The etiology of Alzheimer’s disease (AD) has not been as yet completely defined. Genetic, environmental and neurophysiological aspects should all be taken into account. The disease has also neuroendocrine implications, some of which are discussed in this review. It is known that stress and glucocorticoids may affect neurone survival. On the contrary, some data indicate that DHEA and DHEAS exert a neuroprotective action. In AD, changes in hypothalamic-pituitary-adrenal axis function have been reported. Experimental and clinical evidence indicates that glucocorticoid hypersecretion and DHEAS levels decrement may add to hippocampal dysfunction in aging and in AD. Glucocorticoid and Σ-amyloid concur in the mechanism of neurone damage, as well as excitatory amino acids (EAA), Ca++ and reactive oxygen species (ROS). The neuroprotective effects exerted by IGFs are also hindered in aging and even more in AD. Production and biological actions of IGFs are negatively influenced by cortisol hypersecre-tion and DHEAS decrease in patients with AD.
Subjects with anorexia nervosa (AN) present a number of changes in autonomic system functions, such as thermoregulation, vascular motility, heart rate and rhythm, and blood pressure. We evaluated the changes in the autonomic control of heart rate and blood pressure after postural variation by means of the spectral analysis of R-R interval variability (HRV) in 13 female subjects with AN diagnosed on the basis of diagnostic statistical manual (DSM-IV) criteria, a mean age of 25±5.8 years and a mean body mass index (BMI) of 16.9±2.6. The controls were 16 healthy female subjects with a mean age of 25±2.3 years and a normal BMI. The data were statistically evaluated by means of one-way analysis of variance or Student’s t test. The high frequency (HF) components of the spectral analysis did not significantly change when passing from clino- to orthostatism in the AN subjects, but there were significant changes in the controls. The changes in the low frequency (LF) components were similar in both groups, but smaller in the AN subjects. However, the difference between the two series was not statistically significant. The variance in the orthostatic R-R intervals recorded in the AN subjects was significantly less than the clinostatic intervals, the intervals recorded in the controls. These results indicate that AN subjects show signs of autonomic dysfunction. The increase in the HF component of the spectral analysis suggests that parasympathetic modulation is abnormally persistent during orthostatism; furthermore, the variability of the R-R intervals indicates that orthosympathetic regulation is also altered in AN.
ABSTRACT. Changes in the hypothalamus-pituitary- adrenal axis (HPAA) function, entailing elevated cortisol circulating titres, occur in aging and in some neurological conditions, such as Alzheimer’s disease (AD). Excess cortisol has neurotoxic effects which affect hippocampal neurones. Dehydroepiandrosterone sulphate (DHEAS) has an antiglucocorticoid activity and neuroprotective effects, but its levels decrease with aging. Glucocorticoids influence the production of insulin-like growth factor-I (IGF-I) and modify its systemic and neurotrophic biological activity by inducing changes in IGF-binding proteins (IGFBPs). We looked for relationships between cortisol, DHEAS levels, and IGF-I - IGFBPs system in AD. Cortisol, DHEAS and GH levels at 02:00, 08:00, 14:00, 20:00 h, basal IGF-I, IGFBP-1 and IGFBP-3 levels were determined by RIAs or IRMA in 25 AD patients, aged 58-89 yr, and in 12 age-matched healthy controls. AD subjects had higher cortisol, lower DHEAS levels and increased cortisol/DHEAS ratio (C/Dr) than controls. In AD cases, total IGF-I, IGFBP-3, and IGF-I/IGFBP ratios were significantly lowered, while IGFBP-1 levels were significantly higher than in controls. We found a significant inverse correlation between IGF-I and IGFBP-3 levels vs C/Dr, and between both IGF-I/IGFBPs ratios vs mean cortisol levels. IGFBP-3 correlated directly with DHEAS. Cortisol was directly and IGF-I inversely correlated with cognitive impairment. In AD patients we found that alterations in HPAA function and elevated C/Dr are related to lowered total and free IGF-I levels. These findings and their relationship to cognitive impairment suggest that changes in hormonal set-up might influence the clinical presentation of the disease.
