Original Article
The Mediating Role of Physical Inactivity on the Relationship between Inflammation and Artery Thickness in Prepubertal Adolescents

https://doi.org/10.1016/j.jpeds.2014.12.057Get rights and content

Objective

To analyze the relationship between inflammatory markers and the lipid profile, blood flow, and artery structure in prepubertal adolescents stratified according to sports practice.

Study design

The sample was composed of 120 adolescents (57 boys and 63 girls) with a mean age of 11.7 ± 0.7 years (ranging from 11 to 13 years). Intima-media thickness (IMT) and blood flow were measured with ultrasonography. The lipid profile and high-sensitivity C-reactive protein were measured after the subjects had fasted for 12 hours overnight. Trunk fatness was measured by dual-energy x-ray absorptiometry. Organized sports participation was analyzed as a categorical variable. Biological maturation was determined via the age at peak height velocity.

Results

In the adjusted model, high-sensitivity C-reactive protein was significantly related to high-density lipoprotein-cholesterol (β = −5.797 [−11.500 to −0.093]), femoral IMT (β = 0.062 [0.008-0.116]), and the sum of femoral and carotid IMT (β = 1.107 [0.223-1.919]), but only in the group without sports participation. Slopes of the crude linear regression were greater in the group without sports participation for femoral IMT (t = 2.621; P = .009) and the sum of femoral and carotid IMT (t = 2.876; P = .004) when compared with the group with sports participation.

Conclusion

Independent of body fatness and biological maturation, inflammatory status was related to artery IMT and dyslipidemia in prepubertal adolescents, modulated by sport participation.

Section snippets

Methods

The data presented in this study were collected from the baseline measures of a cohort study, which is being carried out in the city of Presidente Prudente (200 000 inhabitants; western Sao Paulo State, Brazil). This study started in the second half of 2013 and has follow-up measures scheduled for the second half of 2014 (August/September). Before data collection, the minimum sample size was calculated11 based on previous data about the expected relationship between cIMT and hsCRP (r = 0.28,

Results

The characteristics of the adolescents stratified according to hsCRP tertiles are presented in Table I. Maturity offset ranged from −6.07 years to −0.86 years to APHV and sports practice was reported by 50% (95% CI 41.1%-58.9%) of the sample. Among the adolescents who engaged in organized sports participation, the number of steps/day was marginally related to HDL-c (r = 0.24 [−0.01 to 0.46]).

Adolescents with grater hsCRP had increased values of body mass (P = .001), body mass index (P = .001),

Discussion

In these adolescents, inflammatory markers and trunk fatness were significantly related. This finding is particularly interesting because this relationship occurred before the growth spurt.16 This finding is potentially concerning because the natural increase of adipose tissue observed throughout maturational events16 might exacerbate the harmful relationship between body fatness and inflammation already present during adolescence.17, 18 Inflammation is commonly related to increased body

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    Funded by the State of São Paulo Research Support Foundation (FAPESP [Process: 2013/06052-2]) and CNPq (Process: 476295/2013-0). The authors declare no conflicts of interest.

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