The effects of hypercortisolism on the frequency and magnitude of sleep EEG waves in patients with Cushing syndrome: A spectral analysis study.

OBJECTIVES: Our aim was to investigate the effects of endogenous chronic hypercortisolism on sleep electroencephalogram (EEG) and differences between the adrenocorticotropic hormone (ACTH)-dependent and independent Cushing Syndrome (CS) patients through a sleep spectral analysis program. METHODS: A total of 32 patients diagnosed as having endogenous CS (12 ACTH-dependent and 20 ACTH-independent) and a control group comprising 16 healthy individuals were included in the study. Polysomnographic analysis was performed. Blood samples were collected at 08:00 AM for analysis of ACTH and basal cortisol, and at 00:00 AM for midnight cortisol levels. The frequency and power of the slow wave activity (SWA), theta, alpha, and beta waves of the first and last non-rapid eye movement (NREM) cycles were measured with a spectral analysis program. RESULTS: The CS patient group had higher SWA power, especially in the first NREM cycle. In the ACTH-dependent group, SWA maximum and mean power values were higher in the frontal channels in the first NREM, compared to the last NREM sleep stage (p<0.05). CONCLUSION: Cortisol has been found to be associated with SWA waves, making these waves higher in power, especially in the first NREM phase. This difference was much less pronounced in the final NREM sleep stage. The difference between the first and last NREM sleep stages with respect to the power of SWA in the frontal channel in the ACTH-dependent group suggests that not only cortisol but also high levels of ACTH affect the power of slow waves during sleep.

Is biochemical hypoglycemia necessary during an insulin tolerance test?

Objective The insulin tolerance test (ITT) has been accepted as the gold standard test for assessing the integrity of the growth hormone (GH) - insulin-like growth factor (IGF-1) axis and the hypothalamic-pituitary-adrenal (HPA) axis. The goal of the test is to achieve clinical and biochemical hypoglycemia at a blood glucose level ≤ 40 mg/dL to effectively and correctly assess the HPA and GH-IGF-1 axes. In this study, the GH and cortisol responses of patients who achieved and failed to achieve biochemical hypoglycemia during an ITT were compared. Subjects and methods One hundred thirty-five patients with pituitary disorders were included in the study. Samples for blood glucose levels were obtained after clear symptoms of clinical hypoglycemia developed. The patients were enrolled in the hypoglycemic and nonhypoglycemic groups according to whether their plasma glucose level ≤ 40 mg/dL or > 40 mg/dL during an ITT, and the groups were compared in terms of their GH and cortisol responses. Results The mean age, body mass index and waist circumference of the two patient groups were found to be similar. The mean blood glucose level was significantly lower in the hypoglycemic group than in the nonhypoglycemic group (19.3 and 52.0 mg/dL, respectively). When the two groups were compared in terms of peak cortisol and GH responses, no statistically significant differences were found. Conclusion The data presented suggest that clinically symptomatic hypoglycemia is as effective as biochemically confirmed hypoglycemia during an ITT. Arch Endocrinol Metab. 2020;64(1):82-8.

Is biochemical hypoglycemia necessary during an insulin tolerance test?

ABSTRACT Objective The insulin tolerance test (ITT) has been accepted as the gold standard test for assessing the integrity of the growth hormone (GH) - insulin-like growth factor (IGF-1) axis and the hypothalamic-pituitary-adrenal (HPA) axis. The goal of the test is to achieve clinical and biochemical hypoglycemia at a blood glucose level ≤ 40 mg/dL to effectively and correctly assess the HPA and GH-IGF-1 axes. In this study, the GH and cortisol responses of patients who achieved and failed to achieve biochemical hypoglycemia during an ITT were compared. Subjects and methods One hundred thirty-five patients with pituitary disorders were included in the study. Samples for blood glucose levels were obtained after clear symptoms of clinical hypoglycemia developed. The patients were enrolled in the hypoglycemic and nonhypoglycemic groups according to whether their plasma glucose level ≤ 40 mg/dL or > 40 mg/dL during an ITT, and the groups were compared in terms of their GH and cortisol responses. Results The mean age, body mass index and waist circumference of the two patient groups were found to be similar. The mean blood glucose level was significantly lower in the hypoglycemic group than in the nonhypoglycemic group (19.3 and 52.0 mg/dL, respectively). When the two groups were compared in terms of peak cortisol and GH responses, no statistically significant differences were found. Conclusion The data presented suggest that clinically symptomatic hypoglycemia is as effective as biochemically confirmed hypoglycemia during an ITT. Arch Endocrinol Metab. 2020;64(1):82-8

Clinical significance of progastrin-releasing peptide, neuron-specific enolase, chromogranin a, and squamous cell cancer antigen in pulmonary neuroendocrine tumors

Background/aim: It is not always easy to diagnose pulmonary neuroendocrine tumors (PNETs). The aim of the present study is to make a differential diagnosis by studying the same markers in patients with non-small-cell lung carcinoma (NSCLC), patients with benign lung disease (chronic obstructive pulmonary disease and pneumonia), and healthy volunteers to determine the roles of these markers in pulmonary neuroendocrine tumor diagnosis and to identify their power. Materials and methods: A total of 100 participants including 23 PNET patients and 28 NSCLC patients who were pathologically di-agnosed but not yet treated, 25 participants with benign disease, and 24 healthy volunteers were included in this cross-sectional study. Results: No significant difference was found between the chromogranin A (CgA) and squamous cell carcinoma antigen 1 (SCCA1) values among the groups (PNET, NSCLC, benign, healthy volunteers), but the difference in progesterone-releasing peptide (ProGRP), neuron-specific enolase (NSE), and adjusted NSE was statistically significant (P values were respectively ProGRP, P = 0.006; NSE, P = 0.015; NSE adjusted, P = 0.09). In a comparison of the PNET and NSCLC groups, having a ProGRP value higher than 84.6 pg/mL re-vealed PNET with 60.9% sensitivity and 89.3% specificity (P = 0.001). Conclusion: The ProGRP value is the only indicator that distinguishes the PNET group from the other 3 groups.