The hippocampus is involved in Alzheimer's disease (AD) and regulates the hypothalamus-pituitary-adrenal axis (HPAA). Enhanced cortisol secretion has been reported in AD. Increased cortisol levels affect hippocampal neuron survival and potentiate beta-amyloid toxicity. Conversely, dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are believed to antagonize noxious glucocorticoid effects and exert a neuroprotective activity. The present study was aimed at investigating possible correlations between hippocampus perfusion - evaluated by SPECT - and HPAA function in AD. Fourteen patients with AD and 12 healthy age-matched controls were studied by (99m)Tc-HMPAO high-resolution brain SPECT. Plasma adrenocorticotropin, cortisol, and DHEAS levels were determined at 2.00, 8.00, 14.00, 20.00 h in all subjects and their mean values were computed. Cortisol/DHEAS ratios (C/Dr) were also calculated. Bilateral impairment of SPECT hippocampal perfusion was observed in AD patients as compared to controls. Mean cortisol levels were significantly increased and DHEAS titers were lowered in patients with AD, as compared with controls. C/Dr was also significantly higher in patients. Using a stepwise procedure for dependent SPECT variables, the variance of hippocampal perfusional data was accounted for by mean basal DHEAS levels. Moreover, hippocampal SPECT data correlated directly with mean DHEAS levels, and inversely with C/Dr. These data show a relationship between hippocampal perfusion and HPAA function in AD. Decreased DHEAS, rather than enhanced cortisol levels, appears to be correlated with changes of hippocampal perfusion in dementia.
Alterations in the hypothalamic-pituitary-adrenal axis (HPAA) and failure of dexamethasone (DXT) to suppress cortisol secretion occur in Alzheimer’s disease (AD). This study was aimed to settle possible differences in some clinical (age, body weight, body mass index, dementia severity) and hormonal parameters in AD patients non-responders to overnight 1 mg-DXT suppression test compared with the responder subjects. ACTH, cortisol and dehydroepiandrosterone sulphate (DHEAS) day-time levels were assessed in 25 AD patients and in 12 age-matched healthy controls before DXT administration. In view of their neuroprotective effects, plasma levels of Insulin-like Growth Factor-I (IGF-I) and of IGF-Binding Proteins (IGFBPs) were also determined. After DXT, 8 AD subjects (32%) showed cortisol levels above the conventional cut-off of 140 nmol/L. No significant differences were found in clinical parameters in suppressor vs nonsuppressor patients. AD subjects showed higher cortisol, cortisol/DHEAS ratios, and lower DHEAS levels in comparison with controls. Both ACTH and cortisol levels were not different in suppressor and nonsuppressor patients, but DHEAS levels were significantly lower in nonsuppressor cases, who also exhibited ACTH and cortisol periodicities more altered than in suppressor and in control subjects. IGF-I and IGFBP-3 levels were lower and those of IGFBP-1 higher in nonsuppressor than in suppressor cases and in healthy controls. IGF-I/IGFBPs system data were correlated with cognitive impairment and adrenal steroid levels in AD patients.
Serum levels of sex-hormones, sex-hormone binding globulin, gonadotropin, and prolactin were evaluated during the follicular and the luteal phases in 65 women with epilepsy and in 20 healthy controls. Twenty-one patients were treated with sodium valproate (VPA), 21 with phenobarbital (PB), and 23 with carbamazepine (CBZ). VPA does not stimulate liver microsome enzymes, whereas PB and CBZ do. Patients on VPA therapy showed higher body weight and body mass index, but no significant differences in hirsutism score, or in ovary volume or polycystic ovary prevalence (at ultrasound examination). Estradiol levels were lower in all patient groups than in healthy controls in the follicular but not in the luteal phases. VPA affected luteal progesterone surge in 63.6% of cases. This effect was significantly lower in the CBZ and PB groups. Furthermore, increases in testosterone and delta 4-androstenedione levels and in free androgen index, along with a higher luteinizing hormone-follicle-stimulating hormone ratio in the luteal phase, were observed in women treated with VPA. Although sex-hormone binding globulin levels were higher in CBZ and PB than in VPA-treated patients, the differences were not significant because of the wide dispersion of the carrier protein levels. Inducer antiepileptic drugs decreased dehydroepiandrosterone sulfate levels, which remained unchanged during VPA treatment. No significant differences occurred in basal gonadotropin and prolactin levels.
