Sleep and active renin levels--interaction with age, gender, growth hormone and cortisol

AIMS

In young normal male subjects, plasma renin activity (PRA) shows large oscillations with a distinct association to the cyclic occurrence of rapid eye movement (REM) and non-REM (NREM) periods. Until now the sleep-related course of active renin levels is unknown. Furthermore, there are no data on the effects of age and gender on nocturnal renin and the interaction between these variables, sleep, growth hormone (GH) and cortisol.

METHODS

We investigated simultaneously sleep EEG (23:00-07:00 h) and the plasma concentrations (23:00-07:00 h) of active renin (in 10-min intervals) and of GH and cortisol (in 20-min intervals) in 47 healthy volunteers (24 women and 23 men) aged 19-69 years.

RESULTS

In the total sample, significant positive correlations were found between renin concentrations and NREM sleep and the sleep efficiency index, whereas a significant negative correlation exists to wakefulness. Renin shows also a positive correlation to GH levels which is restricted to the younger subjects (<40 years) during NREM sleep. No association exists between renin and cortisol. The averaged nocturnal mean renin levels were significantly lower in female than in male subjects, and in subjects older than 40 years than in younger subjects. Oscillations of active renin levels were found with increases during NREM periods and decreases during REM periods.

CONCLUSIONS

In all, nocturnal averaged renin levels are lower in women than in men, decrease during ageing and correlate positively with GH, whereas the interaction between renin and sleep is independent from age and gender.

Ghrelin affects the hypothalamus-pituitary-thyroid axis in humans by increasing free thyroxine and decreasing TSH in plasma

OBJECTIVE

Ghrelin promotes a positive energy balance, e.g. by increasing food intake. Stimulation of the activity of the hypothalamus-pituitary-thyroid (HPT) axis promotes a negative energy balance, e.g. by increasing energy expenditure. We therefore hypothesized that ghrelin suppresses the HPT axis in humans, counteracting its energy-saving effect.

DESIGN AND METHODS

In this single-blind, randomized, cross-over study, we determined secretion patterns of free triiodothyronine (fT(3)), free thyroxine (fT(4)), TSH, and thyroid-binding globulin (TBG) between 2000 and 0700 h in 20 healthy adults (10 males and 10 females, 25.3+/-2.7 years) receiving 50 microg ghrelin or placebo at 2200, 2300, 0000, and 0100 h.

RESULTS

FT(4) plasma levels were significantly higher after ghrelin administration than after placebo administration from 0000 h until 0620 h except for the time points at 0100, 0520, and 0600 h. TSH plasma levels were significantly lower from 0200 until the end of the study at 0700 h except for the time points at 0540, 0600, and 0620 h. The relative increase of fT(4) (area under the curve (AUC) 0130-0700 h (ng/dl x min): placebo: 1.31+/-0.03; ghrelin: 1.39+/-0.03; P=0.001) was much weaker than the relative decrease of TSH (AUC 0130-0700 h (mIU/ml x min): placebo: 1.74+/-0.12; ghrelin: 1.32+/-0.12; P=0.007). FT(3) and TBG were not affected.

CONCLUSIONS

This is the first study to report that ghrelin affects the HPT axis in humans. The early fT(4) increase was possibly induced by direct ghrelin action on the thyroid where ghrelin receptors have been identified. The TSH decrease might have been caused by ghrelin-mediated inhibition at hypothalamic level by feedback inhibition through fT(4), or both.

Modulation of the mineralocorticoid receptor as add-on treatment in depression: a randomized, double-blind, placebo-controlled proof-of-concept study

Preclinical and clinical studies have suggested a role of the mineralocorticoid receptor (MR) in the response to antidepressants. We tested in a proof-of-concept study whether adding fludrocortisone (an MR agonist) or spironolactone (an MR antagonist) accelerates onset of action and improves efficacy of escitalopram in patients with major depression. We included 64 in- and outpatients with major depression (Hamilton Depression Scale-17 score>18) in a double-blind, randomized, placebo-controlled trial. Patients were randomized in a 2:2:1 fashion to fludrocortisone (0.2 mg/d, n=24) or spironolactone (100 mg/d, n=27) or placebo (n=13) for the first 3 weeks during a 5-week treatment with escitalopram. No differences in mean HAMD change scores and in time to response emerged between treatments. However, among the responders, patients treated with fludrocortisone responded faster (Breslow test, p=0.05). The mean number of days to response was 16.0+/-2.6 days vs. placebo 22.2+/-2.0 vs. spironolactone 22.6+/-2.3 (F=3.78, p=0.03). In the whole group, plasma cortisol increased during spironolactone and decreased during fludrocortisone treatment (F=2.4, p=0.04). In patients treated with fludrocortisone, non-responders had elevated cortisol values compared to responders throughout the study period (F=5.1, p=0.04). Stimulation of MR with fludrocortisone as adjunct to escitalopram accelerated the response in the group of responders while no effect emerged in the sample as a whole. A larger randomized controlled trial is warranted.

