title: Sex differences in vascular compliance in normal-weight but not obese boys and girls: the effect of body composition.
abstract: Objectives. To determine the effect of sex and obesity on vascular function in children and explore potential mechanisms that account for differences in vascular function. Methods. Participants were 61 (30 boys) normal-weight (BMI 25-75% ile for age and sex) and 62 (30 boys) obese (BMI ≥ 95% ile) children of ages 8-18 years. Measurements of large and small artery elastic index (LAEI and SAEI, resp.) and reactive hyperemia index (RHI) were obtained at rest, along with anthropometric and biochemical information. Results. In normal-weight children, LAEI was 16% higher in males than females (P = 0.04) with a similar trend for SAEI (13% higher in males, P = 0.067). In obese children, no sex-related differences in vascular measures were observed. In multivariable models, sex differences in arterial compliance were explained by higher lean mass in normal-weight boys. Fat mass predicted LAEI and SAEI in both normal-weight and obese females, but fat mass predicted arterial compliance in boys when fat mass exceeded 24 kg (37% of the sample). Conclusions. Normal-weight males have higher arterial compliance than normal-weight females due to increased lean mass, but sex-related differences were not observed among obese children due to a lack of sex-related differences in lean or fat mass.
authors.affiliation: Section of Diabetes and Endocrinology, Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
authors.forename: Jeanie B
authors.initials: JB
authors.lastname: Tryggestad
authors.forename: David M
authors.initials: DM
authors.lastname: Thompson
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Copeland
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Short