PON1 and diabetes mellitus: Although the polymorphism at position 192 does not affect PON1 serum concentration, others for example at position 55 (53) and in the promoter region (54) do and there are a huge number of epigenetic and acquired factors, including diabetes, inflammatory disorders, infections and nutrition, reviewed elsewhere (55, 56) that contribute to variation in concentration and activity which in different individuals can vary by as much as 16-fold and 40-fold, respectively (57).