Background: In hypogonadotropic hypogonadism (HH), hypophyseal follicle-stimulating and luteinizing hormones, normally released with GnRH stimulation, are detected low. Since kisspeptin (KP) is a strong stimulant of GnRH neurons, it is considered to have a role in HH aetiology. It may be hypothesized that abnormal plasma levels of KP are indicative of HH.
Aim: Evaluation and comparison of plasma KP levels in boys of pre-pubertal age, with normal puberty and diagnosed HH.
Results: The study comprised 22 boys with HH (median age 14, range 14-17 years), 25 boys with normal puberty (median age 16, range 14-18 years), and 28 pre-pubertal boys (median age 6, range 3-10 years). Statistically significant difference was found for the overall distribution of the plasma KP values across different groups (Kruskal-Wallis H = 21.95, P = < 0.001). The highest values were found in the HH group (median: 45.0 pg/mL, range: 13.1- 471.6 pg/mL). Median value in the pre-pubertal boy was equal to 13.8 pg/mL (range:13.2 - 82.5 pg/mL), median value in normal pubertal adolescents was equal to 13.8 pg/mL (range: 13.1 - 37.2 pg/mL) ROC curve analysis was performed. The area under the ROC curve (AUC) was equal to 0.854 (95% CI: 0.720 to 0.940), enabling rejection of the null-hypothesis (area of 0.5) (P < 0.0001). The criterion value that ensured optimal balance between sensitivity and specificity was equal to 16.9 pg/mL. This corresponds to the value of the Youden index J equal to 0.6473, test sensitivity equal to 72.73, and test specificity equal to 92.0.
Plasma KP level exceeding 16.9 pg/mL was a reliable predictor of HH (sensitivity = 72.73, specificity = 92.0).
Conclusion: Plasma KP levels are elevated in HH cases and may serve as a useful diagnostic tool in evaluating boys with HH.
19 Sep 2019 - 21 Sep 2019