Endocrine Abstracts

Abundant evidence demonstrates that long-term cytokine-mediated inflammation is a risk factor for obesity and type 2 diabetes mellitus (T2DM). Our previous study shows a significant association between IL4 genotypes and T2DM, as well as between IL4 genotypes and the lower circulatory levels of high-density lipoprotein-cholesterol (HDL-C). In addition, IL4 has anti-hyperglycemic function by improving insulin sensitivity and glucose tolerance as well as being involved in lipid metabolism by regulating serum levels of adipokines and free fatty acids. Taking the above results together, it strongly suggests that IL4 involves in the regulation of lipid metabolism. Interleukin 4 receptor α chain (IL4Rα) is a crucial component for binding and signal transduction of IL4. Polymorphisms located in IL4Rα which alter the binding affinity to IL4 or downstream signaling pathways and thus contribute to the fine tune of IL4 responsive phenotypes, would also be linked to disease development. The aim of this study is to investigate the correlation between IL4Rα E400A polymorphisms and lipid metabolism. Genomic DNA from 121 type 2 diabetes mellitus patients and 113 non-diabetic non-obese control study subjects were extracted, and their IL4Rα E400A polymorphisms were analyzed by PCR–RFLP. The correlation between IL4Rα E400A genotypes and study subjects’ lipid profile was then examined. Significant associations of the IL4Rα E400A genotypes and HDL-C levels among control individuals (P=0.007), as well as among the obese T2DM patients (P=0.029), were observed. Significant correlations between IL4Rα E400A genotypes with blood pressure, as well as with blood urea nitrogen, were also observed in lean control subjects. Our results reveal that IL4Rα may play certain roles in the lipid metabolism of Taiwanese population and suggest a novel link between lipid metabolism and the cytokine receptor.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.