BACKGROUND Night shift work has been associated with an increased risk for breast and prostate cancer. The effect of circadian disruption on sex steroid production is a possible underlying mechanism, underinvestigated in humans. We have assessed daily rhythms of sex hormones and melatonin in night and day shift workers of both sexes. METHODS We recruited 75 night and 42 day workers, ages 22 t...

Studies have shown that aspirin may decrease blood pressure when given at bedtime but not when administered on awakening. However, until now, a biologically plausible mechanism of this striking phenomenon was not revealed. We investigated the effect of 100 mg of aspirin administered at bedtime compared with administration on awakening on plasma renin activity and aldosterone levels over 24 hour...

The possible prognostic relevance of different patterns characterizing blood pressure (BP) fluctuations during the day and night was first suggested in the late 1980s,1 based on observations made possible by 24-hour continuous intraarterial ambulatory BP monitoring in normotensive and hypertensive subjects. Since then, this issue has been repeatedly addressed in studies carried out either in an...

Studies have shown that aspirin may decrease blood pressure when given at bedtime but not when administered on awakening. However, until now, a biologically plausible mechanism of this striking phenomenon was not revealed. We investigated the effect of 100 mg of aspirin administered at bedtime compared with administration on awakening on plasma renin activity and aldosterone levels over 24 hour...

On a Saturday night, a 24-year-old male with palpitations was admitted to the Emergency Department. The arrhythmia started 8 h earlier while he was riding his bicycle. He had never experienced this sensation before. He admitted prior usage of cocaine, LSD and XTC. He denied the use of any drugs on the night of presentation. Physical examinations revealed no abnormalities except a very fast hear...

Arterial wall stiffness is considered an independent cardiovascular risk factor. Aim of this study was to evaluate relationship between clinical, 24-hour, average day-time and night-time blood pressure (BP) and measures of arterial stiffness assessed by pulse wave velocity (PWV) (using SphygmoCor applanation tonometer) in essential hypertension (severe-resistant (RH, n=29) and moderate hyperten...

Improvement in motor skill performance is known to continue for at least 24 hr following training, yet the relative contributions of time spent awake and asleep are unknown. Here we provide evidence that a night of sleep results in a 20% increase in motor speed without loss of accuracy, while an equivalent period of time during wake provides no significant benefit. Furthermore, a significant co...

Chronobiology—the science of daily (circadian), monthly, tidal, and seasonal rhythms—has undergone exponential growth in the past decade, with major discoveries at the molecular and neuroanatomic level. The most ubiquitous rhythms are those linked to the 24-hour day-night cycle. These circadian rhythms manifest themselves at every hierarchical level: from the general population (eg, more traffi...

Patients undergoing long-term therapy for PD often experience motor fluctuations and nocturnal disturbances. In a post-hoc analysis, we explored effects of ropinirole prolonged release on sleep, night-time awakenings, and "on" time over 24 hours. Patients with advanced PD suboptimally controlled with L-dopa were randomized to adjunctive ropinirole prolonged release (2-24 mg/day) or placebo for ...