The range of values deemed normal for a physiologic measurement in healthy persons is further complicated by the fact that blood CRP concentrations between 3 and 10 mg/L are considered by some to be indicative of ‘low-grade’ inflammation, i.e. mild inflammation resulting from a variety of persistent metabolic stresses (e.g. atherosclerosis, obesity, obstructive sleep apnea, insulin resistance, hypertension, type 2 diabetes, etc. (4). Here, CRP is linked to obesity due to melanocortin 4 receptor deficiency.