Abstract
BackgroundInflammatory markers, such as high sensitivity C-reactive protein (hs-CRP), and cognitive impairment (CI) are associated with mortality; CRP is related to the deterioration of CI. However, it is still unknown whether these two indices predict mortality independent of each other. Furthermore, their joint effect on all-cause mortality has not been well established, especially in oldest-old adults.MethodsBased on data from the 2012 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we included 1447 oldest-old adults (mean age 84.7 years and 58.7% were female, weighted) with information on hs-CRP (stratified by a cutoff value of 3.0 mg/L) and cognition (quantified by Mini-Mental Status Examination (MMSE) scored according to the personal educational level) at baseline. Mortality was assessed in followed 2014 and 2017 waves. Cox proportional hazards regression models were used, with adjustment for hs-CRP and cognition (mutually controlled) and several traditional mortality risk factors.ResultsDuring a median follow-up period of 32.8 months (Q1-Q3, 9.7–59.0 months), 826 participants died. Hs-CRP [HR > 3.0 mg/L vs ≤ 3.0 mg/L: 1.64 (95% CI, 1.17, 2.30)] and cognition [HR CI vs normal: 2.30 (95% CI, 1.64, 3.21)] each was independent predictor of all-cause mortality, even after accounting for each other and other covariates. Monotonic and positive associations were observed in combined analyses, in which the highest mortality risk was obtained in elders with both high hs-CRP> 3.0 mg/L and CI [HR: 3.56 (95% CI, 2.35, 5.38)].The combined effects were stronger in male and younger oldest-old (aged 80–89 years).ConclusionHigh hs-CRP and CI, both individually and jointly, were associated with increased all-cause mortality risks in Chinese oldest-old. Intervention strategies for preventing inflammation and maintaining adequate cognitive function may be more important in male and younger oldest-old for reducing mortality risk.
Highlights
Inflammatory markers, such as high sensitivity C-reactive protein, and cognitive impairment (CI) are associated with mortality; CRP is related to the deterioration of confidence intervals (CIs)
We did not find significant differences in the baseline characteristics between individuals who were lost to follow-up and those who were remained in the study, except that a higher proportion of regular exercise was found in the former group (Additional file 1: Table S2)
Combined associations of high sensitivity C-reactive protein (hs-CRP) and cognitive status on all-cause mortality Monotonic and positive associations were observed in combined analyses, the higher the joint hs-CRP/cognition group from group1 to group 4, the higher the risk of death (P-trend all< 0.01, Table 3; Fig. 2a)
Summary
Inflammatory markers, such as high sensitivity C-reactive protein (hs-CRP), and cognitive impairment (CI) are associated with mortality; CRP is related to the deterioration of CI. It is still unknown whether these two indices predict mortality independent of each other. Their joint effect on all-cause mortality has not been well established, especially in oldest-old adults. Data about the epidemiology and predictive value of CRP, especially in oldest-old (aged ≥80 years), are sparse [15, 16]; the two previous studies of this age group were limited to less than 300 older persons each. The predictive value of elevated CRP on mortality risk needs further evaluation in oldestold adults aged 80 years or older
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
