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Study Challenges Standard Surgery Protocols for Patients with High A1C

High A1C levels can delay bariatric surgery. However, studies show conflicting results of A1C level’s impact on postoperative outcomes. Further, most of these studies have excluded patients who undergo revisional bariatric surgery, which has a higher complication rate than primary bariatric surgery.

Nabil Tariq, MD

With rising diabetes rates, physician-researcher Nabil Tariq, MD, is investigating if high A1C levels should really hold revisional bariatric surgery patients back from the operating room. As it turns out, the results of Tariq’s latest study challenge the status quo of giving pause to patients with A1C levels of 6.5 or higher. The retrospective study, which included data from a total of 16,234 revisional bariatric surgery patients, revealed no association with worse postoperative outcomes in patients with elevated A1C levels. Specifically, two A1C level groups were studied: ≤8% versus >8% and ≤10% versus >10%. These A1C thresholds were purposely set to be higher than similar studies, adding credibility to the study’s results.

“Other studies have used A1C thresholds of a 7 to a 7.5., so finding no difference in complication outcomes even in patients with an A1C of 10 and higher strengthens the study findings,” explained Tariq, Associate Professor of Clinical Surgery at the Underwood Center for Digestive Health. Tariq and his team were surprised by these results, expecting worse infections in patients with an A1C of 10 and higher. However, Tariq postulates an explanation for the study’s findings. “Bariatric surgery improves glucose levels, which may decrease risk for poor postoperative outcomes in patients with elevated A1C levels,” he explained. “In contrast, other types of surgery further elevate blood glucose levels, potentially increasing the risk for poor postoperative outcomes. Thus, our study suggests that a high A1C shouldn’t prevent patients from getting revisional bariatric surgery because it can help treat high blood glucose while having no associated negative effect on postoperative complications.”

If we continue to apply these thresholds to revisional bariatric surgeries, patients who could really benefit can miss an opportunity to greatly improve their diabetes.

Nabil Tariq, MD

Associate Professor, Clinical Surgery

Health care facilities have data-backed A1C thresholds that are applied to certain elective surgeries, but the study results suggest this standard shouldn't apply to revisional bariatric surgery. “Our population is becoming more diabetic, and patients may have trouble keeping their sugars under control due to various reasons, including income level, dietary factors, and access to appropriate medications and endocrinologists,” Tariq said. “If we continue to apply these thresholds to revisional bariatric surgeries, patients who could really benefit can miss an opportunity to greatly improve their diabetes.” Further, Tariq and his team came to another conclusion about the study’s findings. A1C is the blood glucose levels averaged over a period of two to three months, while perioperative glucose levels are measured around the time of surgery. Therefore, a patient could theoretically have an A1C that may not accurately depict their blood glucose levels in the perioperative setting. With this in mind, “it is likely that perioperative glucose levels matter more than A1C levels in determining postoperative outcomes,” he noted. From here, the team hopes to further explore the relationship between perioperative glucose levels and postoperative complications using continuous glucose monitors. They hope to design a prospective trial in the next year that will help bring clarity to operating standards for this patient subgroup.