Intensive multifactorial intervention improves modelled coronary heart disease risk in screen-detected Type 2 diabetes mellitus: a cluster randomized controlled trial

Aims: To compare the effects of intensive multifactorial cardiovascular risk intervention with standard care in screen-detected Type 2 diabetes.

Methods: Twenty general practices randomly invited 30 950 adults without diagnosed diabetes for screening (World Health Organization, 1999). In a cluster randomized controlled trial, screen-detected cases were assigned by practice allocation to receive intensive protocol-driven cardiovascular risk management (n = 146) or standard care (n = 199) according to local guidelines. Intensive intervention was designed to achieve an HbA(1c) of 48 mmol/mol (6.5%), blood pressure < 130/80 mmHg and total cholesterol < 3.5 mmol/l. Primary outcome was modelled 5-year coronary heart disease risk (UKPDS-CHD). Analysis was via intention to treat.

Results: After 1.1 years 339 (98%) individuals were still participating. There were significant reductions in HbA(1c) , blood pressure and total cholesterol from baseline in both groups [mean change for total study population -27.7 mmol/mol (-0.62%), -11.64/10.01 mmHg, -1.11 mmol/l]. After adjustment for baseline and clustering, significant inter-group differences were observed in mean changes from baseline for HbA(1c) {-28.5 mmol/mol [-0.7% (1.4)] vs. -27.5 mmol/mol [-0.6% (1.6)], P = 0.001}, blood pressure [systolic -16.2 (19.6) vs. -8.4 (18.6) mmHg, P < 0.001], total cholesterol [-1.3 (1.3) vs. -1.0 (1.2) mmol/l, P < 0.001] and weight [-3.8 (5.5) vs. -2.2 (5.5) kg, P = 0.01] in favour of intensive treatment. UKPDS 5-year coronary heart disease risk was reduced by 3.2% and 2.3%, respectively (P < 0.0001). Intensive intervention was associated with more lipid-lowering and anti-hypertensive but not hypoglycaemic medication use [odds ratios 2.5 (1.4-4.4), 5.5 (2.4-11.5), 1.6 (0.8-2.3); compared with standard care, P < 0.001, P = 0.003, P = 0.65]. Treatment satisfaction responses were superior with intensive intervention, with no increase in self-reported hypoglycaemia.

Conclusion: Intensive intervention in patients with diabetes identified through systematic non-risk-factor-based screening significantly reduces modelled coronary heart disease risk. This is achieved predominantly with lipid-lowering and anti-hypertensive treatments with no adverse effect on quality of life or hypoglycaemia.