Obstructive sleep apnoea syndrome as a risk factor for hypertension: population study

OBJECTIVE

To assess whether sleep apnoea syndrome is an independent risk factor for hypertension.

DESIGN

Population study.

SETTING

Sleep clinic in Toronto.

PARTICIPANTS

2,677 adults, aged 20-85 years, referred to the sleep clinic with suspected sleep apnoea syndrome.

OUTCOME MEASURES

Medical history, demographic data, morning and evening blood pressure, and whole night polysomnography.

RESULTS

Blood pressure and number of patients with hypertension increased linearly with severity of sleep apnoea, as shown by the apnoea-hypopnoea index. Multiple regression analysis of blood pressure levels of all patients not taking antihypertensives showed that apnoea was a significant predictor of both systolic and diastolic blood pressure after adjustment for age, body mass index, and sex. Multiple logistic regression showed that each additional apnoeic event per hour of sleep increased the odds of hypertension by about 1%, whereas each 10% decrease in nocturnal oxygen saturation increased the odds by 13%.

CONCLUSION

Sleep apnoea syndrome is profoundly associated with hypertension independent of all relevant risk factors.

Mortality in sleep apnea patients: a multivariate analysis of risk factors

During 1976-1988 we diagnosed sleep apnea syndrome (SAS) in 1,620 adult men and women monitored in the Technion sleep laboratories. Their age at the time of diagnosis ranged between 21 and 79 years. Fifty-seven patients (53 men and 4 women) had died by 1990, 53% due to respiratory-cardiovascular causes. The observed/expected (O/E) mortality rates, calculated for men only, revealed excess mortality of patients under 70 years old. Excess mortality was significant in the fourth and fifth decades (3.33, p < 0.002; 3.23, p < 0.0002, respectively). In patients older than 70 O/E was 0.33 (p < 0.0007). Hierarchical multivariate analysis with four fixed variables [age, body mass index (BMI), hypertension and apnea index] and four additional variables added manually one at a time (heart disease, lung disease, diabetes, apnea duration) was used to determine the predictors of death from all causes, cardiopulmonary causes and from myocardial infarction (MI). All four major variables were found to be significant predictors of mortality from all causes, in addition to lung disease and heart disease. Only age and BMI were significant predictors of cardiopulmonary deaths in addition to lung disease. Age, BMI and hypertension predicted MI deaths in addition to lung disease. These results were interpreted to suggest that SAS affects death indirectly, most probably by being a risk factor for hypertension.

Melatonin replacement therapy of elderly insomniacs

Changes in sleep-wake patterns are among the hallmarks of biological aging. Previously, we reported that impaired melatonin secretion is associated with sleep disorders in old age. In this study we investigated the effects of melatonin replacement therapy on melatonin-deficient elderly insomniacs. The study comprised a running-in, no-treatment period and four experimental periods. During the second, third and fourth periods, subjects were administered tablets for 7 consecutive days, 2 hours before desired bedtime. The tablets were either 2 mg melatonin administered as sustained-release or fast-release formulations, or an identical-looking placebo. The fifth period, which concluded the study, was a 2-month period of daily administration of 1 mg sustained-release melatonin 2 hours before desired bedtime. During each of these five experimental periods, sleep-wake patterns were monitored by wrist-worn actigraphs. Analysis of the first three 1-week periods revealed that a 1-week treatment with 2 mg sustained-release melatonin was effective for sleep maintenance (i.e. sleep efficiency and activity level) of elderly insomniacs, while sleep initiation was improved by the fast-release melatonin treatment. Sleep maintenance and initiation were further improved following the 2-month 1-mg sustained-release melatonin treatment, indicating that tolerance had not developed. After cessation of treatment, sleep quality deteriorated. Our findings suggest that for melatonin-deficient elderly insomniacs, melatonin replacement therapy may be beneficial in the initiation and maintenance of sleep.

