Long-term mortality after community-acquired pneumonia—impacts of diabetes and newly discovered hyperglycaemia: a prospective, observational cohort study

OBJECTIVES: Community-acquired pneumonia is associated with a significant long-term mortality after initial recovery. It has been acknowledged that additional research is urgently needed to examine the contributors to this long-term mortality. The objective of the present study was to assess whether diabetes or newly discovered hyperglycaemia during pneumonia affects long-term mortality. DESIGN: A prospective, observational cohort study. SETTING: A single secondary centre in eastern Finland. PARTICIPANTS: 153 consecutive hospitalised patients who survived at least 30 days after mild-to-moderate community-acquired pneumonia. INTERVENTIONS: Plasma glucose levels were recorded seven times during the first day on the ward. Several possible confounders were also recorded. The surveillance status and causes of death were recorded after median of 5 years and 11 months. RESULTS: In multivariate Cox regression analysis, a previous diagnosis of diabetes among the whole population (adjusted HR 2.84 (1.35–5.99)) and new postprandial hyperglycaemia among the non-diabetic population (adjusted HR 2.56 (1.04–6.32)) showed independent associations with late mortality. New fasting hyperglycaemia was not an independent predictor. The mortality rates at the end of follow-up were 54%, 37% and 10% among patients with diabetes, patients without diabetes with new postprandial hyperglycaemia and patients without diabetes without postprandial hyperglycaemia, respectively (p<0.001). The underlying causes of death roughly mirrored those in the Finnish general population with a slight excess in mortality due to chronic respiratory diseases. Pneumonia was the immediate cause of death in just 8% of all late deaths. CONCLUSIONS: A previous diagnosis of diabetes and newly discovered postprandial hyperglycaemia increase the risk of death for several years after community-acquired pneumonia. As the knowledge about patient subgroups with an increased late mortality risk is gradually gathering, more studies are needed to evaluate the possible postpneumonia interventions to reduce late mortality.