Basal growth hormone (GH) and Insulin-like growth factor I(IGF-I) as well as GH responses to GH-releasing hormone (GHRH) were studied in 22 subjects (7 females, 15 males), aged between 65 and 86 years. The study was aimed at Basal growth hormone (GH) and insulin-like growth factor I(IGF-I) as well as investigating the possible correlations between the age-dependent GH-IGF-I axis decline and the cognitive function - assessed by the Mini Mental State Examination (MMSE). The relationship between hormonal data, cognition and age, body weight, body mass index (BMI), some nutritional indices (triceps skinfolds, TSF, mid-arm circumference, MAC), and physical activity quantified by the physical functioning index (PFI) - were also analyzed. GH basal levels were within the normal range, while GH responses to GHRH were blunted in most cases. GH peaks after GHRH were directly correlated with GH basal values. IGF-I serum levels were found to be in the lower part of the reference range for adult subjects or below it. GH responses to GHRH, but not GH and IGF-I basal levels, were inversely correlated with subject age. GH secretion areas after GHRH were inversely correlated with BMI, but no further correlations between GH data and clinical or nutritional parameters were found. MMSE values directly correlated with MAC and PFI values. IGF-I levels were directly correlated with MMSE scores, being lowered in patients with more advanced cognitive deterioration, and with MAC values - the decrease of which is thought to reflect protein caloric malnutrition - but not with body weight, BMI, TSF and PFI. MMSE-related protein caloric malnutrition and decreased physical activity possibly take part in affecting IGF-I function in subjects with mild cognitive impairment and, reciprocally, IGF-I decrement might affect neuronal function.
Impaired reproductive function is thought to frequently affect women with epilepsy, mainly when seizures originate in the temporal lobe. In this study, we evaluated menstrual cycle features and assessed ovulation by determining luteal progesterone (Pg) levels in 101 consecutive women with epilepsy (36 with idiopathic generalized epilepsy -IGE; 65 with partial epilepsy -PE), aged between 16 and 50 years, treated with various antiepileptic drugs (AED). PE originated in the temporal lobe (TLE) in 40 subjects, in the frontal lobe in 13, in the parietal lobe in 2, while the origin of focal seizures remained undetermined in 10 patients. In all patients, menstrual and reproductive history, body mass index, hair distribution and hormonal pattern were assessed. Suprapubic ovary ultrasound (US) examination was carried out in 83 patients (28 with IGE, 55 with PE). Three patients with IGE and one with PE were amenorrheic. Oligomenorrhea occurred in 16 patients, polymenorrhea in 2. Changes in menstrual cyclicity were independent from epilepsy type (19.4% in IGE; 23.1% in PE) and from origin of focal discharges (22.5% of patients with TLE; 20.0% with origin in other brain areas). Luteal Pg levels remained below 2 ng/ml in 30 patients independently of epilepsy type. Corpus luteum dysfunction was combined with hyperandrogenism in 15 of these patients. In the other cases different alterations of hypothalamus-pituitary-ovary axis were observed. Valproic acid blunted luteal Pg surge more frequently than other AED. Polycystic ovaries (PCO) were observed in 14 (16.9%) patients (21.0% with IGE; 14.5% with PE). These prevalences are not higher than those reported in the general population. Among PE patients, PCO was found in 1 case with undertemined focal origin and in 7 TLE cases, who also had ovary volume significantly larger than patients with seizures originating from the frontal or parietal lobe. Epileptic women exhibited an increased occurrence of multifollicular ovaries (MFO) found in 12 cases (14.4% vs 5% in the general population). However, no defined hormonal or clinical pictures were associated with this US alteration in most patients. These findings reappraise the impact of ovary alterations in women mainly affected by mild to moderate epilepsy, on differing AED regimens, with the exception of more frequent ovulatory dysfunction and PCO occurrence in patients taking VPA.
