Social- and behavioral-specific genetic effects on blood pressure traits: the Strong Heart Family Study.
BACKGROUND
Population studies have demonstrated an important role of social, behavioral, and environmental factors in blood pressure (BP) levels. Accounting for the genetic interaction of these factors may help to identify common BP susceptibility alleles.


RESULTS
We studied the interaction of additive genetic effects and behavioral (physical activity, smoking, alcohol use) and socioeconomic (education) factors on BP in approximately 3600 American Indian participants of the Strong Heart Family Study, using variance component models. The mean and SD of resting systolic and diastolic BPs were 123 + or - 17 and 76 + or - 11 mm Hg, respectively. We detected evidence for distinct genetic effects on diastolic BP among ever smokers compared with never smokers (P = 0.01). For alcohol intake, we observed significant genotype-by-environment interactions on diastolic (rhog = 0.10, P = 0.0003) and on systolic BPs (rhog = 0.59, P = 0.0008) among current drinkers compared with former or never drinkers. We also detected genotype-by-physical activity interactions on diastolic BP (rhog = 0.35, P = 0.0004). Finally, there was evidence for distinct genetic effects on diastolic BP among individuals with less than high school education compared with those with 12 or more years of education (rhog = 0.41, P = 0.02).


CONCLUSIONS
Our findings suggest that behavioral and socioeconomic factors can modify the genetic effects on BP phenotypes. Accounting for context dependent factors may help us to better understand the complexities of the gene effects on BP and other complex phenotypes with high levels of genetic heterogeneity.
Franceschini
Nora
N
Department of Epidemiology, University of North Carolina Chapel Hill, 137 E Franklin St, Suite 306 CB#8050, Chapel Hill, NC 27514, USA. noraf@unc.edu
Rose
Kathryn M
KM
Storti
Kristi L
KL
Rutherford
Sue
S
Voruganti
V Saroja
VS
Laston
Sandy
S
Göring
Harald H H
HH
Dyer
Thomas D
TD
Umans
Jason G
JG
Lee
Elisa T
ET
Best
Lyle G
LG
Fabsitz
Richard R
RR
Cole
Shelley A
SA
MacCluer
Jean W
JW
North
Kari E
KE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking; D000483:Alleles; D001794:Blood Pressure / Q000235:genetics*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012907:Smoking; D012919:Social Behavior; D012959:Socioeconomic Factors