Randomised controlled trial evaluating the effectiveness of behavioural interventions to modify cardiovascular risk factors in men and women with impaired glucose tolerance: outcomes at 6 months

Aims: To evaluate the efficacy of interventions to promote a healthy diet a nd physical activity in people with impaired glucose tolerance (IGT). Metho ds: A randomised controlled trial in Newcastle upon Tyne, UK. 1995-98. Part icipants included 67 adults (38 men: 29 women) aged 24-75 years with IGT. T he intervention consisted of regular diet and physical activity counselling based on the stages of change model. Main outcome measures were changes be tween baseline and 6 months in nutrient intake; physical activity; anthropo metric and physiological measurements including serum lipids; glucose toler ance: insulin sensitivity. Results: The difference in change in total fat c onsumption was significant between intervention and control groups (differe nce - 21.8 (95% confidence interval (CI) - 37.8 to - 5.8) g/day, P = 0.008) . A significantly larger proportion of intervention participants: reported taking up vigorous activity than controls (difference 30.1. (95% CI 4.3-52. 7)%, P = 0.021). The change in body mass index was significantly different between groups (difference - 0.95 (95% CI - 1.5 to - 0.4) kg/m(2), P = 0.00 1). There was no significant difference in change in mean 2-h plasma glucos e between groups (difference - 0.19 (95% CI - 1.1 to 0.71) mmol/l, NS) or i n serum cholesterol (difference 0.02 (95% CI - 0.26 to 0.31) mmol/l, NS). T he difference in change in fasting serum insulin between groups was signifi cant (difference - 3.4 (95% CI - 5.8 to -1.1) mU/l, P = 0.005). Conclusions : After 6 months of intensive lifestyle intervention in participants with I GT. there were changes in diet and physical activity, some cardiovascular r isk factors and insulin sensitivity, but not glucose tolerance.