The renin secretion profile under the influence of sleep deprivation and the neuropeptides CRH and GHRH

It is already known that during normal sleep plasma renin activity (PRA) shows oscillations with decreases during rapid-eye-movement (REM) sleep and increases during non-REM (NREM) sleep. We also know that renin correlates positively with slow-wave sleep (SWS). Sleep deprivation is known to enhance significantly SWS and slow wave activity (SWA, known as δ power). Based on these findings we addressed the question whether and to which extent sleep deprivation may affect the synchronization found between PRA and REM sleep during normal sleep and whether this synchronization is affected by other sleep regulating factors. To investigate these questions we compared sleep EEG and sleep-related free renin levels in 48 normal women and men 19-69 years old between nights before and after 40 h of sleep deprivation. During the recovery night, four bolus injections of either GHRH, CRH or placebo were injected via long catheter around sleep onset. When compared to baseline after each of the treatments SWS, SWA and renin levels increased. The characteristical oscillation profiles of renin during normal sleep were also preserved after sleep deprivation. Similar to normal sleep our data support also a distinct link between nocturnal renin secretion and SWS after sleep deprivation and that independent of the applied treatments.

Sleep after intranasal progesterone vs. zolpidem and placebo in postmenopausal women - A randomized, double-blind cross over study

CONTEXT

The loss of progesterone during menopause is linked to sleep complaints of the affected women. Previously we demonstrated sleep promoting effects of oral progesterone replacement in postmenopausal women. The oral administration of progesterone, however, is compromised by individual differences in bioavailability and metabolism of the steroid.

OBJECTIVE

We compared the sleep-endocrine effects after intranasal progesterone (MPP22), zolpidem and placebo in healthy postmenopausal women.

DESIGN

This was a randomized double-blind cross-over study.

SETTING

German monocentric study PARTICIPANTS: Participants were 12 healthy postmenopausal women.

INTERVENTIONS

Subjects received in randomized order four treatments, 2 doses of intranasal progesterone (4.5 mg and 9 mg of MPP22), 10 mg of zolpidem and placebo.

OUTCOME MEASURES

Main outcome were conventional and quantitative sleep-EEG variables. Secondary outcomes were the subjective sleep variables and the sleep related concentrations of cortisol, growth hormone (GH), melatonin and progesterone.

RESULTS

Sleep promoting effects were found after the higher dosage of MPP22 and after zolpidem. Zolpidem prompted benzodiazepine-like effects on quantitative sleep EEG as expected, whereas no such changes were found after the two dosages of MP22. Nocturnal progesterone levels increased after 9.0 mg MPP22. No other changes of hormone secretion were found.

CONCLUSIONS

Our study shows sleep promoting effects after intranasal progesterone. The spectral signature of intranasal progesterone did not resemble the sleep-EEG alterations induced by GABA active compounds. Progesterone levels were elevated after 9.0 mg MPP22. No other endocrine effects were observed.

Corticotropin-releasing hormone induces depression-like changes of sleep electroencephalogram in healthy women

We reported previously that repetitive intravenous injections of corticotropin-releasing hormone (CRH) around sleep onset prompt depression-like changes in certain sleep and endocrine activity parameters (e.g. decrease of slow-wave sleep during the second half of the night, blunted growth hormone peak, elevated cortisol concentration during the first half of the night). Furthermore a sexual dimorphism of the sleep-endocrine effects of the hormones growth hormone-releasing hormone and ghrelin was observed. In the present placebo-controlled study we investigated the effect of pulsatile administration of 4×50μg CRH on sleep electroencephalogram (EEG) and nocturnal cortisol and GH concentration in young healthy women. After CRH compared to placebo, intermittent wakefulness increased during the total night and the sleep efficiency index decreased. During the first third of the night, REM sleep and stage 2 sleep increased and sleep stage 3 decreased. Cortisol concentration was elevated throughout the night and during the first and second third of the night. GH secretion remained unchanged. Our data suggest that after CRH some sleep and endocrine activity parameters show also depression-like changes in healthy women. These changes are more distinct in women than in men.

