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. 2015 Jan 15;10(1):e0116506.
doi: 10.1371/journal.pone.0116506. eCollection 2015.

BMI as a mediator of the relationship between muscular fitness and cardiometabolic risk in children: a mediation analysis

Ana Díez-Fernández  1 , Mairena Sánchez-López  2 , Roberto Gulías-González  3 , Blanca Notario-Pacheco  4 , Jorge Cañete García-Prieto  4 , Natalia Arias-Palencia  4 , Vicente Martínez-Vizcaíno  5
Affiliations

BMI as a mediator of the relationship between muscular fitness and cardiometabolic risk in children: a mediation analysis

Ana Díez-Fernández et al. PLoS One. .

Abstract

Objective: Muscular fitness levels have been associated with cardiometabolic risk in children, although whether body weight acts as a confounder or as an intermediate variable in this relationship remains controversial. The aim of this study was to examine whether the association between muscular fitness and cardiometabolic risk factors is mediated by body mass index (BMI).

Design and methods: Cross-sectional study using a sample of 1158 schoolchildren aged 8-11 years from the province of Cuenca, Spain. We measured anthropometrics and biochemical variables and we calculated a muscular fitness index as the sum of z-scores of handgrip dynamometry/weight and standing long jump, and we estimated a previously validated cardiometabolic risk index (CMRI). Linear regression models were fitted for mediation analysis to assess whether the association between muscular fitness and cardiometabolic risk was mediated by BMI.

Results: Children with normal weight (NW) had a better cardiometabolic risk profile than their overweight (OW) or obese (OB) peers after controlling for muscular fitness. Marginal estimated mean ± SE values for NW, OW and OB categories of CMRI were -0.75 ± 0.06 < 0.84 ± 0.10 < 2.18 ± 0.16 in boys and -0.73 ± 0.06 < 0.96 ± 0.10 < 2.71 ± 0.17 in girls, both p < 0.001. Children with higher levels of muscular fitness had a better cardiometabolic risk profile (CMRI marginal estimated mean ± SE 1.04 ± 0.13 > 0.05 ± 0.09 >-1.16 ± 0.13 for lower, middle and upper quartiles of muscular fitness in boys and 1.01 ± 0.16 > 0.10 ± 0.09 > -1.02 ± 0.15 in girls, both p < 0.001), but differences disappeared when controlling for BMI. BMI acted as a full mediator between muscular fitness and most cardiometabolic risk factors (Sobel test z = -11.44 for boys; z = -11.83 for girls; p < 0.001 in CMRI mediation model) and as a partial mediator in the case of waist circumference (Sobel test z=-14.86 for boys; z=-14.51 for girls; p<0.001).

Conclusions: BMI mediates the association between muscular fitness and cardiometabolic risk in schoolchildren. Overall, good muscular fitness is associated with lower cardiometabolic risk, but particularly when accompanied by normal weight.

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Conflict of interest statement

Competing Interests: All authors have completed the ICMJE uniform disclosure form at (www.icmje.org/coi_disclosure.pdf) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous years; no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. BMI mediation models of the relationship between muscular fitness and cardiometabolic risk variables, controlling for age, by sex.
A: MAP; B: log fasting insulin; C: log TG/HDL-c; D: WC; E: CMRI. Data in roman type refer to boys. %Med: Percentage mediated by proposed mediator. Data in italics refer to girls. **p≤0.001; *p≤0.05.
See this image and copyright information in PMC

References

    1. Alberti KG, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, et al. (2009) Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation 120: 1640–1645. - PubMed
    1. Marcovecchio ML, Chiarelli F (2013) Metabolic syndrome in youth: chimera or useful concept? Curr Diab Rep 13: 56–62. 10.1007/s11892-012-0331-2 - DOI - PubMed
    1. Bao W, Srinivasan SR, Wattigney WA, Berenson GS (1994) Persistence of multiple cardiovascular risk clustering related to syndrome X from childhood to young adulthood. The Bogalusa Heart Study. Arch Intern Med 154: 1842–1847. - PubMed
    1. Andersen LB, Wedderkopp N, Hansen HS, Cooper AR, Froberg K (2003) Biological cardiovascular risk factors cluster in Danish children and adolescents: the European Youth Heart Study. Prev Med 37: 363–367. 10.1016/S0091-7435(03)00145-2 - DOI - PubMed
    1. Sinaiko AR, Donahue RP, Jacobs DR, Prineas RJ (1999) Relation of weight and rate of increase in weight during childhood and adolescence to body size, blood pressure, fasting insulin, and lipids in young adults. The Minneapolis Children’s Blood Pressure Study. Circulation 99: 1471–1476. - PubMed

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