Plasma hydrogen peroxide production in human essential hypertension - Roleof heredity, gender, and ethnicity

Oxygen free radicals, including hydrogen peroxide, may mediate oxidative st ress in target organ tissues and contribute to cardiovascular complications in hypertension. To examine heritability of hydrogen peroxide production, we investigated this trait in a family-based cohort consisting of family me mbers (n=236) ascertained through probands (n=57) with essential hypertensi on. Significant effects on hydrogen peroxide production were found for gend er and ethnicity, with men having greater values than women (P<0.001) and w hite subjects having greater values than black subjects (P=0.025). Hydrogen peroxide production correlated directly with plasma renin activity (P=0.01 5), suggesting an important interaction between circulating oxygen radicals and the renin-angiotensin system and a potential mechanism for lower hydro gen peroxide values observed in blacks. Heritability estimates from familia l correlations revealed that approximately 20% to 35% of the observed varia nce in hydrogen peroxide production could be attributed to genetic factors, suggesting a substantial heritable component to the overall determination of this trait. Hydrogen peroxide production negatively correlated with card iac contractility (r=-0.214, P=0.001) and renal function (r=-0.194, P=0.003 ) Ln conclusion, these results indicate that hydrogen peroxide production i s heritable and is related to target organ function in essential hypertensi on. Genetic loci influencing hydrogen peroxide production may represent log ical candidates to investigate as susceptibility genes for cardiovascular t arget organ injury.