Evaluation of glucose metabolism in patients with diabetes insipidus

Introduction and Aim: Diabetes insipidus (DI) is a disease characterized by the excretion of abnormally large volumes of dilute urine. It can be caused by any of 4 fundamentally different defects that must be distinguished for safe and effective management. These are central DI due to insufficient secretion and production of ADH, gestational DI due to degradation of ADH by an enzyme made from the placenta, primary polydipsia due to suppression of AVP secretion by excessive fluid intake, and nephrogenic DI due to renal insensitivity to the antidiuretic effect of AVP. To make a diagnosis, first of all, 24-hour urine volume should be checked. Primary causes of polydipsia and osmotic diuresis (such as hyperglycemia, hypercalcemia, renal diseases) should be excluded as other causes of polyuria. The 'thirst test', which is our standard test for diagnosis, is performed. Desmopressin can be used effectively and safely for central DI and gestational DI. In the treatment of nephrogenic DI, the use of thiazide diuretics, a low sodium diet, and amiloride may reduce symptoms and signs. Insulin resistance (ID) is defined as the inability of circulating insulin to exert its biological effects. The basis of insulin resistance is metabolic disorders that occur in the form of decreased insulin-mediated glucose use by tissues and increased glucose production in the liver. There are many measurement methods of insulin resistance. The HOMA-IR method was used in this study to measure insulin resistance. This study was conducted to compare the glucose metabolism of patients with DI and control group. Material and Methods: This retrospective case-control study included 33 patients with DI who applied to the Endocrine Clinic of the Dicle University Medical Faculty Hospital and 33 control groups. Insulin resistance (calculated by HOMA-IR method), HbA1c, biochemistry panel, hematocrit, and urine density values of the patient and control group were evaluated. Anthropometric measurements at the time of admission were evaluated. Bioimpedance measurements at the time of application were evaluated. Data analysis was performed using the SPSS 24 (Statistical Package for the Social Sciences) package program. Results: A total of 33 DI and 33 control groups were included in our retrospective case-control study. The mean age of the DI group was 38.9±12.8 years, while the mean age of the control group was 40.9±12.6 years. Ten (30.3%) patients with DI were male and 23 (69.7%) were female. No significant difference was observed between the anthropometric measurements of the DI and control groups. In our study, 10 (30.3%) of the patients had central DI that developed postoperatively. A statistically significant difference was observed between the HbA1c values of the DI and control groups (p=0.011). The mean HbA1c value of the patients with DI was 5.60±0.55, while the mean value of the control group was 5.24±0.41. A statistically significant difference was observed between the insulin levels of the DI and control groups (p=0.001). The mean insulin value of the patients with DI was 12.6±6.57, while the mean value of the control group was 7.73±3.73. There was a statistically significant difference between the insulin resistance levels of the DI and control groups (p<0.001). The mean value of insulin resistance (HOMA-IR) in DI patients was 2.94±1.50, while the mean value in the control group was 1.78±0.87. In our study, insulin resistance was found in 13 (39.3%) of the patients in the DI group according to HOMA-IR insulin resistance (values above 2.7 were evaluated in favor of insulin resistance). Conclusion: Patients with Diabetes Insipidus show more insulin resistance than the control group. Presence of insulin resistance seems to be independent of patients' weight, BMI and steroid use. Desmopressin use in this patient group may be a factor that triggers insulin resistance. Prospective studies examining the presence of insulin resistance in this patient group from different aspects may provide a better understanding of the subject.