Is insulin resistance associated with fatigue, the severity of the disease and motor disability in idiopathic Parkinson’s disease?

Abstract

Aim: Abnormal glucose metabolism is known to potentially correlate abnormal mitochondrial function and neurodegenerative processes. The purpose of the study was to determine the association of insulin resistance on fatigue, the severity of the disease and motor disability in patients with idiopathic Parkinson's disease (IPD). Methods: A total of 50 patients diagnosed with IPD by a neurologist from university hospital were enrolled to study. Demographic characteristics (age, gender, height, weight and body mass index (BMI) were recorded. Patients were allocated into two groups by insulin resistance (IR), named insulin resistance (+) as group 1 (IR+) (n=30 (10 female, 20 male), age=66 years, height=169 cm, weight=75 kg, BMI=26.6 kg/m 2 (median)) and insulin resistance (-) as group 2 (IR-) (n=20 (8 female, 12 male), age=63.5 years, height=168 cm, weight=75 kg, BMI=26.95 kg/m 2 (median)). The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) test was used for assessment of insulin resistance. The disease severity was assessed by the Modified Hoehn and Yahr Scale, motor disability was assessed by Movement Disorders Society-revised Unified PD Rating Scale (MDS-UPDRS) and fatigue was rated by Fatigue Severity Scale (FSS). Results: MDS-UPDRS scores were statistically significantly different between the groups of IPD patients with IR (+) and IR (-) (P=0.034). Modified Hoehn-Yahr (P=0.300) and FSS (P=0.147) scores were not statistically significantly different between the same groups. Conclusion: This study suggests that IR may have a role for disease severity in patients with IPD. In patients with IPD, insulin resistance should be questioned and considered in the treatment and rehabilitation program.