Association of ghrelin and leptin with reproductive hormones in constitutional delay of growth and puberty

BACKGROUND: Constitutional delay of growth and puberty (CDGP) is a variation of the onset and timing of pubertal development without a defined endocrine abnormality. Recently published studies indicate that leptin and ghrelin play a role in puberty initiation and progress. They have been implicated in regulation of GnRH secretion, with ghrelin having inhibitory and leptin, facilitatory effects. We hypothesized that elevated ghrelin and reduced leptin concentrations could be implicated in altering the tempo of puberty in adolescents with CDGP. So in the current study we evaluate variations in leptin and ghrelin levels in adolescent boys with CDGP, the relationships between both hormones and reproductive hormones including LH, FSH and testosterone were also evaluated. METHODS: The study enrolled 23 adolescent boys with CDGP and 20 healthy controls matched for age and sex. Weight, height, BMI, testicular volume, bone age, bone age delay, serum FSH, LH, testosterone, leptin and ghrelin were assessed. RESULTS: Adolescent boys with CDGP had significantly lower leptin and higher ghrelin than normal controls. Leptin was positively correlated with BMI, bone age, testicular volume, FSH, LH and testosterone and negatively correlated with delayed bone age and ghrelin. Ghrelin was negatively correlated with BMI, bone age, testicular volume, FSH, LH and testosterone. With multiple regression analysis BMI, FSH, LH, testosterone and ghrelin remained independently correlated with leptin while BMI, LH and testosterone remained independently correlated with ghrelin. CONCLUSION: Elevated serum ghrelin and decreased leptin concentrations and their associations with reproductive hormones may explain the sexual immaturity in adolescent boys with CDGP.