Sleep Timing in Late Autumn and Late Spring Associates With Light Exposure Rather Than Sun Time in College Students.

Timing of the human sleep-wake cycle is determined by social constraints, biological processes (sleep homeostasis and circadian rhythmicity) and environmental factors, particularly natural and electrical light exposure. To what extent seasonal changes in the light-dark cycle affect sleep timing and how this varies between weekdays and weekends has not been firmly established. We examined sleep and activity patterns during weekdays and weekends in late autumn (standard time, ST) and late spring (daylight saving time, DST), and expressed their timing in relation to three environmental reference points: clock-time, solar noon (SN) which occurs one clock hour later during DST than ST, and the midpoint of accumulated light exposure (50% LE).

Serum iron and iron stores in non-anemic patients with fibromyalgia.

The aim of the study was to assess iron serum levels and markers of iron stores in non-anemic fibromyalgia (FM) patients and to evaluate their impact on the prevalence and clinical manifestations of FM patients. Eighty-four patients with primary FM and 87 controls were investigated. Demographic and clinical data were collected from all participants.

Effects of successful parathyroidectomy on metabolic cardiovascular risk factors in patients with severe primary hyperparathyroidism.

Objective: To evaluate the effect of parathyroidectomy on metabolic abnormalities associated with cardiovascular disease in patients with primary hyperparathyroidism (PHPT).

Methods: Thirty-four patients with PHPT (aged 51.0 ± 11.

Nonarticular tenderness and functional status in patients with diffuse idiopathic skeletal hyperostosis.

Objective: To investigate the degree of nonarticular tenderness and functional status in patients with diffuse idiopathic skeletal hyperostosis (DISH). We assessed these variables' correlation with their clinical, radiographic, and constitutional measurements and with metabolic syndrome (MS).

Methods: Eighty-seven patients with DISH were compared with 65 controls without DISH.

Shift work in nursing: is it really a risk factor for nurses' health and patients' safety?

There is evidence in the scientific literature of the adverse physiological and psychological effects of shift work, including disruption to biological rhythm, sleep disorders, health problems, diminished performance at work, job dissatisfaction, and social isolation. In this study, the results of health problems and sleep disorders between female and male nurses, between daytime and shift nurses, and between sleep-adjusted and non-sleep-adjusted shift nurses were compared. Also the relationship between adjustment to shift work and organizational outcomes (errors and incidents and absenteeism from work) was analyzed.

Mortality risk factors in sleep apnoea: a matched case-control study.

Sleep apnoea syndrome was reported to be associated with increased mortality but it is not known if this association is independent of obesity and co-morbidities. The present study investigated predictors of mortality in a large cohort of men with sleep apnoea using a case-control design. The study population consisted of 10,981 men diagnosed during 1991-2000 by whole-night polysomnography with sleep apnoea; 331 men died prior to 1 September 2001, of whom 277 were matched by age, gender, site and time of study to patients who were alive in September 2001.

Altered luteinizing hormone and testosterone secretion in middle-aged obese men with obstructive sleep apnea.

Objective: To elucidate the causes for the decline in testosterone levels observed in men with obstructive sleep apnea (OSA).

Research Methods And Procedures: We determined serum luteinizing hormone (LH) and testosterone levels every 20 minutes between 7 pm and 7 am with simultaneous sleep recordings in five obese middle-aged men with OSA, in five age- and BMI-matched controls, and in six lean young healthy men.

Results: The mean and area under the curve (AUC) values of LH and testosterone were significantly lower in men with OSA compared with controls.

Cardiovascular risk factors in middle-aged women with subclinical hypothyroidism.

Objectives: Overt hypothyroidism (OH) is associated with premature atherosclerosis and coronary heart disease (CHD). Recently, C-reactive protein (CRP) and total homocysteine (tHct) emerged as additional independent cardiovascular risk factors. Subclinical hypothyroidism (SH), affecting as many as 15% of middle-aged women is not known to be associated with risk for CHD.

Evaluation of the pituitary-adrenal axis in hyperandrogenic women with polycystic ovary syndrome.

