Slavica Savic

Cortisol response to ACTH stimulation correlates with blood interleukin 6 concentration in healthy humans

OBJECTIVE Interleukin 6 (IL6) has the ability to influence each level of the hypothalamo-pituitary-adrenocortical (HPA) axis. The aim of the study was to test whether IL6 concentration correlates with the adrenal cortex response to ACTH in healthy humans. We postulated that higher basal IL6 concentration would be associated with the higher cortisol response to the stimulation. DESIGN AND METHODS Basal IL6 concentration was measured and a low dose (1 microg) ACTH test was performed to assess cortisol response. Twenty-seven apparently healthy subjects (11 male, 16 female, mean age 31.1 years, age range 22-47 years) were included in the study. RESULTS Data are presented as mean+/-S.E.M. Basal IL6 level was 0.84+/-0.10 pg/ml. Basal cortisol was 351.9+/-18.3 nmol/l. Maximal cortisol during synacthen test was 653.0+/-20.6 nmol/l. Maximal cortisol increment was 301.1+/-20.0 nmol/l. IL6 concentration was not correlated with basal or maximal cortisol concentration, but correlated significantly with cortisol increment (r=0.63, 95% confidence interval) 0.42-0.83). CONCLUSIONS In our study, we found that higher basal IL6 concentration is associated with the higher cortisol response to ACTH stimulation. Based on previous research and our data, IL6, even in low concentrations and under physiologic conditions, modulates adrenal cortex responsivity to ACTH. Therefore, it seems that immune modulation of HPA axis is also present under physiologic and not only pathologic conditions.

Efficacy and safety of combined parenteral and oral steroid therapy in Graves' orbitopathy.

OBJECTIVEGlucocorticoids (GC) are the treatment of choice for moderate-to-severe and active Graves’ orbitopathy (GO), but optimal treatment is still undefined. The aim of the present study was to analyze the efficacy and tolerability of combined parenteral GC pulse therapy followed by oral GC in the interpulse period.DESIGNThe study included 50 patients (48 ± 10 years; 37 female) with untreated, active and moderate-to-severe GO. Patients received 500mg of methylprednisolone in 500ml of physiologic saline. Infusion was repeated after 48h and then followed by tapering doses of oral prednisone and the cycle repeated each month for the next 5 months. The cumulative dose was 10.2g. Ophthalmic assessment was performed before and 6 months after start of treatment. Side effects of GC therapy were evaluated and recorded each month.RESULTSGC showed the greatest effectiveness on soft tissue changes (incorporated in the CAS). Median CAS values decreased from 4.5 to 2 (p>0.001). Improvement was demonstrated in 37 patients (74%), there was no change in 13 patients (26%) and none of the patients presented with deterioration of inflammatory status. Diplopia improved in 21 patients (42%), was unchanged in 28 patients (56%) and deteriorated in 1 patient (2%). Improvement in visual acuity occurred in 36% of patients. At 6 months, 33/50 patients (66%) demonstrated overall treatment response. Response to GC therapy was influenced by CAS, TSHRAb and smoking behavior. The only independent parameter associated with positive treatment response was CAS ≥4 (p<0.001). Side effects occurred in 35/50 patients (70%) and the vast majority of them were mild to moderate. During the 6-months follow-up period, 2/33 patients (6%) had relapsing GO.CONCLUSIONWith appropriate selection of patients and careful monitoring during and after treatment, combined parenteral and oral GC therapy is effective and safe.

