Cardiovascular risk factors in primary hyperparathyroidism.

BACKGROUND AND AIMS: Severe primary hyperparathyroidism (PHP) has been associated with increased cardiovascular morbidity. Such an association in mild PHP is not known. We conducted a cross-sectional study to assess the correlation between mild and traditional PHP and emergent cardiovascular risk factors. SUBJECTS AND METHODS: A total of 139 patients with PHP (72 with severe PHP and indications for parathyroidectomy, 67 with mild PHP and no indications for surgery) and 111 control subjects, of similar age and body weight, were enrolled in this study. Participants had measurement of fasting blood levels of calcium, PTH, insulin, glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, interleukin-6, and C-reactive protein. Body mass index (BMI), waist and hip circumferences, blood pressure, homeostasis model assessment 2-insulin resistance index (IR) and the presence of metabolic syndrome (MS) were evaluated. RESULTS: Severe PHP patients had significantly higher rates of MS (37.5%), IR (38.9 %) vs mild PHP (34.3 and 23.9%, respectively) and controls (14.4 and 14.4%, respectively). Multivariate logistic-regression model, adjusted for age and BMI, and for age and waist size, revealed that severe PHP had significantly higher likelihood of cardiovascular risks [odds ratio (OR) 3.5, 95% confidence interval (CI) 1.5-8.125, p=0.004 for MS, and OR 3.7, 95% CI 1.64-8.29, p=0.002 for IR]. Serum calcium significantly predicted the presence of MS (OR 1.875, 95% CI 1.259-2.793, p=0.002) and IR (OR 2.043, 95% CI 1.365-3.057, p=0.002). CONCLUSIONS: Greater probability of MS and insulin resistance was observed in patients with severe PHP. Serum calcium is a predictor of these cardiovascular risk factors.

Concurrent nonfunctioning parathyroid carcinoma and parathyroid adenoma.

Parathyroid carcinoma is a rare etiology of primary hyperparathyroidism characterized by severe clinical symptoms of hypercalcemia and markedly elevated serum parathormone levels. Nonfunctioning parathyroid carcinoma is an inactive form of the disease. There are less than 30 reports of nonfunctioning parathyroid carcinoma in the English literature and the association with parathyroid adenoma has not been described. This report describes a patient with concurrent nonfunctioning parathyroid carcinoma and a functioning parathyroid adenoma.

Prevalence and risk factors for asymptomatic bacteriuria in women with Type 2 diabetes mellitus.

AIMS: Asymptomatic bacteriuria (ASB) has been considered as a complication in diabetic women. The reported data on the prevalence and various risk factors for ASB appear to be conflicting. Consequently, we investigated the prevalence and major risk factors of ASB in women with Type 2 diabetes mellitus. METHODS: A total of 411 non-pregnant women (aged 59.6 +/- 10.8 years) with Type 2 diabetes, and 160 women without diabetes (aged 53.3 +/- 15.1 years) assigned as controls, attending an outpatient endocrine clinic in a university-affiliated teaching hospital, were included. All participating women were interviewed and screened for the presence of ASB. In all participants, fasting blood glucose, HbA(1c) and renal function were measured. Complications of diabetes were also assessed. RESULTS: Of the 411 diabetic women, 25 (6.1%) had ASB, compared with four of 160 (2.5%) in control women (P = 0.07). Independent risk factors for the presence of ASB were albuminuria > 150 mg/24 h [odds ratio (OR) 4.96 (95% CI 1.64-15.0, P = 0.005)] and serum creatinine [OR 3.5 (95% CI 1.4-8.8, P = 0.008)]. No significant association was evident with age, BMI, duration of disease, glycaemic control assessed by HbA(1c) or chronic complications of diabetes, namely macrovascular disease, neuropathy and retinopathy. CONCLUSIONS: Women with Type 2 diabetes are not at higher risk of developing ASB than non-diabetic women. Independent and significant risk factors for ASB are macroalbuminuria and serum creatinine. The low prevalence of ASB found in this study may be as a result of the ethnic origin of these women and the circumcised state of their partners.

