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43. What are the diagnostic tests to differentiate between CDGP and congenital
    IHH?
    The diagnostic tests that help to differentiate between CDGP and congenital
    IHH include basal LH and testosterone. With the advent of ultrasensitive
    gonadotropin assays, the utility of GnRH stimulation test is limited only in
    those situations where basal gonadotropin levels are in prepubertal range. The
    utility of the various diagnostic tests is depicted in the figure given below. The
    measurement of inhibin B and α-subunit has been used for the differentiation
    between CDGP and IHH; however, the data are limited (Fig. 7.13).


44. How is short-term testosterone therapy beneficial in children with CDGP?

Short-term low-dose testosterone therapy is used in children with CDGP who

have completed 14 years of age and have significant psychosocial concerns

regarding their growth and/or pubertal development. The commonly used regi-

men is testosterone enanthate or cypionate 50–100 mg intramuscularly every

Delayed puberty

(14–18 years)

Basal T

>1.7 nmol/L(RIA)

PPV 100 %

CDGP

≤1.7 nmol/L(RIA)

NPV 59 %

Basal LH (ECLIA)

>0.3 mIU/ml

PPV 100 %

≤0.3 mIU/ml

CDGP Triptorelin stimulation

LH >14 mIU/mL

PPV 100 %

hCG stimulation

LH <14 mIU/mL

NPV 72 %

Hypogonadotropic

hypogonadism

T-treatment

Follow-up

∆T 3–9 nmol/L ∆T < 3 nmol/L

PPV 100 %

CDGP

∆T > 9 nmol/L

PPV 100 %

Fig. 7.13 Approach to a child with delayed puberty

7 Delayed Puberty