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.