Urinary 6-sulfatoxymelatonin excretion in hyperandrogenic women: the effect of cyproterone acetate-ethinyl estradiol treatment.

Evidence for a relationship between melatonin and the reproductive hormones in humans is based on observations of abnormal melatonin secretion in clinical disorders of the pituitary-gonadal axis. The aim of this study was to investigate melatonin production in hyperandrogenic women before and during treatment with cyproterone acetate and ethinyl estradiol (Diane 35). Twelve women with polycystic ovary syndrome (PCOS), 10 women with idiopathic hirsutism (IH), and 10 women with late onset adrenal hyperplasia due to 21-hydroxylase deficiency (LOCAH) were studied. Patients were treated with Diane 35 for four months. Fasting blood samples for the determination of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and dihydroepiandrosterone sulfate (DHEAS) and 24-hour urine collections for the determination of 6-sulfatoxymelatonin (aMT6s) excretion were obtained from all patients at baseline and after 4 months of treatment. Results were compared with those obtained in 15 control women. At baseline, women with PCOS and LOCAH had significantly higher testosterone and aMT6s values than women with IH and controls. Diane 35 treatment significantly decreased testosterone, LH, FSH and aMT6s values in PCOS and LOCAH patients compared with pretreatment values. These results indicate that hyperandrogenic women with PCOS and LOCAH have increased melatonin production. The decrease in aMT6s excretion together with reduced serum LH, FSH, DHEAS and testosterone values during treatment with cyproterone acetate-ethinyl estradiol, suggest that sex steroids either directly or through the suppression of gonadotropins, modulate melatonin secretion in these patients.

Urinary 6-sulfatoxymelatonin excretion in hyperandrogenic women with polycystic ovary syndrome: the effect of ethinyl estradiol-cyproterone acetate treatment.

The role of melatonin in human reproduction is still unknown. Data obtained in patients with hypogonadism and precocious puberty suggest that melatonin and the reproductive hormones are interrelated. The aim of this study was to determine melatonin production in hyperandrogenic women. We studied 12 women with polycystic ovary syndrome (PCOS) and 10 women with idiopathic hirsutism (IH). Patients were treated with cyproterone acetate-ethinyl estradiol (Diane 35) for 4 months. Fasting blood samples for the determination of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and dehydroepiandrosterone sulfate (DHEAS) and 24-h urine collections for the determination of 6-sulfatoxymelatonin (alpha MT6s) excretion were obtained from all patients at baseline and after 4 months of treatment. The results were compared with those obtained in 15 control women. At baseline, women with PCOS had significantly higher LH and testosterone levels than those with IH and controls. Their alpha MT6s values (52.6 +/- 20.3 micrograms/24 h) were significantly higher than the values in women with IH (34.3 +/- 7.1) and controls (30.5 +/- 6.5) (p < 0.001). Diane 35 treatment significantly decreased LH, FSH, testosterone and alpha MT6a values in PCOS (28.0 +/- 13.9 micrograms/24 h) (p < 0.0001). These results indicate that women with PCOS have increased melatonin production. The normalization of alpha MT6s and testosterone values during Diane 35 treatment suggests that sex steroids modulate melatonin secretion in these patients either directly or through the suppression of gonadotropin.

Seminal plasma androgen/oestrogen balance in infertile men.

