PON1 activity is decreased in coronary heart disease [126,127,128,129], familial hypercholesterolemia [130], type1 and 2 diabetes mellitus [131,132], familial dysbetalipoproteinemia [133] (Figure 6), metabolic syndrome [134,135,136,137,138,139,140], polycystic ovary syndrome [141], and chronic renal disease [142]. Here, PON1 is linked to metabolic syndrome.