Leptin signalling genetic variants and insulin resistance in multiple sclerosis patients

Abstract

Last decade provided multiple evidence that link disturbances in metabolic processes and energy metabolism with diseases of central nervous system and neurodegeneration. Initial phases of insulin resistance (IR) are present in natural course of multiple sclerosis (MS) and leptin was recognized as a player in MS pathophysiology and moreover cognitive decline. We aimed to investigate association of genetic variants in leptin (LEP) rs7799039, its receptor LEPR rs1137101 and proliferator-activated receptor gamma co-activator 1-alpha (PGCA1A) rs8192678 with IR parameters (HOMA-IR index, area under the curve for insulin and glucose, Cederholm insulin sensitivity index (ISIced), the insulinogenic index in the first 30 min of oral glucose tolerance test (OGTT) in patients with MS. Seventy eight relapsing-remitting patients in clinical remission, free of corticosteroids for at least three months, were included in the study. None of the 3 variants’ genotypes were associated with HOMA-IR index, area under the curve for insulin and glucose and the insulinogenic index in the first 30 min of OGTT. PGC1A variant was significantly associated with ISIced (Kruskal-Wallis ANOVA, p = 0.04). Leptin gene variant was significantly associated with impaired GT (p=0.029 adjusted for gender and other two variants). None of the variant showed association with IR. In conclusion, we found that genetic variants in leptin signalling pathway affect glucose tolerance and insulin sensitivity in patients with MS. As both, leptin and PGC1A have role in preventing neuronal death and reducing oxidative stress neuronal damage current results favour further investigation toward preserving cognitive status and neuroprotection in MS.