The goal of this study is to measure the prevalence and risks of hyperglycemia in surgical patients with prediabetes. The main questions it aims to answer are:

• What is the prevalence of hyperglycemia in surgical patients with prediabetes?
• What is the relative risk of postoperative complications associated with hyperglycemia?

To answer these questions, surgical patients with prediabetes will undergo universal glucose measurement in the perioperative period. Glucose data will be analyzed in conjunction with electronic health record (EHR) data describing patient outcomes.

Background

Day-of-surgery and postoperative ('perioperative') hyperglycemia are modifiable risk factors for complications after non-cardiac surgery, including surgical site infections, 30-day readmissions, and mortality. Data from Alberta suggests perioperative hyperglycemia is common among people without diabetes, affecting about 13% of people with prediabetes on the day-of-surgery and 18% of people without diabetes after surgery. Paradoxically, the risks of perioperative hyperglycemia appear to be two-times greater for people with prediabetes than for people with diabetes and the reasons for this are unknown. Current estimates of the prevalence of perioperative for people with prediabetes are limited. Understanding the true prevalence would inform individual decision-making around surgery, the need for further research about the true association of hyperglycemia and adverse outcomes, and clinical decisions about the utility of measuring glucose for all people with prediabetes around the time of surgery.

Objectives

This prospective cohort study will establish the prevalence of perioperativehyperglycemia in people with prediabetes undergoing scheduled (elective and urgent) non-cardiac surgeries. This information will inform:

1. Patients, to better understand their individual risks of elective surgery.
2. Clinicians, on the need for perioperative glucose measurement for patients with prediabetes.
3. Researchers, on the need for and design of further studies.

Methods Overview

We will measure glucose in all adult patients with prediabetes undergoing scheduled (elective and urgent) non-cardiac surgeries throughout the perioperative period (referring to the day of surgery and up to the first 3 postoperative days or discharge, whichever comes first) to determine the prevalence of perioperative dysglycemia in people with prediabetes.

This project will leverage established data sources and linkages to address secondary and exploratory objectives: (1) Use in-hospital insulin prescribing data to describe current practices for treatment of perioperative hyperglycemia in people with prediabetes; (2) Explore the association between clinical outcomes like infections and length of stay with perioperative hyperglycemia in people with prediabetes; and (3) Compare the prevalence of perioperative hyperglycemia and the association of hyperglycemia with clinical outcomes between the intervention period and a historical control period (pre-intervention at the same hospital) and a contemporaneous, non-intervention site (UAH, Edmonton) to examine whether the 'prediabetes paradox' is a result of confounding by indication or another cause.

Outcomes

If the prevalence of perioperative hyperglycemia in people with prediabetes is sufficiently high, clinical guidelines should recommend perioperative glycemic monitoring for patients with prediabetes. Further, if there is an association between hyperglycemia and adverse outcomes, intervention-based studies are needed to determine whether this risk is modifiable with hyperglycemia treatment.

Team

The NPI and co-investigators have led a 5-year implementation science and quality improvement study to improve perioperative glycemic management for people with diabetes in Alberta. This interdisciplinary group of patients, nurses, endocrinologists, surgeons, anesthesiologists, internists, and implementation scientists will leverage their existing data access, professional networks, and content expertise to conduct this study.

Inclusion Criteria:

• Hemoglobin A1c measurement between 6 and 6.4%
• Scheduled for non-cardiac surgery

Exclusion Criteria:

• Age>18
• Pregnancy
• Any formal diabetes diagnosis
• Current use of medications that influence blood glucose regardless of the indication
• Undergoing cardiac, intracranial neurosurgery, bariatric, or pancreatic surgeries

Surgical in-patients at the Foothills Medical Centre.

IPD, specifically deidentified patient data will be shared upon reasonable request by fellow research teams.

Data will be available after analyses have completed, approximately in the month of March, 2028. Data will be retained in accordance with the University of Calgary's Master Records Retention Schedule(MaRRS). During this time period, data will be available upon reasonable request.