Differences in maternal and paternal transmission of coronary heart disease

Background: Few studies have investigated the possible differential transmission of maternal and/or paternal coronary heart disease (CHD) to offspring, after accounting for sociodemographic characteristics. Methods: The Multigeneration Register was linked to hospital data in this study of all Swedish individuals born since 1932 and their parents. Registered cases of CHD between January 1, 1987, and December 31, 2001, were evaluated. Poisson regression was used to calculate standardized incidence ratios (SIRs) for men and women with mothers and/or fathers affected by CHD compared with men and women whose parents were not affected. All analyses were conducted in 2005. Results: Maternal transmission was stronger than paternal transmission and the confidence intervals did not overlap. For women, the overall SIRs were 1.43 (95% confidence interval [CI]=134-1.51) for maternal transmission and 1.17 (95% CI=1.11-1.23) for paternal transmission. For men, the corresponding SIRs were 1.55 (95% CI=1.50-1.60) and 1.41 (95% CI=1.37-1.45). Even higher SIRs were found in the youngest age groups, among those with both parents affected by coronary heart disease, and among those with premature parental CHD. Conclusions: These findings might ultimately influence treatment decisions regarding risk factors and suggest the need for research focusing on genetic and intrauterine risk factors.