Association between the glycemic variability and mortality in critically ill neurological patients - A hospital based observational study

Background: In diabetic patients, the glycemic control is usually represented by hemoglobin A1c (HbA1c), fasting plasma glucose (FPG) and postprandial glucose (PPG), which are usually referred as the “glucose triad”. Apart from these three, “glucose variability” (GV) has been considered as an additional marker, and may be equally important. Materials and methods: The study was a prospective observational study conducted in critical care unit of NRI General Hospital. The study has included all the critically ill neurological patients admitted in the study setting during the study period. A total of 114 participants were included in the study. All critically ill neurological patients were included in the study and were assessed with hourly Glucometric random blood sampling (GRBS) for 6 hours for initial 15 days of admission. Glycemic variables have been recorded including Mean blood glucose (MBG), Glycemic liability index (GLI), Standard deviation of blood glucose. APACHE II scores were also recorded. Results: The mean age of the study participants was 51.69 (±20.21) years. Males constituted 57% and females constituted 43% of study population. The proportion of subjects with diabetes was 51.8%.The mean days of ICU stay was 8.19 (±3.86) days. The morality risk in study population was 28%. Univariate logistic regression analysis showed highest mortality in < 30 year age group. When compared to below 30 year age group, the risk of mortality in 30 to 49 year group was 44%, was 27.6% in 50 to 69 years age group and 71.4% in above 70 years age group. The mortality was almost similar in both genders. The mean APACHE II score was 4 units higher in mortality group, compared to non-mortality group (95% CI 1.64 to 6.37, p value 0.001). Even though the mean GLI, SD GLI values were 39.24 and 73.67 times higher in people with mortality these differences were statistically not significant. The differences in the mean values of mean blood glucose and SDBG were very negligible between the subjects with and without mortality. Conclusion: The study findings reveal that though, APACHE II scores seem to positively associated with mortality among critically ill neurological patients, the glycemic variability though positively influenced the mortality, it is not significant. Further studies assessing the role of GV specifically among such patient groups with a larger sample might reveal the true influence of such interaction.