Association of different risk factors with exercise and resting blood pressure in 532 subjects aged 12-17 years

Abstract

High blood pressure (BP) values in adolescents are caused by a variety of risk factors. In this group, the reproducibility of resting office BP is poor due to emotional and situational factors. With adults, it is the case that exercise BP is more closely associated with cardiovascular prognosis. However, it is unclear whether exercise BP in children and adolescents has a higher prognostic relevance than resting BP. In the present study, the association of resting vs. exercise BP values with classic risk factors was compared in order to evaluate the importance of BP during exercise. In the Kiel EX.PRESS. (EXercise and PRESSure) study, resting and exercise BP of 532 young subjects (aged 12-17 years) was determined. Systolic exercise BP was measured at 1.5 Watt / kg body weight using a standardized cycle ergometer exercise test. Age, height, body weight and waist circumference of all participants were collected. The physical working capacity at heart rate of 170/min (PWC 170) was used as a fitness parameter. The volume of moderate-to-vigorous physical activity (MVPAindex) and screen time (h / day) were determined using questionnaires. In addition, family history of hypertension, parental smoking and educational level were included in the study. The association of resting vs. exercise BP values with these variables was calculated and compared. After adjustment for age, sex and height, there were significant correlations of both resting and exercise BP with BMI (r1⁄40.289 vs. r1⁄40.312, p 2h / day, fit vs. unfit, high ( 5 days / week) vs. low (< 5 days / week) MVPA, non-smoking vs. smoking parents, active vs. inactive parents and high vs. low educational level, mean systolic exercise BP was significantly higher in the latter variable, respectively. However, no significant difference was found concerning resting BP. Group differences for mean systolic exercise BP values were between 3.7 and 5.2 mmHg. In contrast, groups with high vs. normal BMI or waist circumference and positive vs. negative family history of hypertension had higher exercise and resting BP values. In conclusion, exercise BP in this group of 12-17 year-old subjects was closely related to a variety of classic risk factors mainly concerning fitnessand activity-related parameters. In addition, a number of other lifestyleand family-related parameters demonstrated a correlation with exercise BP at least as closely as with resting BP. Our data support the importance of exercise BP in young subjects. Thus, the determination of BP during exercise in clinical practice might be of prognostic significance not only in adults.