mass index, systolic blood pressure, diastolic blood pressure, type 2 diabetes, dyslipidaemia and chronic kidney disease. Competing risk analyses were performed for cause-specific mortality. Restricted cubic splines were used to assess potential non-linear associations. We evaluated improvements in mortality prediction by calculating changes in the C-index, integrated discrimination improvement and net reclassification improvement after adding CRP to conventional risk factor models.

RESULTS

Over a median follow-up of 10.52 (IQR: 10.43-10.56) years, 920 deaths (9.68 per 1000 person-years) were recorded. After adjusting for traditional risk factors, higher baseline CRP levels were significantly associated with increased risk of all-cause mortality, cardiovascular mortality and cancer mortality. Non-linear associations were observed between CRP levels and all-cause and cancer mortality. The addition of CRP level significantly improved the reclassification and discrimination ability beyond the conventional risk factor models for all-cause mortality and cancer mortality.

CONCLUSIONS

Elevated CRP levels, indicative of low-grade inflammation, are an independent risk factor for all-cause, cardiovascular and cancer mortality.