Longitudinal Study of the Simultaneous Secretion of Melatonin and Leptin during Normal Puberty

Abstract

Background/Aims: Pubertal changes are a consequence of the activation of the hypothalamic-pituitary-gonadal axis due to an increase in the frequency and magnitude of pulses of gonadotropin-releasing hormone (GnRH), which may depend on the intrinsic properties of the neurons of the hypothalamic arcuatus nucleus, or on the influence of neurotransmitters and/or neuromodulators. We evaluated the serum concentrations of melatonin and leptin in healthy prepubertal and adolescent subjects of both sexes, to define their participation at the initial stages and during the progression of pubertal development. Methods: 80 pediatric subjects (47 females and 33 males), aged 6–18 years, were divided into 2 groups, prepubertal (n = 25) and adolescent (n = 55), according to the absence or presence, respectively, of physical signs of pubertal development. The subjects were assessed on two occasions: at the time of their inclusion in the study, and 12–18 months later when the subject had advanced one pubertal stage according to the Tanner classification. Blood was obtained in fasting for clinical purposes and for the hormonal study. Melatonin and leptin were measured by radioimmunoanalysis. Results: As described previously, melatonin decreases at the onset of puberty and during pubertal development. Both the absolute melatonin value and the decrease between evaluations tended to be greater in females; the variations were correlated with neither an increase in body weight nor with the degree of pubertal development. The concentration of leptin increased in both sexes with the progression of puberty, this value being 40% greater in women, and correlated with the indicators of an increase in body volume and fat accumulation. Although its concentration remained stable between evaluations for both sexes, among the males the association between leptin and pubertal development took place at the start of the process, while for the females we observed a significant overall association between pubertal stage and leptin concentration, this association being stronger at more advanced Tanner stages. Neither at the onset of puberty nor during its course did we observe any significant relation between melatonin concentration and any of the Tanner stages, whether for males or for females. Neither was there any correlation between the absolute values or rates of modification of melatonin and leptin. Conclusion: According to the evolutionary dynamics of their respective concentrations, both initially and during pubertal progress, melatonin and leptin do not interact in the initiation or progression of human pubertal development, and do not seem to play a key role in this process.

Metabolic programming of lipid profile and reproductive organs weight by leptin treatment on early life

“…Only the isoform OBRb is considered to be capable of signal transduction across the cell membrane 6 . The concept of metabolic programming is a permanent change related to a particular function, as a result of some event which occurs during the perinatal period 7 . Several animal experiments have shown that hormones as leptin and nutrition status, which affect development during sensitive periods early in life, permanently program the structure and function of body tissues and systems [8][9][10] .…”

Leptin regulation of pubertal maturation in intact and pinealectomized female rats

“…It informs the brain about whether there are sufficient energy stores to initiate reproductive functions (38). Increases in serum leptin levels have been observed around the beginning of the menarche (39) or the estrous cycle (40). Therefore, it is generally accepted that leptin is essential in the induction of puberty in the female.…”

Longitudinal Associations between Endogenous Melatonin Production and Reported Sleep Duration from Childhood to Early Adulthood

“…6-OHMS is the major enzymatic metabolite of melatonin [48] and has frequently been shown to correlate with serum melatonin concentrations [34,35]. The well-documented rapid fall of melatonin levels in serum from childhood to puberty [47] is mainly correlated with an increase in body mass during that period with a corresponding increase in serum volume rather than a decreasing melatonin production, analyzed here with 24-hour urine samples. Thus, mean urinary 6-OHMS excretion, and therefore melatonin production, remained relatively stable in our subjects between the ages of 4 and 19 years, as previously shown by Griefahn et al [28].…”

“…As melatonin production is suppressed by light [13], we controlled for the season in which the urine collection took place. As body composition could also have an influence on melatonin secretion [47], the variables age, BMI-SDS, overweight and percent body fat were considered as potential confounders. For these variables, we considered the values at baseline and their interaction with time, and the change in the values during the study period.…”