Lower-than-recommended BP may improve CV outcomes in diabetes
medwireNews: Swedish researchers have shown that a lower-than-recommended systolic blood pressure (BP) is associated with a significantly reduced risk of cardiovascular (CV) events in patients with Type 2 diabetes.
The study of 187,106 patients with no previous CV events or other major disease, entered into the Swedish national diabetes register, revealed that patients with a systolic BP of 110–119 mmHg had a significant 12% lower risk of CV disease (acute myocardial infarction or stroke) than those with a systolic BP of 130–139 mmHg, which would meet the currently recommended goal.
The patients with the lowest blood pressure also had a 24% lower risk of non-fatal acute myocardial infarction, a 15% lower risk of acute myocardial infarction, an18% lower risk of non-fatal CV disease and a 12% lower risk of non-fatal coronary heart disease, compared with those in the 130–139 mmHg reference group.
In addition, Samuel Adamsson Eryd (Centre of Registers Västra Götaland, Gothenburg) and colleagues found no indication of a J-shaped relationship between these outcomes and systolic BP.
That is in spite of the fact that the target BP for patients with diabetes has recently been raised from below 130 mmHg to below 140 mmHg because of “a lack of conclusive randomised studies to support the lower goal, together with observational studies showing a J shaped relation between blood pressure and complications”, the authors point out.
There was, however, a J-shaped relationship between systolic BP and both heart failure and total mortality, with patients in the lowest systolic BP group (110–119 mmHg) having significant 20% and 28% increased risks, respectively, compared with those in the reference group.
But Adamsson Eryd et al note that patients with the lowest blood pressure also received the least antihypertensive treatment.
“We cannot therefore draw any conclusions about harmful effects of intensive antihypertensive treatment”, they write in The BMJ.
The researchers also found that when they included individuals with previous disease in a secondary analysis, the relationship between systolic BP and each of the outcomes studied became J-shaped.
“Accordingly, the J curve relation observed in real world data depends on patient selection and the extent to which comorbidity can be adjusted for”, Adamsson Eryd and co-authors remark.
They conclude: “The association between low blood pressure and increased mortality could be due to concomitant disease rather than antihypertensive treatment.”
By Laura Cowen
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