Incidence of Hypoglycemia with Tight Glycemic Control Protocols: A Comparative Study

Background: Comparison of hypoglycemia incidence among tight glycemic control (TGC) protocols is a crucial aspect that has not been done in previous trials. This study compared the incidence of hypoglycemia using three TGC protocols in critically ill patients. Methodology: This was a prospective study of 420 patients over 18 months. Patients were divided into three groups by TGC protocol: A (modified Leuven protocol), B (Georgia Hospital Association protocol, target blood glucose [BG] 80-110 mg/dL), and C (modified Georgia Hospital Association protocol, target BG 90-140 mg/dL). End points included differences in the incidence of first-degree hypoglycemia (BG <= 60 mg/dL), second-degree hypoglycemia (BG <= 40 mg/dL), and hyperglycemia (BG <= 180 mg/dL). Results: A total of 34,497 BG samples were analyzed: group A, 11,202 (32.47%); group B, 9,627 (27.91%); and group C, 13,668 (39.62%). First-degree hypoglycemia was more frequent in group A (348 episodes [3.11%]) compared to group B (209 episodes [2.17%] [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.25-1.172, P = 0.001]) and group C (266 episodes [1.95%] [OR 1.66, 95% CI 1.37-1.89, P = 0.001]). Second-degree hypoglycemia was more frequent in group A (131 episodes [1.17%]) compared to group B (62 episodes [0.64%] [OR 1.83, 95% CI 1.22-1.72, P=0.001]) and group C (58 episodes [0.42%] [OR 2.77, 95% CI 2.04-3.79, P=0.001]). No significant difference was found when groups B and C were compared (P=0.10 and P=0.06, respectively). Hyperglycemia was significantly more common in group A (2,175 episodes [19.42%]) compared to group B (1,333 episodes [13.83%] [OR 1.49, 95% CI 1.39-1.62, P=0.001], but there was no significant difference compared to group C (2,560 episodes [18.73%] [P=0.17]). Conclusions: TGC protocols vary in their risk of inducing hypoglycemia. Whether this translates into differences in clinical outcomes such as mortality and adverse effects is still to be determined by future studies.