Multiple Sclerosis 40% more likely in obese than in overweight (Mendelian randomization)

Created January 2018

Mendelian randomization in multiple sclerosis: A causal role for vitamin D and obesity?

Multiple Sclerosis Journal, January 8, 2018

Adil Harroud, J Brent Richards

Not a surprise * Obese have lower levels of vitamin D * Lower level of vitamin D (for any reason) increases the risk of Multiple Sclerosis Items in both categories Multiple Sclerosis and Obesity are listed here: {category}

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The etiology of multiple sclerosis (MS) involves a complex interplay of genetic and environmental factors. Epidemiologic studies have furthered our understanding of these risk factors but remain limited by residual confounding and potential for reverse causation, particularly in MS where time of disease onset is not known. Mendelian randomization (MR) uses genetic variants to study the causal effect of modifiable exposures on an outcome. This method avoids some of the limitations of classical epidemiology and can strengthen causal inference. Here, we introduce the basic concepts of MR and review its contributions to the field of MS. Indeed, several studies using MR have now provided support for a causal role for low vitamin D level and obesity in the development of MS.

Table 1. Limitations of MR and how to address them

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Tags: Multiple Sclerosis Obesity