Low-blood sugar episodes linked to higher survival

January 9th, 2012

written by Michael O’Leary

Dr. Elizabeth Seaquist

Adults with type 2 diabetes who maintain intensive blood sugar control experience more low-blood sugar events than similar people with diabetes who maintain their blood sugar in the standard target range, but they also have a slightly lower risk of dying.

That is the result of an analysis of 10,096 people who participated in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, led by Dr. Elizabeth Seaquist, of the University of Minnesota, Minneapolis.

The results reported by HealthDay News on the DoctorsLounge website were published in the Dec. 16 Diabetes Care.
(Published site)

In the ACCORD study about half the participants were randomly assigned to an intensive control group and tried to keep their blood sugar in the 6 percent range, while the other half randomly assigned to the standard range group tried to keep their blood sugar between 7.1 percent and 7.9 percent.

Seaquist and colleagues looked at the data from the trial to see if there was a link between low-blood sugar events as reported by the participants, and deaths that occurred among the entire study group. Low blood sugar events were defined as a reading of less than 70 mg/dL or 3.9 mmol/L. Not surprisingly, they found that low-blood sugar events were more common among the intensive control group. They found that patients in the intensive control group experienced an average of 1.06 low-blood sugar events in the week before their regularly scheduled four-month visit. That compared to an average of 0.29 low blood sugar events in the same period for those in the standard control group.

When they performed a number of statistical analyses they found that the risk of dying among the intensive control group was lower than that of the standard target group. Taking a closer look at the frequency of low-blood sugar events in those who died they found that the highest risk of dying occurred among those with the lowest number of low-blood sugar events, and that those with the lowest risk of dying had the most frequent low blood sugar events.

While the lower risk was statistically significant, meaning it was not likely to be due to chance, the difference in risk between those with frequent low-blood sugar events and those with few low-blood sugar events was small. In the analysis of the risk of dying that included frequency of low-blood sugar episodes the risk averaged 0.93 for the intensive group and 0.98 for the standard group. In other words those with high frequency of low-blood sugar episodes had about a 5 percent lower risk of dying compared to those with less frequent low-blood sugar episodes.

While the finding is interesting, the researchers acknowledge that the clinical value of it is unknown. If you are able to intensively control your blood sugar at 6 percent, you are likely to have more low-blood sugar events, but you may have a lower risk of dying. Of course doctors would not want to put patients at risk of low-blood sugar events, which makes the intensive control strategy more controversial, which will generate more clinical trials.