Objectives To investigate the associations of serum lipid profile with disease progression in high-risk clinically isolated syndromes (CIS) after the first demyelinating event.

Methods High density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) were obtained in pretreatment serum from 135 high risk patients with CIS (≥2 brain MRI lesions and ≥2 oligoclonal bands) enrolled in the Observational Study of Early Interferon β-1a Treatment in High Risk Subjects after CIS study (SET study), which prospectively evaluated the effect of intramuscular interferon β-1a treatment following the first demyelinating event. Thyroid stimulating hormone, free thyroxine, 25-hydroxy vitamin D3, active smoking status and body mass index were also obtained. Clinical and MRI assessments were obtained within 4 months of the initial demyelinating event and at 6, 12 and 24 months.

Results The time to first relapse and number of relapses were not associated with any of the lipid profile variables. Higher LDL-C (p=0.006) and TC (p=0.001) levels were associated with increased cumulative number of new T2 lesions over 2 years. Higher free thyroxine levels were associated with lower cumulative number of contrast-enhancing lesions (p=0.008). Higher TC was associated as a trend with lower baseline whole brain volume (p=0.020). Higher high density lipoprotein was associated with higher deseasonalised 1,25-dihydroxy vitamin D3 (p=0.003) levels and a trend was found for deseasonalised 25-hydroxy vitamin D3 (p=0.014).

Conclusions In early multiple sclerosis, lipid profile variables particularly LDL-C and TC levels are associated with inflammatory MRI activity measures.