Study Questions Recommended Target Blood Pressure for Diabetics

A new study suggests that the recently raised target blood pressure for diabetic patients could actually lead to more patients experiencing a stroke or heart attack.

In February 2015, the Swedish National Board of Health and Welfare raised the recommended goal for systolic blood pressure in their diabetes care guidelines, increasing the target level of below 130 mm Hg to below 140 mm Hg, matching recent changes to recommendations in both Europe and America. In this study, the researchers sought to compare the risk associated with systolic blood pressure that meets current recommendations with the risk associated with lower levels in patients who have type 2 diabetes and no previous cardiovascular disease.

To do so, the authors conducted a population-based cohort study with nationwide clinical registries, ranging from the years 2006 to 2012, with a mean follow-up time of 5 years. The analysis encompassed 861 Swedish primary care units and hospital outpatient clinics, and included 187,106 patients registered in the Swedish national diabetes register who had had type 2 diabetes for at least a year, age 75 or younger, and with no previous cardiovascular or other major disease.

Clinical events were obtained from the hospital discharge and death registers with respect to acute myocardial infarction, stroke, a composite of acute myocardial infarction and stroke (cardiovascular disease), coronary heart disease, heart failure, and total mortality.

The authors found that the group with the lowest systolic blood pressure (110-119 mm Hg) had a significantly lower risk of non-fatal acute myocardial infarction, total acute myocardial infarction, non-fatal cardiovascular disease, total cardiovascular disease, and non-fatal coronary heart disease compared with the reference group (130-139 mm Hg).

The key finding was the lack of a "J-shaped relationship between blood pressure and risk of cardiovascular disease," says Samuel Adamsson Eryd, MD, a researcher at Lund University and lead author of the study.

"One should always be cautious about drawing conclusions about treatment recommendations from associations found in observational studies," says Adamsson Eryd.

But, he adds, "our results support those from randomized studies, such as the ACCORD BP and SPRINT trials, which point to the conclusion that more intensive hypertensive treatment than the current recommendation provides additional protection from cardiovascular events."

—Mark McGraw

Reference

Eryd S, Gudbjornsdottir S, Manhem K, et al. Blood pressure and complications in individuals with type 2 diabetes and no previous cardiovascular disease: national population based cohort study [published online August 4, 2016]. BMJ. doi: http://dx.doi.org/10.1136/bmj.i4070