The hypothesis that the balance between oestrogen and androgen in seminal plasma is important for normal fertility was investigated. We determined the concentrations of oestradiol and testosterone in blood and seminal plasma from 62 infertile men and 32 normozoospermic men. Infertile men were classified according to semen analysis (concentration, motility and morphology): asthenozoospermia, oligozoospermia and oligoteratoasthenozoospermia. Serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were determined in all participants. For all subjects, mean testosterone levels were lower and mean oestradiol were higher in seminal plasma than in blood. Seminal plasma testosterone levels were lower in the infertile groups vs. control men ( p < 0.0002). Oligpzoospermic and oligoteratoasthenozoospermic men had significantly higher seminal plasma oestradiol levels compared with controls ( p < 0.03). The three infertile groups had significantly lower seminal plasma testosterone/oestradiol ratio than control men ( p < 0.001). Sperm analysis data (concentration, motility and morphology) significantly correlated with seminal plasma testosterone/oestradiol ratio. The findings of elevated seminal plasma oestradiol, decreased testosterone and testosterone/oestradiol ratio in infertile men, and the significant correlation between hormone levels and sperm analysis data suggest that the local balance between androgen and oestrogen is important for spermatogenesis.

Seminal plasma melatonin and gonadal steroids concentrations in normal men.

The authors determined semen quality and the concentrations of estradiol, testosterone, and melatonin in blood and seminal plasma of 8 normal men. To investigate the reproducibility of these parameters, semen analysis and hormone concentrations were determined on 3 occasions, 6 weeks apart. All 8 men had normal semen analysis. Blood melatonin (9.7-45.4 pg/mL) and testosterone (3.5-12.3 ng/mL) levels were significantly higher than the comparable seminal plasma levels (0.6-5.0 pg/mL, p <.02; 0.1-0.9 ng/mL, p <.0001, respectively). Seminal plasma estradiol levels (46.9-91.3 pg/mL) were significantly higher than the blood levels (13.3-44.7 pg/mL) (p <.0001). The intraindividual variations in seminal plasma estradiol levels ranged between 8.7 and 13.8%. There was no correlation between sperm concentration, motility or morphology and blood or seminal plasma hormone levels. Also, blood and seminal plasma hormone levels were not correlated. These results indicate that in normospermic men seminal plasma estradiol levels are higher than blood hormone levels, suggesting local production of estradiol. This may imply that estrogen and/or the balance andorgen/estrogen is important in normal human spermatogenesis.

Increased urinary 6-sulfatoxymelatonin excretion in women with non-classical steroid 21-hydroxylase deficiency.

OBJECTIVES: To determine melatonin production in hyperandrogenic women. MATERIAL AND METHODS: Seventeen women with late onset adrenal hyperplasia due to 21-hydroxylase deficiency (LOCAH) and 15 control women were studied in early follicular phase of the menstrual cycle. Fasting serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E(2)), testosterone, dihydroepiandrosterone sulfate (DHEA-S), 17-hydroxyprogesterone (17-OHP) as well as the peak 17-OHP response to ACTH (250 microg IV) and 24h urinary 6-sulfatoxymelatonin (aMT6s) were determined in all participants. RESULTS: All 17 hyperandrogenic women were carrying mutations of the CYP21 gene. Women with LOCAH had significantly higher serum testosterone, DHEA-S, 17-OHP and ACTH stimulated 17-OHP values compared with controls. Their aMT6s values (44.6+/-20.3 microg/24h) were significantly higher than the values in control women (31.5+/-20.3) (p<0.03). The urinary aMT6s values were positively correlated with testosterone (p<0.04), DHEA-S (p<0.02) and peak 17-OHP (p<0.04). CONCLUSIONS: Women with LOCAH have increased melatonin production. There is a relationship between adrenal androgens and melatonin in these women.

Increased 6-sulfatoxymelatonin excretion in women with polycystic ovary syndrome.

