Plasma CRP concentrations have been shown to be chronically influenced by a wide range of disease states and physiological factors, such as heart disease, renal insufficiency, diabetes mellitus, obstructive sleep apnea, arterial hypertension, obesity, metabolic syndrome, frequent physical activity, alcohol consumption, high-protein diets, and depressive symptoms. This evidence concerns the gene CRP and obesity due to melanocortin 4 receptor deficiency.