All-cause mortality in males with sleep apnoea syndrome: declining mortality rates with age

The objective of this study was to assess whether an increasing severity of sleep apnoea is associated with increased all-cause mortality hazards and to assess whether the syndrome is associated with excess mortality, in comparison with the general population. Participants included 14,589 adult males, aged 20-93 yrs, referred to the sleep clinics with suspected sleep apnoea or diagnosed with sleep apnoea. Altogether, 372 deaths were recorded after a median follow-up of 4.6 yrs. The crude all-cause mortality rate was 5.55/1,000 patient yrs, increasing with apnoea severity. Cox proportional analysis revealed that both respiratory disturbance index (RDI) and body mass index significantly influenced all-cause mortality hazard but there was no interaction between them. Males with respiratory disturbance index >30 had a significantly higher mortality hazard rate than the reference group of males with RDI < or =10. Comparing mortality rates of males with moderate/severe sleep apnoea to the general population revealed that only males aged <50 yrs showed an excess mortality rate. The hazard of mortality in sleep apnoea increases with apnoea severity as indexed by respiratory disturbance index. Moderate and severe levels of sleep apnoea are moderately associated with an increased risk of all-cause mortality, in comparison with the general population, particularly in males aged <50 yrs. The lack of information about possible confounders and treatment effects should be taken into consideration in the interpretation of these results.

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.

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.

Hypnotic and hypothermic effects of melatonin on daytime sleep in humans: lack of antagonism by flumazenil

In this double-blind, placebo-controlled study we investigated whether 10 mg flumazenil, a pure benzodiazepine antagonist, can block the hypnotic and hypothermic effects of 3 mg melatonin. The design comprised four 7-h (1200-1900 h) testing periods, preceded by a 'no-treatment' adaptation period of the "7/13' sleep-wake paradigm. Six young healthy adult males were paid to participate. During each experimental period, tablets were administered at 1145 h (flumazenil or placebo) and at 1200 h (melatonin or placebo) in a randomized, double-blind, partially repeated Latin square design. Polysomnographic recordings and core body temperature recordings revealed that melatonin, either in combination with placebo or with flumazenil, significantly increased the amounts of sleep, and decreased core body temperature in comparison with placebo alone or the combination of flumazenil plus placebo. These results do not support the hypothesis that melatonin exerts its hypothermic and hypnotic effects via the central benzodiazepine receptors.

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.

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.

Daily and seasonal variations in the concentration of melatonin in the human pineal gland

To elucidate whether pineal melatonin secretion is affected by changes in day length, we determined the concentration of melatonin in human pineal glands obtained at autopsy from 66 male subjects, aged 16-84 years over a period of 12 consecutive months. Based on the time of death, a day-night difference in pineal melatonin levels was evident only in the long photoperiod (April-September) with significantly higher melatonin concentrations occurring at night (2200-1000 h). Nighttime values in the long photoperiod were significantly higher than the nighttime values during the short photoperiod (October-March). During the short photoperiod, the data suggested a possible phase-delay in melatonin secretion. Day-night difference was evident in young subjects (30-60 years), but not in elderly subjects (61-84 years). Elderly subjects had lower total melatonin levels (day and night values) although statistically not significant. Therefore, melatonin levels did not decline with age and when the data were analyzed by age there was no significant day-night difference in melatonin levels. These data indicate that the concentration of melatonin in the human pineal is augmented only during the long photoperiod. The results suggest a partial effect of photoperiod on melatonin secretion in humans. This may result from living in an artificial light environment or due to other nonphotic signals involved in generating melatonin rhythm.

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.

Abnormal melatonin secretion in hypogonadal men: the effect of testosterone treatment

OBJECTIVE

We have recently demonstrated that GnRH deficient male patients have increased nocturnal melatonin secretion, whereas hypergonadotrophic hypogonadal males have decreased melatonin levels. We were interested in determining whether testosterone (T) treatment (when T levels were well matched with pubertal control values) has an effect on melatonin secretory profiles in these patients.

DESIGN

Prospective, controlled.

SUBJECTS

Six male patients with idiopathic hypogonadotrophic hypogonadism (IGD), six males with hypergonadotrophic hypogonadism due to Klinefelter's syndrome (KS) and seven controls. Patients were examined before and during the administration of 250 mg testosterone enanthate/month for four months.

