Original researchEffectiveness of a brief theory-based health promotion intervention among adults at high risk of type 2 diabetes: One-year results from a randomised trial in a community setting

•Strong evaluations of brief diabetes prevention interventions were lacking.•A brief theory-based health promotion intervention was delivered in routine care.•The effect was evaluated in a randomised trial.•1-year follow-up indicated effect on weight, waist and systolic blood pressure.

AimTo examine the effect of a brief theory-based health promotion intervention delivered in the community on health behaviour and diabetes-related risk factors among Danish adults at high risk of diabetes.MethodsA randomised trial was conducted among 127 individuals aged 28 to 70 with fasting plasma glucose: 6.1-6.9 mmol/l and/or HbA1c: 6.0-<6.5% (42- < 48 mmol/mol) recruited from general practice in Holstebro, Denmark. Participants were randomised to a control group or to receive the intervention delivered over four 2 h group sessions during five weeks, and two further sessions after one and six months. Questionnaire data and clinical measures were collected at baseline, three months and one year after intervention. Primary outcomes; total-fat intake <30% of energy intake; saturated-fat intake <10% of energy intake; fibre-intake≥15 g/1000 kcal; weight reduction >5%; changes in physical activity.Results85% attended one-year follow-up. After adjusting for gender, age and education, Odds ratio (OR) (95% CI) intervention vs control: total-fat intake <30% energy intake: 0.52 (0.22;1.20), saturated-fat intake <10% energy intake: 1.22 (0.52;2.87), fibre intake ≥15 g/1000 kcal: 1.18 (0.48;2.92), weight reduction >5%: 2.47 (0.95;6.39). β(95% CI) between intervention vs control in changes from baseline: IPAQ, MET min/week: −236 (−2760; 2288), waist circumference,cm: −2.5 (−4.5; −0.5); systolic blood pressure, mmHg: −4.6 (−8.8; −0.3).ConclusionA brief theory-based health promotion intervention delivered in the community indicated effect on weight, waist circumference and systolic blood pressure at one year among Danish adults at high risk of diabetes. No effect was shown on diets or physical activity.