Abstract
Background and aims
Serotonin affects intestinal physiology, mood, as well as circadian rhythm. Moreover, serotonin has proinflammatory function. Therefore, the aim of this study was to investigate the role of serotonin in clinical severity of Crohn’s Disease (CD) and its effect on pain and sleep quality.
Methods
Fifty-nine CD patients (34 in exacerbation and 25 in remission according to the Harvey-Bradshaw Index-HBI) and 25 health control individuals(HC) were recruited. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI) and subjective severity of pain by the Visual Analog Scale (VAS). Seventeen patients were treated with anti-TNF-α induction therapy for 14 weeks.
Results
Serotonin level was higher in CD (145.12ng/mL, IQR:98.14–179.25) compared to HC (87.52ng/mL, IQR:70.04–129.39; p=0.002) and in exacerbation of CD (157.66ng/mL, IQR:111.94–197.64) compared to remission (122.33ng/mL, IQR:83.28–163.67; p=0.029). Serotonin level with cut-off point of 92.45 ng/mL is useful for distinguishing participants with CD from HC (sensitivity: 78%, specificity: 60%, positive predictive value: 82%). Positive correlation between serotonin and HBI (r=0.279, p=0.032) and severity of diarrhoea (r=0.260, p=0.047) were found. Serotonin does not correlate with PSQI (r=0.152, p=0.168), but correlates with presence of sleep fragmentation for example by getting up to use the bathroom (joined 5b-5j PSQI questions; r=0.270, p=0.039). Correlations between serotonin and VAS were also obtained (r=0.220, p=0.045). Moreover, serotonin level significantly decreased after anti-TNF-α therapy (192.35ng/mL, IQR:150.36–225.56 vs. 121.11ng/mL, IQR:91.28–188.87; p=0.006). The study was funded by National Science Centre, Poland (#2018/31/N/NZ5/03715).
Conclusions
Serotonin level correlates with the severity of CD and decreases after anti-TNF-α therapy. It is associated with sleep fragmentation, which may be caused by diarrhea.