Growth in congenital adrenal hyperplasia.

Individuals with congenital adrenal hyperplasia (CAH) are shorter, on an average, than the general population. A recent meta analysis of final height in CAH indicated that the height deficit is typically 1 to 2 standard deviations below the mean in both males and females. Growth in CAH due to 21-hydroxylase deficiency is influenced by a number of factors, related both to the underlying disease and its treatment. In general, males with the simple virilising form have the poorest height prognosis. This relates in part to late diagnosis and treatment and the bone age advancement seen in individuals with untreated postnatal androgen excess. Obesity in CAH patients also appears to be correlated with reduced height potential. Glucocorticoid treatment which is vital for cortisol replacement, prevention of adrenal crises and androgen suppression, results in growth inhibition when administered in larger doses. Current evidence suggests that infancy and peripubertal periods are the time periods where height outcome is most sensitive to glucocorticoid dose. More recent estimates of physiological cortisol secretion rates indicate that standard cortisol replacement schedules may result in overtreatment. In addition, dose titration to achieve complete androgen suppression and normalization of 17-hydroxyprogesterone is likely to result in overtreatment and consequent growth impairment. Optimization of current treatment may lead to further improvements in height prognosis. The potential benefits of more complex treatment regimes, using aromatase inhibitors and antiandrogens, in combination with a reduced glucocorticoid dose remain uncertain.

Growth in precocious puberty.

Growth in precocious puberty is a subject of concern to families and clinicians alike. The definition of precocious puberty and the role of obesity in the age of onset have also been areas of debate since the Lawson Wilkins Society recommended a lowering of the age of onset of precocious puberty in US girls. An understanding of growth patterns in normal children with earlier or later onset of puberty and the variable rate of progression between individuals with central precocious puberty as well as the imprecision in available height prediction methods are important in assessing height outcomes in this condition. In the absence of randomised controlled trials in this area, only qualified conclusions about the effectiveness of interventions can be drawn. In general, it appears that height outcome is not compromised in untreated slowly progressive variants of central precocious puberty. In rapidly progressing central precocious puberty in girls, gonadotrophin releasing hormone agonists (GnRH agonists) appear to increase final height by about 5 cm in girls treated before the age of eight, but there is no height benefit in those treated after eight years. Scanly data is available to assess treatment effects in boys. GnRH agonists appear to be relatively safe. The decision to treat central precocious puberty should take into account rate of progression of pubertal changes as well as biochemical markers and may need to address other factors (for example psychosocial and behavioural issues) as well as height outcome.