PURPOSE This study was designed to determine whether the amount of endochondral growth response to mechanical compression and the underlying growth mechanism differed with night-time or day-time loading, relative to full-time loading. METHODS Mechanical compression (nominally 0.1 MPa stress) was applied across tibial and tail vertebral growth plates of growing Sprague-Dawley rats. Four groups...

A large number of people in highly industrialized society are employed in night-shift work. Night-shift work interrupts the 24-hour daily cycle known as the circadian rhythm, as well as melatonin synthesis. These disruptions can make the body susceptible to oxidative stress and neural damage. In this regard, it is recommended that employees avoid long-term exposure to night-shift work.

For centuries, the circadian clock has been observed in behavioural and physiological patterns in plants and animals. These patterns seemed to regulate themselves very strictly around the 24 hour cycles of day and night and hence led early biologists to suggest that there was an inner mechanism that regulated these changes. In humans, the circadian clock has a genetic background and many circad...

BACKGROUND & OBJECTIVES Decline in cognitive functions is a major challenge for professionals during sustained wakefulness. We used middle latency response (MLR), event related potentials P300-ERP and contingent negative variation (CNV) and Raven's Advanced Progressive Matrices (RAPM) - a standard neuropsychological test were used to evaluate cognitive impairment after total sleep deprivation (...

The purpose of this study was to compare the effects of yoga to an active control (non-aerobic exercise) in individuals with preand Stage 1 hypertension. A randomized clinical trial was performed using two arms: 1) yoga and 2) active control. Primary outcomes were 24-hour, day and night ambulatory systolic and diastolic blood pressures. Within-group and between-group analyses were performed usi...

BACKGROUND Left ventricular hypertrophy (LVH) is an independent cardiac risk factor in hypertensives and the structural classification of left ventricular (LV) geometry provides additional prognostic information. Ambulatory blood pressure (ABP) monitoring has been shown to be superior to office blood pressure (BP) in relation to hypertension LVH. We investigated ambulatory BP variables in relat...

Nondipping, ie, failure to reduce blood pressure by >/=10% during the night, is considered an important prognostic variable of 24-hour ambulatory blood pressure monitoring. However, some people wake up at night to urinate. Usually, 24-hour ambulatory blood pressure monitoring-derived blood pressure includes these rises in the nighttime blood pressure mean. We identified 97 subjects undergoing 2...

BACKGROUND Light-at-night has been shown in experimental studies to disrupt melatonin production but this has only partly been confirmed in studies of night shift workers. In this cross-sectional study, we examined the circadian variation of melatonin in relation to shift status, individual levels of light-at-night exposure, and diurnal preference, an attribute reflecting personal preference fo...

BACKGROUND Whether independent relationships between white coat effects (office minus day (office-day blood pressure (BP))) and organ damage or arterial stiffness may be explained by associations with an attenuated nocturnal BP dipping, has not been determined. METHODS In 750 participants from a sample of African ancestry, office and 24-hour BP, carotid-femoral pulse wave velocity (PWV) (appl...

OBJECTIVE To evaluate circadian fluctuations and night/day ratio of Heart Rate Variability (HRV) spectral components in patients with obstructive sleep apnea (OSA) in comparison with controls. PARTICIPANTS AND METHODS This is a simultaneous HRV-polysomnographic (PSG) study including 29 patients with OSA and 18 age-sex-matched controls. Four patients with OSA dropped out. All participants unde...