Aggressive BP Treatment Has No Benefit in Cardiovascular Disease Risk

Philadelphia—A subanalysis of a major randomized blood pressure trial found that patients who are centrally obese and have type 2 diabetes do not benefit in terms of cardiovascular disease risk when they are treated aggressively to lower blood pressure (BP) compared with undergoing standard treatment.

The results were similar to the ACCORD (Action to Control Cardiovascular Risk in Diabetes) study, which previously reported that intensive lowering of BP only reduced stroke risk, but not the primary outcome of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke.

Joshua Barzilay, MD, the study’s lead author from the Southeast Permanente Medical Group in Atlanta, Georgia, presented the data in a symposium at the ADA meeting. The findings were also published in Diabetes Care [35:1401-1405, 2012].

Dr. Barzilay cited statistics from the National Health and Nutrition Examination Survey that showed the combination of overweight and obese adults in the United States has increased from approximately 40% of the population in 1960 to approximately 60% in 2004. He added that 41.9% of men and 37.8% of women with a body mass index >30 have hypertension, which is defined as people having a mean systolic BP ≥140 mm Hg or mean diastolic BP ≥90 mm Hg or who are taking antihypertensive medication.

The ACCORD trial included 10,251 patients with type 2 diabetes who were randomly assigned to intensive (defined as hemoglobin A1c level [HbA1c] <6%) or standard (HbA1c between 7.0%-7.9%) glycemic control. They were also assigned to lipid or BP substudies.

This subanalysis examined patients assigned to the BP substudy, which had a 2x2 factorial design. They had systolic BP between 130 and 180 mm Hg, were taking ≤3 antihypertensive medications, and had <1.0 g protein excretion in a 24-hour urine collection. They were then randomly assigned to intensive (<120 mm Hg) or standard (<140 mm Hg) systolic BP groups.

At baseline, participants had their waist circumference measured. The authors in this subanalysis used a ratio of waist circumference to height to determine central obesity. Of the 4687 people in the study, 47.7% were women, and the mean age was 62.2 years. Similar to the ACCORD trial, the primary outcome was a composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke and secondary outcomes were nonfatal myocardial infarction, fatal or nonfatal stroke, and cardiovascular death.

For the primary outcome, there was no statistically significant difference between the intensive versus standard BP groups when measuring cardiovascular outcomes based on their waist to height ratios. There were also no statistically significant differences when measuring total stroke, cardiovascular mortality, or nonfatal myocardial infarction.

When the authors controlled for the waist to height quartiles, intensive BP lowering had a significant effect on total stroke incidence (P=.022), but not for the primary outcome, cardiovascular mortality, or nonfatal myocardial infarction. They also found that waist to height quartiles led to increased cardiovascular mortality (P=.0009 comparing the first to fourth quartiles), but central obesity was not associated with the other end points.