The correlation between dyslipidemia and cognitive impairment in multiple sclerosis patients.

BACKGROUND: A large number of multiple sclerosis [MS] patients suffer from cognitive dysfunction affecting their routine life in family and society. Investigating modifiable factors for cognition decline and controlling them, could improve the quality of life in MS patients. Therefore, the present study was aimed to evaluate the association between lipid profile components and cognition in MS patients.

METHODS: A cross-sectional study was conducted on 50 Relapsing-Remitting MS (RRMS) patients referred to Sina hospital, Tehran, Iran. The definite diagnosis of MS was done based on the revised McDonald criteria. Data on demographic and clinical data of patients were obtained. 5 cc blood samples were taken from all subjects after 10-hour night fasting, and lipid profile components including LDL, HDL, triglyceride, and total cholesterol were evaluated. The Persian version of the Minimal Assessment of Cognitive Functions in MS [MACFIMS] battery was administered to assess the cognitive function. Spearman and Pearson correlation tests were applied to investigate the correlation between lipid profile components and MACFIMS subtests or clinical features of MS patients.

RESULTS: The mean age of subjects was equal to 32.26 years old, and 85% of them were women. There was no significant correlation between MACFIMS subtests results with disease duration, patient's disability according to Expanded Disability Status Scale (EDSS), annual attack rate, and disease-modifying drug onset year (P value >0.05). A significant inverse correlation was found between greater serum total cholesterol and lower scores of Symbol Digit Modalities subtest [SDMT] (P value 0.02; r: -0.31), the Delis-Kaplan Executive Function System [DKEFS] sorting (P value 0.01; r: -0.34) and DKEFS-descriptive (P value 0.04; r: -0.28) subtests. This significant inverse correlation was also found in terms of the correlation between higher serum LDL and impairment in the case of DKEFS-sorting score (P value 0.05; r: -0.27), and DKEFS-descriptive score (P value 0.05; r: -0.27). No significant correlation was found in case of serum HDL or triglyceride and MACFIMS subtests (P value >0.05).

DISCUSSION: Our findings proposed a possible correlation between the increased serum LDL cholesterol, serum total cholesterol and cognitive dysfunction among MS patients.