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

Aim: The overall aim was to study the effect of physical activity in individual with 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 individuals with IGT; 3. Study the association between self-reported physical activity and circulating concentrations of the inflammatory marker CRP in IGT-subjects; 4. Study the predictive value of insulin resistance on cardiovascular disease (CVD) in individuals without diabetes considering 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 impaired glucose metabolism in primary care. Fifty-two individuals with IGT participated in an explorative randomized controlled trial 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 they were characterized with anthropometry blood sampling for estimation of HOMA, random blood glucose and an OGTT. Validated questionnaires on lifestyle were completed. The participants were restudied after 8 years and information on hosipital care for CVD diagnoses and mortality was collected. Results: The FINDRISC questionnaire was sent out to 9734 individuals and was found to have a positive predictive value (PPV) for impaired glucose metabolism of 55% but was less efficient to identify IGT-subjects (PPV=16%). The short questionnaire might be used as an additive tool for screening at the Health Care Unit or in an advertisement. Our method to implement physical activity in individuals with IGT showed tendencies to decrease body weight, waist circumference and sagittal diameter, 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, such as jogging or swimming ≥ 2 hrs/week eliminated the apparent increased risk of insulin-resistant male individuals to develop CVD. Conclusions: FINDRISC is an efficient screening tool for detection of undiagnosed individuals with impaired glucose metabolism while the opportunistic screening method was less efficient but may be used as an additive tool in primary care. Our intervention method aiming at an increased physical activity also induced less calorie intake in IGT-subjects. However, the collective lifestyle changes observed with intensive care decreased waistcircumference and sagittal diameter compared with individuals with IGT given usual care. Finally, more vigorous physical activity than generally recommended may be required to limit subclinical inflammation in male IGT-subjects and to protect male insulinresistant individuals from developing cardiovascular disease.