OBJECTIVE: To determine melatonin production in hyperandrogenic women. DESIGN: Controlled prospective study. SETTING: Outpatients in an academic medical center. PATIENT(S): Twenty-two women with polycystic ovary syndrome (PCOS), 20 women with idiopathic hirsutism, and 15 age-matched individuals who had similar body mass indexes as controls. INTERVENTION(S): Fasting blood samples and 24-hour urinary samples were obtained from all participants. MAIN OUTCOME MEASURE(S): All participants provided serum samples for the measurement of LH, FSH, testosterone, E(2), DHEAS, 17 alpha-hydroxyprogesterone (17-OHP), and insulin levels, as well as urinary 6-sulfatoxymelatonin (aMT6s). RESULT(S): Women with PCOS had higher aMT6s, testosterone, LH/FSH ratio, and insulin values than either women with idiopathic hirsutism or control women. Testosterone inversely correlated with aMT6s in PCOS. Regression analysis revealed that only testosterone was an important determinant of aMT6s in PCOS. CONCLUSION(S): Women with PCOS have increased melatonin production.

Actigraphic sleep-wake patterns and urinary 6-sulfatoxymelatonin excretion in patients with Alzheimer's disease.

Recent studies suggest melatonin, due to its antioxidant and free-radical-scavenging actions, may play a role in the neuroprotection against amyloid, which is implicated in the pathogenesis of Alzheimer's disease (AD). In this study, we determined urinary 6-sulfatoxymelatonin (aMT6s) excretion together with actigraphic sleep-wake patterns of untreated male patients with AD who lived at home. Results were compared with those obtained from normal age-matched elderly and normal young male subjects. Similar measurements were also performed in another group of patients with AD who were treated with a cholinesterase inhibitor (Donepezil, Aricept). Total 24h aMT6s values were significantly reduced in elderly controls (19.9h +/- 5.2 microg/ 24h), in those with untreated AD (12.7 +/- 4.4 microg/24h), and in patients treated for AD (12.4 +/- 4.4 microg/24h) compared with normal young men (32.8 +/- 3.1 microg/24h). A day-night difference in aMT6s was evident in all young controls, in 50% of elderly controls, in only 20% of patients with untreated AD, and in 67% of those with AD receiving Aricept. Sleep quality (expressed as sleep efficiency, wake time, and long undisturbed sleep duration) was better in young and elderly controls compared with the two groups of patients with AD. There was no significant correlation between aMT6s values or sleep patterns and the severity of cognitive impairment in patients with AD. Taken together, these data suggest that disrupted sleep, decreased melatonin production, and partial lack of day-night difference in melatonin secretion were observed equally in normal elderly and in patients with AD. Our results do not permit drawing any conclusion as to whether changes in urinary aMT6s excretion is correlated with disturbed sleep in patients with AD.

Disruption of the nocturnal testosterone rhythm by sleep fragmentation in normal men.

Recently, we have demonstrated that in normal men the nocturnal testosterone rise antedated the first rapid eye movement (REM) sleep episode by about 90 min and was correlated with REM latency. To further elucidate whether the diurnal testosterone rhythm is a sleep-related phenomenon or controlled by the circadian clock, we determined serum testosterone levels in 10 men during the ultrashort 7/13 sleep-wake cycle paradigm. Using this schedule, subjects experienced partial sleep deprivation and fragmented sleep for a 24-h period. Serum testosterone levels were determined every 20 min between 1900-0700 h with simultaneous sleep recordings during the 7-min sleep attempts. The results were compared with those obtained in men during continuous sleep. Although mean levels and area under the curve of testosterone were similar in both groups, fragmented sleep resulted in a significant delay in testosterone rise (03:24 h +/- 1:13 vs. 22:35 h +/- 0:22). During fragmented sleep, nocturnal testosterone rise was observed only in subjects who showed REM episodes (4/10). Our findings indicate that the sleep-related rise in serum testosterone levels is linked with the appearance of first REM sleep. Fragmented sleep disrupted the testosterone rhythm with a considerable attenuation of the nocturnal rise only in subjects who did not show REM sleep.

Decreased melatonin secretion in a phenotypically male 46,XX patient with classic 21-hydroxylase deficiency.

