PCV32 Population Attributable Risk (PAR) of Macrovascular Events Associated with HbA1C, Blood Pressure or Weight in Patients with Type 2 Diabetes Mellitus: Evidence from a Dutch Cohort

To determine the population attributable risk (PAR) of macrovascular events associated with HbA1c, systolic blood pressure (SBP), or weight (BMI) in patients with type 2 diabetes mellitus (T2DM). The population-based PHARMO database contains T2DM patients regularly monitored in primary care for cardiovascular risk factors HbA1c, SBP and BMI. In the period 2000-2008 patients without baseline macrovascular events and on antidiabetic treatment for ≥6 months were followed from start of monitoring until monitoring ended. Multivariate survival modeling of the composite outcome of macrovascular events was used to estimate the expected number of events after 5 years, either with unchanged risk factors (base-case) or with reductions in risk factors. The PAR was calculated as the number of averted events divided by the number of expected events in the base-case analysis. Mean age of 5841 included patients was 66 years (55% male), 45% had HbA1c levels ≥7%, 66% had a SBP ≥140 mmHg and 85% had a BMI >25 kg/m2. The base case expected number of macrovascular events at 5 years was 796, and 687 after reduction to target of all 3 risk factors. The combined PAR of elevated HbA1c, SBP and BMI was 14%, ranging from 5% among those with one elevated risk factor to 21% among those with three risk factors elevated. Incremental reductions of 0.5% HbA1c, 10mmHg SBP and 10% BMI led to 4% fewer events, ranging from 2-10%. The PAR of reducing HbA1c to target (7%) was 5%, ranging from 2-10%. The PAR of reducing SBP to target (135 mmHg) was 9%, ranging from 3-12%. There was no effect of reduction in BMI alone. Reducing elevated HbA1c and blood pressure levels was associated with improvements in cardiovascular risk. Even modest reductions in risk factors lead to significant reductions in macrovascular events in T2DM patients.