Abstract:
Cardiovascular diseases include diseases of heart, vascular diseases of brain and diseases of
blood vessels. Cardiovascular diseases are responsible for over 17.3 million deaths per year
and are the leading cause of death worldwide. Most of these deaths occur before age of 60
and could have largely been prevented. PON 1 is a cardioprotective enzyme synthesized in
liver. It can be used as a personalized, proactive measure in assessing CVD risk in people.
Serum samples of 155 apparently healthy individuals between 19-70 years were used for the
study. Phenotype distribution was assessed using dual substrate method. Salt stimulated PON
1 activity (with 1M NaCl) and arylesterase activity was measured spectrophotometrically
using paraoxon and phenyl acetate as substrates. Out of 155 participants 77 were females and
78 were males. In this study population, a wide interindividual variability (up to 18 folds) of
PON1 activity was found. The mean of basal, salt stimulated paraoxonase and arylesterase
activities were 222.4 ± 122.57U/l, 302.36 ± 204.03U/l and 1.72±1.14 U/l respectively. The
ratio of salt stimulated PON1 activity to arylesterase activity was used for definition of
phenotypes. Based on the observed ratios, 3 distinct phenotypes AA (low activity), AB
(Intermediate activity) and BB (high activity) were determined. The PON1 ratio varied from
0.21 to 4.99. The paraoxonase phenotype frequencies were approximately 44.52% (AA),
46.45 % (AB) and 9.03% (BB). The distribution of PON 1 phenotypes in this Sri Lankan
population was trimodal. Individuals with low PON 1 activity may be more susceptible to
CVD. They were advised to make necessary changes in life style and diet to mitigate risk of
getting CVD.
