Author(s)

Yuichiro Nishida, Kumpei Tokuyama, Shoichiro Nagasaka, Akira Kiyonaga, Yasuki Higaki, Megumi Hara, Keitaro Tanaka, Hiroaki Tanaka

Department of Preventive Medicine, Faculty of Medicine, Saga University, Saga, Japan.
Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi, Japan.
Laboratory of Biochemistry of Exercise and Nutrition, Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.
Laboratory of Exercise Physiology, Faculty of Health and Sports Science, Fukuoka University, Fukuoka, Japan.

Rodent study suggests that interleukin (IL)-15 administration enhances insulin sensitivity. Although it is well known that circulating levels of typical inflammatory markers (C-reactive protein [CRP] and IL-6) are positively associated with homeostasis model assessment-insulin resistance (HOMA-IR), there are no studies investigating the associations of other inflammatory markers including IL-15 with peripheral/hepatic insulin sensitivity in humans. The current study aimed to examine the relationship between the levels of adiopokines or inflammatory cytokines and insulin sensitivity in 8 healthy middle-aged men. Circulating levels of 10 insulin sensitizing adipokines or inflammatory cytokines (total adiponectin [APN], high molecular weight adiponectin [HMW-APN], IL-4, IL-5, IL-6, IL-8, IL-15, interferon [IFN]-γ, tumor necrosis factor [TNF]-α, and TNF-β) were measured. A stable-labeled frequently sampled intravenous glucose tolerance test was performed to assess peripheral () and hepatic () insulin sensitivity estimated by 2-compartment minimal model. The levels of 3 inflammatory cytokines (IL-4, IL-6, and IL-15) were significantly and inversely correlated with either and . The association between IL-15 and either or was significant even after adjusting for age and percent body fat (p < 0.01). The current study showed a possible inverse association between serum IL-15 level and peripheral/hepatic insulin sensitivity in healthy middle-aged males, independent of percent body fat; this association in humans warrants further study.

Inflammatory Cytokine; Interleukin; Adipokine; Insulin Sensitivity

Nishida, Y. , Tokuyama, K. , Nagasaka, S. , Kiyonaga, A. , Higaki, Y. , Hara, M. , Tanaka, K. and Tanaka, H. (2014) Short Report: Association of IL-15 with Peripheral and Hepatic Insulin Sensitivity in Healthy Middle-Aged Men. Open Journal of Endocrine and Metabolic Diseases, 4, 59-67. doi: 10.4236/ojemd.2014.43007.