Investigation of the relationship of hypothalamo-pituitary-adrenal axis and thyroid functions with disease progression in intensive care patients

INVESTIGATION OF THE RELATIONSHIP OF HYPOTHALAMO-PITUITARY-ADRENAL AXIS AND THYROID FUNCTIONS WITH DISEASE PROGRESSION IN INTENSIVE CARE PATIENTS Critical illness is hallmarked by major changes in all hypothalamic–pituitary–peripheral hormonal axes. In the acute phase of critical illness, rapid neuroendocrine changes try to direct the human body toward a catabolic state to ensure provision of elementary energy sources, whereas costly anabolic processes are postponed. Whereas the alterations in hormonal levels during the first hours and days after the onset of critical illness are selected and are likely beneficial for survival, endocrine changes in prolonged critically ill patients could be harmful and may hamper recovery. The aim of our study is to determine the hormone levels in the chronic period of critical illness, and to evaluate the relationship between hormone levels and disease severity indicators. Our study was carried out with 50 consecutive patients who were treated at the medical intensive care unit of Fırat University Faculty of Medicine and 50 healthy controls applied to Fırat University endocrinology polyclinics. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone, estradiol, thyroid stimulating Hormone (TSH), free thyroxine (fT4), adrenocorticotropic hormone (ACTH), cortisol and prolactin levels were evaluated on the 1st and 8th days of ICU stay in all patients. These hormone levels were evaluated only at baseline in the control group. Illness severity is assessed with acute physiology and chronic health evaluation ii (APACHE-II) and sequential organ failure assessment score (SOFA). The mean age of the patients was 74.7 ± 13.7 years, and the control group was 70.8 ± 8.0 years. 48% of the patients were male and 52% were female, while the control group was 46% male and 54% female. The patient and control groups were similar in age (p = 0.089) and sex (p = 0.841). On the 1st day, LH (p<0.001), FSH (p<0.001), total testosteron (p<0.001), TSH (p=0.005) levels were lower and estradiol (p<0.001), fT4 (p=0.046), cortisol (p=0.014) and prolactin levels (p<0.001) were higher in the patient group compared to the control group. On the 8st day, LH (p<0.001), FSH (p<0.001), total testosteron (p=0.005) levels were lower and estradiol (p<0.001), fT4 (p=0.046), cortisol (p=0.014) and prolactin levels (p<0.001) were higher in the patient group compared to the control group. In patients, TSH (p=0.018) and ACTH (p=0.005) levels increased and cortisol (p<0.001) levels decreased on day 8, compared to day 1. ACTH (p=0.043) and cortisol (p<0.001) levels corelated positively with APACHE-II on the first and 8th day in patients. Moreover, the estradiol levels on the 8th day were positively correlated with APACHE-II and SOFA scores. In medical intensive care patients, there are significant changes in the hypothalamus-pituitary-peripheral hormone axis both in acute and chronic phases of critical illness. The awarness of these changes may contribute to patient care and prognosis. Key words: Medical critical care, Hypothalamus-pituitary-peripheral, Adrenal, Thyroid, Chronic phase.