title: Longitudinal factor analysis reveals a distinct clustering of cardiometabolic improvements during intensive, short-term dietary and exercise intervention in obese children and adolescents.
abstract: OBJECTIVE
  The aim of this study was to investigate changes in cardiometabolic clustering characteristics in response to highly significant weight loss.
  
  
  BACKGROUND
  Pre-post analysis of a lifestyle intervention for the treatment of obesity and the assessment of interrelated metabolic changes were analyzed using principal component analysis (PCA). A total of n=75 clinically obese boys and girls [standardized body mass index (sBMI) 3.07±0.59] aged 8-18 years were assessed after lifestyle intervention (30±12 days).
  
  
  RESULTS
  There were favorable improvements in BMI waist circumference, fasting insulin, triglycerides (TGs), systolic blood pressure (SBP) and diastolic blood pressure (DBP) (all P<0.001). PCA was performed using a simple conceptual model of changes in six metabolic variables: Overall and central obesity (BMI and waist circumference), dyslipidemia [TG and high-density lipoprotein cholesterol (HDL-C)], insulin resistance [fasting insulin or homeostasis model assessment of insulin resistance (HOMA-IR)], and blood pressure [SBP or mean arterial pressure (MAP)]. PCA models consistently identified two factors underlying the changes in six cardiometabolic variables. These were labeled a "metabolic" factor, typically including waist circumference, fasting triglyceride, insulin, or HOMA-IR and HDL-C (negatively) and an "obesity/blood pressure" factor, typically loading waist, BMI, SBP or MAP, and occasionally fasting insulin/HOMA-IR). The metabolic and obesity/blood pressure factors explained 26.5%-28.4% and 30.4%-31.9%, of the variance in metabolic risk factors changes, respectively. Reductions in BMI, waist circumference, and HOMA-IR (or fasting insulin) were central underlying features of cardiometabolic changes.
  
  
  CONCLUSIONS
  There were significant and favorable cardiometabolic risk factor changes to short-term weight-loss. A distinct clustering of cardiometabolic responses supports the etiological importance of both overall and central obesity and insulin resistance in the modification of cardiometabolic risk in obese youths.
authors.affiliation: Department of Academic Cardiology, Castle Hill Hospital, Hull, United Kingdom. james.hobkirk@hey.nhs.uk
authors.forename: James P
authors.initials: JP
authors.lastname: Hobkirk
authors.forename: Roderick F
authors.initials: RF
authors.lastname: King
authors.forename: Paul
authors.initials: P
authors.lastname: Gately
authors.forename: Philip
authors.initials: P
authors.lastname: Pemberton
authors.forename: Alexander
authors.initials: A
authors.lastname: Smith
authors.forename: Julian H
authors.initials: JH
authors.lastname: Barth
authors.forename: Sean
authors.initials: S
authors.lastname: Carroll
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D015992:Body Mass Index; D031204:Caloric Restriction; D002648:Child; D016000:Cluster Analysis; D004739:England; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy / Q000503:physiopathology / Q000628:therapy*; D010641:Phenotype; D025341:Principal Component Analysis; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D055105:Waist Circumference; D015431:Weight Loss
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids