The predictability of C-reactive protein, lipoprotein-associated phospholipase A2, and depression on later health outcomes in patients experiencing a first-time stroke

Abstract

Stroke is the third leading cause of death and the most common cause of neurologic disability for adults in developed nations. Strokes trigger an acute inflammatory response prompted by brain tissue injury at the infarct site and the surrounding ischemic penumbra raising plasma levels of inflammatory markers. C-reactive protein (CRP), an acute-phase inflammatory marker, has been significantly correlated with infarct size and post-stroke complications. Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) may also predict long-term cardiovascular risk in the stroke population. In addition to physiologic changes, up to 60% of all stroke survivors are known to experience depression, which may contribute to decreased physical and cognitive functioning, decreased health-related quality of life, and deterioration of mobility after stroke.

The specific aims of this study are to: (1) determine the effect of baseline CRP and Lp-PLA₂ levels shortly after first-time stroke on subsequent health outcomes (functionality, neurological impairment, and quality of life) at 3 months post stroke, (2) determine the effect of baseline depression shortly after first-time stroke on subsequent health outcomes at 3 months post stroke, and (3) determine the interactive effect of CRP and Lp-PLA₂ and depression on subsequent health outcomes at 3 months post-stroke.

A prospective, descriptive cohort design was used. Participants with a first time stroke, over the age of 45, were recruited from the emergency department at a large, hospital in Northern Alabama with 881 licensed beds.

The biological markers of CRP and Lp-PLA₂ were collected at baseline and at 3 months post-stroke. Depression and health outcomes were assessed on hospital admission, on day 4 of hospital admission or on the day of discharge whichever occurred first, and at 3 months post-stroke. Recurrence of stroke was monitored for 3 months post-stroke.

For the specific aims 1-3, data were analyzed using hierarchical multiple regression. Controlling for the effects of the covariates (age, baseline National Institute of Stroke Scale (NIHSS), and t-PA usage), the main effects of CRP, Lp-PLA₂, and depression as well as their interactive effects (CRP x depression, Lp-PLA₂ x depression, and CRP x Lp-PLA₂ x depression) on health outcomes were determined. In this small study, only depression was predictive of functionality and quality of life at 3 months post-stroke.

Keywords: Stroke, CRP, Lp-PLA₂, Depression, Health Outcomes