The gonadotropin-releasing hormone (GnRH) stimulation test is a valuable tool in diagnosing and differentiating causes of early pubertal occurrences. Utility of the test can be limited in some instances, however, including the early phases of pubertal hypothalamic-pituitary-gonadal axis activation, in girls showing commonly overlapping pictures, and in obese children due to excess circulating estrogen that suppresses luteinizing hormone (LH). A lack of consistent baseline and stimulated gonadotropin cutoffs observed in different studies also contributes to limitations in testing. Nevertheless, early detection of true pathological causes for pubertal disorders is needed to allow prompt treatment and better prognosis. While basal LH can be beneficial as a good screening tool for detecting pubertal disorder, it does not preclude the need for GnRH testing. The aim of this review was to highlight the role of GnRH stimulation tests and varying testing cutoffs in diagnosis of precocious puberty and its classification.
It is well known that the endocrine-disrupting chemical (EDC) dibutylphthalate (DBP) inhibits testosterone synthesis and can lead to feminisation in male laboratory animals. Moreover, it has long been speculated that human exposure would result in the similar effects, but this is difficult to study because specific human exposure cohorts are rare. We report increases in the incidences of hypospadias (p<0.05), cryptorchidism (p<0.05) and breast cancer (p<0.05) in the children of New Zealand soldiers who served in Malaya (1948-1960) and were exposed to DBP applied daily to their clothing as an acaricide to prevent tick-transmitted bush typhus. In addition, we modelled absorption of DBP from the soldiers' clothing and using published data for skin absorption, and calculated a large theoretical absorbed dose of 64 mg/kg body weight/day which is similar to DBP's lowest observed adverse effect level (LOAEL) of 50 mg/kg body weight/day and thus indicates a biological effect is possible. This is the first report of a multigenerational developmental effect following DBP exposure in human males.