Hyperglycemia, with or without diabetes, is a common comorbidity for surgical and nonsurgical patients in the hospital. About a third of ICU and non-ICU hospital patients have point-of-care blood glucose values greater than 180 mg/dL, and an additional 23% have values greater than 200 mg/dL. Compared to patients with normal glycemia, nonsurgical hospital patients with hyperglycemia are at five-fold increased risk for hospital mortality. Similarly, perioperative hyperglycemia significantly increases the risk of hospital infection, reoperation, and death.

“Hyperglycemia is a marker for poor outcomes with or without diabetes at the time of admission,” said Guillermo E. Umpierrez, MD, CDCES, FACP, FACE, ADA President, Medicine & Science. “Acute illness increases stress hormones, increasing glucose and inhibiting insulin levels while increasing circulating levels of free fatty acids. The combination of immunologic and inflammatory responses contributes to increased complications and mortality in the hospital.”

Dr. Umpierrez described 20 years of research linking hyperglycemia and hospital complications during his President, Medicine & Science Address Inpatient Management of Diabetes in Non-ICU Settings: The Need for Individualized Care on Sunday, June 5. The session was livestreamed and can be viewed on-demand by registered meeting participants at ADA2022.org. If you haven’t registered for the 82nd Scientific Sessions, register today to access the valuable meeting content.

While hyperglycemia is a recognized risk factor in the hospital, there are no generally accepted glucose targets, noted Dr. Umpierrez, Professor of Medicine at Emory University School of Medicine. The ADA recommends a range of 140 mg/dL to 180 mg/dL for most patients, while the Endocrine Society suggests less than 140 mg/dL pre-meal and less than 180 mg/dL on random test. The Joint British Diabetes Society for Inpatient Care recommends a range of 110 mg/dL to 180 mg/dL with an acceptable upper limit as high as 200 mg/dL. The American College of Physicians has no specific glucose targets and recommends avoiding blood glucose less than 140 mg/dL.

Treatment recommendations previously called for insulin and advised against oral agents. Those early approaches suggested a regimen of long-acting basal insulin plus preprandial bolus dosing with rapid-acting insulin or sliding scale insulin (SSI) dosing. The RABBIT 2 trial showed that the basal-bolus approach brought blood glucose below 180 mg/dL more quickly and reduced hyperglycemia more effectively than SSI in patients with type 2 diabetes, Dr. Umpierrez said. The RABBIT 2 Surgery trial showed the basal-bolus approach significantly reduces postoperative complications, including wound infection, pneumonia, acute renal failure, and mortality.

Later trials showed no differences in hospital outcomes between analog and human insulins, Dr. Umpierrez added. Nor were there clinically significant differences between different basal analog insulins.

Evolving treatment recommendations continued to advise against oral antidiabetic agents, but inpatient surveys revealed that more than a quarter of inpatients with type 2 diabetes were receiving oral agents alone or in combination with basal insulin. Trials comparing dipeptidyl peptidase 4 (DPP-4) inhibitors to insulin in hospitalized patients with type 2 diabetes found similar outcomes for patients with blood glucose less than 180 mg/dL. Basal insulin was more effective in patients whose blood glucose was greater than 200 mg/dL.

But clinicians were not convinced. In 2018, the Cochrane Review concluded there was insufficient evidence to definitively recommend basal bolus insulin over SSI in non-ICU hospital patients with type 2 diabetes. And a 2021 survey of 44 hospitals found that 41% of noncritical patients were treated with SSI alone, Dr. Umpierrez said.

“We should individualize treatment for non-ICU patients with type 2 diabetes,” he said. “Those with blood glucose less than 180 mg/dL do well with SSI and oral agents. Patients with blood glucose between 200 mg/dL and 300 mg/dL do better adding basal insulin, and those greater than 300 mg/dL do better with basal-bolus plus SSI. Not everyone in the hospital needs to be treated with bolus insulin.”

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