SERPINA1 and obesity due to melanocortin 4 receptor deficiency: To investigate the relationship between GlycA and its constituent glycoproteins in a population setting we utilised matched serum NMR-metabolite measures and immunoassays for AAT, AGP, HP, and TF in 626 adults previously measured in the population-based DIetary, Lifestyle, and Genetic determinants of Obesity and Metabolic syndrome 2007 study (DILGOM07) [15,24].