Melatonin secretion during adrenarche in normal human puberty and in pubertal disorders

The relation between human melatonin secretion and adrenarche was investigated in 113 subjects ages 5.5-17 years. Melatonin nocturnal profile was determined obtaining hourly blood samples from 2000 to 0800 and DHEA-S was measured in pooled plasma of these samples. In 62 normal subjects, melatonin peak by stages of adrenarche was 152.5 +/- 65.4, 125.9 +/- 59.4, and 115.2 +/- 40.7 pg/ml for stages 1, 2, and 3-5, respectively, and the linear trend components were significant; no significant relation remained after partialling the variance associated with age and pubertal stages. In 41 subjects with disorders of pubertal onset, mean melatonin peak by stages of adrenarche was 149.0 +/- 54.4, 194.0 +/- 34.2, and 129.8 +/- 52.2 pg/ml for stages 1, 2, and 3-5, respectively, and the linear trend components were not significant. In seven prepubertal girls with precocious adrenarche, melatonin peak was not significantly different from values in seven normal prepubertal, preadrenarchal girls. The relation between time of melatonin peak and adrenarche was not significant in any of the diagnostic groups. The linear correlation between melatonin peak and DHEA-S was not significant in either adrenarche stage 1 (r = -0.19, n = 41) or stages 3-5 (r = -0.13, n = 23). The results do not support a role for adrenarche in the pineal-puberty relation in humans.