Affiliations: [a] Department of Neurology, Cedar-Sinai Medical Center, Los Angeles, CA, USA
| [b] Department of Neurosurgery, Cedar-Sinai Medical Center, Los Angeles, CA, USA
Correspondence to: Michele Tagliati, MD, Department of Neurology, Cedar-Sinai Medical Center, 127 S. San Vicente Ave., A6600, Los Angeles, CA 90048, USA. Tel.: +1 310 248 6704; Fax: +1 310 967 0601; E-mail: Michele.Tagliati@cshs.org.
Abstract: Background:Reduced glucose tolerance has been long recognized as a potential risk factor for Parkinson’s disease (PD), and increasing scrutiny is currently being placed on insulin resistance (IR) as a pathologic driver of neurodegeneration. However, the prevalence of IR in PD is unknown. Objective:To determine IR prevalence in non-diabetic patients with PD and to correlate IR with other metabolic indicators, motor and non-motor symptoms (NMS) of PD, and quality of life (QoL). Methods:Non-diabetic patients with a diagnosis of PD were identified and tested for fasting insulin, fasting glucose, and HbA1c. Patients were also offered to take a battery of clinical tests (MoCA, NMSQ, and PDQ-39) and had their PD medications, height, weight, and other demographic features recorded. IR was defined as HOMA-IR≥2.0 and/or HbA1c≥5.7. IR abnormalities were correlated with BMI and demographic features, in addition to motor and NMS. Results:154 subjects (109 M, 45F, mean age 67.7±10.5) were included in this study. Mean HOMA-IR was 2.3±1.8. Ninety out of 154 (58.4%) subjects had abnormal IR. IR was more frequent in overweight and obese subjects (61.1% and 82.8% respectively) than normal weight subjects (41.5%). Multivariate analysis showed that BMI was the only significant predictor of IR (p < 0.0001). There was no significant correlation between HOMA-IR and MoCA, PDQ-39, and NMSQ scores. Conclusions:IR is prevalent in PD and it correlates with BMI. A correlation between IR with cognitive and QoL measures cannot be determined on the basis of this sample.
Keywords: Body mass index, cognition, insulin resistance, Parkinson’s disease