Effect of angiotensin-converting enzyme insertion/deletion polymorphism DD genotype on high-frequency heart rate variability in African Americans.

Seventy-nine African-American participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) pilot study were genotyped for the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and had spectral power of their high-frequency (HF) heart rate variability (HRV) determined by fast-Fourier transformation. HF HRV was highest in II, intermediate in ID, and lowest in DD (II vs DD, p <0.043) genotypes, thus making an association of the ACE I/D DD genotype with decreased HF HRV that is consistent with the hypothesis that the DD genotype confers susceptibility to increased cardiovascular risk. The urban African-American population we studied had a particularly high cardiovascular risk, and these findings suggest that ACE I/D genotypes may modify that risk.