Increased DHEA and DHEA-S plasma levels in patients with post-traumatic stress disorder and a history of childhood abuse

Current findings about dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEA-S) in patients with post-traumatic stress disorder (PTSD) have been inconsistent. We investigated whether a history of severe childhood traumatisation affects these steroids in PTSD patients. Patients of 33 with chronic PTSD (15 with and 18 without sexual and/or severe physical abuse before age 12) were studied in a combined low dose dexamethasone/corticotropin-releasing hormone (CRH) test. Mean pre-CRH levels of both plasma DHEA and DHEA-S were significantly increased in the subgroup with childhood abuse, the respective ratios with plasma cortisol were significantly lower. In the entire population of PTSD patients significant amounts of the variation of these parameters could be explained by childhood trauma history. Further studies are needed to clarify the potential role of DHEA and DHEA-S as biomarkers for severe early adverse events in patients suffering from PTSD and in other stress-related disorders.

Ghrelin plasma levels are not altered in major depression

BACKGROUND

In patients with major depression, the function of most endocrine axes is altered compared to healthy subjects. The orexigenic hormone ghrelin, which shows higher plasma levels in females than males, interacts with several of these endocrine axes. In addition, ghrelin levels in depressed patients decrease with psychopathological improvement. Therefore, we hypothesized that ghrelin levels in patients with major depression would be higher than in healthy subjects.

METHODS

Nocturnal (20:00-07:00 h) secretion patterns of ghrelin in 20 patients with major depression [11 females, age 39.4 +/- 10.2 years (mean +/- standard deviation); 9 males, age 38.3 +/- 10.4 years] with a total score on the Hamilton Depression Rating Scale, 21-item version, of 24.8 +/- 5.2 and 20 healthy subjects [11 females, age 38.7 +/- 10.8 years; 9 males, age 39.1 +/- 11.2 years] were determined following an adaptation night.

RESULTS

Ghrelin plasma levels of depressed patients and matched healthy subjects did not differ at any point in time when stratified for sex. Accordingly, the area under the curve was comparable: depressed females, 423.3 +/- 103.4; healthy females, 398.0 +/- 94.6; depressed males, 266.3 +/- 56.9, and healthy males, 228.4 +/- 41.3.

CONCLUSION

This is the first comparison of ghrelin secretion patterns in patients with major depression and healthy controls. Surprisingly, no relevant differences were ascertained between the two groups.

Tumor ZAC1 expression is associated with the response to somatostatin analog therapy in patients with acromegaly

Somatostatin analogs (SSA) with their potent antisecretory and antiproliferative effects are the main medical treatment option for patients with neuroendocrine tumors, such as gastroenteropancreatic and acromegaly-associated growth hormone secreting pituitary tumors. Although a good portion of acromegalic patients gets normalized after SSA treatment, strict hormonal control is not achieved in a sizeable proportion of these patients. The reasons for this incomplete response to SSA treatment are unclear. We have found that the tumor suppressor ZAC1 (LOT1/PLAGL1) is essential for the antiproliferative effect of SSA in pituitary tumor cells. The aim of the present retrospective cohort study was to determine whether ZAC1 immunoreactivity in archival somatotrophinoma tissue derived from 45 patients with acromegaly routinely pretreated with SSA before surgery, was associated with response to SSA (normalization of GH, IGF-I and presence of tumor shrinkage). All tumors displayed ZAC1 immunoreactivity [weak (+; n = 15), moderate (++; n = 16) and strong (+++; n = 14)]. A significant positive correlation was found between strong ZAC1 immunoreactivity and IGF-I normalization and presence of tumor shrinkage after SSA treatment, which was not affected by age at diagnosis, gender or duration of SSA treatment. These in vivo data combined with the antiproliferative properties of ZAC1/Zac1 provide evidence of a mechanistic role for this transcription factor on SSA induced tumor shrinkage and hormone normalization.

Heterogeneity of hypothalamic-pituitary-adrenal system response to a combined dexamethasone-CRH test in multiple sclerosis

The endocrine system participates in the regulation of the immune and neural systems and therefore hormonal factors probably play an important role in the development and course of multiple sclerosis (MS). Specifically, the hypothalamic-pituitary-adrenal (HPA) system seems crucial because (a) the inflammatory response is accompanied by HPA activation; (b) animal models with an inherited HPA defect are prone to developing experimental autoimmune encephalitis; and (c) most important, corticosteroids are still the most widely used treatment. We administered a recently developed neuroendocrine function test that combines dexamethasone suppression (1.5 mg orally at 2300 h) and corticotropin-releasing hormone (CRH) stimulation (100 micrograms i.v. at 1500 h the following day) and measured the response of plasma cortisol and corticotrophin (ACTH) secretion in 19 patients with an acute exacerbation of MS. These patients had a significantly higher mean plasma cortisol response than age-matched controls (peak minus baseline; 48.1 +/- 10.5 ng/ml [mean +/- SEM] versus 19.8 +/- 4.2 ng/ml; p < 0.05), but the corresponding ACTH values for the two groups were indistinguishable (13.4 +/- 1.4 pg/ml [mean +/- SEM] versus 11.3 +/- 1.4 pg/ml; n.s.). The response range in the patients was broader and we identified six patients with excessive cortisol release (peak minus baseline: 100.5 +/- 14.4 ng/ml [mean +/- SEM]), whereas four patients failed to respond at all. The hormonal response patterns were not related to previous treatments with corticosteroids or other immunosuppressants or to psychopathological features. These results point to a heterogeneity of HPA system function, most likely at the corticosteroid receptor level, which has clinical implications for all those treatments that affect the HPA system and the course of MS.

