Studies of an Association in Boys of Blood Pressure and the Y Chromosome

BACKGROUND: Variations in the Y chromosome have shown significant, albeit inconsistent, associations with hypertension in men. Studies of peripubertal subjects might reveal more information on the origins of the Y chromosome's influence on blood pressure (BP). In the current study, we examined the association of a HindIII restriction site on the Y chromosome with BP in a cohort of young men. METHODS: Pubertal growth-based analyses were performed in 80 unrelated males with multiple measurements spanning time points beginning before and extending to after their pubertal growth. Blood pressure, height, and weight were measured approximately every 6 months. The period of pubertal growth was used to approximate the time for puberty. The association of the HindIII restriction site to systolic and diastolic BP was determined using a mixed model ANOVA. RESULTS: Estimated systolic and diastolic BPs were higher in HindIII(-) males in the period before, as well as in the period after pubertal growth (systolic BP 2.6 +/- 1.3 mm Hg higher, P < .05), and diastolic BP 2.3 +/- 1.2 mm Hg higher, P = .050). In addition, HindIII(-) males were younger at onset of peak height velocity (12.7 +/- 0.1 v 13.3 +/- 0.1 years, P < .001). In African Americans, an earlier age of maximal height velocity was associated with a higher systolic and diastolic BP (P < .05 and .02, respectively). CONCLUSIONS: The results suggest that variations in genes on the Y chromosome may affect BP in peripubertal males, possibly even before onset of puberty.