Risk factors and outcome of hyponatremia in patients with Guillain–Barré syndrome

Abstract

Abstract The objective of the present study was to evaluate the risk factors and outcomes associated with hyponatremia in patients with Guillain-Barré Syndrome (GBS). We retrospectively studied 80 consecutive patients with GBS who visited our hospital and compared clinical, laboratory, and electrophysiological findings of patients with and without hyponatremia. Disability was evaluated using the Hughes grading system. The well-established Erasmus GBS Outcome Score (EGOS) prognostic model was used for covariate adjustment to examine the independent association between hyponatremia and patient outcomes. Of the 80 patients, 18 (23%) had hyponatremia. Hyponatremia was significantly associated with older age (P = 0.003), autonomic dysfunction (P < 0.0001), higher Hughes grade at peak (P < 0.001), acute inflammatory demyelinating polyneuropathy subtype (P = 0.017), and poor outcome (P < 0.001). Multivariate analysis performed to assess the risk factors of hyponatremia revealed that a Hughes grade at peak ≥ 4 (odds ratio [OR] 6.4, 95% confidence interval [CI] 1.1–35.2; P = 0.034) and autonomic dysfunction (OR 11.3, 95% CI 2.1–59.7; P = 0.004) were significant independent risk factors of hyponatremia. In assessing the outcomes of patients with hyponatremia, the EGOS-adjusted analyses showed that hyponatremia was significantly and independently associated with poor outcome (OR 15.0, 95% CI 1.2–194.4; P = 0.038). Therefore, we demonstrate that, along with disease severity, autonomic dysfunction is a risk factor of hyponatremia in GBS. Moreover, we confirm that hyponatremia is associated with poor outcome in GBS.