Sex steroid peripheral pattern, pulsatile luteinizing hormone (LH) secretion, gonadotropin and prolactin responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) were studied in 35 male epileptics treated with phenobarbital (PB), carbamazepine (CBZ), or phenytoin (PHT), and in age-matched healthy males. Idiopathic generalized epilepsy (IGE) was diagnosed in 12 cases and partial epilepsy (PE) in 23 cases. Patients were seizure-free and did not show EEG abnormalities at repeated controls in the last 5 years, so that interfering effects of seizures were possibly excluded. The aim of the study was to evaluate both the role of epileptic syndromes and of anti-epileptic drugs on the endocrine function. Changes in sex hormone binding globulin, total and free testosterone, dihydrotestosterone and delta 4-androstenedione were found to be independent of the epileptic syndrome type. The LH response to LHRH was lower in PB-treated PE than in IGE subjects on the same drug regimen. An impairment of LH pulsatility with respect to controls was found in PE but not in IGE patients taking PB. Among antiepileptic drugs, PHT is associated with higher sex hormone binding globulin and estradiol and lower free testosterone and dihydrotestosterone levels. PB and CBZ, but not PHT, blunt the LH response to exogenous LHRH in PE. Prolactin responses to TRH were consistently enhanced in PE subjects treated with CBZ or PHT.
Nocturnal urinary melatonin excretion was significantly decreased throughout an ovarian cycle in 12 migraine without aura patients compared to 8 healthy controls. Normal increases in urinary melatonin excretion during the luteal phase was less pronounced in the migraine patients. Melatonin excretion was further decreased during headache. The data indicate impaired pineal function in migraine.
Changes in central neurotransmission and in hypothalamo-pituitary function occur in both ethanol (ETOH) intake and withdrawal. Melatonin (MLT) secretion is regulated by the noradrenergic system, which is activated upon ETOH withdrawal. Experimental evidence exist that pineal gland may have a role in ETOH intake and preference in rats. Twenty-four hour urinary excretion of MLT was found to be increased during ETOH intake in chronic alcoholics. In this study we have determined 24h plasma levels of MLT and cortisol in 8 chronic alcoholic males hospitalized for a detoxication program and in 8 healthy controls. The study was performed just after admission, on the first day of ETOH withdrawal and after 14 days of controlled abstinence. Circadian periodicity has been evaluated by the cosinor method. The initial determinations corresponded to the acute withdrawal phase. Twenty-four hour plasma MLT mean levels on acute withdrawal were higher than after 14 days abstinence and than those found in controls. Large interindividual differences prevented the detection of statistical significance. The cosinor analysis disclosed the loss of circadian periodicity in the acute withdrawal. Significant 24h periodicity was restored after 14 days abstinence. Cortisol levels were significantly higher than those found on day 14 and in healthy controls. Twenty-four hour periodicity was maintained in both alcoholics series. A delay in cortisol acrophase occurred in acute withdrawal. The effects of Corticotropin Releasing Hormone infusion on cortisol secretion were significantly enhanced in the acute withdrawal phase in comparison with those occurring when patients were retested and with healthy controls.
The circannual secretion of melatonin in 14 Swedish and 15 Italian patients suffering from episodic cluster headache was compared with 14 Swedish and 15 Italian healthy controls matched for sex and age. Overnight samples of urine were collected once a month from 8 to 14 months and kept at -20° C until analysed with RIA. The melatonin concentrations in nocturnal urine were permanently low in cluster headache and there was no consistent change of the melatonin concentration in relation to cluster periods occurring during the study. There was no definitive circannual or infraannual rhythmicity of melatonin in patients or controls. Multiple analysis of variance with repeated measurements showed a significant effect of disease (p < 0.05), but not of time. Sex, geographical location, age, and smoking also had significant effects (p < 0.001) on the melatonin concentrations. Lower melatonin levels in cluster headache patients than in controls may in part be related to a larger number of smokers in the patient group. The relation between tobacco use and melatonin should be further studied.