Ghrelin suppresses secretion of FSH in males

BACKGROUND

Ghrelin decreases the secretion of LH probably by suppressing the release of hypothalamic GnRH. So far however, there is no evidence that ghrelin affects also the secretion of FSH in humans, the other gonadotrophin regulated by GnRH.

OBJECTIVE

Our objective was to study the effect of ghrelin on secretion of FSH in humans. DESIGN/STUDY SUBJECTS: Nocturnal (20:00-07:00 h) secretion profiles of FSH were measured in 10 healthy males (25.3 +/- 3.2 years) twice, receiving 50 microg ghrelin or placebo at 22:00, 23:00, 24:00, and 01:00 h, in this single-blind, randomized, cross-over study.

RESULTS

Mean FSH plasma levels were significantly (P < 0.05) lower with ghrelin than placebo between 01:00 and 02:20. Consistently, a significant decrease from baseline was only observed in the ghrelin but not in the placebo condition.

CONCLUSION

This study provides first evidence that ghrelin suppresses the secretion of FSH in humans.

Outcome in delusional depression comparing trimipramine monotherapy with a combination of amitriptyline and haloperidol--a double-blind multicenter trial

BACKGROUND

Patients with delusional depression are difficult to treat. The atypical antidepressant trimipramine was effective in a previous 4-week open label pilot study in patients with this disorder. The major neurobiological effect of trimipramine is the inhibition of the hypothalamic-pituitary-adrenocortical (HPA) system. In delusional depression HPA overactivity is more distinct than in other subtypes of depression. HPA suppression is thought to contribute to the action of trimipramine.

METHODS

In a double-blind, randomized, placebo controlled multicenter trial we compared the effects of trimipramine monotherapy versus a combination of amitriptyline and haloperidol. Dosage was increased stepwise from 100mg up to 400mg trimipramine and from 100mg up to 200mg amitriptyline combined with 2mg up to 7.5mg haloperidol. The average dose of trimipramine was higher than that of amitriptyline throughout the trial. During sixth week mean dosage (+/-standard deviation) were 356.1+/-61.2mg trimipramine, 184.0+/-23.6 mg amitriptyline and 6.3+/-1.8 mg haloperidol. During six weeks psychometric assessments were performed weekly. For HPA monitoring a dexamethasone/corticotropin-releasing hormone (Dex/CRH) test was performed before active medication and at the end of treatment. Additionally tolerability was monitored by ECG, EEG assessment of extrapyramidal symptoms and akathisia, clinical laboratory routine and recording of blood pressure and heart rate. Adverse events were documented.

RESULTS

94 patients were enclosed into the study. The per protocol sample consisted of 33 patients of the trimipramine group and of 24 patients of the amitriptyline/haloperidol group. The decrease of the Hamilton depression (HAMD) score (24 items) showed non-inferiority of trimipramine compared to amitriptyline/haloperidol. Twenty-eight patients (84.84%) in the trimipramine arm and 17 patients (70.83%) in the amitriptyline/haloperidol arm were responders (HAMD <or=50%). Remission (HAMD<8) was found in 18 (54.55%) patients after trimipramine and in 11 (45.83%) patients after amitriptyline/haloperidol. No significant differences were found concerning response and remission. The cortisol and ACTH response in the Dex/CRH test decreased between days 1 and 42 in both groups. Serious side effects were not reported.

CONCLUSION

In all, trimipramine monotherapy appears to be an effective treatment in delusional depression.

A new strategy to analyze possible association structures between dynamic nocturnal hormone activities and sleep alterations in humans

The human sleep process shows dynamic alterations during the night. Methods are needed to examine whether and to what extent such alterations are affected by internal, possibly time-dependent, factors, such as endocrine activity. In an observational study, we examined simultaneously sleep EEG and nocturnal levels of renin, growth hormone (GH), and cortisol (between 2300 and 0700) in 47 healthy volunteers comprising 24 women (41.67 ± 2.93 yr of age) and 23 men (37.26 ± 2.85 yr of age). Hormone concentrations were measured every 20 min. Conventional sleep stage scoring at 30-s intervals was applied. Semiparametric multinomial logit models are used to study and quantify possible time-dependent hormone effects on sleep stage transition courses. Results show that increased cortisol levels decrease the probability of transition from rapid-eye-movement (REM) sleep to wakefulness (WAKE) and increase the probability of transition from REM to non-REM (NREM) sleep, irrespective of the time in the night. Via the model selection criterion Akaike's information criterion, it was found that all considered hormone effects on transition probabilities with the initial state WAKE change with time. Similarly, transition from slow-wave sleep (SWS) to light sleep (LS) is affected by a “hormone-time” interaction for cortisol and renin, but not GH. For example, there is a considerable increase in the probability of SWS-LS transition toward the end of the night, when cortisol concentrations are very high. In summary, alterations in human sleep possess dynamic forms and are partially influenced by the endocrine activity of certain hormones. Statistical methods, such as semiparametric multinomial and time-dependent logit regression, can offer ambitious ways to investigate and estimate the association intensities between the nonstationary sleep changes and the time-dependent endocrine activities.

