A tyrosine hydroxylase microsatellite and hemodynamic response to stress in a multi-ethnic sample of youth.
OBJECTIVE
Behavioral stress is believed to have an impact on cardiovascular health. As the rate-limiting enzyme in the pathway for catecholamine synthesis, tyrosine hydroxylase is a candidate gene for variability in cardiovascular function. The aim of this study was to determine whether a relationship exists between a tyrosine hydroxylase microsatellite and resting hemodynamic function, and/or hemodynamic responsivity to laboratory stress.


METHODS
Subjects underwent 2 laboratory stressors: a video game challenge and a social competence interview.


METHODS
The stressors were administered in a laboratory setting.


METHODS
Subjects were 292 10- to 20-year-old normotensive African-American and European-American twin pairs.


METHODS
Blood pressure (BP) and heart rate (HR) were measured at rest and in response to the stressors.


RESULTS
Chi-square analyses using re-sampling to account for the twin design indicated that allele and genotype frequencies were significantly different between European Americans and African Americans (P < or = .0001). Analyses of variance indicated that the 184 and 199 bp alleles were associated with an attenuation of the hemodynamic response to stress with increasing age (P < or = .003, P < or = .002, respectively), while the 188 bp allele was associated with a higher resting systolic blood pressure (SBP) (P < or = .02), and greater hemodynamic response to stress with increasing BMI (P < or = .02).


CONCLUSIONS
This study showed that in a multi-ethnic sample of normotensive adolescents, specific alleles of this tyrosine hydroxylase microsatellite were associated with protective or deleterious cardiovascular effects with subjects at rest and responding to stress.
Barbeau
Paule
P
Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, Georgia 30912, USA. pbarbeau@mail.mcg.edu
Litaker
Mark S
MS
Jackson
Robert W
RW
Treiber
Frank A
FA
D000293:Adolescent; D000328:Adult; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000235:genetics; D005006:Ethnicity; D005260:Female; D005787:Gene Frequency; D006580:Genetic Carrier Screening; D005838:Genotype; D006439:Hemodynamics / Q000235:genetics*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D018895:Microsatellite Repeats; D013315:Stress, Psychological / Q000208:ethnology / Q000235:genetics*; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*; D014481:United States
D014446:Tyrosine 3-Monooxygenase