As low-grade systemic inflammation is a hallmark of both obesity and type 2 diabetes (T2D) we studied the levels of plasma calprotectin and S100A8 skeletal muscle mRNA levels using a cross-sectional case control design in which patients with T2D and healthy controls were closely matched, not only according to age and sex but also according to body mass index (BMI). This evidence concerns the gene S100A8 and obesity due to melanocortin 4 receptor deficiency.