Case-control Investigation of Previously Undiagnosed Diabetes in the Critically Ill

Abstract

Context The outcome of patients requiring intensive care can be influenced by the presence of previously undiagnosed diabetes (undiagDM). Objective – To define the clinical characteristics, glucose control metrics and outcomes of patients admitted to the ICU with undiagDM, and compare these to patients with known DM (DM). Methods This case:control investigation compared undiagDM (HbA1c ≥ 6.5%, no history of diabetes) to patients with DM. Glycemic ratio (GR) was calculated as the quotient of mean ICU BG and estimated preadmission glycemia, based on HbA1c ([28.7*HbA1c]-46.7 mg/dL). GR was analyzed by bands: < 0.7, 0.7-≤0.9, 0.9-<1.1, ≥ 1.1. Risk-adjusted mortality was represented by the Observed:Expected mortality ratio (OEMR), calculated as the quotient of observed mortality and mortality predicted by the severity of illness (APACHE IV prediction of mortality). Findings - Of 5,567 patients 294 (5.3%) were undiagDM. UndiagDM had lower ICU mean blood glucose (p < 0.0001), coefficient of variation (p < 0.0001) but similar rates of hypoglycemia (p = 0.08). Mortality and risk-adjusted mortality were similar in patients with GR <1.1 comparing undiagDM and DM. However, for patients with GR ≥ 1.1 mortality (38.5% vs. 10.3% [p = 0.0072]) and risk-adjusted mortality (OEMR 1.18 vs 0.52 [p < 0.0001]) were higher in undiagDM than in DM. Conclusions These data suggest that patients with diabetes may develop tolerance to hyperglycemia that occurs during critical illness, a protective mechanism not observed in undiagDM, for whom hyperglycemia remains strongly associated with higher risk of mortality. These results may shed light on the natural history of diabetes.

Postoperative Length of Stay in Patients With Stress Hyperglycemia Compared to Patients With Diabetic Hyperglycemia: A Retrospective Cohort Study

“…Some evidence in critical care patients with SH suggests that the degree of deviation from preadmission glucose values is an important factor. 9,26 A similar relationship could be postulated for postoperative patients. Mannion et al, 27 in their 2021 study of patients undergoing major joint replacement, found that insulin treatment of patients with SH reduced the risk of infection.…”

Use of Continuous Glucose Monitors in the Hospital: The Diabetes Technology Society Hospital Meeting Report 2023

“…However, it has been shown that the frequency of glucose monitoring is more important than analytic accuracy. 8,9 CGM devices can monitor glucose values every 1 to 5 minutes, which allows early detection and treatment of hypo- or hyperglycemia.…”