Low diastolic BP risks CVD events in patients with Type 2 diabetes
MedWire News: US study findings suggest that low diastolic blood pressure (BP) readings may place patients with Type 2 diabetes at increased risk for cardiovascular disease (CVD) events.
The study authors found that while elevated systolic BP was associated with an increased risk for CVD events, a diastolic BP of less than 70 mmHg also increased this risk, even if accompanied by a systolic BP within guideline-recommended target ranges.
"Our results underscore a dilemma for physicians who identify Type 2 diabetes patients with mild increases in systolic BP (eg, 130-139 mmHg or 140-145 mmHg) and diastolic BP 60-69 mmHg or lower," say Robert Anderson (Veterans Affairs Medical Center, Omaha Nebraska) and colleagues.
"Should they treat the systolic BP aggressively with attendant lowering of diastolic BP, the consequence could be a shift of the patient into a higher CVD risk category."
The findings come from the Veterans Affairs Diabetes trial, a prospective study comparing intensive versus standard glucose treatment for up to 7 years in 1791 patients with a substandard response to maximum oral agents or insulin.
Those with hypertension (n=1289; defined as current treatment for hypertension or a BP of 140/90 mmHg or greater) received stepped treatment to maintain BP below 130/80 mmHg.
All patients were followed for the primary outcome of a first occurrence of myocardial infarction, stroke, congestive heart failure, surgery for vascular disease, inoperable coronary disease, amputation for ischemic gangrene, or CVD death.
As an individual component, systolic BP of at least 140 mmHg was associated with a significant risk for this outcome, both at baseline and on-study (hazard ratio [HR] =1.51 and 1.47, respectively).
Diastolic BP less than 70 mmHg was also significantly associated with these events at baseline and on-study (HR=1.48 and 1.49).
Combining BP categories showed that systolic readings of at least 140 mmHg with diastolic BP less than 70 mmHg at baseline and on-study were associated with the primary outcome (HR=1.79 and 2.04). The same was true for nearly all systolic readings with a diastolic BP of less than 70 mmHg.
Reporting in the journal Diabetes Care, the researchers say: "Our results support the identification of a new category of high CVD event risk for the group of Type 2 diabetes patients with low diastolic BP."
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By Anita Wilkinson