The selective serotonin re-uptake inhibitor escitalopram modulates the panic response to cholecystokinin tetrapeptide in healthy men depending on 5-HTTLPR genotype

Selective serotonin re-uptake inhibitors, such as escitalopram, are currently the treatment of choice for patients with panic disorder. The panic response to intravenous cholecystokinin tetrapeptide, a potentially useful paradigm for volunteer translational studies, has so far not been investigated in healthy man after respective pre-treatment. In a double-blind, placebo-controlled, randomized, within subject cross-over design 30 healthy young men, 15 each with the long/long or short/short genotype for the serotonin transporter linked polymorphic region, were pre-treated with 10mg/d of escitalopram orally for six weeks and then challenged with 50 microg of cholecystokinin tetrapeptide. The primary outcome measure was the increase of Acute Panic Inventory ratings by cholecystokinin tetrapeptide. The increase of anxiety, tension and stress hormone secretion were secondary outcome measures. A significant treatment by genotype effect on the increases of Acute Panic Inventory ratings emerged. Panic induced by cholecystokinin tetrapeptide was significantly more pronounced in the short/short genotype subjects under escitalopram vs. placebo pre-treatment. With the exception of significantly elevated serum prolactin after escitalopram, no effects in the secondary outcome measures were detected. Contrary to our expectation, no inhibitory effect of escitalopram upon panic symptoms elicited by choleystokinin tetrapeptide could be demonstrated in healthy men. These findings do not support the potential usefulness of this panic model for proof-of-concept studies. The biological underpinnings of the increased panic symptoms after escitalopram in our volunteers with short/short genotype need further research.

No effect of six weeks of treatment with escitalopram on mood in healthy volunteers--irrespective of genotype for the promoter of the serotonin transporter

Data on emotional effects of chronic antidepressants in normal subjects are scarce and contradictory. Thirty healthy men were given 10 mg/day of escitalopram for 6 weeks in a double-blind, placebo-controlled, within-subject cross-over study. No significant effect on negative affect, positive affect, or state anxiety was detected, irrespective of serotonin transporter gene-linked polymorphism.

Progesterone reduces wakefulness in sleep EEG and has no effect on cognition in healthy postmenopausal women

Sleep is frequently impaired in postmenopausal women. Progesterone prompted benzodiazepine-like effects on sleep EEG in young normal male subjects. Aim of this study was to test if treatment with progesterone improves sleep after menopause. A randomised double blind crossover design study with 2 treatment intervals of 21 days duration separated by a 2 weeks washout was performed. An oral dose of 300 mg micronized progesterone was given each for 21 days. At the beginning and the end of the two intervals a sleep EEG was recorded and cognitive performance was assessed in 10 healthy postmenopausal women (age: 54-70 years). Progesterone treatment led to a decrease of intermittent time spent awake. During the first third of the night rapid eye movement (REM) sleep increased. The spectral analysis of the EEG resulted in no significant differences of the power spectra. Progesterone did not affect cognitive performance. In summary progesterone demonstrated a distinct sleep promoting effect by reduction of time of wake without impairing cognitive functions during daytime. As possible mechanisms of progesterone a GABA-agonistic effect and the regulation of gene expression via the progesterone receptor are discussed. Progesterone might be useful in the treatment of sleep disturbances of postmenopausal women.

Heritability of sleep electroencephalogram

BACKGROUND

Understanding the basis of sleep-related endophenotypes might help to pinpoint factors modulating susceptibility to psychiatric disorders. However, the genetic underpinnings of sleep microarchitecture in humans remain largely unknown. Here we report on the results of a classical twin study in monozygotic (MZ) and dizygotic (DZ) twin pairs examining the genetic effect on sleep electroencephalogram (EEG) composition.

METHODS

Polysomnographic recordings were obtained in 35 pairs of MZ (26.4 +/- 5.4 years, 17-43 years, 17 male pairs, 18 female pairs) and 14 same-gender pairs of DZ twins (22.1 +/- 2.7 years, 18-26 years, 7 male pairs, 7 female pairs). The EEG power spectra were generated on the basis of Fast Fourier transformations combined with conventional sleep parameters, according to standardized criteria.

