Insulin resistance is associated with cognitive dysfunction in multiple sclerosis patients: A cross‐sectional study

• Published in: Journal of neuroendocrinology 2023-06, Vol.35 (6), p.e13288-n/a
• Main Authors: Ayromlou, Hormoz, Hosseini, Samaneh, Khalili, Mohammad, Ayromlou, Samin, Khamudchiyan, Shagayeg, Farajdokht, Fereshteh, Hassannezhad, Sina, Amiri Moghadam, Shirin
• Format: Article
• Language: English
• Subjects: Cognition; Cognitive ability; Cognitive Dysfunction - etiology; Cross-Sectional Studies; Demyelination; Executive function; Fasting; Glucose metabolism; Humans; Information processing; Insulin Resistance; Insulins; Laboratory testing; Memory; Multiple sclerosis; Multiple Sclerosis - complications; Nervous system; Neurodegenerative Diseases; Neuropsychological Tests; Spatial memory
• ISSN: 0953-8194; 1365-2826
• DOI: 10.1111/jne.13288

Multiple sclerosis (MS) is a progressive inflammatory neurodegenerative disease of the nervous system accompanied by demyelination. MS‐associated cognitive impairments mainly involve recent memory, information processing speed, stable memory, and executive function. Moreover, MS is associated with impaired glucose and insulin metabolism, which can exacerbate cognitive decline. The present study aimed to compare the cognitive status of MS patients with and without insulin resistance. In this cross‐sectional study, 74 relapsing–remitting multiple sclerosis diagnosed patients were enrolled. Indicators of insulin resistance, including fasting blood glucose, insulin level, and homeostatic model assessment of insulin resistance (HOMA‐IR) index, were measured. They were then divided into two groups based on the results of the HOMA‐IR index. Cognition status was evaluated by the minimal assessment of cognitive function in multiple sclerosis battery. The prevalence of insulin resistance was 37.8%, and the prevalence of cognitive decline was estimated to be 67.56%. Mean scores of the California verbal learning test (CVLT), CVLT delayed free recall, controlled oral word association test, and judgment of line orientation tests were significantly lower in MS patients with insulin resistance than without. In addition, a negative correlation was demonstrated between the results of the CVLT, CVLT delayed free recall, controlled oral word association test, judgment of line orientation tests, brief visuospatial memory test, and Delis‐Kaplan executive function system sorting tests and fasting insulin levels. Greater verbal memory and spatial comprehension impairments were observed in MS patients with insulin resistance. Greater verbal memory and spatial comprehension impairments were observed in multiple sclerosis (MS) patients with insulin resistance, which was aggravated by an increase in fasting insulin level.