The possible role of gonadal steroids and gonadotropins in regulating melatonin secretion has been suggested in clinical syndromes of the hypothalamic-pituitary-gonadal axis. We describe the results of melatonin secretion in a 37-year old male patient who presented with azoospermia. The patient was an XX male, had classic simple virilizing form of 21-hydroxylase deficiency, which led to a masculine phenotype. He was ovariectomized at the age of three years and reared as a male. Melatonin production (aMT6s) was determined at baseline and during 12 months of replacement therapy. Results were compared with those obtained in age-matched male controls. Pretreatment aMT6s values were decreased (14.3 microg/24 h vs. 29.0+/-5.5 in controls). Dexamethasone replacement was associated with an increase in aMT6s values (19.3-20.9 microg/24 h). The addition of testosterone to dexamethasone replacement resulted in normalization of aMT6s (27.6-33.1 microg/24 h) and serum 17OH progesterone, testosterone and estradiol levels. The present data indicate that androgen excess due to 21 hydroxylase deficiency is associated with decreased melatonin secretion. These results support the hypothesis that sex steroids modulate melatonin secretion.

Melatonin hypersecretion in male patients with adult-onset idiopathic hypogonadotropic hypogonadism.

Increased melatonin secretion observed in male patients with congenital isolated hypogonadotropic hypogonadism and its normalization during testosterone treatment had suggested that melatonin and the reproductive hormones are inter-related. Since these patients have a congenital form of hypogonadism, it is likely that hypermelatoninemia is the consequence of hypogonadism. To further study the relations between the pineal and the reproductive axis in humans, we evaluated melatonin secretion in two men (aged 35 and 50 yrs.) with acquired adult-onset hypogonadotropic hypogonadism. The diagnosis was based on the findings of normal testicular volume, azoospermia, low serum testosterone, normal LH and FSH levels, but apulsatile LH secretion, and intact anterior pituitary hormones secretion, normal findings on skull radiographic imaging, prior sexual maturation and paternity. Melatonin secretion was assessed as urinary 24 h 6-sulphatoxymelatonin excretion (aMT6s) prior to and during the administration of 250 mg testosterone enanthate per month for 4 months. Pretreatment melatonin production was markedly increased in both patients: 427-915 ng/kg/24 h vs. 204+/-81 [mean+/-SD] in 16 age-matched male controls. During testosterone treatment, aMT6s levels were normalized in one patient (range: 81-287 ng/kg/24 h) and remained elevated in the other patient (range: 830-1280 ng/kg/24 h). These data indicate that male patients with acquired GnRH deficiency have increased melatonin secretion. Melatonin hypersecretion in these patients may reflect a functional association.

Management of benign thyroid nodules based on the findings of fine-needle aspiration.

Fine-needle aspiration (FNA) biopsy is a safe, simple, and inexpensive procedure that is particularly applicable for lesions of the head and neck. In our department, it is widely used for the evaluation of thyroid nodules. A total of 189 patients participated in a prospective study of benign thyroid nodules. Our aim was to verify the modality of treatment used in our department and the reliability of benign cytologic results of colloid goiter. All patients had cold nodules on thyroid scanning. The patients were divided into two groups, the first comprising 93 patients who did not undergo thyroid surgery and were followed up for 5 to 11 years. One case of malignancy was found in this group during the follow-up. The second group was comprised of 96 patients who were operated on despite FNA results of colloid goiter. Among them, five cases of malignancy were found. Four of these five cases could not be regarded as FNA failure. Our study confirms that the combination of clinical findings with those of the FNA is a reliable approach to the management of benign thyroid nodules. Nevertheless, long-term follow-up is mandatory and repetitive aspirations should be considered.

Prevalence of hypothyroidism and diabetes mellitus in elderly kibbutz members.

