title: Prediabetes Phenotype Influences Improvements in Glucose Homeostasis with Resistance Training.
abstract: OBJECTIVE
  To determine if prediabetes phenotype influences improvements in glucose homeostasis with resistance training (RT).
  
  
  METHODS
  Older, overweight individuals with prediabetes (n = 159; aged 60±5 yrs; BMI 33±4 kg/m2) completed a supervised RT program twice per week for 12 weeks. Body weight and composition, strength, fasting plasma glucose, 2-hr oral glucose tolerance, and Matsuda-Defronza estimated insulin sensitivity index (ISI) were assessed before and after the intervention. Participants were categorized according to their baseline prediabetes phenotype as impaired fasting glucose only (IFG) (n = 73), impaired glucose tolerance only (IGT) (n = 21), or combined IFG and IGT (IFG/IGT) (n = 65).
  
  
  RESULTS
  Chest press and leg press strength increased 27% and 18%, respectively, following the 12-week RT program (both p<0.05). Waist circumference (-1.0%; pre 109.3±10.3 cm, post 108.2±10.6 cm) and body fat (-0.6%; pre 43.7±6.8%, post 43.1±6.8%) declined, and lean body mass (+1.3%; pre 52.0±10.4 kg, post 52.7±10.7 kg) increased following the intervention. Fasting glucose concentrations did not change (p>0.05) following the intervention. However, 2-hr oral glucose tolerance improved in those with IGT (pre 8.94±0.72 mmol/l, post 7.83±1.11 mmol/l, p<0.05) and IFG/IGT (pre 9.66±1.11mmol/l, post 8.60±2.00 mmol/l) but not in those with IFG (pre 6.27±1.28mmol/l, post 6.33± 1.55 mmol/l). There were no significant changes in ISI or glucose area under the curve following the RT program.
  
  
  CONCLUSIONS
  RT without dietary intervention improves 2-hr oral glucose tolerance in individuals with prediabetes. However, the improvements in glucose homeostasis with RT appear limited to those with IGT or combined IFG and IGT.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT01112709.
authors: Department of Internal Medicine, Carilion Clinic-Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States of America.
authors: Joshua D
authors: JD
authors: Eikenberg
authors: Center for Gerontology & Department of Human Development, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Jyoti
authors: J
authors: Savla
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Elaina L
authors: EL
authors: Marinik
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Kevin P
authors: KP
authors: Davy
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: John
authors: J
authors: Pownall
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Mary E
authors: ME
authors: Baugh
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Kyle D
authors: KD
authors: Flack
authors: Department of Internal Medicine, Carilion Clinic-Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States of America.
authors: Soheir
authors: S
authors: Boshra
authors: Department of Psychology, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Richard A
authors: RA
authors: Winett
authors: Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States of America.
authors: Brenda M
authors: BM
authors: Davy
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000378:metabolism*; D055070:Resistance Training / Q000379:methods*
chemical_list: D001786:Blood Glucose; D005947:Glucose