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

Furthermore women with low levels of melatonin secretion have been found to more likely to develop type 2 diabetes than women with high levels.

They wondered if sufferers of SAD might have seasonal variations in their melatonin secretions.

The winter patterns of melatonin secretion were long and more sustained; the summer pattern, shorter and with a lower maximum crest.

The researchers found a significant reduction in the duration and overall amount of melatonin secretion among the PMS patients.

In sighted people, melatonin secretion is synchronized with the 24-hour cycle of daylight and darkness, turning on at nightfall, and continuing for about 12 hours.

Light at night can also interfere with the chronobiology of many animals, including humans, through suppression of melatonin secretion.

The synchronicity of the erythrocytic cycle is at least in part dependent on melatonin secretion by the host.

Dusk or darkness triggers the pineal gland's melatonin secretion, while sunlight shuts it down.

The longer a person is in darkness the longer the duration of melatonin secretion.