Impact of serum phosphate on severity and functional outcomes after ischemic stroke in young adults

Serum phosphate is an essential nutrient that plays multiple physiological roles in cardiovascular function. The aim of this study was to investigate the association between serum phosphate and stroke severity and prognosis in ischemic stroke and transient ischemic attack (TIA) among young adults.We retrospectively recruited patients with acute ischemic stroke and TIA aged 18-45 years. The primary outcome was 90-day poor functional outcome (modified Rankin Scale score of 2-6). The secondary outcomes included stroke severity (NIHSS ≥5 was defined as moderate to severe stroke) and poor functional outcome at hospital discharge. A total of 687 patients with a mean age of 36.8 years were enrolled. Lower serum phosphate levels were significantly associated with more severe stoke (P for trend = 0.017). Compared with the fourth quartile, the odds ratio (95% CI) of the first quartile was 1.85 (1.19-3.22) for moderate to severe stroke. After adjusting for confounders other than stroke severity, the odds ratio (95% CI) of the first quartile was 1.74 (1.06-2.86) for poor functional outcome at hospital discharge and 1.90 (1.09-3.31) at 90-day follow-up compared with the fourth quartile. However, the significant association between serum phosphate and poor functional outcomes disappeared after stroke severity was further adjusted.Serum phosphate is more likely a marker of stroke severity than a contributor to poor functional outcomes after ischemic stroke and TIA in young adults. Lower serum phosphate levels were associated with more severe stroke.