UNLABELLED: The aim of this study was to determine the prevalence of hypothyroidism and diabetes mellitus (DM) in elderly (aged 65-92 years) kibbutz members in Northern Israel. METHOD: The medical records of 1096 elderly (642 females and 454 males) residing in 11 kibbutzim were reviewed for data regarding thyroid function tests (TSH and FT4) and fasting blood glucose. Fasting blood glucose levels above 7.8 mmol/l was considered diagnostic for diabetes mellitus. RESULTS: The prevalence of hypothyroidism was 14% (9.7% in males and 18.2% in females) and that of DM was 11.5% (12.1% in males and 11.1% in females). In 74% of the diabetics the diagnosis was made after the age of 60 years. Distribution of treatment modalities in diabetics was as follows: diet only 42%. oral hypoglycemic agents 52% and Insulin 6%. Subclinical hypothyroidism (serum TSH levels above 4.5 mU/L with normal FT4 levels) was detected in 38% of all the hypothyroid subjects. CONCLUSION: The data suggest that diabetes mellitus and primary hypothyroidism are common disorders in elderly subjects. DM in the elderly can usually be handled with diet and oral hypoglycemic drugs. Since the clinical features of hypothyroidism in the elderly are often atypical, we suggest that elderly subjects should be screened for hypothyroidism.

Endocrine activity during sleep.

Almost all functions of humans are subject to cyclic changes and are governed by the nervous system. Most rhythms are driven by an internal biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) and can be synchronized by external signals such as light-dark cycles. Homeostatic activities such as body temperature, blood volume, water balance and sleep, are rhythmic. Likewise, most hormones are secreted in a rhythmic fashion. Both sleep and circadian effects interact to produce the overall rhythmic pattern of the pituitary and pituitary-dependent hormones. Some of the 24-h hormonal rhythms depend on the circadian clock (ACTH, cortisol and melatonin), or are sleep related (prolactin and TSH). GH secretion is influenced by the first slow wave sleep (SWS) episode at the beginning of the night. Pulses of prolactin and GH are positively linked to increases in delta wave activity, i.e. deepest phases of sleep, occurring primarily during the first third of the night. Pulses of TSH and cortisol are related to superficial phases of sleep. As a result of the consolidation of the sleep period in humans, the wake-sleep transition is associated with physiological changes with the endocrine system being part of the adaptive mechanism to reduce physical activity during sleep.

Long-term melatonin administration does not alter pituitary-gonadal hormone secretion in normal men.

The role of melatonin in the regulation of reproduction in humans is still controversial. In the present study the effects of melatonin were examined, 6 mg given orally every day at 1700 h for 1 month in a double-blind, placebo controlled fashion, on the nocturnal secretory profiles of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and inhibin beta in six healthy adult men. Serum concentrations of LH, FSH, testosterone and inhibin beta were determined before and after treatment every 15 min from 1900 to 0700 h over 3 nights in a controlled dark-light environment with simultaneous polysomnographic sleep recordings. The following sleep parameters were determined: total recording time, sleep latency, actual sleep time, sleep efficiency, rapid eye movement (REM) sleep latency and percentages of sleep stages 2, 3/4 and REM. There were no statistically significant differences in all sleep parameters between baseline and placebo or between baseline and melatonin except for longer REM latency and lower percentage REM at baseline than under melatonin treatment. These are explained as reflecting first-night effect at baseline. The mean nocturnal LH, FSH, testosterone and inhibin beta integrated nocturnal secretion values did not change during the treatment period. Likewise, their pulsatile characteristics during melatonin treatment were not different from baseline values. Taken together, these data suggest that long-term melatonin administration does not alter the secretory patterns of reproductive hormones in normal men.

Relationship between rapid eye movement sleep and testosterone secretion in normal men.

