Dynamics of Cortisol-Insulin Index and Individual Insulin Resistance in Patients after Surgery on the Lumbar Spine

The article deals with the dynamics of the insulin-cortisol coefficient and the index of insulin resistance in patients during surgical interventions on the lumbar spine. Material and methods. The study included 23 patients aged 18-65, ASA I-II with degenerative-dystrophic spinal diseases, undergoing planned surgical interventions with transpedicular stabilization of 1-2 segments. None of the patients had a history of diabetes mellitus. All of the patients under study were scheduled to be in the first operational phase (at 8 o'clock in the morning). Patients in the SA (spinal anesthesia) group (n=11) were performed spinal anesthesia with a hyperbaric 0.5 % solution of bupivacaine (4 ml) in sedentary position. Subsequently, the patients were in the back position for 5 minutes followed by turning to the abdomen. Patients in the TA (total anesthesia) group (n=12) were performed general intravenous anesthesia with artificial ventilation of lungs (propofol, fentanyl, atracurium in common doses). The intubation of the trachea was performed on the back with subsequent rotation of the patient on the stomach. Distribution of patients by groups was performed randomly. The control group consisted of 11 practically healthy people. Blood collection was carried out at the following time intervals: T1 – before the start of anesthesia, T2 – 30 minutes after the incision, T3 – 3 hours after the incision, T4 – 24 hours after surgery. Patients in the serum of blood determined the content of cortisol and insulin performed by the method of ELISA, the content of glucose – enzymatic method. The cortisol-insulin ratio was determined by the formula: K/I = ((K at the study stage × 100 %) / (K before surgery) / ((I and stage of the study × 100 %) / (I before surgery), where K – cortisol, and – Insulin. The Index of Insulin Resistance (NOMA – Homeostasis Model Assesment) was determined by the formula: NOMA = (glycaemia on empty stomach (mmol/l) × insulin on an empty stomach (μU/l)) / 22.5. Results and discussion. The cortisol-insulin ratio in the SA group was significantly lower than the AR group, but no statistically significant difference was found between the groups. The index of insulin resistance (NOMA) was lowered in the group of patients with TA within 30 minutes after surgery by 46.4 % compared to the T1 in the same group as well as by 25.0 % compared to the T2 in the SA group. In terms of T3 and T4 in patients of both groups, the level of the NOMA index was higher than the current referent norm, indicating an increase in insulin resistance in patients in the first day after surgery. Conclusions. Thus, the cortisol-insulin ratio in the TA group had higher digital values at the most traumatic stage of the operation; however, it was not statistically significantly different from the SA group. The Insulin Resistance Index (NOMA) was lower 30 minutes after the start of surgery in patients who underwent general anesthesia compared with those who performed spinal anesthesia. After 3 and 24 hours after the operation, the NOMA index was elevated compared to the reference standard in healthy people, requiring further control of this index in the early postoperative period.