Educational attainment and the heritability of self-reported hypertension among male Vietnam-era twins.
OBJECTIVE
To investigate the potential for gene x environment interaction in hypertension by examining the extent to which educational attainment modifies the heritability of hypertension in male twins. Prior twin and family studies have established that hypertension runs in families and is heritable. In addition, epidemiological research indicates that the prevalence of hypertension differs by socioeconomic factors, such as educational attainment.


METHODS
Twin structural equation modeling was used to examine educational attainment as a moderator of heritability of hypertension. Participants were 4301 monozygotic and 3414 dizygotic male Vietnam-era twins who provided data on both education (in years) and self-report of physician diagnosis of hypertension or medication usage.


RESULTS
Heritability was 17 points lower among co-twins concordant for educational attainment of < or =14 years (0.46, 95% CI = 0.32-0.57) relative to co-twins concordant for >14 years of education (0.63, 95% CI = 0.54-0.71). The significant moderation of the heritability (p = .04) was confirmed in twin models examining educational attainment as a continuous moderator of hypertension.


CONCLUSIONS
These results demonstrate that the expression of genetic vulnerability to hypertension can vary as a function of environmental factors, including education level, and that nongenetic pathways may differentially contribute to risk among those with fewer years of education.
McCaffery
Jeanne M
JM
Weight Control and Diabetes Research Center, Brown Medical School, The Miriam Hospital, Providence, Rhode Island 02903, USA. Jeanne_McCaffery@brown.edu
Papandonatos
George D
GD
Lyons
Michael J
MJ
Niaura
Raymond
R
D000328:Adult; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics; D004493:Education / Q000706:statistics & numerical data*; D004522:Educational Status; D020022:Genetic Predisposition to Disease; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D012042:Registries; D012307:Risk Factors; D012650:Self Disclosure; D014481:United States / Q000453:epidemiology; D047829:Vietnam Conflict