RESULTS

We tested the genetic variance contributing to the observed overall variance of the sleep measures and found that the relative contributions of the delta, theta, alpha, and sigma frequency bands at central derivations were significantly correlated to the genetic background. In these frequency bands, MZ twins also showed within-pair concordance in spectral power that was significantly higher than that of DZ twins.

CONCLUSIONS

The broad overlap of EEG frequencies during non-REM sleep and wakefulness, which shows a significant genetic variance, supports the hypothesis of common neuronal mechanisms generating EEG oscillations in humans. Our findings strongly support the suitability of the spectral composition of non-REM sleep for defining endophenotypes.

A combined dexamethasone/corticotropin-releasing hormone test in patients with chronic PTSD--first preliminary results

BACKGROUND

Reports about alterations of hypothalamic-pituitary-adrenocortical (HPA) function in patients with chronic posttraumatic stress disorder (PTSD) are inconsistent and controversial. More refined laboratory tests and subgrouping of PTSD patients might help to decrease variance of findings.

METHODS

14 subjects with chronic PTSD and 14 healthy controls were examined between 13:00 and 17:00 using a modified combined dexamethasone/CRH test (0.5 mg dexamethasone at 23:00, 100 microg CRH at 15:00). Plasma adenocorticotropic hormone (ACTH), cortisol and blood pressure were measured every 15 min from 14:45 until 17:00.

RESULTS

No significant differences between patients and controls were found in the analyses of ACTH and cortisol levels, but a significantly elevated systolic and diastolic blood pressure in PTSD. Severity of depressive symptoms had no influence. However, explorative analyses showed that patients with a history of childhood traumatization had significantly higher post-dexamethasone-ACTH levels and a significantly lower diastolic blood pressure in comparison to patients without early trauma.

CONCLUSIONS

In this first pilot study in a typical clinical sample of patients with chronic PTSD we found effects of severe adverse events in childhood on HPA axis regulation. Maybe, childhood traumatization could influence HPA axis findings in PTSD. Further research is needed, especially dose-response studies with different doses of dexamethasone in dexamethasone/CRH tests in PTSD.

Ghrelin alone or co-administered with GHRH or CRH increases non-REM sleep and decreases REM sleep in young males

Ghrelin activates the somatotropic and the hypothalamic-pituitary-adrenal axes, being crucially involved in sleep regulation. Simplified, growth hormone releasing hormone (GHRH) increases slow-wave sleep and REM sleep in males, whilst corticotropin-releasing hormone (CRH) increases wakefulness and decreases REM sleep. Ghrelin's role in sleep regulation and particularly its interactions with GHRH and CRH are not entirely clear. We aimed to elucidate the interactions between ghrelin, GHRH and CRH in sleep regulation and the secretion of cortisol and GH. Nocturnal GH and cortisol secretion and polysomnographies were determined in 10 healthy males (25.7+/-3.0 years) four times, receiving placebo (A), ghrelin (B), ghrelin and GHRH (C), or ghrelin and CRH (D) at 22:00, 23:00, 00:00, and 01:00h, in this single-blind, randomized, cross-over study. Non-REM sleep was significantly (p<0.05) increased in all verum conditions (mean+/-SEM: B: 355.3+/-7.4; C: 365.4+/-8.1; D: 371.4+/-3.9min) compared to placebo (336.3+/-6.8min). REM sleep was decreased (B: 84.3+/-4.2 [p<0.1]; C: 74.2+/-7.0 [p<0.05]; D: 80.4+/-2.7min [p<0.05]) compared to placebo (100.9+/-8.3). CRH+ghrelin decreased the time spent awake and enhanced the sleep efficiency; furthermore, the REM latency was decreased compared to the other treatment conditions. CRH enhanced the ghrelin-induced cortisol secretion but had no relevant effect on GH secretion. In turn, GHRH enhanced the ghrelin-induced GH secretion but had no effect on cortisol secretion. In conclusion, ghrelin exhibited distinct sleep effects, which tended to be enhanced by both GHRH and CRH. CRH had sleep-improving and REM permissive effects when co-administered with ghrelin, being in contrast to the effect of CRH alone in previous studies.

Predictors of anterior pituitary insufficiency after traumatic brain injury

BACKGROUND

Several studies have reported a high prevalence of hypopituitarism after traumatic brain injury (TBI). Risk stratification is a prerequisite for cost-effective hormonal screening of these patients. However, it is still unclear which risk factors predispose patients to develop anterior hypopituitarism after TBI.

OBJECTIVE

To assess clinical and radiological risk factors for post-traumatic hypopituitarism.

PATIENTS AND METHODS

Seventy-eight consecutive patients (52 men, 26 women; mean age 36.0 years, range 18-65 years) with mild, moderate or severe TBI were studied. Endocrine and clinical parameters were assessed 3 and 12 months after TBI.

RESULTS

We found diffuse axonal injury, basal skull fracture and older age to be major risk factors of post-traumatic hypopituitarism.

CONCLUSIONS

We have defined specific risk factors for the development of post-traumatic hypopituitarism that are consistent with pathophysiological considerations. These findings might help to identify at-risk patients.

