Clinical Question

What is the long-term effect of intensive blood glucose control in patients with type 2 diabetes mellitus?

Bottom Line

The initial Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, which compared standard treatment with intensive control, found that despite good intentions, cardiovascular (CV) and overall mortality are significantly higher when blood glucose levels are lower. This study, which followed patients for an additional five years, found that patients in the intensive treatment group continued to maintain lower A1C levels than patients in the standard care group; they also continued to be at increased risk of death from a CV event. (Level of Evidence = 2b)

Synopsis

This report is a follow-up of patients who were enrolled in the ACCORD study, which randomly assigned patients with type 2 diabetes and a high risk of CV outcomes to receive usual care or treatment aimed at intensive control of blood glucose. After the 3.7-year study, patients were followed for an additional five years to determine the long-term effect of their initial treatment. The patients were no longer on a protocol, and their treatment goals were at the discretion of their clinician, but A1C levels were still lower overall in the patients who had been in the intensive-care group. The investigators did a thorough job of keeping track of the patients, following up with 98% of them (n = 8,601) who did not experience a primary outcome or death during the original trial. Over this additional time, intensive glucose lowering did not increase or decrease the primary composite outcome of nonfatal myocardial infarction, nonfatal stroke, CV death, death from any other cause, or overall mortality. The increased CV mortality rate seen with intensive control during the active treatment stage decreased in the subsequent years but was still higher than in the group initially treated with standard treatment (hazard ratio = 1.20; 95% confidence interval, 1.03 to 1.39; P = .02).

Study design: Cohort (prospective)

Funding source: Government

Setting: Outpatient (any)

Reference: ACCORD Study GroupNine-year effects of 3.7 years of intensive glycemic control on cardiovascular outcomes. Diabetes Care2016;39(5):701–708.