Analyses of univariate correlations between IPF characteristics and metabolic factors associated with obesity resulted in a significant correlation between TNFA and TC (r2 ​= ​0.13, P ​= ​0.01), LDL (r2 ​= ​0.13, P ​= ​0.01) and LDL/HDL ratio (r2 ​= ​0.14, P ​= ​0.01). This evidence concerns the gene TNF and obesity due to melanocortin 4 receptor deficiency.