Smoking, cardiovascular risk factors and LRP2 gene variation: Associations with disease severity, cognitive function and brain structure in primary progressive multiple sclerosis

• Published in: Multiple sclerosis and related disorders Vol. 56; p. 103296
• Main Authors: Chow, Helene Højsgaard, Talbot, Jacob, Marstrand, Lisbet, Lundell, Henrik, Roman Siebner, Hartwig, Bach Søndergaard, Helle, Sellebjerg, Finn
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2021
• Subjects: Age-related multiple sclerosis severity score; Brain - diagnostic imaging; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - genetics; Cognition; Cross-Sectional Studies; Framingham risk score; Heart Disease Risk Factors; Humans; Low Density Lipoprotein Receptor-Related Protein-2; Multiple Sclerosis - epidemiology; Multiple Sclerosis - genetics; Multiple Sclerosis, Chronic Progressive; Primary progressive multiple sclerosis; Risk Factors; Severity of Illness Index; Smoking; Smoking - genetics; Primary progressive multiple sclerosis; Age-related multiple sclerosis severity score; Low-density lipoprotein receptor-related protein 2; Framingham risk score; Smoking
• ISSN: 2211-0348; 2211-0356
• DOI: 10.1016/j.msard.2021.103296

•Smoking after onset of PPMS is associated with increased disability.•Smoking after onset of PPMS is associated with cognitive impairment.•Smoking after PPMS onset is associated with lower myelin content in lesions.•Framingham risk score may be associated with atrophy of cortex.•The risk variant of the LRP2 gene is associated with CI. Smoking, cardiovascular risk factors, and genetic factors can have adverse effects in MS. To determine if smoking after disease onset, cardiovascular risk factors, and genetic variants influence primary progressive MS (PPMS). In this cross-sectional study, smoking habits, Framingham Risk Score (FRS), genetic variants, including the low-density lipoprotein receptor-related protein 2 (LRP2) SNP rs12988804 and MRI were collected in 60 PPMS trial participants. Disability and cognition were assessed with the Age-Related Multiple Sclerosis Severity (ARMSS) score, the Progressive-Onset MS Multiple Sclerosis Severity Score, and the Brief International Cognitive Assessment for MS. Smoking after PPMS onset was significantly associated with higher ARMSS (95% CI 0.8–2.4, p = 0.00016) statistically significant after Bonferroni correction. Lower magnetization transfer ratio in lesions was also significantly associated with smoking after onset of PPMS after correction (95% CI -0.9–-4.4, p = 0.0035). Pack-years in people who smoked after onset was likewise significantly associated with higher ARMSS score (b = 0.06 95% CI 0.02–0.09, p = 0.0021) as well as lower Symbol Digit Modalities Test scores (b = -0.40; 95% CI -0.66–-0.13, p = 0.0037), both statistically significant after Bonferroni correction. The LRP2 risk allele was associated with decreased performance on the California Verbal Learning Test 2 after correction (CC vs. CT+TT 95% CI -14.2–-3.4, p = 0.0018). If validated, these findings suggest that intervention regarding smoking may be beneficial in PPMS. If confirmed, assessment of the LRP2 gene variant may aid in the understanding of underlying pathological mechanisms in PPMS.