361- What is the rationale for the estimation of androstenedione and testosterone in
children with CAH due to 21α-hydroxylase defi ciency?
Although estimation of serum 17(OH)P is a sensitive test for the diagnosis of
CAH due to 21α-hydroxylase defi ciency, it is a suboptimal parameter for moni-
toring the effi cacy of therapy when used alone. This is because serum 17(OH)P
levels has only modest correlation with circulating androstenedione and testoster-
one as circulating levels of 17(OH)P are 100–1,000 times higher in patients with
CAH as compared to normal individuals. In addition, serum 17(OH)P levels
show high variability as compared to androstenedione and testosterone. Hence,
estimation of androstenedione and testosterone should be used in conjunction
with serum 17(OH)P for monitoring therapy of children with CAH. Normalization
of androstenedione and testosterone is a biochemical marker of optimal therapy,
whereas normalization of 17(OH)P suggests overtreatment. Estimation of DHEA
or DHEAS is not recommended as they are easily suppressible with glucocorti-
coids and the levels poorly correlate with circulating 17(OH)P.- How to monitor an adult with CAH due to 21α-hydroxylase defi ciency?
In children with CAH, prevention of salt-wasting crisis, optimization of linear
growth, and attainment of fi nal adult height are the major concerns, whereas in
adults, achievement of fertility, prevention of metabolic syndrome, and osteoporo-
sis are important issues. The clinical parameters to be monitored in an adult with
CAH include blood pressure, signs of glucocorticoid excess, and regression/pro-
gression of virilization (in females). Biochemical monitoring includes estimation
of serum 17(OH)P, testosterone, androstenedione, plasma renin activity, and serum
potassium and sodium. However, serum testosterone has limited utility in men as
it is predominantly produced from the testes. Serum 17(OH)P should be targeted
between 4 and 12 ng/ml, whereas androstenedione and testosterone (the later in
females) should be maintained in the age- and gender-specifi c normal range. In
addition, testicular ultrasonography, measurement of gonadotropins, and semen
analysis in men and serum progesterone in women should be performed while
planning fertility. Beside this, periodic monitoring with fasting plasma glucose,
lipid profi le, and DXA should also be performed in adults with CAH.- What are the causes of increase in serum 17(OH)P in a child with CAH due to
21 α-hydroxylase defi ciency who was previously well controlled?
Compliance to therapy must be ensured prior to further investigation in a child
with CAH who was previously well controlled. The most common cause of
increase in 17(OH)P in a child on therapy is onset of puberty. In addition, develop-
ment of adrenal rest tumors in gonads and evolution of ACTH- independent adre-
nal nodular hyperplasia may also result in increase in serum 17(OH)P levels.10 Congenital Adrenal Hyperplasia