MEASUREMENTS

Serum samples for melatonin levels were obtained every 15 minutes from 1990 to 0700 h in a controlled light-dark environment. The results of FSH, LH, T and oestradiol (E2) (determined at hourly intervals) and melatonin profiles, were compared with the pre-treatment values in each group, and with values obtained in the control group.

RESULTS

All 12 patients had low pre-treatment T levels (1.4 +/- 0.7 in IGD and 2.0 +/- 0.4 in KS vs. 19.8 +/- 2.3 nmol/l in controls) and attained normal levels after four months of T treatment (19.5 +/- 7 in IGD and 22.7 +/- 3.8 nmol/l in KS). Serum LH, FSH and E2 levels (11 +/- 4 IU/l, 24 +/- 10 IU/l and 113 +/- 12 pmol/l, respectively) were still elevated in KS during T treatment as compared with values in controls (2 +/- 1 IU/l, 2 +/- 1 IU/l and 67 +/- 4 pmol/l, respectively). In IGD, serum LH (0.12 +/- 0.1 IU/l) and FSH (0.16 +/- 0.2 IU/l) levels during T treatment were suppressed. Pretreatment melatonin levels in IGD were greater than those in age-matched pubertal controls while in KS, melatonin levels were lower than values in controls. Melatonin levels were equal in all 12 hypogonadal patients and controls when T levels were well matched. Mean (+/- SD) dark-time melatonin levels decreased from 286 +/- 18 to 157 +/- 26 pmol/l in IGD and increased from 92 +/- 19 to 183 +/- 48 pmol/l in KS (vs 178 +/- 59 pmol/l in controls). The integrated melatonin values decreased in IGD (from 184 +/- 14 to 102 +/- 21 pmol/min. 1 x 10(3)) and increased in KS (from 64 +/- 13 to 123 +/- 40, vs. 116 +/- 39 pmol/min. 1 x 10(3) in controls). No correlations were found between melatonin and LH, FSH or E2 levels.

CONCLUSIONS

These data indicate that male patients with GnRH deficiency have increased nocturnal melatonin secretion while in hypergonadotrophic hypogonadal males melatonin secretion is decreased. Testosterone treatment normalized melatonin concentrations in these patients. Taken together, the results suggest that GnRH, gonadotrophins and gonadal steroids modulate pineal melatonin in humans.

Abnormal melatonin secretion in male patients with hypogonadism

Recently we have demonstrated that melatonin secretion is increased in untreated male patients with GnRH deficiency. Testosterone administration to these patients decreased melatonin secretion to normal levels. These data, however, did not exclude a gonadotropic effect on melatonin secretion. To further elucidate whether gonadal steroids and/or gonadotropins modulate melatonin secretion in humans we compared untreated young males with hypogonadotropic hypogonadism (IGD, n = 6), and hypergonadotropic hypogonadism caused by KlinEfelter's syndrome (KS, n = 11) to normal pubertal male controls (n = 7). KS patients were subdivided into two groups: KS-1, with low testosterone; and KS-2, with normal testosterone levels. Serum samples for melatonin concentrations were obtained every 15 min from 7 PM to 7 AM in a controlled light-dark environment with simultaneous sleep recordings. All KS patients had elevated gonadotropin levels and decreased melatonin levels. Mean (+/- SD) dark-time nocturnal melatonin levels in KS-1 were 92 +/- 21 pmol/L and were 146 +/- 46 pmol/L in KS-2 compared with 178 +/- 64 pmol/L in controls. Integrated nocturnal melatonin secretion values (AUC) were 64 +/- 14 pmol/min x L x 10(3) in KS-1 and 96 +/- 29 pmol/min x L x 10(3) in KS-2 compared with 116 +/- 42 pmol/min x L x 10(3) in controls. All IGD patients had low gonadotropin and testosterone levels. Their dark-time melatonin levels (286 +/- 26 pmol/L) and the AUC values (184 +/- 15 pmol/min/L x 10(3)) were increased. These data indicate that melatonin secretion is increased in male patients with GnRH deficiency and decreased in low testosterone hypergonadotropic hypogonadal patients. Taken together, our results suggest that both gonadotropins and gonadal steroids modulate melatonin secretion in humans.

