Abstract
Melatonin’s concentration is high in early childhood and declines gradually thereafter. In the elderly serum melatonin levels are very low. Melatonin, the “light of night”, among other functions is involved in human sexual maturation and in osteogenesis.
Hormesis is the response of cells or organisms to an exogenous (eg drug or toxin) or intrinsic factors (eg hormone), where the factor induces stimulatory or beneficial effects at low doses and inhibitory or adverse effects at high doses [bimodal dose-response] or vice versa.
At the age around 10 years, when idiopathic scoliosis may appear, the circulating melatonin level is about 120 pg/ml – positive hormesis for menses – and menarche appears. Melatonin deficiency may result in a delay of the age at menarche and consequently the girl is susceptible to scoliosis. In these terms melatonin could be certainly involved in the scoliosis pathogenesis. Around the age of 45 years when the circulating melatonin levels are about 20 pg/ml – negative hormesis for menses, menopause starts and the woman has an increased risk for osteoporosis and fractures.
It is documented the bone-protecting effect of melatonin in ovariectomized rats which can depend in part on the free radical scavenging properties of melatonin. Additionally, melatonin may impair development of osteopenia associated with senescence by improving non-rapid eye movement sleep and restoring GH secretion. Whether modulation of melatonin blood levels can be used as a novel mode of therapy for scoliosis and augmenting bone mass in diseases deserves to be studied
Correspondence should be addressed to Anastasia C. Tilentzoglou MD, General Secretary of the Board of Directors of HAOST, 20 A. Fleming Str. (N.Filothei), Gr. 15123 Maroussi, Athens Greece. E-mail: info@eexot.gr
