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.