Seasonal variation of gonadotropins and gonadal steroids receptors in the human pineal gland

Recently abnormal melatonin secretion was demonstrated in hypogonadal male patients which was normalized during testosterone administration. These results suggested that both gonadal steroids and gonadotropins may modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize luteinizing hormone, follicle stimulating hormone, estrogen and androgen receptors in human pineal glands. Tissues were obtained at autopsy from 53 adult males (aged 19-94 years) over a period of 1 year. Positive staining for the four types of receptors was evident in all 53 specimens examined. The percent of positively stained cells revealed a significant seasonal variation of gonadotropin receptors with higher values in the winter than in the summer. Day-night difference was evident only for follicle stimulating hormone-receptors during the summer and winter, with higher values at night. Androgen receptors and estrogen receptors were present in all specimens but did not reveal day-night or seasonal variations. These data demonstrate the presence of gonadotropin and gonadal steroid receptors in the human pineal gland. Gonadotropin receptors exhibited seasonal variation with higher values in the winter.

The effects of substituting zopiclone in withdrawal from chronic use of benzodiazepine hypnotics

Twenty-four volunteers (19 women and five men) with insomnia and a history of chronic use of benzodiazepine hypnotics participated in a randomized, double blind, controlled clinical trial. The study was designed to assess the effects of substituting zopiclone (ZOP)- as an hypnotic- among chronic users of flunitrazepam (FLU), and to compare the subsequent withdrawal of ZOP with placebo controlled withdrawal of FLU. During the 5 weeks of a withdrawal protocol, sleep and physiological parameters were assessed by polysomnographic measures for 11 nights and by nightly actigraphic recordings for weeks 1, 3, and 5. Subjective effects of the withdrawal process were evaluated with daily sleep diaries, and with various weekly self-report symptom checklists. Paired t-tests performed on differences in objective sleep parameters between baseline and the last weeks of the withdrawal program showed a significant decrease in sleep quality within the FLU group, but not in the ZOP group. Subjective sleep diaries consistently reflected the objectively measured changes in sleep throughout the withdrawal program, indicating significant changes in sleep parameters only in the FLU group. The results obtained from the self report inventories aimed at assessing withdrawal symptoms, however, revealed no differences between the baseline week and the termination week of the program in any of the groups. After completing the pharmacological withdrawal, all subjects received a short-term cognitive behavioral intervention focused on improving their coping strategies with symptoms of insomnia; they were evaluated immediately after concluding the intervention, and at 3 and 12 month follow- ups.

Melatonin administered in the afternoon decreases next-day luteinizing hormone levels in men: lack of antagonism by flumazenil

The role of melatonin in the regulation of human reproduction remains unclear. In the present study, we examined the influence of exogenous melatonin on pulsatile luteinizing hormone (LH), diurnal rhythm of testosterone, and endogenous melatonin profile in six healthy young adult males. To test the hypothesis that the effect of melatonin on LH or testosterone secretory patterns may be mediated through the benzodiazepine-(BNZ) gamma-amino-butyric acid (GABA) receptor complex, a benzodiazepine receptor antagonist (Flumazenil) was administered. The study design comprised four 10-h (4:00 PM-2:00 AM) testing periods. During each experimental period, subjects were given an oral dose of placebo, or 3 mg melatonin or 10 mg flumazenil, at 5:00 PM, in a randomized, double-blind, partially repeated Latin square design in the following combinations: placebo-placebo, placebo-melatonin, flumazenil-placebo, and flumazenil-melatonin. The following day, serum samples were obtained every 20 min between 4:00 PM and 2:00 AM in a controlled light-dark environment for the determination of LH and melatonin levels. Serum testosterone concentrations were determined every 20 min between 7:00 and 8:00 AM and 7:00 and 8:00 PM. A significant decrease in mean serum LH levels (p < 0.02) was observed in the melatonin-treated groups as compared with placebo-flumazenil groups. There was no change in LH pulse frequency, testosterone levels, or in melatonin onset time and amplitude. No additional effect of flumazenil on LH or testosterone levels was observed. These data indicate that an evening melatonin administration decreases the next-day LH secretion in normal adult males without altering testosterone levels or the endogenous nocturnal melatonin secretory pattern. This effect of melatonin is not mediated through the benzodiazepine-GABA receptor complex.

