Racial differences in paraoxonase-1 (PON1): a factor in the health of southerners?
BACKGROUND
The southern United States (excluding Florida) has the highest age-adjusted rate of cardiovascular disease (CVD) in the country, with African Americans having a higher prevalence of CVD than Caucasians. Paraoxonase-1 (PON1), an enzyme associated with high-density lipoprotein particles, participates both in the hydrolysis of oxidized lipids (thus protecting against atherosclerosis) and in the hydrolysis of organophosphates. Higher paraoxonase activity has been associated with lower risk of atherosclerosis.


OBJECTIVE
In this study we characterized the distribution of the functional PON1(Q192R) polymorphisms (PON status as assessed by diazoxonase to paraoxonase ratios) and the PON1 activity levels in 200 adult males and females of both races (50 in each race/sex class) from the southern United States from commercially obtained blood bank serum samples.


METHODS
We used spectrophotometric methods with serum to determine PON1 status, arylesterase activities (phenyl acetate hydrolysis), and levels of cotinine and C-reactive protein (CRP).


RESULTS
African Americans had higher paraoxonase activities but lower diazoxonase activities than did Caucasians, consistent with African Americans having a lower proportion of the functional genotype QQ (QQ 15%, QR 34%, RR 44%, 7% indeterminate), than did Caucasians (QQ 60%, QR 31%, RR 7%, 2% indeterminate). Cotinine levels indicated that all samples came from non-smokers and that CRP levels were higher in African Americans than in Caucasians and higher in females than in males. CRP levels showed no association with paraoxonase activities.


CONCLUSIONS
These data present initial observations for use in characterizing the poorer cardiovascular health status of the population in the southern United States and more specifically southern African Americans.
Davis
Kimberly A
KA
Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi 39762-6100, USA.
Crow
J Allen
JA
Chambers
Howard W
HW
Meek
Edward C
EC
Chambers
Janice E
JE
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D043303:Aryldialkylphosphatase / Q000235:genetics* / Q000378:metabolism*; D050197:Atherosclerosis / Q000453:epidemiology / Q000235:genetics*; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D015144:Southeastern United States / Q000453:epidemiology; D044465:White People / Q000235:genetics*
D002097:C-Reactive Protein; D043303:Aryldialkylphosphatase