Does Pregnenolone Enhance Exposure Therapy in Obsessive-Compulsive Disorder? - A Pilot, Interim Report of a Randomized, Placebo-Controlled, Double-Blind Study

Exposure therapy is an effective cognitive-behavioral treatment for patients with obsessive-compulsive disorder (OCD). However, a further amelioration of symptoms by additional drugs that enhance extinction learning is desirable. An interesting candidate is pregnenolone, which positively modulates NMDA and GABAA receptors in preclinical studies and influences amygdala and prefrontal activity in humans. We present pilot data showing high acceptance and good tolerability of pregnenolone given 2 h before exposure sessions in OCD patients. As per our interim analyses, exposure treatment resulted in significantly improved main outcome parameters, but no effects of pregnenolone vs. placebo pretreatment were detectable thus far.

Interferon β-1a reduces increased interleukin-16 levels in multiple sclerosis patients

OBJECTIVES

There is convergent evidence for an important role of interleukin-16 (IL-16) in the pathogenesis of multiple sclerosis (MS). IL-16 serves as a chemoattractant for different immune cells that are involved in developing lesions. Here, we compared IL-16 levels of MS patients and controls and addressed the long-term effect of IFN-β, the most common immunomodulatory MS therapy, on IL-16 serum levels in MS patients over 2 years. Beyond this, we analysed the expression of IL-16 in two CD4(+) T-cell subsets, Th1 and Th17 cells, which are important autoimmune mediators and affected by IFN-β treatment, derived from myelin-specific T-cell transgenic mice.

MATERIALS AND METHODS

IL-16 serum levels of 17 controls and of 16 MS patients before therapy and at months 1, 2, 3, 6, 9, 12 and 24 during IFN-β1a therapy were determined by ELISA. MRI was performed before therapy, at months 12 and 24. IL-16 expression of in vitro differentiated murine myelin oligodendrocyte glycoprotein (MOG)-specific Th1 and Th17 cells was quantified by real-time PCR.

RESULTS

Before therapy, MS patients showed significantly elevated IL-16 levels compared with controls irrespective of disease activity determined by MRI. Therapy with IFN-β1a led to a significant linear decrease in IL-16 serum levels beginning after 2 months. MOG-specific Th17 cells expressed more IL-16 than Th1 cells.

CONCLUSIONS

Reduction in increased IL-16 levels may be of relevance for the therapeutic effect of IFN-β1a in MS. Easily accessible IL-16 serum levels hold a potential as biomarker of treatment efficacy in MS.

Polymorphisms of the drug transporter gene ABCB1 predict side effects of treatment with cabergoline in patients with PRL adenomas

INTRODUCTION

Treatment with dopamine agonists in patients with prolactin (PRL) adenomas and Parkinson's disease is associated with central side effects. Central side effects may depend on a substance's ability to pass the blood-brain barrier, which can be actively controlled by transporter molecules such as the P-glycoprotein (P-gp) encoded by the ABCB1 gene.

MATERIALS AND METHODS

We aimed to determine whether cabergoline is transported by the P-gp and whether polymorphisms of its encoding ABCB1 gene predict central side effects of cabergoline therapy in patients with PRL adenomas. i) In an experimental mouse model lacking the homologues of the human ABCB1 gene (Abcb1ab double knockout mouse model), we examined whether cabergoline is a substrate of the P-gp using eight mutant and eight wild-type mice. ii) In a human case-control study including 79 patients with PRL adenomas treated with cabergoline at the Max Planck Institute of Psychiatry in Munich, we investigated the association of four selected ABCB1 gene single nucleotide polymorphisms (SNPs) (rs1045642, rs2032582, rs2032583 and rs2235015), with the occurrence of central side effects under cabergoline therapy.