Increased nocturnal secretion of ACTH and cortisol in obsessive compulsive disorder

Information on the function of the hypothalamic-pituitary-adrenal (HPA) axis, the main mammalian system of stress response, in obsessive compulsive disorder (OCD) is inconsistent. In this study, nine inpatients with a DSM-IV diagnosis of OCD without comorbid major depression (Yale-Brown Obsessive Compulsive Scale [Y-BOCS] score >15; HAMD-21 total score 16) and nine healthy matched controls were included. Blood of patients (seven males; 31.8 +/- 9.3 years, Y-BOCS: 27.3 +/- 4.3, HAMD-21: 13.3 +/-1.9) and controls (seven males, 31.6 +/- 9.1 years) was drawn every 20 min between 23:00 and 7:00 h during sleep using a long catheter for later ACTH and cortisol analysis. Secretion patterns of cortisol and ACTH were similar in both groups, in OCD, however, at a higher level. Area under the curve plasma concentrations of both ACTH (p<0.05) and cortisol (p<0.005) were significantly greater in patients with OCD (ACTH: 674.3 +/- 57.4; cortisol: 2148.4 +/-271.7) than in controls (ACTH: 460.2 +/- 61.0; cortisol: 1191.2 +/- 124.1). In conclusion, our findings suggest that the activity of the HPA axis in patients with OCD is increased compared to healthy controls.

Systemic growth hormone-releasing hormone (GHRH) impairs sleep in healthy young women

In young male subjects peripherally administered growth hormone-releasing hormone (GHRH) enhances GH and slow wave sleep (SWS) and blunts cortisol. In contrast, in a sample of females 19-76-year old, GHRH impairs sleep and enhances adrenocorticotropic hormone (ACTH) and cortisol. In the latter study, the days of investigation were not adapted to the menstrual cycle and premenopausal and postmenopausal women as well were included. Placebo and GHRH were given during consecutive nights. In order to confirm or reject the sexual dimorphism of the effects of GHRH on sleep we applied an improved study design. In the present study we examined the effect of pulsatile administration of two dosages of GHRH (4x25 or 4x50 microg intravenously, respectively) on sleep electroencephalogram (EEG) and nocturnal hormone secretion in healthy young women according to a randomized schedule. To rule out the influence of gonadal hormone activity, the study was adapted to the phase of the menstrual cycle and was performed at 4-6th day of menstrual cycle. A carry-over effect was excluded by the interval of at least 4 weeks between examinations. Compared to placebo rapid-eye-movement sleep decreased during the first half of the night after 4x25 microg GHRH and sleep stage 4 decreased after 4x50 microg GHRH. After both dosages GH increased whereas ACTH and cortisol remained unchanged. This study confirms that systemic GHRH impairs sleep in women.

Ghrelin enhances the nocturnal secretion of cortisol and growth hormone in young females without influencing sleep

Ghrelin was shown to increase slow wave sleep (SWS) and the secretion of growth hormone (GH) and cortisol in young males. In terms of sleep, such information for females, however, is lacking. Therefore, polysomnographies were recorded (23:00-07:00 h) and nocturnal (20:00-07:00 h) secretion profiles of GH and cortisol were determined in 10 healthy females (24.9+/-2.4 years, body mass index: 21.2+/-1.1) twice, receiving four boluses of 50 microg ghrelin or placebo at 22:00, 23:00, 00:00, and 01:00 h, in this single-blind, randomized, cross-over study. No significant differences of conventionally or quantitatively analyzed sleep were observed between ghrelin and placebo condition. First administration of ghrelin caused a marked mean increase of GH by 53.3 to 64.4+/-14.2 ng/ml (placebo: 5.9+/-1.5 ng/ml) and cortisol by 54.2 to 96.4+/-15.3 ng/ml (placebo: 27.5+/-4.7 ng/ml). The following ghrelin injections were associated with smaller increases of GH and cortisol. In the ghrelin condition, GH plasma levels remained significantly (P<0.05) higher from 22:20 to 02:00 h and cortisol plasma levels from 22:20 to 02:20 h. In contrast to findings in young men, ghrelin did not affect sleep in young women, indicating a sexual dimorphism. In accordance with the findings in young men, ghrelin stimulated secretion of GH and cortisol.

Ghrelin suppresses secretion of luteinizing hormone in humans

CONTEXT

Ghrelin affects the hypothalamic-pituitary-gonadal axis in various nonhuman mammalians, predominantly by suppressing secretion of LH. However, for humans, no such evidence exists.

OBJECTIVE

Our objective was to study the effect of ghrelin on secretion of LH and testosterone in humans.

DESIGN, PARTICIPANTS, AND INTERVENTION

Nocturnal (2000-0700 h) secretion profiles of LH and testosterone were determined in 10 healthy males (25.7 +/- 3.0 yr) twice, receiving 50 microg ghrelin or placebo at 2200, 2300, 2400, and 0100 h, in this single-blind, randomized, cross-over study.

