title: Cardiometabolic plasticity in response to a short-term diet and exercise intervention in young Hispanic and nonHispanic white adults.
abstract: BACKGROUND
  Young adult Mexican Americans (MA) exhibit lower insulin sensitivity (Si) than nonHispanic whites (NHW), even when controlling for fitness and adiposity. It is unclear if MA are as responsive to the same lifestyle intervention as NHW.
  
  
  OBJECTIVE
  We developed a model to examine cardiometabolic plasticity (i.e., changes in Si and plasma lipids) in MA compared to NHW adults in response to a diet-exercise intervention.
  
  
  METHODS
  Sedentary subjects (20 NHW: 11F, 9M, 23.0 y, 25.5 kg/m(2); 17 MA: 13F, 4M, 22.7 y, 25.4 kg/m(2)) consumed their habitual diets and remained sedentary for 7 days, after which fasting blood samples were obtained, and a 3-h intravenous glucose tolerance test (IVGTT) was performed with the insulin area under the curve (IAUC) used to estimate Si. Subjects then completed a 7-day diet/exercise intervention (diet: low saturated fat, low added sugar, high fiber; exercise: cycling, six total sessions lasting 40-45 min/session at 65% VO(2) max). Pre-intervention tests were repeated.
  
  
  RESULTS
  Pre intervention IAUC was 28% higher (p<0.05) in MA (IAUC pre  =  2298 µU*180 min/mL) than in NHW (IAUC = 1795 µU*180 min/mL). Following the intervention, there was a significant reduction in IAUC in MA (29%) and NHW (32%), however, the IAUC remained higher (p<0.05) for MA (post  = 1635 µU*180 min/mL) than for NHW (post = 1211 µU*180 min/mL). Pre test plasma lipids were not different in MA compared to NHW. Plasma cholesterol and TG concentrations significantly improved in both groups, but concentrations of low density lipoprotein-cholesterol and small dense LDL particles significantly improved only in the NHW.
  
  
  CONCLUSIONS
  With a short-term diet-exercise intervention, the magnitude of improvements in Si and serum cholesterol and TG in Hispanics are similar to those in NHW. However, because at the outset MA were less insulin sensitive compared to NHW, within the short timeframe studied the ethnic gap in insulin sensitivity remained.
authors.affiliation: Nutrition and Metabolic Fitness Laboratory, Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Stacy L
authors.initials: SL
authors.lastname: Schmidt
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Hickey
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Koblenz
authors.forename: Holly
authors.initials: H
authors.lastname: Klamer
authors.forename: Maria F
authors.initials: MF
authors.lastname: Botero
authors.forename: Kyle T
authors.initials: KT
authors.lastname: Pfaffenbach
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pagliassotti
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Melby
mesh_terms: D000328:Adult; D000367:Age Factors; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D004038:Diet, Reducing; D005081:Exercise Therapy; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D050356:Lipid Metabolism / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D008659:Metabolic Diseases / Q000208:ethnology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D012307:Risk Factors; D013997:Time Factors; D044465:White People; D055815:Young Adult
chemical_list: D008055:Lipids