Alterations of neuroendocrinological indices determined by the impaired regulating effects of cholinergic neurotransmission have been described in primary dementia. In this study we have evaluated the effects of acetylcholinesterase inhibition by pyridostigmine on growth hormone (GH), adrenocorticotropic hormone (ACTH) and cortisol secretion and on their responses to GH-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) in 7 patients with primary degenerative dementia and in 8 sex- and age-matched controls. Demented subjects showed higher cortisol basal levels and lower ACTH levels than controls. Pyridostigmine increased the GH response to GHRH in both groups, the effect being significantly enhanced in patients. An increase of ACTH and cortisol levels was found in both groups after pyridostigmine and CRH administration. Pyridostigmine pretreatment significantly increased the ACTH response to CRH in controls but not in patients. The obtained data may indicate that a muscarinic receptor upregulation and an impairment of somatostatinergic function are operative in the regulation of GH secretion in dementia. An underlying hyperactivity of the hypothalamic-pituitary-adrenal axis impairs the responses of ACTH and cortisol to CRH in this disorder.
Neuroendocrine dysfunctions, in part similar to those found in depression, are present in chronic alcoholism. The aim of this investigation was to evaluate the effects of chronic alcohol intake on cortisol secretion in basal conditions, after dexamethasone (DXT) suppression or corticotropin (ACTH) stimulation in 10 alcoholic men, during active drinking and after two weeks of alcohol withdrawal. The 24-hour, day- and night-time urinary cortisol and melatonin levels, and the effects of thyrotropin releasing hormone (TRH) on thyrotropin (TSH) and prolactin (PRL) secretions were studied in the same subjects. The data were correlated to the scores obtained by the Hamilton Rating Scale for depression and compared to those found in healthy subjects. Increased cortisol levels and the lack of DXT suppression of cortisol secretion are considered to be alcohol-dependent inasmuch as they disappear in most patients after alcohol withdrawal. The cortisol response to ACTH 1-24 infusion measured before and after alcohol withdrawal was similar in the patients we studied; moreover no significant difference was found between patients and controls. The increment of urine free cortisol levels in active alcoholics was not statistically significant. Urine cortisol levels became similar to those of the control subjects after alcohol withdrawal. The increased diurnal values of urine melatonin and the inversion of the physiological ratio between nocturnal and diurnal levels observed during alcohol intake became normal upon alcohol withdrawal. The TSH and PRL responses after the administration of 50 or 200 micrograms TRH were higher in alcoholics than in controls, while a blunted response is known to occur in depression.
Ethanol is known to alter central neurotransmission and endocrine functions. Urine melatonin was studied in 10 male chronic alcoholic patients, before and after two weeks of controlled alcohol abstinence, and in sex and age matched healthy controls. In both groups, 24-hour urines were collected in two fractions corresponding to day- (D) (08:00–20:00) and night- (N) (20:00–08:00) time. Urine melatonin was assayed by RIA after methylene chloride extraction. Twenty-four hour urine melatonin levels were calculated adding up D and N values. In patients during alcohol intake, the 24-hour urine melatonin levels were significantly higher than in controls (p=0.004, Student’s t test). A disruption of the physiological ratio between N and D values was also observed, since the higher melatonin levels occurred in the D fraction. In drinking alcoholics, melatonin D values were significantly higher than the D values found in controls (p < 0.01, Student’s t test) and in the same patients after alcohol withdrawal (p < 0.05). The N/D ratio approximated 1 during alcohol intake and became larger than 1 after alcohol withdrawal, as in the controls. The melatonin data were correlated with the suppressive effects of dexamethasone (DXT) on cortisol secretion evaluated both during alcohol intake and during abstinence. After alcohol withdrawal, the two (out of 10) patients, who remained unresponsive to the DXT suppression test, showed high D melatonin values and a low N/D ratio. These preliminary data indicate that in chronic alcoholism the pattern of urinary “melatonin- like immunoreactivity” is altered.
HEADACHE Elisabet Waldenlind*, Karl Ekbom*, Lennart Wetterberg**, Marcello Fanciullacci***, Simone Marabini***. Federigo Sicuteri***, Alessandro Polleri****, Giovanni Murialdo****, Ugo Filippi****, Department of Neurology, Soder Hospital*, Department of Psychiatry, S:t Goran's Hospital**, Stockholm, Sweden, Department of Internal Medicine and Clinical Pharmacology, University of Florence***, Department of Internal Medicine, University of Genoa****, Italy.