The Effects of Sex and Pubertal Maturation on Cardiovagal Baroreflex Sensitivity.
OBJECTIVE
To examine baroreflex sensitivity (BRS) across different stages of pubertal maturation in healthy children and adolescents.


METHODS
This study was cross-sectional and included 104 participants (53 males and 51 females) aged 8-18 years old. Participants were organized into 5 pubertal groups based on the criteria of Tanner; prepubertal (Tanner 1, n = 19), early-pubertal (Tanner 2, n = 16), peripubertal (Tanner 3, n = 24), late-pubertal (Tanner 4, n = 23), and postpubertal (Tanner 5 and 6, n = 22). Adiposity (fat-free mass, fat mass, and body fat%), body mass index, and demographic variables were collected. Beat-by-beat blood pressure and R-R interval were collected during supine rest to determine BRS. BRS was assessed by transfer function analysis in the low frequency range (0.05-0.15 Hz).


RESULTS
The results demonstrated a sex-by-maturation interaction [F(4, 94) = 3.202, P = .019]. BRS decreased from early-to postpuberty in males (30 [7.1] vs 13.2 [7.8] ms/mm Hg), and remained unchanged in females. This led to significantly greater BRS in females compared with males, postpuberty (27 [7.3] vs 13.2 [7.8] ms/mm Hg).


CONCLUSIONS
Controlling for both sex and maturation when examining BRS in children and adolescents with cardiovascular disease risk factors will aid in interpreting abnormally high or low BRS values.
Department of Health Sciences, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada.
Daniele
D
Chirico
Department of Health Sciences, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada.
Jian
J
Liu
Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada.
Panagiota
P
Klentrou
School of Kinesiology, University of Western Ontario, London, Ontario, Canada.
J Kevin
JK
Shoemaker
Department of Health Sciences, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada; Brock-Niagara Centre for Health and Well-Being, Brock University, St. Catharines, Ontario, Canada. Electronic address: doleary@brocku.ca.
Deborah D
DD
O'Leary
D000293:Adolescent; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000503:physiopathology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D015994:Incidence; D008297:Male; D009864:Ontario / Q000453:epidemiology; D012016:Reference Values; D012307:Risk Factors; D012737:Sex Factors; D012741:Sexual Maturation / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*