Prediabetes Phenotype Influences Improvements in Glucose Homeostasis with Resistance Training

PurposeTo determine if prediabetes phenotype influences improvements in glucose homeostasis with resistance training (RT).MethodsOlder, 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).ResultsChest press and leg press strength increased 27% and 18%, respectively, following the 12-week RT program (both pp>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, pConclusionsRT 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.Trial RegistrationClinicalTrials.gov: NCT01112709