Long-term morbidity in congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is one of the most common autosomal recessive disorders and is characterized by cortisol deficiency. The most common cause of CAH is a mutation in the CYP21A2 gene, resulting in 21-hydroxylase deficiency in the adrenal cortex. The lack of cortisol causes an increase in adrenocorticotropic hormone (ACTH), which in turn results in an excess of adrenal androgens. Aldosterone synthesis may also be impaired. The clinical manifestation of CAH depends on the residual activity of 21-hydroxylase and the subsequent lack of cortisol and adrenal androgen excess. While classic CAH is a potentially life-threatening condition, non-classic CAH is mild to asymptomatic. Therapy of classic CAH consists of glucocorticoid and mineralocorticoid substitution. Despite optimization of therapy, CAH still leads to increased morbidity and mortality in patients. The clinical consequences of androgen excess in affected women range from intrauterine virilisation of external genitalia in classic CAH patients to mild symptoms of hyperandrogenism in non-classic forms. Increased demand for cortisol during illness or physical and psychological stress situations can trigger life-threatening adrenal crises. As current glucocorticoid therapy cannot mimic the physiological circadian rhythm and is usually supraphysiological in dose to control androgen excess, therapy-associated long-term consequences such as decreased bone health and an increased cardiometabolic risk profile are common. The burden of the disease may also lead to impaired quality of life and mental health. For this reason, regular screening and follow-up of patients with CAH should be performed in specialized centers to detect and treat possible comorbidities at an early stage.