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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Aged, Body Mass Index, Cohort Studies, Evidence-Based Medicine, Female, Forecasting, Humans, Immunologic Factors, Interferon-beta, Kaplan-Meier Estimate, Longitudinal Studies, Male, Middle Aged, Multiple Sclerosis, Proportional Hazards Models, Prospective Studies, Recurrence, Sunlight, Survival Analysis, Ultraviolet Rays, Vitamin D, Young Adult.
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Do interferon-β and serum 25-hydroxyvitamin D interact to modulate relapse risk in MS? Context: To determine whether interferon-β (IFN-β) medication use is associated with vitamin D levels and whether the two interact in exerting effects on relapse risk. In a prospective cohort of 178 persons with clinically definite multiple sclerosis (MS) living in southern Tasmania in 2002-2005, serum 25-hydroxyvitamin D [25(OH)D] was measured biannually, with assessment by questionnaire for relevant factors, including IFN-β treatment. Subjects reporting IFN-β use had significantly higher mean 25(OH)D than persons who did not (p < 0.001). This was mediated by an interaction between personal sun exposure and IFN-β, with treated persons realizing nearly three times 25(OH)D per hour of sun exposure of persons not on therapy. The association between 25(OH)D and 1,25-dihydroxyvitamin D did not differ by IFN-β therapy (p = 0.82). 25(OH)D was associated with a reduced relapse risk only among persons on IFN-β (p < 0.001). Importantly, IFN-β was only protective against relapse among persons with higher 25(OH)D (hazard ratio [HR] 0.58 [95% confidence interval (CI) 0.35-0.98]), while among 25(OH)D-insufficient persons, IFN-β increased relapse risk (HR 2.01 [95% CI 1.22-3.32]).
assistant
In this study, we found that IFN-β therapy is associated with greater production of vitamin D from sun exposure, suggesting part of the therapeutic effects of IFN-β on relapse in MS may be through modulation of vitamin D metabolism. These findings suggest persons being treated with IFN-β should have vitamin D status monitored and maintained in the sufficiency range. Final Decision: yes