High-sensitivity C-reactive protein is a predictor of all-cause mortality in a rural Japanese population

Background

High-sensitivity C-reactive protein (hsCRP) is a sensitive marker of inflammation. This study aimed to determine whether increased hsCRP levels are associated with all-cause mortality rate.

Methods

We examined data for participants from the 2002 Nomura Cohort Study who attended follow-ups for 20 years (follow-up rate: 93.3%). Of these, 793 were male (aged 61 ± 14 years) and 1040 were female (aged 63 ± 11 years). The Japanese Basic Resident Registry provided data on adjusted relative hazards for all-cause mortality. The data were subjected to a Cox regression analysis using a time variable of age and confounding risk factors.

Results

The median (interquartile range) follow-up period was 6548 days (6094–7452 days). The follow-up confirmed that there were 632 (34.8%) deaths, of which 319 were male (40.2% of all males) and 313 were female (30.6% of all females). Multivariable-adjusted hazard ratio (1.27; 95% confidence interval, 1.01–1.59) in the highest hsCRP category was also significantly higher compared with reference. A higher hsCRP was associated with a greater risk of all-cause mortality in male participants aged ≥65 years, a BMI < 25 kg/m², and no history of CVD or diabetes, and this association was particularly significant among participants with both of the latter two risk factors (p = 0.004 and 0.022 for interaction, respectively).

Conclusions

Our results indicate a significant association between hsCRP levels and all-cause mortality in a rural Japanese population. Specifically, hsCRP appears to be a crucial biomarker for predicting long-term survival, particularly among older persons.