The relation between the pituitary-gonadal hormones' rhythm and sleep physiology in men is not fully elucidated. To examine whether the reproductive hormones are correlated with sleep architecture, we determined the nocturnal serum levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in six healthy young men. Serum hormone levels were obtained every 15 minutes from 1900 to 0700 hours with simultaneous polysomnographic sleep recordings. Hourly testosterone levels were lowest when subjects were awake (1900-2200 hours) than during sleep (2300-0700 hours). Testosterone nocturnal rise antedated the first REM by about 90 minutes. The rise in testosterone levels was slower when REM latency was longer. Mean nocturnal testosterone levels did not correlate with the number of rapid eye movement (REM) episodes. Also, pre-non-REM (NREM) testosterone levels were higher as compared with the pre-REM periods and lower during the first NREM period as compared with other nocturnal NREM periods. Serum LH levels disclosed a nocturnal rise that preceeded a similar rise in testosterone by about an hour. We conclude that in young adult men, testosterone levels begin to rise on falling asleep, peak at about the time of first REM, and remain at the same levels until awakening.

The association between melatonin and sleep stages in normal adults and hypogonadal men.

The role of melatonin in normal sleep-wake regulation has been inferred from the temporal relationships between its cycle and the 24 h cycle in sleep propensity. Pharmacological doses of melatonin were reported to have sleep-inducing effects in insomniacs. The current study investigated the relationship between melatonin and sleep stages in groups of hypogonadal men with abnormal melatonin levels. We were also interested in examining what would happen to these relationships during testosterone replacement therapy. Male patients with hypogonadotropic hypogonadism (IGD, n = 6), constitutional delayed puberty (DP, n = 6), and Klinefelter's syndrome (KS, n = 5) before and during testosterone replacement therapy were studied. Six patients with KS and normal testosterone levels were also studied. Results were compared with those obtained in normal controls (n = 6). Serum samples were obtained at 15 min intervals from 1900-0700h in a controlled light-dark environment with simultaneous polysomnographic sleep recordings. Serum melatonin levels were the highest in IGD and DP and lowest in KS patients. A lower percentage of sleep stage 2 and higher percentage of stage 3/4 were observed in IGD and DP groups while KS patients had higher percentage of stage 2 and lower percentage of stage 3/4 as compared to controls. Slow wave sleep was the highest in IGD and the lowest in KS groups. Serum melatonin levels were lowest in KS groups. Serum melatonin levels were lowest in sleep stage 3/4, higher in stage 2 and highest in REM sleep when all groups were combined and averaged together. However, in the IGD group, melatonin levels were actually lowest in REM sleep. Also in the KS group, melatonin levels were lower in REM than during sleep stage 2. Serum melatonin levels were lowest in sleep stage 3/4 in all groups, higher in stage 2, and highest in REM sleep. During waking periods, melatonin levels were the highest in untreated IGD, DP and KS patients. Testosterone treatment given to these patients, although normalized, their melatonin levels did not statistically significantly change these correlations. These data demonstrate that relative melatonin concentrations are associated with sleep stages in hypogonadal and normal men. The results also indicate that the association between melatonin and the reproductive hormones are independent of the synchronizing effects of melatonin on sleep homeostasis.

Auditory brain-stem evoked potentials in patients with thyroid and parathyroid dysfunction: adaptation to chronic hormonal dysequilibrium.

Auditory Brainstem Evoked Potentials (ABEPs) and pure tone audiograms were obtained from 24 patients with parathyroid dysfunction (17 hypercalcemia and 7 hypocalcemia) and 12 patients with thyroid dysfunction (6 hyperthyroid and 6 hypothyroid) and from 10 control subjects. ABEPs were characterized by I-V interpeak latency difference at 10/sec click rate and by the effect of increasing stimulus rate to 55/sec. None of the ABEP measures were significantly affected by levels of serum calcium, thyroid hormones or their interactions. Moreover no correlation was found between biochemical and electrophysiological measures. This stability of ABEP measures contrasts with earlier reports on acute effects of calcium and thyroid hormonal levels on auditory brainstem evoked potentials. We propose that chronic calcium or thyroid hormonal homeostatic changes are associated with adaptive mechanisms resulting in normal function of the auditory brainstem.