RESULTS

Ghrelin was associated with significantly (P < 0.05) lower mean plasma levels of both LH (2340-0200 h) and testosterone (0040-0300 h) than placebo. LH peak levels of the pulse after first administration of ghrelin/placebo were significantly (P = 0.014) smaller in the ghrelin (2.98 +/- 1.34 mIU/ml) than in the placebo condition (4.37 +/- 1.09 mIU/ml). In addition, the interval between this and the preceding peak was significantly (P = 0.010) longer in the ghrelin (255.8 +/- 79.1 min) than in the placebo condition (190.8 +/- 51.0 min). Significantly (P = 0.005) more LH pulses occurred with placebo (3.2 +/- 0.75) than ghrelin (2.6 +/- 0.7) subsequent to ghrelin/placebo administration.

CONCLUSIONS

Ghrelin caused both a delay and suppression of the amplitude of LH pulses. These findings are in accordance with those in nonhuman mammalians.

Sleep onset REM periods in obsessive compulsive disorder

Sleep studies in patients with obsessive compulsive disorder (OCD) are sparse and results inconsistent. Moreover, in 3 out of 4 published studies up to 50% of patients suffered from secondary major depression. In this study, 10 inpatients with a DSM-IV diagnosis of OCD without comorbid major depression (Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score >15; Hamilton Depression Rating Scale (HAMD)-21 total score <17) and 10 healthy matched controls were included. Polysomnography of patients (7 males, 3 females, 34.5+/-12.7 years, Y-BOCS: 27.8+/-4.6, HAMD-21: 13.3+/-1.9) and controls (7 males, 3 females, 34.4+/-12.8 years) was recorded, following an adaptation night. Sleep variables did not significantly differ in both groups except that stage 4 sleep was reduced in patients. Three of the patients with OCD, however, exhibited sleep onset REM periods (SOREMPs), i.e. rapid-eye-movement (REM) latencies <10 min. Obsessive compulsive symptoms were significantly (P<0.05) more severe in these patients (Y-BOCS: 32+/-2.0) compared to those without SOREMPs (Y-BOCS 26+/-4.2). This is, to our knowledge, the first report of sleep onset REM periods in OCD.

Time of interferon-β 1a injection and duration of treatment affect clinical side effects and acute changes of plasma hormone and cytokine levels in multiple sclerosis patients

During initiation of interferon-beta (IFN-β) therapy, many multiple sclerosis (MS) patients experience systemic side effects which may depend on the time point of IFN-β injection. We investigated the time course of plasma hormone-, cytokine- and cytokine-receptor concentrations after the first injection of IFN-β either at 8.00 a.m. (group A) or at 6.00 p.m. (group B) and quantified clinical side effects within the first 9 h in 16 medication free patients with relapsing-remitting MS. This investigation was repeated after 6-month IFN-β therapy.

Plasma ACTH and cortisol concentrations followed their physiological rhythms, with lower levels in the evening compared to the morning, but raised earlier and stronger in group B after IFN-β administration. IFN-β injection in the evening led to a prompter increase of plasma IL-6 concentrations and temperature during the first hours and correlated to more intense clinical side effects compared to group A. Plasma IL-10 concentrations increased more in group A compared to group B, but sTNF-RI and sTNF-RII concentrations raised 7 h after IFN-β injection only in group B. Acute effects on plasma hormone and cytokine concentrations adapted after 6-month IFN-β treatment, while diurnal variations were still present. Baseline sTNF-RII concentrations were elevated after 6-month IFN-β therapy only in group A.

Our results show that time point of IFN-β injection has differential effects on acute changes of plasma hormone and cytokine concentrations and is related to systemic side effects. This may have implications on the tolerability and effectiveness of IFN-β therapy. Multiple Sclerosis 2007; 13: 1138—1145. http://msj.sagepub.com

Acute and chronic neuroendocrine effects of interferon-beta 1a in multiple sclerosis

OBJECTIVE

Treatment of multiple sclerosis with interferon-beta (IFN-beta) results in variable responses interindividually. Cytokine-hormone interactions may modulate the therapeutic effects of IFN-beta. Since hyperactivity of the hypothalamo-pituitary-adrenal (HPA) axis and other neuroendorine disturbances occur in multiple sclerosis, we determined the detailed neuroendocrine response of patients with multiple sclerosis to IFN-beta.

DESIGN

Longitudinal open-label study.

PATIENTS

Eight patients with relapsing-remitting multiple sclerosis (four women, age 31.9 +/- 1.5 years, EDSS 1.5-2.5).

MEASUREMENTS

Plasma ACTH, cortisol, prolactin, GH, TSH, LH and FSH were determined in 30-min intervals during 8 h on four occasions: after intramuscular injection of saline; after the first dose of IFN-beta 1a; after the second IFN-beta dose with oral indomethacin pretreatment; and after 3 months of IFN-beta therapy. Dexamethasone-corticotropin-releasing hormone test was performed before and at 3 months on IFN-beta.