Objectives: Impaired adrenal function is common in patients with polycystic ovary syndrome (PCOS). Abnormal regulation of cytochrome P450 17 alpha is believed to cause the exaggerated 17-hydroxyprogesterone (17OHP) response to ACTH stimulation. The aim of the study was to evaluate cortisol and 17OHP response to low dose (1 microg) ACTH test and to compare it with the standard ACTH (250 microg) test in hyperandrogenic women with PCOS.

Haptoglobin polymorphism is a risk factor for cardiovascular disease in patients with obstructive sleep apnea syndrome.

Study Objectives: Obstructive sleep apnea syndrome is associated with a marked increase in the risk for cardiovascular disease. Increased oxidative stress and leukocyte adhesiveness have been implicated as fundamental pathophysiologic mechanisms underlying the increased susceptibility in these patients. Haptoglobin is an antioxidant and immunomodulatory protein encoded by 2 alleles with profoundly different biophysical and biochemical properties.

Middle-aged men secrete less testosterone at night than young healthy men.

Aging men largely maintain their testicular androgen production. Cross-sectional studies have demonstrated that after the age of 40 yr a 0.2-2% annual decline is observed in morning total testosterone.

Cyproterone acetate-ethinyl estradiol treatment alters urinary 6-sulfatoxymelatonin excretion in hyperandrogenic women.

Objectives: To investigate melatonin production in hyperandrogenic women before and during treatment with cyproterone acetate and ethinyl estradiol (Diane 35).

Material And Methods: We studied 10 women with late onset adrenal hyperplasia due to 21-hydroxylase deficiency (LOCAH) and 10 women with idiopathic hirsutism (IH). Patients were treated with Diane 35 for four months.

Decreased pituitary-gonadal secretion in men with obstructive sleep apnea.

Decreased libido is frequently reported in male patients with obstructive sleep apnea (OSA). The decline in morning serum testosterone levels previously reported in these patients was within the normal adult male range and does not explain the frequent association of OSA and sexual dysfunction. We determined serum LH and testosterone levels every 20 min between 2200-0700 h with simultaneous sleep recordings in 10 men with sleep apnea and in 5 normal men free of any breathing disorder in sleep.

Risk factors for cardiovascular disease in women with subclinical hypothyroidism.

Overt hypothyroidism may result in accelerated atherosclerosis and coronary heart disease (CHD) presumably because of the associated hypertension, hypercholesterolemia, and hyperhomocysteinemia. As many as 10%-15% of older women have subclinical hypothyroidism (SH) and thyroid autoimmunity. Whether SH is associated with risk for CHD is controversial.

The effect of pyridoxine administration on melatonin secretion in normal men.

Objectives: To determine pineal response to pyridoxine in normal men.

Material And Methods: Twelve healthy men were given orally pyridoxine (100 mg) or placebo at 1700h. Serum melatonin levels were determined every 30 minutes with simultaneous measurement of core body temperature between 1700h to 0300h.

Haptoglobin phenotype and the risk of restenosis after coronary artery stent implantation.

We recently demonstrated that an allelic polymorphism in the haptoglobin gene is a major determinant of susceptibility to a number of vascular disorders. We set out to determine if haptoglobin phenotype was predictive of the development of restenosis in a consecutive series of patients, all of whom underwent stent implantation followed by repeat angiography with quantitative coronary angiography analysis 6 months later. This study included 214 consecutive patients undergoing stent implantation for de novo lesions between 1998 and 1999 in Aalst, Belgium.

Residual effects of daytime administration of melatonin on performance relevant to flight.

There is a general consensus that melatonin possesses time-dependent hypnotic effects, but there is no information yet whether it has residual effects on neurobehavioral performance, especially after daytime administration. In the present study we investigated the possible residual effects of 3 mg melatonin on performance relevant to flight and on subjective feelings of sleepiness, arousal, activation and affect after a daytime nap, as a function of nap length. Fifteen reserve pilots of the Israeli Air Force participated in the study.