Identifying Patients at Risk for Surgical Complications from a High Blood Glucose Level
Because patients with diabetes are at greater risk for serious complications after joint replacement surgery, including heart attack, stroke, and wound infections, than patients without diabetes, current guidelines suggest that surgeons obtain an HbA1c level to ensure these patients are in stable glucose control prior to surgery.
The problem is, the HbA1c is slow to detect changes in the blood glucose level and does not correlate well with risk of surgical complications.
Researchers from Thomas Jefferson University in Philadelphia, Pennsylvania, have identified a different blood glucose marker that can more accurately predict which patients are at highest risk of complications, as well as detect changes in glucose control much faster than the HbA1c – a finding that could potentially change clinical practice.
“This study gives us a better method for identifying patients who need intervention prior to surgery. It could be immensely useful in preventing life-threatening post-surgery complications,” said senior author Javad Parvizi, MD, Vice Chairman of Research and Professor of Orthopaedic Surgery at The Rothman Institute at Thomas Jefferson University.
The study results were published in The Journal of Bone and Joint Surgery.
The American Diabetes Association recommends that people with diabetes maintain an HbA1c levels stay below 7% to prevent general complications from diabetes. However, there are no current guidelines governing glucose levels prior to surgery, and there has been little evidence to showing that staying within this level will help prevent complications from surgery. In addition, using this test can delay surgery by many months while waiting for a reduction in a patient’s HbA1c level.
As an alternative, the researchers from Thomas Jefferson University evaluated the blood levels of a similar glucose-monitoring compound called fructosamine. It can more rapidly detect changes in glycemic control – in 14 to 21 days versus 120 days for HbA1c – making it an intriguing candidate for use in the surgical setting.
“To our knowledge, this is the first study to test whether blood fructosamine levels could give us better information about glycemic control before surgery,” Dr. Parvizi said.
Dr. Parvizi and colleagues enrolled 829 patients who had a planned total joint replacement procedure between 2012 and 2013. They assessed patients’ glycemic levels via HbA1c and fructosamine to determine whether fructosamine could predict which patients had a higher risk of complications. They used the same relative cut-off level for both HbA1c and fructosamine – 7% HbA1c correlated to 292 micromolar/liter of fructosamine.
Their study showed that high HbA1c levels did not predict an increased risk of complications. However, high fructosamine levels were associated with a greater risk for deep infection, readmission, and reoperation. In addition, 35% of patients with fructosamine levels higher than the cut-off had no history of diabetes, indicating increased risk for complications in patients who might not otherwise have been identified.
“The fact that we can use this test to detect poor glucose control in non-diabetic patients may be significant, and could help us improve outcomes for non-diabetic patients as well,” said first author Noam Shohat, MD, a research fellow affiliated with The Rothman Institute at Jefferson.
Clinical and preclinical studies have shown that even short-term spikes in the blood level can impair the immune system (specifically, innate immunity) and the body’s ability to fight infection. The short-term changes detected by fructosamine are also associated with changes in cytokine levels, another factor in promoting strong immune responses to infection.
“Because of its promising role in determining who has poorly controlled glucose levels, we have already begun to use the fructosamine test at our institution to determine who is at high risk of complications and allocate resources to optimizing the glycemic control in these patients,” Dr. Parvizi said.
Shoat N, Tarabichi M, Tischler EH, Jabbour S, Parvizi J. Serum fructosamine: a simple and inexpensive test for assessing pre-operative glycemic control. J Bone Joint Surg Am 15 Nov 2017; 99(22):1900-1907.