Effect of sex on annual variations in plasma LH and FSH levels in prepubertal subjects

: We studied, from 1977 to 1979, 61 females and 72 males (aged 6 to 10 years) in order to demonstrate the occurrence of FSH and LH circannual variations. The data were fitted a cosine function by least square method in order to describe any rhythm and to estimate its parameters:mesor, amplitude, acrophase. Our data suggest that in prepubertal age the behaviour of FSH secretion is different in two sexes, but without circannual rhythm. LH instead shows a statistically significant circannual rhythm in both groups, without differences in mean levels between the two sexes.