A cross-sectional study on 2583 participants without clinically recognized chronic kidney disease from the National Health and Nutrition Examination Survey 1999 to 2002 identified the association between obesity determined by BMI and cystatin C independent of age, sex, race, education, smoking, alcohol intake, cholesterol, and CRP levels [32]. This evidence concerns the gene CST3 and obesity due to melanocortin 4 receptor deficiency.