Studies suggest that sex differences in blood pressure (BP) are established early in life. Sex differences in BP increases that occur during adolescence may be due to differences in changes in anthropometric characteristics.
Using sex-specific individual growth models, we assessed the effect of height, body mass index (BMI; kg/m), waist circumference, and triceps and subscapular skinfold thickness on changes in systolic BP in a cohort of 1293 adolescents in Montreal, Canada. BP and anthropometry were assessed biannually (1999/2000, 2002, 2004) at mean ages 12.8, 15.2, and 17.0.
On average, systolic BP increased by 11.1 mm Hg in boys and 3.2 mm Hg in girls during 5 years. Changes in height explained half of the overall increase in systolic BP in boys and virtually all of the increase in systolic BP in girls. No meaningful sex differences were observed in the association of changes in BMI, waist circumference, and triceps and subscapular skinfold thickness with systolic BP change during 5 years. Increases in 1 BMI unit, 1 cm waist circumference, or 1 mm triceps or subscapular skinfold thickness were associated with increases of 0.7, 0.24, 0.3, and 0.4 mm Hg systolic BP, respectively.
Although sex differences in mean systolic BP changes during adolescence were largely attributable to differences in gains in height, the effect of gaining weight or body fat on systolic BP change was similar in boys and girls.