title: Low muscle mass is associated with cardiometabolic risk regardless of nutritional status in adolescents: A cross-sectional study in a Chilean birth cohort.
abstract: BACKGROUND
  Increased cardiometabolic risk (CMR) is documented in obese and non-obese adolescents with low muscular fitness. However, the association of low muscle mass (LMM) with CMR, independent of weight status, has not been examined. We analyzed the relationship of LMM with CMR in adolescents, regardless of their weight status.
  
  
  METHODS
  Observational study in 660 adolescents. BMI, waist circumference (WC), arterial blood pressures (ABP) were measured. Total fat mass (TFM), total lean tissue (TLT), and appendicular skeletal muscle mass (ASM) were estimated (DXA). Fasting lipid profile, glucose, and insulin were measured. HOMA-IR was estimated. Metabolic Syndrome (MetS) was diagnosed (AHA/NHLBI/IDF). ROC analysis was performed to find the optimal cutoffs of TLT percentage for MetS diagnosis. Values below these cutoffs defined LMM. ANCOVA examined the association of LMM with selected cardiometabolic biomarkers.
  
  
  RESULTS
  In both sexes, TLT showed better sensitivity and specificity than ASM for MetS diagnosis. In males and females, TLT of 66.1% and 56.3%, respectively, were the optimal cutoff for MetS diagnosis. In the sample, 17.3% of males and 23.7% of females had LMM. In both sexes, adolescents with LMM had significantly higher values of WC, ABP, TG, TC/HDL, HOMA-IR, and MetS z-score than non-LMM participants. Adolescents with LMM, regardless nutritional status, had significantly increased values of MetS z-score, ABP, TG, TC/HDL-chol, and HOMA-IR than non-obese non-LMM adolescents. Adolescents having both obesity and LMM had the unhealthiest CMR profile.
  
  
  CONCLUSIONS
  In adolescents, LMM was associated with higher CMR, regardless of nutritional status. In obese adolescents, LMM increased obesity-associated CMR.
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: R
authors.identifier: http://orcid.org/0000-0001-9155-0689
authors.initials: R
authors.lastname: Burrows
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: P
authors.initials: P
authors.lastname: Correa-Burrows
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: M
authors.initials: M
authors.lastname: Reyes
authors.affiliation: Division of Child Development and Community Health, University of California San Diego, La Jolla, California.
authors.forename: E
authors.initials: E
authors.lastname: Blanco
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Albala
authors.affiliation: Division of Child Development and Community Health, University of California San Diego, La Jolla, California.
authors.forename: S
authors.initials: S
authors.lastname: Gahagan
mesh_terms: D000293:Adolescent; D001823:Body Composition; D002677:Chile / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000209:etiology; D018482:Muscle, Skeletal; D009752:Nutritional Status; D009765:Obesity / Q000150:complications; D018570:Risk Assessment
keywords: adolescents; cardiometabolic risk; low lean mass; metabolic syndrome; obesity