C-reactive protein and lipid parameters in older persons aged 80 years and older

Aims of the study were 1) to investigate the association of C-reactive protein (CRP) with lipid (i.e. total, LDL, and HDL cholesterol, triglycerides) concentrations, and to evaluate their predictive value for mortality in very old subjects.

Cross-sectional and longitudinal analyses in a prospective cohort study.

Participants. Data are from 336 community-dwelling subjects aged > or = 80 years old enrolled in the "Invecchiamento e Longevità nel Sirente" (ilSIRENTE) study.

High sensitivity CRP and lipid concentrations were measured at the baseline clinical visit. High sensitivity CRP concentrations were measured by ELISA assessment. Mortality outcome was evaluated over a 24-month follow-up.

Participants had a mean age of 85.8 (SD 4.8) years old. Spearman's correlations showed significant (p values < 0.01) inverse correlations between CRP and lipid parameters (except triglycerides). Adjusted linear regressions between CRP and lipid parameters concentrations showed no significant association in participants aged lower than 85 years old (all p values > 0.5). In the older age group, significant inverse associations of CRP with total (p=0.002), LDL (p=0.007), and HDL cholesterol (p=0.002) were found, even after adjustment for potential confounders. Adjusted Cox proportional hazard models demonstrated that CRP was the only biomarker significantly predictive of mortality, independently of age and lipid parameters.

An inverse relationship of total, LDL, and HDL cholesterol with CRP is present in very old persons. The prognostic value of CRP is particularly important among very old persons whereas lipid parameters tend to lose their capacity to predict events.