Blood pressure levels and risk of cardiovascular events and mortality in type-2 diabetes: cohort study of 34 009 primary care patients.

OBJECTIVE

The optimal blood pressure (BP) in persons with type-2 diabetes is debated. We investigated shapes of the associations of SBP and DBP levels with risk of cardiovascular events and mortality in a large primary care-based sample of diabetic patients.

METHODS

We investigated all 34 009 consecutive cardiovascular disease-free type-2 diabetes patients aged 35 years or older (mean age 64 years) at 84 primary care centers in central Sweden between 1999 and 2008. We followed this cohort until the end of 2009 in national registries for the incidence of major cardiovascular events (a composite endpoint of myocardial infarction, stroke, heart failure, or cardiovascular mortality) or total mortality.

RESULTS

During up to 11 years of follow-up, 6344 patients (18.7%) had a first cardiovascular event, and 6235 died (18.3%). The associations of annually updated SBP and DBP with risk of major cardiovascular events were U-shaped. The lowest risk of cardiovascular events was observed at a SBP of 135-139 mmHg and a DBP of 74-76 mmHg, and the lowest mortality risk at a SBP of 142-150 mmHg and a DBP of 78-79 mmHg, in both antihypertensive drug-untreated and drug-treated persons.

CONCLUSION

In a large primary care-based sample of patients with type-2 diabetes, associations of SBP and DBP with risk of major cardiovascular events and mortality were U-shaped. This may have implications for risk stratification of persons with diabetes.