title: Does endurance training affect IGF-1/IGFBP-3 and insulin sensitivity in patients with type 2 diabetes?
abstract: OBJECTIVE
  The aim of the present study was to determine whether six weeks of submaximal endurance training using a cycle ergometer would result in a modified serum insulin-like growth factor-1 (IGF-1), an insulin-like growth factor binding protein 3 (IGFBP-3), and insulin resistance in middle-aged men with type 2 diabetes (T2D).
  
  
  METHODS
  Twenty male patients with T2D voluntarily participated in this study and were randomly divided into two groups: the training group (N.=10) and the control group (N.=10). The training protocol consisted of a 45-minutes cycling session/day, three days/week for six weeks with intensity 60-70% of the maximum heart rate. To examine the IGF-1 and the IGFBP-3, fasting blood glucose levels, and insulin resistance, blood sampling was performed before and immediately after the first and 18th sessions. The homeostatic model assessment (HOMA-IR) method was used to determine insulin resistance.
  
  
  RESULTS
  Before the study began, no significant difference between the two groups was observed in the anthropometric and blood factors. After a session of aerobic exercise, IGF-1 and IGFBP-3 levels were significantly increased (153.79% and 64.3%, respectively), and fasting glucose and insulin resistance levels were significantly decreased (15.82% and 27.82%, respectively); however, the changes resulting from a six-week training period were not significant.
  
  
  CONCLUSIONS
  According to the present study, one session of aerobic exercise for middle-aged men with T2D leads to increased IGF-1 and IGFBP-3, and to decreased fasting glucose and insulin resistance. Considering the lack of changes after a six-week training, it seems that the amount of change depends on subjects' fitness level and exercise parameters. From a clinical point of view, the beneficial effects of acute exercise inT2D subjects show that such exercises should be part of the daily program for them.
authors: Endocrinology and Metabolic Research Institute of Tehran University of Medical sciences Tehran Shariati Hospital, Tehran, Iran - Kahrizis@modares.ac.ir.
authors: M R
authors: MR
authors: Mohajeri Tehrani
authors: M
authors: M
authors: Tajvidi
authors: S
authors: S
authors: Kahrizi
authors: M
authors: M
authors: Hedayati
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D011897:Random Allocation
chemical_list: D001786:Blood Glucose; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I