Adrenal cortex function impairment in chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is defined as constellation of the prolonged fatigue and several somatic symptoms, in the absence of organic or severe psychiatric disease. However, this is an operational definition and conclusive biomedical explanation remains elusive. Similarities between the signs and symptoms of CFS and adrenal insufficiency prompted the research of the hypothalamo-pituitary-adrenal axis (HPA) derangement in the pathogenesis of the CFS. Early studies showed mild glucocorticoid deficiency, probably of central origin that was compensated by enhanced adrenal sensitivity to ACTH. Further studies showed reduced ACTH response to vasopressin infusion. The response to CRH was either blunted or unchanged. Cortisol response to insulin induced hypoglycaemia was same as in the control subjects while ACTH response was reported to be same or enhanced. However, results of direct stimulation of the adrenal cortex using ACTH were conflicting. Cortisol and DHEA responses were found to be the same or reduced compared to control subjects. Scott et all found that maximal cortisol increment from baseline is significantly lower in CFS subjects. The same group also found small adrenal glands in some CFS subjects. These varied and inconsistent results could be explained by the heterogeneous study population due to multifactorial causes of the disease and by methodological differences. The aim of our study was to assess cortisol response to low dose (1 µg) ACTH using previously validated methodology. We compared cortisol response in the CFS subjects with the response in control and in subjects with suppressed HPA axis due to prolonged corticosteroid use. Cortisol responses were analyzed in three subject groups: control (C) secondary adrenal insufficiency (AI), and in CFS. The C group consisted of 39 subjects, AI group of 22, and CFS group of nine subjects. Subject data are presented in table 1. Low dose ACTH test was started at 0800 h with the iv injection of 1 µg ACTH (Galenika, Belgrade, Serbia). Blood samples for cortisol determination were taken from the iv cannula at 0,15, 30, and 60 min. Data are presented as mean standard error (SE). Statistical analysis was done using ANOVA with the Games-Howell post-hoc test to determine group differences. ACTH dose per kg or per square meter of body surface was not different between the groups. Baseline cortisol was not different between the groups. However, cortisol concentrations after 15 and 30 minutes were significantly higher in the C group than in the AI group. Cortisol concentration in the CFS group was not significantly different from any other group (Graph 1). Cortisol increment at 15 and 30 minutes from basal value was significantly higher in C group than in other two groups. However there was no significant difference in cortisol increment between the AI and CFS groups at any time of the test. On the contrary, maximal cortisol increment was not different between CFS and other two groups, although it was significantly higher in C group than in the AI group. Maximal cortisol response to the ACTH stimulation and area under the cortisol response curve was significantly larger in C group compared to AI group, but there was no difference between CFS and other two groups. Several previous studies assessed cortisol response to ACTH stimulation. Hudson and Cleare analysed cortisol response to 1 µg ACTH in CFS and control subjects.They compared maximum cortisol attained during the test, maximum cortisol increment, and area under the cortisol response curve.There was no difference between the groups in any of the analysed parameters. However, authors commented that responses were generally low. On the contrary Scott et all found that cortisol increment at 30 min is significantly lower in the CFS than in the control group. Taking into account our data it seems that the differences found in previous studies papers are caused by the methodological differences. We have shown that cortisol increment at 15 and 30 min is significantly lower in CFS group than in C group. Nevertheless, maximum cortisol attained during the test, maximum cortisol increment, and area under the cortisol response curve were not different between the C and CFS groups. This is in agreement with our previous findings that cortisol increment at 15 minutes has the best diagnostic value of all parameters obtained during of low dose ACTH test. However, there was no difference between CFS and AI group in any of the parameters, although AI group had significantly lower cortisol concentrations at 15 and 30 minutes, maximal cortisol response, area under the cortisol curve, maximal cortisol increment, and maximal cortisol change velocity than C group. Consequently reduced adrenal responsiveness to ACTH exists in CFS. In conclusion, we find that regarding the adrenal response to ACTH stimulation CFS subjects present heterogeneous group. In some subjects cortisol response is preserved, while in the others it is similar to one found in secondary adrenal insufficiency.

Variability of HOMA and QUICKI insulin sensitivity indices

Abstract Assessment of insulin sensitivity based on a single measurement of insulin and glucose, is both easy to understand and simple to perform. The tests most often used are HOMA and QUICKI. The aim of this study was to assess the biological variability of estimates of insulin sensitivity using HOMA and QUICKI indices. After a 12-h fast, blood was sampled for insulin and glucose determination. Sampling lasted for 90 min with an intersample interval of 2 min. A total of 56 subjects were included in the study, and in nine subjects sampling was done before and after weight reduction, so total number of analyzed series was 65. To compute the reference value of the insulin sensitivity index, averages of all 46 insulin and glucose samples were used. We also computed point estimates (single value estimates) of the insulin sensitivity index based on the different number of insulin/glucose samples (1–45 consecutive samples). To compute the variability of point estimates a bootstrapping procedure was used using 1000 resamples for each series and for each number of samples used to average insulin and glucose. Using a single insulin/glucose sample HOMA variability was 26.18 ± 4.31%, and QUICKI variability was 3.30 ± 0.54%. For 10 samples variability was 11.99 ± 2.22% and 1.62 ± 0.31% respectively. Biological variability of insulin sensitivity indices is significant, and it can be reduced by increasing the number of samples. Oscillations of insulin concentration in plasma are the major cause of variability of insulin sensitivity indices.

Ambulatory blood pressure monitoring in patients with hyperthyroidism before the introduction of therapy and on therapy

The increased secretion of thyroid gland hormones affects the cardiovascular system by increasing heart rate and often by increasing systolic and diastolic blood pressure. We examined the influence of elevated thyroid hormone on blood pressure. Blood pressure monitoring was performed prior to the introduction of therapy in people with increased FT4 and on therapy when FT4 was in the normal range. We analyzed 32 people, of which 26 women had normal blood pressure values measured by blood pressure monitoring. Average age 45 and body mass index 27 kg / m. Blood pressure was measured by monitoring blood pressure for 24 hours. On average, before the introduction of the therapy, it was 133/83 mmHg P 96 / min. The blood pressure on average on therapy with tireosuppressive was 128/82 mmHg P 74 / min. The Wilcoxon-Mann-Whitney paired test showes a significant P <0.05 higher systolic blood pressure and pulse rate during the day and night before the treatment, when FT4 was higher, than the time when medication was taking, when the FT4 was in the normal range. No significant difference was found for diastolic blood pressure before the introduction of therapy and during therapy with tireosuppressives. When values of FT4 are increased, monitoring of blood pressure showes significantly higher values of systolic blood pressure and pulse during day and night compared to systolic blood pressure and pulse values when FT4 is in the normal range.