Coronary artery disease predisposing haplogroup I of the Y chromosome, aggression and sex steroids--genetic association analysis.

OBJECTIVE: Amongst middle-aged men, haplogroup I is associated with ≈ 50% higher risk of coronary artery disease than other paternal lineages of Y chromosome. We hypothesised that carriers of haplogroup I had higher levels of aggression and estrogens and/or lower levels of androgens early in life and thus might be more prone to cardiovascular disease than men with other lineages of Y chromosome. METHODS: We reconstructed phylogenetic tree of the Y chromosome in >1000 young apparently healthy white men from the general population. Each Y chromosome was classified into one of 13 most common European lineages. Androgens (DHEA-S, androstenedione, total testosterone) and their metabolites (total estradiol, estrone) were measured by radioimmunoassays. Information on five dimensions of aggression (total, physical, verbal, anger and hostility) was collected using Buss and Perry questionnaire. RESULTS: Approximately 17% men inherited haplogroup I from their fathers. Carriers of haplogroup I showed lower scores of verbal aggression than men with other haplogroups (β = -0.72, SE = 0.29, P = 0.012) and when further compared to carriers of most common R1a lineage and other haplogroups (β = -1.03, SE = 0.34, P = 0.003). However, these associations did not survive a correction for multiple testing. Sex steroids did not show even nominal level of association with haplogroup I. CONCLUSION: Our data show no overall association between haplogroup I and sex-related phenotypes in young white men. These results also suggest that the previously identified association between haplogroup I and coronary artery disease is not likely mediated by unfavourable profile of sex steroids or heightened aggression early in life.