RESULTS

Compared to saline, IFN injection resulted in marked rise in plasma ACTH (mean, 370% of baseline), cortisol (214%), prolactin (253%) and GH (756%), between 2 and 6 h after injection. With indomethacin, hormone secretion occurred with reduced peak values. Endocrine response adapted partially after 3 months of treatment. HPA axis activity decreased in most patients, but increased in one patient with frequent relapses.

CONCLUSIONS

Marked neuroendocrine effects occur in response to IFN-beta in multiple sclerosis. Upon prolonged treatment, these effects partially adapt, and HPA axis hyperactivity is reduced. Prospective studies to determine the relation to individual treatment response can be based on these findings.

Blockade of the mineralocorticoid receptor in healthy men: effects on experimentally induced panic symptoms, stress hormones, and cognition

Animal studies have shown that blockade of central mineralocorticoid receptors (MR) has anxiolytic effects and impairs several aspects of cognitive function. No study to date assessed the effects of MR blockade on anxiety and cognitive function in humans. In the present study, 16 healthy young men were treated either with placebo or with 300 mg spironolactone, a MR-antagonist, at 1100, 1330, and 1630 hours in a balanced cross-over design with the two study conditions being 1 week apart. At 1500 hours, the panic symptoms provoking compound cholecystokinin-tetrapeptide (CCK-4) was administered i.v. on both occasions and panic symptoms were assessed. We measured plasma ACTH and cortisol between 1300 and 1900 hours and assessed cognitive function between 1800 and 1900 hours. CCK-4 elicited panic symptoms and increased ACTH and cortisol secretion in both conditions. Intensity of panic symptoms after CCK-4 was not different between spironolactone and placebo. Spironolactone significantly impaired selective attention and delayed recall of visuospatial memory, and diminished set shifting/mental flexibility on a trend level. Pretreatment with spironolactone led to higher baseline cortisol levels compared to placebo whereas no differences in stimulated cortisol, baseline ACTH, and stimulated ACTH emerged. Blockade of MR with spironolactone increases baseline cortisol secretion and impairs cognitive function but has no effect on experimentally induced panic symptoms in humans, for the study design and dosage of spironolactone used. The domains of cognitive function that are impaired after blockade of MR in men, that is, selective attention, visuospatial memory, and mental flexibility/set shifting appear to be remarkably similar to those described in animal studies.

Blood-brain barrier penetration and pharmacokinetics of amitriptyline and its metabolites in p-glycoprotein (abcb1ab) knock-out mice and controls

In earlier studies with P-gp (abcb1) knock-out mice, we showed that P-gp exports the antidepressants citalopram, paroxetine, venlafaxine and amitriptyline and its metabolites across the blood-brain barrier, thereby reducing cerebral bioavailability of some substances up to 9 times. The present study investigated the pharmacokinetics of amitriptyline and whether abcb1ab double knock-out mice metabolize amitriptyline and its metabolites differently. P-gp knock-out mice and controls received a s.c. injection of 10mug amitriptyline/g of body weight. The animals were sacrificed after 30, 60, 120 and 240min and concentrations of amitriptyline and its metabolites were measured with HPLC in brain, plasma, liver, kidney, spleen, lung, muscle, fat and ovaries. Cerebral concentrations of amitriptyline and its metabolites were higher in P-gp-deficient mice compared to controls. No significant group effect was found for spleen, liver, lung, kidney and fat tissue. The results of our study indicate that amitriptyline and its metabolites are substrates of P-gp. Overall pharmacokinetics between knock-outs and controls were very similar. This confirms the validity of the P-gp knock-out model and allows for a continued research of the interactions between P-gp, the blood-brain barrier and CNS substances such as antidepressants, neuroleptics and others.

Altered nocturnal growth hormone (GH) secretion in obsessive compulsive disorder

Nocturnal patterns of growth hormone (GH) in obsessive compulsive disorder (OCD), which is physiologically released predominantly during the first half of night, have not been reported. However, altered GH responses to pharmacological challenges suggest a disturbed function of the somatotropic axis in OCD. In this study, nine inpatients with a DSM-IV diagnosis of OCD without comorbid major depression (Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score >15; HAMD-21 total score 16) and 9 healthy matched controls were included. Blood of patients (7 males, 31.8+/-9.3 years, Y-BOCS: 27.3+/-4.3, HAMD-21: 13.3+/-1.9) and controls (7 males, 31.6+/-9.1 years) was drawn every 20 min between 2300 and 0700 h during sleep using a long catheter for later GH analysis. Mean plasma GH levels peaked at 0040 h, however this peak was significantly blunted in patients (maximum 4.3+/-1.5 ng/ml) compared to controls (maximum 12.3+/-4.0 ng/ml; p<0.05). In patients but not controls two other, smaller peaks were observed (0220 and 0620 h). In patients but not in controls, GH values exceeding maximum GH values of the peak at 0040 h were observed already at 2300 h or during the second half of night. In conclusion, our results indicate that the nocturnal GH secretion in patients with OCD is altered compared to controls.