Puberty timing and sex-specific trajectories of systolic blood pressure: a prospective cohort study

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 English birth cohort study were analysed. Repeated measures of height from age 5 to 20 years were used to identify puberty timing (age at peak height velocity). SBP was measured on ten occasions from 3 to 24 years (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 including BMI gain from age one up to 9 years. Results Mean age at peak height velocity was 11.7 years (standard deviation (SD) =0.8) for females and 13.6 years (SD=0.9) for males. In adjusted models, females and males had similar SBP at age 3. 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 24 years [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 24 years in females only. Conclusion A large proportion of the higher SBP observed in males compared to females in early adulthood is accrued before puberty. Prevention of high SBP in adult males may therefore benefit from a life course approach starting from before puberty. Interventions targeting puberty timing are unlikely to greatly influence SBP in females and males in early adulthood.