Milos Zarkovic

Prolonged psychological stress suppresses cortisol secretion

objective  Response to acute psychological stress is characterized by activation of the hypothalamic–pituitary–adrenal (HPA) axis and the sympathetic nervous system. However, response to the prolonged psychological stress is less well known.

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.

Effect of hyperglycemia and hyperinsulinemia on glutathione peroxidase activity in non-obese women with polycystic ovary syndrome

OBJECTIVE: In order to gain deeper insight into molecular mechanisms underlying oxidative stress (OS) and its relation to insulin resistance and hyperandrogenemia, plasma markers of OS and antioxidant glutathione-peroxidase (GPX) activity were studied in non-obese polycystic ovary syndrome (PCOS) women via the oral glucose tolerance test (OGTT) and hyperinsulinemic euglycemic clamp. DESIGN: In 36 PCOS women, plasma nitrotyrosine, thiol groups, uric acid (UA) and GPX activity were studied during OGTT and clamp. Insulin resistance was assessed by the homeostasis model (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), Matsuda insulin sensitivity index (ISI) and M/I ratio. RESULTS: In PCOS patients, significant positive correlations were obtained for UA with testosterone (r=0.385, p=0.039) as well as indices of insulin resistance. Acute hyperglycemia during OGTT induced alteration in both OS markers and GPX. The change in nitrotyrosine and GPX during OGTT correlated with testosterone (r=0.543, p=0.036 and r=−0.457, p=0.025, respectively). The most significant association was found between OS markers and ISI. CONCLUSIONS: Our results indicate that non-obese PCOS women are prone to oxidative stress induced by hyperglycemia, but this seems not to be related to the direct effect of hyperinsulinemia during clamp. Oxidative stress markers correlated with indices of insulin resistance and circulating testosterone.

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.

Gonadotropin pulsatility in Cushing's syndrome compared with polycystic ovary syndrome

Many of the presenting features in women with Cushings syndrome (CS) are similar to those observed for patients with polycystic ovary syndrome (PCOS). The aim of this study was to compare gonadotropin pulsatility characteristics in CS and PCOS. We evaluated 32 females divided into three groups. The first group comprised 12 females with clinically and biochemically proven CS, subsequently confirmed by histology (seven with Cushings syndrome, five with adrenal adenoma). The second group comprised ten females with clinical, endocrine and ultrasonographic parameters for PCOS, while the third group comprised ten healthy females with regular menstrual cycles to serve as controls. Blood samples were taken at 15-min intervals for 6 h in the follicular phase, for determination of luteinizing hormone (LH) and follicle-stimulation hormone (FSH). Pulse analysis was carried out using the PulsDetekt program, and statistical analysis was done using the Kruskal–Wallis test. The following data, presented as median (minimum–maximum), were found for the three groups respectively. Number of LH pulses: 0 (0–5), 7 (3–8) and 3 (2–7); LH pulse amplitude: 2.29 (1.98–3.49), 2.27 (1.15–5.90) and 2.03 (1.02–4.46) mU/l; LH pulse mass: 17.81 (14.82–26.20), 29.85 (8.59–185.82) and 27.57 (7.63–66.69) mU/l × min. Number of FSH pulses: 3 (0–3), 2 (0–5) and 3 (1–5); FSH pulse amplitude: 1.62 (1.29–1.94), 1.49 (1.19–4.40) and 2.02 (1.37–2.52) mU/l; FSH pulse mass: 12.17 (9.64–41.69), 11.18 (8.92–33.02) and 15.16 (10.31–18.93) mU/l × min. Only the number of pulses was compared because other parameters of pulsatile secretion cannot be estimated when no pulses are detected. The difference in number of LH pulses between groups was statistically significant (p < 0.05); however, there was no difference in the number of detected FSH pulses between groups (p > 0.05). Attenuation of pulsatile LH secretion indicating gonadotropin deficiency in the majority of women with CS is mostly due to alterations in serum cortisol levels. Our data also suggest that different mechanisms alter LH pulsatile secretion in CS and PCOS.

Temporal coupling of luteinizing hormone and follicle stimulating hormone secretion in polycystic ovary syndrome

The aim of this study was to assess the luteinizing hormone (LH) and follicle stimulating hormone (FSH) pulsatile secretion and their temporal relation (concordance) in subjects with polycystic ovary syndrome (PCOS). Fifteen subjects were included in the study (age 17–30 years ,body mass index (BMI) 19.38–33.46 kg/m2). For the LH and FSH determinations ,blood sampling started at 23.00 and lasted for 6 h with an intersample interval of 10 min. Pulse analysis was carried out using the PulsDetekt program. LH/FSH pulse concordance was calculated using the specific concordance index. Gonadotropin co-pulsatility was found in six subjects who were significantly younger than the others (median 18.5 vs. 22.5 years ,p = 0.036). BMI ,hirsutism grade ,insulin sensitivity ,estradiol ,progesterone, testosterone ,prolactin ,cortisol and results obtained from the pulsatility analysis did not significantly differ between the groups. A serum cortisol concentration was correlated with the increased LH/FSH lag time (ρ = 0.851 ,p = 0.036) all subjects were included. In conclusion ,two distinct LH/FSH secretory patterns were found in PCOS patients ,manifested by the presence or absence of the concordance of gonadotropin secretion. In the group where LH/FSH co-pulsatility was present ,correlation was found between the serum cortisol and the LH/FSH lag. We also confirmed the finding of previous studies that LH and FSH secretion are regulated by two different mechanisms.

Associations of GSTM1*0 and GSTA1*A genotypes with the risk of cardiovascular death among hemodialyses patients.

BackgroundThe presence of glutathione transferase (GST) M1 null genotype (GSTM1-null) in end-stage renal disease (ESRD) patients is associated with lower overall survival rate in comparison to those with GSTM1-active variants. We examined association between GSTM1 and GSTT1 deletion polymorphisms as well as SNPs in GSTA1/rs3957357 and GSTP1/rs1695 genes with overall and cause-specific cardiovascular mortality in ESRD patients.MethodsTotal of 199 patients undergoing hemodialysis were included in the study. Median value of time elapsed from dialysis initiation until the death, or the end of follow-up was 8 ± 5 years. The effect of GSTM1, GSTT1, GSTP1 and GSTA1 gene polymorphisms on predicting overall and specific cardiovascular outcomes (myocardial infarction, MI or stroke) was analyzed using Cox regression model, and differences in survival were determined by Kaplan-Meier.ResultsGSTM1-null genotype in ESRD patients was found to be independent predictor of overall and cardiovascular mortality. However, after false discovery rate and Bonferroni corrections this effect was lost. The borderline effect modification by wild-type GSTA1*A/*A genotype on associations between GSTM1-null and analyzed outcomes was found only for death from stroke. Homozygous carriers of combined GSTM1*0/GSTA1*A genotype exhibited significantly shorter time to death of stroke or MI in comparison with carriers of either GSTM1-active or at least one GSTA1*B gene variant. The best survival rate regarding cardiovascular outcome was found for ESRD patients with combined GSTM1-active and mutant GSTA1*B/*B genotype.ConclusionsCombined GSTM1*0/GSTA1*A genotypes might be considered as genetic markers for cardiovascular death risk in ESRD patients, which may permit targeting of preventive and early intervention.

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.