Analysis of thyroid function and related factors in narcolepsy patients

The loss of hypocretin is thought to be the main pathophysiological mechanism of narcolepsy. There is strong evidence that hypocretin is related to the regulation of endocrine functions and depression. To explore thyroid hormone levels in narcolepsy patients was our aim. In addition, further is to analyze the relationship between thyroid hormone levels and sleep quality, anxiety, and depression in narcolepsy patients. There are 40 patients with narcolepsy and 40 healthy controls (HCs) were conducted. Blood samples were explored for thyroid function. Correlation analysis between thyroid hormones and clinical characteristics of narcolepsy was performed using Pearson or Spearman. Narcolepsy patients had significantly lower free thyroxine (FT₄) levels in comparison to controls (p < 0.001). No subject was diagnosed with primary hypothyroidism. There were 4 (10%) subjects with subclinical hypothyroidism. The serum FT4 levels were positively correlated with HAMA₁₄ score (r = - 0.343, p = 0.030) by Pearson correlation analysis. The serum TSH levels and HAMD₂₄ score (r = - 0.807 p ˂0.001), and ESS score (r = - 0.317, p = 0.046) both showed a negative correction. Hypocretin deficiency may be associated with the regulation of thyroid hormones in narcolepsy patients. The serum thyroid hormones may affect the severity and neuropsychological functions of narcolepsy patients.