Puberty and sex-specific trajectories of systolic blood pressure across

Background
Sex differences in systolic blood pressure (SBP) emerge during adolescence but the role of puberty is not well understood. We examined sex-specific changes in SBP preceding and following puberty and examined the impact of puberty timing on SBP trajectories in females and males.

Methods
Trajectories of SBP before and after puberty and by timing of puberty in females and males in a contemporary birth cohort study were analysed. Repeated measures of height from age 5-20 years (y) were used to identify puberty timing (age at peak height velocity). SBP was measured on ten occasions from 3-24y (N participants=4,062, repeated SBP measures=29,172). Analyses were preformed using linear spline multilevel models based on time before and after puberty and were adjusted for parental factors and early childhood factors.

Results
Mean age at peak height velocity was 11.7y (standard deviation (SD)=0.8) for females and 13.6y (SD=0.9) for males. Males had faster rates of increase in SBP before puberty leading to 10.19mmHg (95%CI:6.80,13.57) higher mean SBP at puberty which remained similar at 24y [mean difference; 11.43mmHg (95%CI:7.22,15.63)]. Puberty timing was associated with small transient differences in SBP trajectories post-puberty in both sexes and small differences at 24y in females only.

Conclusion
A large proportion of the higher SBP observed in males compared with females in early adulthood is accrued before puberty. Interventions targeting puberty timing are unlikely to influence SBP in early adulthood.