RESULTS

i) In the experimental mouse model, we observed that brain concentrations of cabergoline were tenfold higher in the mutant mice compared with their wild-type littermates, implying that cabergoline is indeed a substrate of the transporter P-gp at the blood-brain barrier level. ii) In the human study, we observed significant negative associations under cabergoline for the C-carriers and heterozygous CT individuals of SNP rs1045642 with two central side effects (frequency of fatigue and sleep disorders) and for the G-carriers of SNP rs2032582 with the enhancement of dizziness. For the SNPs rs2235015 and rs2032583, no associations with central side effects under cabergoline were found.

DISCUSSION

This is the first study demonstrating that individual ABCB1 gene polymorphisms, reflecting a different expression and function of the P-gp, could predict the occurrence of central side effects under cabergoline. Our findings can be viewed as a step into personalised therapy in PRL adenoma patients.

FC24-03 - Lack of cortisol response during exposure therapy in patients with obsessive-compulsive disorder

Introduction

Exposure therapy with response prevention (ERP) is the most effective treatment for patients with obsessive-compulsive disorder (OCD), but associated with considerable temporary stress during initial sessions.

Objectives

Amazingly, only scant information is available about stress hormone release during exposure therapy and its implication on therapy outcome in OCD.

Aims

To characterize hypothalamic-pituitary-adrenocortical activation during ERP treatment in OCD.

Methods

15 patients with OCD were studied twice from 13:00 to 16:00 - on the day before and of their first ERP therapy session (14:00 to 15:00). Subjective units of distress (SUD, 100 mm visual analogue scale) and salivary cortisol concentrations were assessed every 20 minutes.

Results

Before and during (but not after) ERP SUD were significantly increased versus the control day (mean SUD before ERP: 49.8 vs. 31.4, mean peak vaules during ERP: 72.6 vs. 34.0). Salivary cortisol decresed significantly during the study period (as expected according to the regular diurnal rhythm), but no significant differences between ERP and the control day were detected at any time point.

Conclusions

Despite clear-cut psychological stress before and during ERP, no increased release of cortisol was observed. Our findings resemble respective results in panic disorder. Possible neurobiological underpinnings of this unexpected regulatory pattern will be discussed. Furthermore, we will speculate on the impact of lacking cortisol response on extinction learning during ERP.

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.

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.

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.

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

Growth hormone-releasing hormone and corticotropin-releasing hormone enhance non-rapid-eye-movement sleep after sleep deprivation

The neuropeptides growth hormone (GH)-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) regulate sleep and nocturnal hormone secretion in a reciprocal fashion, at least in males. GHRH promotes sleep and GH and inhibits hypothalamo-pituitary-adrenocortical (HPA) hormones. CRH exerts opposite effects. In women, a sexual dimorphism was found because GHRH impairs sleep and stimulates HPA hormones. Sleep deprivation (SD) is the most powerful stimulus for inducing sleep. Studies in rodents show a key role of GHRH in sleep promotion after SD. The effects of GHRH and CRH on sleep-endocrine activity during the recovery night after SD are unknown. We compared sleep EEG, GH, and cortisol secretion between nights before and after 40 h of SD in 48 normal women and men aged 19-67 yr. During the recovery night, GHRH, CRH, or placebo were injected repetitively. After placebo during the recovery night, non-rapid-eye-movement sleep (NREMS) and rapid-eye-movement sleep (REMS) increased and wakefulness decreased compared with the baseline night. After GHRH, the increase of NREMS and the decrease of wakefulness were more distinct than after placebo. Also, after CRH, NREMS increased higher than after placebo, and a positive correlation was found between age and the baseline-related increase of slow-wave sleep. REMS increased after placebo and after GHRH, but not after CRH. EEG spectral analysis showed increases in the lower frequencies and decreases in the higher frequencies during NREMS after each of the treatments. Cortisol and GH did not differ between baseline and recovery nights after placebo. After GHRH, GH increased and cortisol decreased. Cortisol increased after CRH. No sex differences were found in these changes. Our data suggest that GHRH and CRH augment NREMS promotion after SD. Marked differences appear to exist in peptidergic sleep regulation between spontaneous and recovery sleep.