Perioperative Stress Hyperglycemia in General and Vascular Surgery Patients

Stress hyperglycemia (SH), defined as a blood glucose \>140 mg/dl in hospitalized patients without a prior history of diabetes mellitus (DM) is associated with increased risk of complications and mortality compared to patients with normoglycemia and with known history of DM. Increased counterregulatory hormones (cortisol, glucagon, epinephrine, growth hormone), free fatty acids, inflammation and oxidative stress are likely involved in the pathogenesis of impaired insulin secretion and action leading to stress hyperglycemia. However, no prospective studies have comprehensively examined preoperative glycemic control profiles and their association with the incidence, clinical predictors and underlying mechanisms of SH in general surgical patients. Accordingly, the researchers propose a prospective study investigating clinical, metabolic and inflammatory/oxidative stress biomarker profiles leading to SH. This study will use continuous glucose monitoring (CGM) technology to fully characterize the onset, duration and severity of SH during the perioperative period. Given the association between stress hyperglycemia and poor hospital outcomes, this study aims to determine if the prevention of stress hyperglycemia is feasible with the single administration of a weekly glucagon-like peptide-1 receptor agonist (GLP-1 RA), a common medication used to treat patients with established diabetes. In addition, the researchers will explore the role of beta-cell function, insulin resistance, and inflammation on the pathogenesis of stress hyperglycemia. The goals of this study are to: 1) conduct an extensive analysis of preoperative glycemic control and its relationship to clinical, metabolic and biomarker profiles of SH in a high-risk population, and 2) conduct a pilot randomized controlled trial to prospectively determine if single dose use of dulaglutide can improve perioperative glycemic control compared to insulin administration (standard-of-care). Patients qualifying for the study will be approached at their preoperative clinic visit and invited to participate in the prospective observational study arm (Aim 1), and in the interventional trial for prevention of SH with dulaglutide (Aim 2) if they meet inclusion criteria based on oral glucose tolerance testing (OGTT) or lab testing performed for Aim 1. Within 72 hours prior to planned surgery, consented patients will present to the clinical research center (CRC) to undergo evaluation with OGTT and lab testing with CGM placement. Those patients with OGTT or lab results consistent with a diagnosis of prediabetes or newly diagnosed diabetes will be asked if they would like to participate in Aim 2. Patients consenting to participate in Aim 2 will be randomized to receive a subcutaneous injection of dulaglutide 0.75 mg or placebo during the CRC visit, and glycemic control parameters will be followed postoperatively during surgical admission (up to 14 days). In addition to the above, baseline and postoperative levels of serum inflammatory and oxidative stress markers will be obtained to provide further information regarding beta-cell function and insulin resistance in relation to the development of stress hyperglycemia.