Data from: Baseline C-reactive protein level and life prognosis in Parkinson disease

Background: C-reactive protein (CRP) is a biomarker of inflammation, and
high levels of CRP correlate with vascular death. Chronic inflammation is
considered to be involved in neurodegeneration, although there is no
evidence linking it with the process of neurodegenerative diseases.
Objective: To determine the role of baseline CRP levels in the prognosis
of patients with Parkinson disease (PD). Methods: A cohort of 313 patients
with a mean age of 69.1 and mean PD duration of 7.9 years was
retrospectively followed for a mean observation time of 1,753 days. CRP
was measured when patients were not diagnosed with any infections, and
levels were repetitively measured to investigate a tendency of “regression
to mean.” The primary outcome measure was a survival time from study
enrollment to death. Results: During the observation period 56 patients
died. Baseline CRP was log-linearly associated with a risk of death in PD.
Mean survival time was 3,149 (95% confidence interval; 3,009-3,289) days
in patients with CRP ≤ 0.8mg/L (lower two thirds) and 2,620 (2,343-2,897)
days in those with CRP > 0.8 mg/L (top third, p < 0.001,
log-rank test). The adjusted hazard ratio (HR) per two-fold higher CRP
concentration for all deaths was 1.29 (1.10-1.52), and after excluding
PD-unrelated deaths, such as cancer or stroke, HR was 1.23 (1.01-1.49)
(adjusted for age, sex, PD duration, modified Hohen-Yahr stages, MMSE
scores, and serum albumin). Conclusions: Baseline CRP concentrations were
associated with the risk of death and predicted life prognosis of patients
with PD. The associations were independent from PD duration, PD severity,
cognitive function, ages, and nutritional conditions, suggesting the
possibility that subclinical chronic inflammation is associated with a
neurodegenerative process in PD.