Prospective evaluation of biomarkers for prediction of quality of life in community-acquired pneumonia

BACKGROUND: Most clinical research investigated prognostic biomarkers for their ability to predict cardiovascular events or mortality. It is unknown whether biomarkers allow prediction of quality of life (QoL) after survival of the acute event. Herein, we investigated the prognostic potential of well-established inflammatory/cardiovascular blood biomarkers including white blood cells (WBC), C-reactive protein (CRP), procalcitonin (PCT), pro-adrenomedullin (proADM) and pro-atrial natriuretic peptide (proANP) in regard to a decline in QoL in a well-defined cohort of patients with community-acquired pneumonia (CAP). METHODS: Within this secondary analysis including 753 patients with a final inpatient diagnosis of CAP from a multicenter trial, we investigated associations between admission biomarker levels and decline in QoL assessed by the EQ-5D health questionnaire from admission to day 30 and after 6 years. RESULTS: Admission proADM and proANP levels significantly predicted decline of the weighted EQ-5D index after 30 days (n=753) with adjusted odds ratios (ORs) of 2.0 ([95% CI 1.1-3.8]; p=0.027) and 3.7 ([95% CI 2.2-6.0]; p<0.001). Results for 6-year outcomes (n=349) were similar with ORs of 3.3 ([95% CI 1.3-8.3]; p=0.012) and 6.2 ([95% CI 2.7-14.2]; p<0.001). The markers were associated with most of the different QoL dimensions including mobility, self-care, and usual activities, but not pain/discomfort and to a lesser degree anxiety/depression and the visual analogue scale (VAS). Initial WBC, PCT and CRP values did not well predict QoL at any time point. CONCLUSIONS: ProADM and proANP accurately predict short- and long-term decline in QoL across most dimensions in CAP patients. It will be interesting to reveal underlying physiopathology in future studies.