Decreased nocturnal melatonin secretion in patients with Klinefelter's syndrome

OBJECTIVE

We have recently demonstrated that GnRH deficient male patients have increased nocturnal melatonin secretion which decreases to normal levels during testosterone treatment. The results suggested that sex steroids, rather than LH, modulate pineal melatonin in an inverse fashion. The purpose of this study was to characterize circulating melatonin levels in untreated males with hypergonadotrophic hypogonadism due to Klinefelter's syndrome (KS).

DESIGNS

Prospective, controlled.

SUBJECTS

Eleven patients with Klinefelter's syndrome and seven controls. Patients were subdivided into two groups: (1) with low testosterone, and (2) with normal testosterone levels.

MEASUREMENTS

Serum samples for melatonin concentrations were obtained every 15 minutes from 1900 to 0700 h in a controlled light-dark environment.

RESULTS

All patients had elevated FSH, LH and oestradiol (E2) levels. Mean (+/-SD) dark time nocturnal melatonin levels were significantly lower in low testosterone KS (92 +/- 19 pmol/l) compared with 146 +/- 42 pmol/l in normal testosterone KS and 179 +/- 59 pmol/l in controls (P < 0.02). A similar pattern was observed for the mean (+/-SD) peak melatonin levels (165 +/- 41, 236 +/- 59 and 293 +/- 89 pmol/l) in low testosterone KS, normal testosterone KS and controls, respectively (P < 0.01). Integrated nocturnal melatonin secretion values (AUC) were also lower in low testosterone KS (64 +/- 13) compared with 96 +/- 26 in normal testosterone KS and 116 +/- 39 pmol/min 1 x 10(3) in controls (P < 0.02). The time of melatonin peak and the time of the nocturnal melatonin rise as well as the light-time mean (+/-SD) serum melatonin levels were similar in all three groups. No correlations were found between melatonin and LH, FSH, or E2 levels.

CONCLUSIONS

Melatonin secretion is decreased in male patients with low testosterone hypergonadotrophic hypogonadism whereas in normal testosterone Klinefelter's syndrome patients, melatonin secretory profiles are normal. The results suggest that the suppression of melatonin secretion in these patients is mediated by GnRH (either directly or indirectly) and/or oestradiol.

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.

Pulsatile patterns of melatonin secretion in patients with gonadotropin-releasing hormone deficiency: effects of testosterone treatment

Recently, we have demonstrated that male patients with gonadotropin-releasing hormone (GnRH) deficiency had increased nocturnal melatonin secretion that decreased to normal levels during testosterone treatment. The purpose of the current study was to examine if the abnormally increased melatonin levels in these patients were associated with pulsatile secretory patterns, and, if these were modified during testosterone administration. Characteristics of nocturnal melatonin and luteinizing hormone (LH) secretion were compared in six normal young males, six males with idiopathic hypogonadotropic hypogonadism (IGD), and in six males with constitutional delayed puberty (DP). Patients were examined in the untreated state and following the administration of 250 mg testosterone enanthate/month for 4 months. Serum samples for melatonin and LH levels were obtained every 15 min from 19.00 hr to 07.00 hr in a controlled light-dark environment. Pulse detection and pulse characteristics were determined by the program ULTRA. In comparison with normal controls, untreated IGD patients showed significantly higher pulse frequency, lower relative increments and shorter half-life times for melatonin. Similar findings were observed in DP patients, although statistically of borderline significance. Treatment with testosterone normalized melatonin pulse characteristics in both IGD and DP patients. The secretory pattern of LH release in these patients was characterized by significantly higher relative and absolute increments and shorter half-life time without any significant change in the number of LH pulses. Taken together, these data suggest that melatonin is secreted in a pulsatile pattern in normal adult males and in male patients with GnRH deficiency. The abnormally increased nocturnal melatonin secretion observed in these patients may indicate that the pineal pulse generator is expressing an altered activity pattern within its normal capabilities. Testosterone administration normalized melatonin secretory patterns in IGD and DP patients. The lack of relationship between the pulsatile LH and melatonin secretory patterns suggest an independent signal for the nocturnal pulsatile melatonin and LH secretions.

