Pentraxin-3 and C-reactive protein plasma levels predict survival in older adults with or without metabolic syndrome – results of the PolSenior2 substudy

Abstract

Objective

There are no published data on the associations between plasma concentration of pentraxin-3 (PTX-3) - a marker of vascular inflammation and mortality in older subjects with or without metabolic syndrome (MS). Therefore, we aimed to compare the prognostic significance of increased PTX-3 and CRP levels on overall survival in subjects aged 60 and older with and without MS.

Materials and methods

Study participants (N = 3534) were categorized according to the presence or absence of MS and then each of these groups was stratified into 3 subgroups based on concentrations of CRP (≤ 3 mg/dL and > 3 mg/dL) and PTX-3 (< and ≥ the sex-specific cut-off values, based on the ROC curve analysis with the Youden index): double-negative inflammatory markers (low CRP and PTX-3 plasma concentrations); single-positive inflammatory marker (increased CRP or PTX-3 plasma concentrations) and double-positive inflammatory markers subgroup (increased CRP and PTX-3 plasma concentrations). During the 4.19-year follow-up, 678 (19.2% of the entire cohort) individuals died including 401 men (22.9%) and 277 women (15.5% ).

Results

The optimal cut-off for PTX-3 plasma concentration associated with an increased risk of death was 2.07 ng/mL for men and 2.23 ng/mL for women. The death rates were increased for single-positive and were highest in double-positive subgroups both for men and women, with or without MS. Kaplan-Meier analysis showed no effect of MS on survival in men and women in subgroups within specific inflammatory marker categories. Of note, the inflammatory markers class effect on survival was already significant in the single-positive subgroups (34% and 44% higher risk for death for men and women), and even more pronounced for the double-positive subgroup (more than two and almost three times higher risk of death for men and women, respectively). In the entire study group, a weak correlation was found between plasma concentrations of PTX-3 and hs-CRP (ρ = 0.11, p < 0.001) and slightly higher in undernourished subjects with hs-CRP > 3 mg/dL (ρ = 0.28, p < 0.001).

Conclusion

Our study suggests that in the age-advanced Caucasian population, the inflammatory status with increased plasma levels of both PTX-3 and CRP is associated with a higher risk of all-cause mortality, regardless of the occurrence of MS. However, due to the retrospective study design, these results require confirmation in prospective studies with an analysis of the underlying causes of death.