Relationship between subjective sleep quality and serum ghrelin levels in Parkinson’s disease

Objectives: This study aimed to investigate the relationship between serum ghrelin levels and subjective sleep quality in patients with Parkinson's disease (PD). Patients and methods: This prospective case-control study was conducted between July 2020 and September 2021. Sixty-three patients (39 males, 24 females; mean age: 64.8±12.8; range, 52 to 76 years) diagnosed with idiopathic PD and 59 healthy participants (34 males, 25 females; mean age: 63.9±6.2 years; range, 57 to 59 years) were included in the study. The patients' modified Hoehn and Yahr and Unified Parkinson's Disease Rating Scale scores were determined. Subjective sleep quality of study groups was evaluated with the Pittsburgh Sleep Quality Index, and serum fasting ghrelin levels were measured. Results: The patient and control groups did not show any significant differences in terms of sociodemographic characteristics. The Pittsburgh Sleep Quality Index values of the patient group were higher compared to the control group (p≤0.001). There was no significant difference between serum ghrelin levels (p=0.329). Conclusion: A significant relationship was not identified between subjective sleep quality and serum ghrelin levels in PD, and ghrelin did not support the diagnosis of PD. Further studies with larger samples that account for the variability in food intake and the timing of serum ghrelin measurements are needed.