GHRL and multiple sclerosis: Additionally, apelin levels correlated positively with BMI in the fingolimod-treated group (p=0.001, R = 0.694).<h4>Conclusion</h4>The study demonstrates differences in serum apelin and ghrelin levels between RRMS patients treated with natalizumab or fingolimod and healthy controls, suggesting a potential association between immunomodulatory treatment, metabolic factors, and peptide hormone regulation in multiple sclerosis.