Nocturnal secretory patterns of melatonin, luteinizing hormone, prolactin and cortisol in male patients with gonadotropin-releasing hormone deficiency

To clarify whether disorders of gonadotropin releasing hormone (GnRH) deficiency are associated with altered melatonin and pituitary hormones secretory patterns, we studied male patients with hypogonadotropic hypogonadism (IGD; n = 6), delayed puberty (DP; n = 7) and age-matched pubertal controls (n = 7). Serum samples for the determination of melatonin, luteinizing hormone (LH), prolactin and cortisol levels were obtained at 15 min intervals from 1900 to 0700 in a controlled light-dark environment, complete bed-rest and fasting with simultaneous sleep recordings. Mean (+/- SD) dark-time melatonin levels were significantly higher in IGD (286 +/- 26 pmol/L) and DP (205 +/- 44 pmol/L) compared with 178 +/- 64 pmol/L in controls (P < 0.003). So were the mean (+/- SD) peak melatonin levels (453 +/- 63, 346 +/- 106 and 292 +/- 96 pmol/L) in IGD, DP and controls, respectively (P < 0.03). Integrated nocturnal melatonin (AUC) values were also higher in IGD and DP (184 +/- 15 and 134 +/- 28 pmol/min/L x 10(3)) compared with 116 +/- 42 pmol/min/L x 10(3) in controls (P < 0.003). The time of onset of the nocturnal melatonin rise was observed earlier in IGD and DP patients as compared to controls. No correlations were found between melatonin and LH levels, between melatonin and prolactin levels, or between melatonin and cortisol levels. These data indicate that melatonin secretion is enhanced in male patients with GnRH deficiency. The lack of correlation between melatonin and LH suggest that circulating gonadal steroids, rather than LH, modulate melatonin secretion in a reverse fashion.

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.

Immunohistochemical localization of gonadotropin and gonadal steroid receptors in human pineal glands

Recently, we demonstrated that melatonin secretion was increased in male patients with GnRH deficiency and decreased to normal levels during testosterone treatment. These data suggested that gonadal steroids modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize gonadotropin (LH and FSH) and gonadal steroid (androgens and estrogens) receptors in human pineal glands. Tissues were obtained at autopsy from 25 males, aged 19-87 yr, and five prepubertal children, aged 0.2-10 yr. Positive staining for all four types of receptors (LH, FSH, androgen, and estrogen) in the pineal parenchymal cells, pinealocytes, was evident in all 30 glands examined. Double staining revealed that nuclear receptors (androgen or estrogen) co-existed with cytoplasmatic receptors (LH or FSH) in the same cells. The results demonstrate the presence of gonadotropin and gonadal steroid receptors in human pinealocytes from infancy to old age.

Nonreplicability of seasonal rhythm in REM sleep in a subtropical climate

The present paper attempts to replicate Askenasy and Goldstein's (1995) findings of seasonality in rapid eye movement (REM) sleep measures in patients recorded in Israel. Analysis of sleep stage data of 706 nonselected male sleep apnea patients failed to find seasonality in REM sleep measures. In contrast, our data revealed stability of REM time with a maximum difference between seasons of 7.0 minutes. Age differences were found in sleep efficiency, true sleep time, and amount and percentage of REM sleep, with patients over 60 having a lower sleep efficiency, shorter true sleep, and REM sleep time than patients under 60. Rapid eye movement latency was also found to differ according to apnea severity, with patients who had > 40 apneas and hypopneas per hour of sleep having a longer latency than those with fewer apneas and hypopneas.