Umea Sweden—Lower isn’t better when it comes to treating hypertension in patients with diabetes, according to a new study.

That’s according to a new Swedish study, published in BMJ (British Medical Journal), which points out that those patients often are recommended for more intensive blood pressure therapy because diabetes increases their cardiovascular risk. Lowering their systolic blood pressure to less than 140, however, also appears to raise their risk of dying, according to study authors led by researchers from Umeå University.

“Our study shows that intensive blood pressure lowering treatment using antihypertensive drugs may be harmful for people with diabetes and a systolic blood pressure less than 140 mm Hg,” explained lead author Mattias Brunström, MD, a PhD candidate at the university’s Department of Public Health and Clinical Medicine. “At the same time, it is important to remember that blood pressure lowering treatment is crucial for the majority of people with diabetes whose blood pressure measures above 140.”

For the investigation, the study team carried out a systematic review and meta-analyses of the medical literature, using both published and unpublished patient data for 49 trials involving 73,738 participants. The researchers primarily focused on type 2 diabetes patients with elevated blood pressure levels.

The benefit of antihypertensive treatment was tied to patient blood pressure level before initiation of medication: If the systolic blood pressure before treatment was higher than 140 mmHg, treatment was associated with a decreased risk of death, stroke, heart attack, and heart failure, according to the results.

On the other hand, if the systolic blood pressure before treatment was less than 140 mmHg, the risk of cardiovascular death increased, odds ratio 1.15, as did the risk of all-cause mortality, OR 1.05.

In fact, metaregression analyses showed a worse treatment effect with lower baseline systolic blood pressures for cardiovascular mortality, average OR of for each 10 mmHg lower systolic blood pressure, and myocardial infarction, average OR of 1.12 for each 10 mmHg lower systolic blood pressure.

“Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg,” study authors conclude. “If systolic blood pressure is less than 140 mm Hg, however, further treatment is associated with an increased risk of cardiovascular death, with no observed benefit.”

“Many treatment guidelines, both Swedish and international, will be redrawn in the next few years,” Brunstrom added in an Umea University press release. “It has been discussed to recommend even lower blood pressure levels for people with diabetes—maybe as low as 130. We are hoping that our study, which shows potential risks of such aggressive blood pressure lowering treatment, will come to influence these guidelines.”

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