How much might cardiovascular disease risk be reduced by intensive therapy in people with screen-detected diabetes?

Aims: To assess the cardiovascular disease (CVD) risk of people with screen-detected Type 2 diabetes and to estimate the risk reduction achievable through early intensive pharmacological intervention. Methods: In ADDITION-Cambridge, diabetic patients were identified among people aged 40-69 years through a stepwise screening procedure including a risk score, random and fasting capillary blood glucose, HbA_1c and oral glucose tolerance test. In those without prior macrovascular disease, 10-year CVD risk was computed using UK Prospective Diabetes Study (UKPDS) and Framingham engines. The absolute risk reduction achievable and its plausible range were predicted using relative risk reductions for individual therapies from published trials and sensitivity analysis. Results: Of the 867 individuals with undiagnosed diabetes, 19% had pre-existing CVD, 97% were overweight or obese, 86% had hypertension, 75% had dyslipidaemia, 20% had microalbuminuria and 18% were smokers. Of those with hypertension, 35% were not prescribed drugs and 42% were suboptimally treated. Of participants with dyslipidaemia, 68% were not prescribed medications and 22% were poorly controlled. Median 10-year CVD risk was 34.0% [interquartile range (IQR) 26.2-44.6] in men and 21.5% (IQR 15.7-28.7) in women using the UKPDS engine; 38.6% (IQR 27.8-53.0) in men and 24.6% (IQR 17.2-32.9) in women using Framingham equations. In the most conservative scenario (no additive effect of therapies), the absolute risk reduction achievable through multifactorial therapy ranged from 4.9 to 9.5% (UKPDS) and from 5.4 to 10.5% (Framingham). The corresponding ranges of numbers needed to treat were 11-20 and 10-19. Conclusions: People with screen-detected diabetes have an adverse cardiovascular risk profile, which is potentially modifiable through application of existing treatment recommendations.