Effect of lowering blood pressure on risk for cognitive decline in patients with diabetes

Patients with type 2 diabetes (T2DM) are at increased risk for decline in cognitive function, for reduced brain volume and increased white matter lesions on brain imaging, according to the study. The authors examined the effect of intensive treatment to lower blood pressure (BP) and lipid levels as part of the Memory in Diabetes (MIND) substudy of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

The trial randomized 2,977 participants without baseline cognitive impairment or dementia and with hemoglobin A 1C levels less than 7.5 percent to a systolic BP goal of less than 120 or less than 140 mm Hg (n=1,439) and to a fibrate or placebo in patients with statin-treated, low-density lipoprotein cholesterol levels less than 100 mg/dL (n=1,538).

Researchers assessed cognition at baseline, 20 and 40 months. Also, 503 participants underwent baseline and 40-month brain magnetic resonance imaging to look for changes in total brain volume (TBV) and other structural measures of brain health.

There were no differences in cognitive function in the intensive BP-lowering trial (<120 target) or in the fibrate groups. At 40 months, the intensive BP intervention group had a lower TBV compared with the standard BP intervention group. Fibrate therapy had no effect on TBV.

"During the past two decades, the belief that more intensive treatment strategies for controlling T2DM-related comorbidities [related illnesses], such as hyperglycemia, hyperlipidemia and hypertension, would reduce clinical complications has driven large investment in new medications for this disease syndrome," the study concludes. "These results do not negate other evidence that intensive strategies to control BP and lipid levels may be indicated for other conditions such as stroke or coronary heart disease. However, this randomized clinical trial in 2,977 older adults with a mean baseline Mini-Mental State Examination score higher than 27, a mean HbA 1c level of 8.3 percent, and long-term T2DM shows no overall reduction of the rate of T2DM-related cognitive decline through intensive BP therapy or adding a fibrate to well-controlled LDL-C levels."