title: Effect of 12-week resistance exercise program on body composition, muscle strength, physical function, and glucose metabolism in healthy, insulin-resistant, and diabetic elderly Icelanders.
abstract: BACKGROUND
  Insulin is a stimulator of skeletal muscle protein anabolism and insulin resistance might therefore negatively affect muscle protein metabolism. We investigated muscle mass and physical function before and after a resistance exercise program in participants with prediabetes or type 2 diabetes mellitus (T2DM) in comparison to healthy controls.
  
  
  METHODS
  This was a secondary analysis of a randomized controlled intervention designed to investigate resistance training among older adults. Glucose metabolism status was not a selection criteria for the trial, and group designation was done retrospectively. Participants (N = 237, 73.7 ± 5.7 y, 58.2% women) participated in a 12-week resistance exercise program (3 times/week; three sets, six to eight repetitions at 75%-80% of the one-repetition maximum), designed to increase strength and muscle mass of major muscle groups. Body composition, muscular strength, timed up and go test, 6-minute walk for distance, and blood chemical variables were measured at baseline and endpoint.
  
  
  RESULTS
  Participants completing the study (n = 213) experienced significant changes in muscle strength or muscle function, which did not differ significantly between healthy (n = 198), prediabetic (n = 20), and T2DM participants (n = 17). Changes in serum glucose during the intervention differed by group: only glucose improved significantly in the prediabetic group, glucose and triacylglycerol improved significantly in the healthy group, whereas no serum parameter improved significantly in the T2DM group.
  
  
  CONCLUSIONS
  A 12-week resistance exercise program improves muscle strength and muscle function to a similar extent in healthy, prediabetic, and T2DM elderly people. However, according to our data, T2DM participants do not experience favorable changes in fasting glucose or HbA(1C).
authors.affiliation: Unit for Nutrition Research, Eiriksgata 29, Landspitali National University Hospital, IS-101 Reykjavik, Iceland. olofgg@landspitali.is
authors.forename: O G
authors.initials: OG
authors.lastname: Geirsdottir
authors.forename: A
authors.initials: A
authors.lastname: Arnarson
authors.forename: K
authors.initials: K
authors.lastname: Briem
authors.forename: A
authors.initials: A
authors.lastname: Ramel
authors.forename: P V
authors.initials: PV
authors.lastname: Jonsson
authors.forename: I
authors.initials: I
authors.lastname: Thorsdottir
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007055:Iceland; D007333:Insulin Resistance / Q000502:physiology; D016014:Linear Models; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology; D011236:Prediabetic State / Q000175:diagnosis / Q000628:therapy*; D015397:Program Evaluation; D012016:Reference Values; D055070:Resistance Training / Q000458:organization & administration*; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D005947:Glucose