title: A lifestyle intervention in primary care prevents deterioration of insulin resistance in patients with impaired glucose tolerance: A randomised controlled trial.
abstract: OBJECTIVE
  We hypothesised that the expected increase in insulin resistance over three years' time in individuals with impaired glucose tolerance (IGT) and/or impaired fasting glucose could be attenuated by an intervention with focus on physical activity in ordinary primary care.
  
  
  METHODS
  We conducted a randomised controlled trial with 96 participants over three years. Examination of the participants included anthropometric measures, blood pressure, body weight and height, blood samples, an oral glucose tolerance test, and questionnaires about diet and lifestyle. The study subjects were randomised to either an intense intervention with information, group sessions, referral to physical activity and a step-counter ( n = 31), a less intense intervention without the group sessions ( n = 35), or care as usual group (CAUG) ( n = 30). Differences between the groups were analysed with general linear models adjusted for age, gender, baseline values and time in the intervention.
  
  
  RESULTS
  Individual insulin resistance increased in the CAUG. Due to having a similar effect, we combined the two intervention groups into a combined intervention group (CIG; n = 66) in the analyses. In individuals with IGT, the increase in the homeostatic model assessment-insulin resistance differed significantly between those in the CAUG and the CIG (Δ = 0.8; CI: 0.1-1.6; p = 0.034). Likewise, diastolic blood pressure decreased more in the CIG than in the CAUG (Δ = 5.1; CI: 0.1-10.0; p = 0.047). A total of 17 individuals developed Type 2 diabetes, 23% were in the CIG and 33% in the CAUG; so there was a 32% reduced risk in the intervention group.
  
  
  CONCLUSIONS
  A lifestyle intervention focused on physical activity is feasible in ordinary primary care and prevents deterioration in insulin sensitivity in individuals with IGT over a three-year period.
authors.affiliation: 1 Department of Public Health and Community Medicine/Primary Health Care, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Margareta I
authors.initials: MI
authors.lastname: Hellgren
authors.affiliation: 2 Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Per-Anders
authors.initials: PA
authors.lastname: Jansson
authors.affiliation: 3 The Nordic School of Public Health, the University of Gothenburg.
authors.forename: Hans
authors.initials: H
authors.lastname: Wedel
authors.affiliation: 1 Department of Public Health and Community Medicine/Primary Health Care, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Lindblad
keywords: Type 2 diabetes; early intervention; fasting glucose; glucose tolerance; insulin; insulin resistance; lifestyle intervention; physical activity; primary health care; randomised controlled trial