DIAVIP - Diabetes Prevention in Primary Care - Implications for Physical Activity

Abstract

Aim: The overall aim was to study the effect of physical activity in impaired glucose tolerance (IGT) and insulin resistance. We set out to: 1. Evaluate different screening instruments to identify individuals with IGT; 2. Study feasibility and metabolic effects of an intervention focusing on physical activity in IGT-subjects; 3. Study the association between self-reported physical activity and subclinical inflammation in individuals with IGT; 4. Study the predictive value of insulin resistance on cardiovascular disease (CVD) in non-diabetic individuals and the modifying effect of physical activity. Methods: Paper I, II and III: The FINDRISC questionnaire was delivered by mail to people in the Skaraborg County. Individuals with a risk-score ≥15 underwent testing of their fasting blood glucose and an oral glucose tolerance test (OGTT, 75 g). In addition, opportunistic screening by asking three short questions was used to identify individuals with IGT. Fifty-two individuals participated in a randomized controlled trial (RCT) comparing two different interventions focusing on increased physical activity with usual care. The participants were metabolically phenotyped at baseline and after one year. Paper IV and V: A population-based survey was performed 2002 – 2005 in the Skaraborg County. A total of 2816 individuals 35-75 years old participated and characterized with anthropometry, blood sampling and an OGTT. Questionnaires on diet and lifestyle were completed. The participants were restudied after 8 years and information on CVD diagnoses and mortality in the cohort was collected. Results: The FINDRISC questionnaire was sent out to 9734 individuals and was found to be predictive of impaired glucose metabolism (55%) but was less efficient to identify individuals with IGT (16%). Our method to implement physical activity in IGT-subjects showed tendencies to decrease body weight, waist circumference and sagittal diameter, when adjusted for changes in dietary intake, in the intensive care group compared with the basic care and the control groups. Vigorous self-reported physical activity eliminated the difference observed in circulating CRP concentrations in male IGT-subjects compared with men showing normal glucose tolerance. Finally, data from the same Skaraborg cohort showed that self-reporting a high level of leisure time physical activity eliminated the apparent increased risk of insulinresistant male individuals to develop CVD. Conclusions: FINDRISC is an efficient screening tool for detection of individuals with impaired glucose metabolism while the opportunistic screening method may be used as an additive tool in primary care. The intervention with focus on physical activity decreased several metabolic risk factors and induced changes in diet. Finally, self-reported physical activity was shown to associate with limited subclinical inflammation in individuals with IGT and was also related to the predictive value of insulin resistance with regard to development of CVD.