Interleukins as a Common Indicator for the Effects of Both Weather and Obesity on Human Health

Abstract

The influence of weather on human health has been studied for diseases including stroke and ischemic heart disease. The effect of obesity on human health has also been reported, and a connection to insulin resistance has been discussed as a main cause of ischemic diseases. Thus meteorological factors and obesity threaten human health leading to disease such as stroke and ischemic heart diseases. However, there has been no common measure to evaluate the effects both of meteorological factors and obesity simultaneously. In this paper, we propose, as a candidate for this measure, the evaluation of gene expression of interleukins including interleukin 6 (IL-6). Interleukins are a group of small proteins and a subgroup of cytokines, which are important for communications among cells. We extracted from the Gene Expression Omnibus (GEO) database several datasets of experiments associated with cold exposure and fat diet. As a method to measure the variability of gene expressions, we used the method of log2-Fold Change (log2FC), which was known as a basic method of normalization and transformation for microarray data. To investigate a common measure of the effects of cold exposure and obesity, we examined the gene expression of interleukins and found the increase of interleukinrelated genes played an important role in inflammatory reactions. We conclude that interleukins, including IL-6, can be a candidate for common indicators of both weather effects and obesity on human health. Our findings, together with a recent supply of simple kits to measure interleukins, may contribute to making a system to avoid the onset of diseases including stroke and ischemic heart diseases.