| 1. |
- Bjørnevik, Kjetil, et al.
(author)
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Negative interaction between smoking and EBV in the risk of multiple sclerosis : The EnvIMS study
- 2017
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In: Multiple Sclerosis Journal. - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 23:7, s. 1018-1024
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Journal article (peer-reviewed)abstract
- BACKGROUND: Results from previous studies on a possible interaction between smoking and Epstein-Barr virus (EBV) in the risk of multiple sclerosis (MS) are conflicting.OBJECTIVES: To examine the interaction between smoking and infectious mononucleosis (IM) in the risk of MS.METHODS: Within the case-control study on Environmental Factors In Multiple Sclerosis (EnvIMS), 1904 MS patients and 3694 population-based frequency-matched healthy controls from Norway, Italy, and Sweden reported on prior exposure to smoking and history of IM. We examined the interaction between the two exposures on the additive and multiplicative scale.RESULTS: Smoking and IM were each found to be associated with an increased MS risk in all three countries, and there was a negative multiplicative interaction between the two exposures in each country separately as well as in the pooled analysis (p = 0.001). Among those who reported IM, there was no increased risk associated with smoking (odds ratio (OR): 0.95, 95% confidence interval (CI): 0.66-1.37). The direction of the estimated interactions on the additive scale was consistent with a negative interaction in all three countries (relative excess risk due to interaction (RERI): -0.98, 95% CI: -2.05-0.15, p = 0.09).CONCLUSION: Our findings indicate competing antagonism, where the two exposures compete to affect the outcome.
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| 2. |
- Holmøy, Trygve, et al.
(author)
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Vitamin D supplementation and neurofilament light chain in multiple sclerosis.
- 2019
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In: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 139:2, s. 172-176
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Journal article (peer-reviewed)abstract
- The effect of vitamin D supplementation on the disease course of multiple sclerosis (MS) is not established. Neurofilament light chain (NFL) is a sensitive marker of axonal degeneration. The aim of this study was to establish whether high-dose vitamin D supplementation reduces serum levels of NFL.We have performed a 96weeks placebo-controlled randomized study of weekly supplementation with 20000IU vitamin D3 in 71 patients with relapsing remitting MS (RRMS). Serum levels of NFL were measured at baseline, week 48 and week 96 with a single molecule (Simoa) assay in 69 of these patients.Serum levels of 25-hydroxyvitamin D more than doubled in the vitamin D group. Compared to placebo, vitamin D supplementation had no overall effect on the change in serum levels of NFL from baseline (P=0.93 at week 48 and P=0.56 at week 96). In the subgroup of patients not receiving disease-modifying therapy, NFL decreased by 30.9% to week 48% and 32.6% to week 96 from baseline in the vitamin D group as compared to the placebo group (P=0.06 for both time points).With a possible exception for patients not treated with disease-modifying drugs, weekly supplementation with 20000IU vitamin D3 did not affect NFL levels in these RRMS patients.
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| 3. |
- Nordin, Angelica, et al.
(author)
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Sequence variations in C9orf72 downstream of the hexanucleotide repeat region and its effect on repeat-primed PCR interpretation : a large multinational screening study
- 2017
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In: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : Informa UK Limited. - 2167-8421 .- 2167-9223. ; 18:3-4, s. 256-264
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Journal article (peer-reviewed)abstract
- A large GGGGCC-repeat expansion mutation (HREM) in C9orf72 is the most common known cause of ALS and FTD in European populations. Sequence variations immediately downstream of the HREM region have previously been observed and have been suggested to be one reason for difficulties in interpreting RP-PCR data. Our objective was to determine the properties of these sequence variations with regard to prevalence, the range of variation, and effect on disease prognosis. We screened a multi-national cohort (n = 6981) for the HREM and samples with deviant RP-PCR curves were identified. The deviant samples were subsequently sequenced to determine sequence alteration. Our results show that in the USA and European cohorts (n = 6508) 10.7% carried the HREM and 3% had a sequence variant, while no HREM or sequence variants were observed in the Japanese cohort (n = 473). Sequence variations were more common on HREM alleles; however, certain population specific variants were associated with a non-expanded allele. In conclusion, we identified 38 different sequence variants, most located within the first 50 bp downstream of the HREM region. Furthermore, the presence of an HREM was found to be coupled to a lower age of onset and a shorter disease survival, while sequence variation did not have any correlation with these parameters.
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| 4. |
- Wesnes, Kristin, et al.
(author)
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Body size and the risk of multiple sclerosis in Norway and Italy : The EnvIMS study.
- 2015
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In: Multiple Sclerosis Journal. - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 21:4, s. 388-395
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Journal article (peer-reviewed)abstract
- BACKGROUND: Obesity may be a risk factor for developing multiple sclerosis (MS).OBJECTIVE: We examined if body size influences the risk of MS in a population-based, case control study.METHODS: A total of 953 cases and 1717 controls from Norway and 707 cases and 1333 controls from Italy reported their body size by choosing a silhouette 1 to 9 (largest) every fifth year from age 5 to 30 and at time of study. The body size-related MS risk was defined by odds ratios (ORs) in logistic regression analyses adjusting for age, smoking and outdoor activity.RESULTS: In Norway a large body size (silhouettes 6-9) compared to silhouette 3 increased the risk of MS, especially at age 25 (OR 2.21; 95% CI 1.09-4.46 for men and OR 1.43; 95% CI 0.90-2.27 for women). When comparing silhouette 9 to 1, we found a significant dose-response from age 10 until age 30 peaking at age 25 (sex-adjusted OR 2.83; 95% CI 1.68-4.78). The association was present for at least 15 years prior to disease onset. No significant associations were found in Italy.CONCLUSIONS: Obesity from childhood until young adulthood is a likely risk factor for MS with a seemingly stronger effect in Norway than in Italy.
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