BACKGROUND: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). OBJECTIVE: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. METHODS: We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. RESULTS: 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. CONCLUSION: The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.
BACKGROUND: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). OBJECTIVE: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. METHODS: We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. RESULTS: 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. CONCLUSION: The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.
Authors: Anja Mähler; Silvia Mandel; Mario Lorenz; Urs Ruegg; Erich E Wanker; Michael Boschmann; Friedemann Paul Journal: EPMA J Date: 2013-02-18 Impact factor: 6.543
Authors: Anne-Hilde Muris; Joost Smolders; Linda Rolf; Lieke J J Klinkenberg; Noreen van der Linden; Steven Meex; Jan Damoiseaux; Raymond Hupperts Journal: PLoS One Date: 2016-06-08 Impact factor: 3.240