A new study has evaluated the effect of more “liberal” blood sugar control in critically ill hospitalized patients. Researchers learned that higher glucose targets reduced the risk of hypoglycemia, but did not otherwise improve health outcomes.
In the United States, the American Diabetes Association sets the current standards for glycemic control in the hospital. Most patients with diabetes, both critically ill and noncritically ill, are recommended to target a glucose range of 140–180 mg/dL (7.8–10.0 mmol/L).
If managing blood sugar is a balancing act at the best of times, it’s an even trickier one in the hospital. Patients may lose some or all of their ability to self-manage their diabetes; they also may lose the ability to perceive the symptoms of hypoglycemia or the ability to communicate them to medical staff. And whatever ailment they’re suffering from may well have a significant effect on glucose levels, in addition to the treatment they need for it.
Hospitals are therefore wisely very concerned with the risk of hypoglycemia, but playing it too safe can be dangerous too. We know that patients recovering from cardiac surgery, for example, do much better if their blood sugars are at close to normal levels, and the ADA allows them to target a more stringent blood sugar range of 110–140 mg/dL. We also recently learned that hyperglycemia was highly associated with poor outcomes for Covid-19 patients, leading to recommendations that doctors intensively manage the blood sugar of patients even without any demonstrated history of diabetes.
A generation ago, conventional treatment in American hospitals employed much looser glycemic management standards: patients with type 2 diabetes would only be given insulin if their blood sugar exceeded 215 mg/dL. That changed after a 2001 trial, described as a “landmark” in ADA’s literature, found that this protocol increased the need for intensive care and resulted in higher risks of all sorts of poor outcomes, including renal failure and blood infections.
The ADA’s current guidance is most significantly informed by the NICE-SUGAR trial, the results of which were published in 2009 by the New England Journal of Medicine. That trial investigated the efficacy of a middle ground – blood sugar less than 180 mg/dL – and found that it was best for most patients. In contrast, very tight glucose control (81-108 mg/dL) resulted in much more severe hypoglycemia, but no other health improvements. That’s where we stand today: for most patients, the ADA recommends a happy medium that reduces the risk of both hypoglycemia and hyperglycemia.
The latest study on the topic, the work of a team of Australian researchers, appears to have taken a fresh look at the old question, testing different blood sugar management strategies in a sample of over 400 patients with type 2 diabetes in intensive care units (ICUs). One group was treated with the conventional “happy medium” approach. The other was treated with an experimental high glucose target, from 180 to 252 mg/dL. The results:
Unsurprisingly, patients in the high glucose target group experienced significantly less hypoglycemia. Those in the conventional treatment group were nearly four times as likely to have at least one episode of hyperglycemia (defined as <72 mg/dL).
Despite the lower risk of hypoglycemia, the patients in the experimental treatment group did not have otherwise improved clinical outcomes. In fact, more of the higher glucose target group died (29.5 percent versus 24.9 percent), although analysis determined that this difference was not statistically significant.
This study, which showed mixed results, is unlikely to budge diabetes authorities from their current recommendations. The results shouldn’t be generalized to patients with type 1 diabetes, or for those outside of critical care settings.
We’ve written previously about the importance of knowing your hospital rights as a person with diabetes. The ADA asserts that hospitalized patients who “successfully conduct self-management of diabetes at home and whose cognitive and physical skills needed to successfully self-administer insulin and perform self-monitoring of blood glucose are not compromised” should be allowed to manage their own blood sugar decisions, including insulin use, while at the hospital. But we also know from reports in the diabetes online community that some hospitals are hesitant to allow patients to manage their own condition; patients that feel confident in their self-management skills sometimes need to assert themselves.
Glucose management is always a challenge – in the hospital, it’s even more so. Studies like this one help doctors settle on the approaches that are most likely to foster recovery and good health.