Serum Leptin Levels and Cognition in Parkinson's Disease Patients

Introduction: To investigate the relationship between serum leptin levels and cognition in Parkinson's disease (PD) patients. Methods: Thirty patients with idiopathic PD and 30 healthy controls were enrolled. At baseline, all patients had their standing height, weight, and waist circumference measurements taken using a standard scale. Their body mass index was then calculated. A fasting blood of 5 ml was obtained from each patient in the morning. ELISA was used to analyze leptin concentrations. The severity of PD was evaluated using the Hoehn and Yahr scale, and the clinical status of patients was evaluated using the Unified Parkinson's Disease Rating Scale. The cognitive status of whole patients was evaluated using a validated form of the Montreal Cognitive Assessment Scale in Turkey (MoCA-TR). Results: The mean ages of the patients and controls were 59.37 +/- 9.22 and 58.50 +/- 9.85 years, while the mean leptin levels were 4.13 +/- 3.61 and 3.12 +/- 2.43 ng/mL, respectively. Leptin levels did not differ between PD patients and the controls. PD patients had significantly lower MoCA-TR scores than the controls (p=0.028). MoCA-TR scores were not correlated to leptin levels in PD patients. Conclusion: In this study, we could not find a relationship between blood leptin levels of PD patients and cognition as assessed by MoCA-TR. Larger longitudinal studies are needed.